Chip partibility prediction device, controller, and chip partibility prediction method

Abstract

To make it easy to determine requirements for cutting at a time of performing cutting.SOLUTION: A chip partibility prediction device 10 includes: a storage unit 14 that stores information concerning lumbers to be cut and tools required in cutting; a receiving part 12a that receives information concerning a tool and a lumber to be cut as an object of cutting which are selected from among the lumbers to be cut and the tools indicated in the information stored in the storage unit 14, and receives information indicating a feed speed and a notching quantity for cutting; an arithmetic part 12b that derives information needed to predict whether chips can be parted by using the information received by the receiving part 12a; and a display part 16a that displays the information which is derived by the arithmetic part 12b and is needed to predict whether or not the chips can be parted.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a chip breakability prediction device, a control device, and a chip breakability prediction method. [Background technology]

[0002] Generally, the optimum range of the chip breaker can be referred to in the tool manufacturer's catalog to determine whether or not chips can be broken. However, the optimum range varies greatly depending on the material, so the optimum range is often not correct. For this reason, it is common to carry out many experiments by changing the conditions and tools to narrow down the optimum conditions.

[0003] Also, at the research level, there are efforts to predict whether chips can be broken using FEM analysis software, as in the following Non-Patent Document 1. This Non-Patent Document 1 states that by analyzing the chip breaking process using a thermo-elastic-plastic finite element method, it was confirmed that the results matched the experimental results. However, FEM analysis requires a long analysis time per condition, so it is not suitable for predicting whether chips can be broken for many tools or under a wide range of conditions.

[0004] There are also efforts to theoretically grasp the breakage of chips (for example, see Non-Patent Document 2 below). As disclosed in Non-Patent Document 2, the conditions when the chip breaks can be obtained by using the chip breakage strain determined by the chip material and the tensile strain generated in the chip, which is obtained from the chip thickness and the initial curl radius of the chip. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Thermal elastic-plastic finite element simulation of chip breaking process by chip breaker, Shinozuka et al., Journal of the Japan Society for Precision Engineering, Vol. 62, No. 8, p1161-1166, 1996 [Non-Patent Document 2] Research on Chip Breaker, Kazuo Nakayama, Transactions of the Japan Society of Mechanical Engineers (Part C) 27(178), p833-843, June 1961

Summary of the Invention

Problems to be Solved by the Invention

[0006] In Non-Patent Document 1, a theoretical consideration using the thermo-elastoplastic finite element method is shown, and in Non-Patent Document 2, it is shown that the fragmentation of chips can be theoretically grasped. However, since only general theoretical considerations are shown in these non-patent documents, when setting cutting conditions for specific workpieces in the field of cutting, it is not always possible to directly use this theoretical consideration.

[0007] Therefore, the present invention has been made in view of the above prior art, and its object is to facilitate the determination of cutting conditions when performing cutting.

Means for Solving the Problems

[0008] To achieve the above object, a chip fragmentation prediction device according to the present invention includes a storage unit that stores information related to a workpiece and a tool in cutting; a reception unit that receives information related to the workpiece and the tool to be used, which are selected from the workpiece and the tool shown in the information stored in the storage unit, and also receives information indicating the feed rate and the depth of cut in the cutting; a calculation unit that derives information for predicting whether the chips can be fragmented using the information received by the reception unit; and a display unit that displays the information for predicting whether the chips can be fragmented, which is derived by the calculation unit.

[0009] In the chip breakability prediction device according to the present invention, a reception unit receives information regarding a workpiece to be cut and a tool to be used, and information indicating a feed rate and a depth of cut. Then, an arithmetic unit derives information for predicting whether the chips can be broken in the case of the workpiece, tool, feed rate, and depth of cut indicated by the information received by the reception unit. Since this derived information is displayed on a display unit, it becomes possible to determine whether the chips will break from the information displayed on the display unit. Further, even when it is predicted that the chips will not break, information regarding the break prediction can be obtained again by changing at least one of the feed rate and the depth of cut. Therefore, it is possible to easily set conditions for performing cutting.

[0010] The arithmetic unit may be configured to calculate tensile strain generated in the chips by the cutting process based on an initial curl radius and a chip thickness of the chips, and correct the tensile strain using a chamfer width or a cutting edge radius of the tool indicated by the information received by the reception unit, and a cutting thickness obtained from a nose radius of the tool, a side cutting edge angle of the tool, the feed rate, and the depth of cut indicated by the information received by the reception unit.

[0011] In this aspect, since the influence on the tensile strain of the chips by the chamfer width or the cutting edge radius of the tool and the cutting thickness is considered, the chip breakability predictability can be further improved.

[0012] That is, when there is a relatively large chamfer or cutting edge radius compared to the cutting thickness determined by the cutting conditions, the chip shape is determined by the chamfer or cutting edge radius regardless of the chip breaker behind it. For this reason, unlike the initial assumption (the initial curl radius of the chip is geometrically determined by the chip breaker), the prediction accuracy of whether the chip can be broken may decrease. On the other hand, in this aspect, since the tensile strain is corrected, it is possible to avoid a situation in which the prediction accuracy decreases.

[0013] The calculation unit may be configured to obtain an initial curl radius and a rake angle in each cross-section from a cross-section perpendicular to the cross-cutting edge in the tool indicated by the information received by the reception unit and a cross-section of the bisector of the tip angle of the tool, and calculate, by interpolation or extrapolation, the initial curl radius and the rake angle in the chip outflow direction by the cutting from the obtained initial curl radius and rake angle in each cross-section.

[0014] In this aspect, since the initial curl radius and the rake angle taking into account the chip outflow direction are used, the predictability of chip segmentation can be further improved.

[0015] That is, even when the same tool is used, the chip outflow direction changes depending on the cutting conditions and the workpiece material, so the cross-section of the tool in the chip outflow direction changes, and the chip breaker cross-sectional shape that affects the chip segmentation changes. Therefore, in practice, it is necessary to capture the tool shape three-dimensionally, but it requires the storage of 3D data and data processing for each cutting condition, which involves complex procedures. On the other hand, as in this aspect, since the initial curl radius and the rake angle in the chip outflow direction by cutting are calculated by interpolation or extrapolation from the initial curl radius and the rake angle in each obtained cross-section, complex procedures can be made unnecessary. Also, unlike the method using FEM analysis, the analysis time per condition does not become long.

[0016] The display unit may display, as the information for predicting the chip segmentation, an image representing the distribution of tensile strain generated in the chip by contour lines and representing the fracture boundary of the chip in a coordinate system with the cutting conditions as coordinate axes.

[0017] In this aspect, when the information derived by the calculation unit predicts that the chip will not be segmented, by referring to the image displayed on the display unit, it is possible to easily infer the cutting conditions under which the chip will be segmented.

[0018] The display unit may display the distribution of tensile strain generated in the chips by one or more methods selected from color, shade of hue, and luminance.

[0019] In this aspect, in the image displayed on the display unit, the distribution of tensile strain can be made easier to identify.

[0020] The calculation unit may compare the distance from the cutting edge of the tool to the breaker apex with the chip thickness, and predict that the chips will not break when the chip thickness is larger.

[0021] When the chip thickness is large with respect to the breaker shape, the rigidity of the chips is too high and the chips do not enter the valley of the breaker. For this reason, the chips may not take the assumed shape along the breaker, and there is a risk that the prediction accuracy of the breakability will decrease. On the other hand, in this aspect, since the breakability is predicted by comparing the distance from the cutting edge of the cutting tool to the breaker apex with the chip thickness during cutting, it is possible to prevent the prediction accuracy from decreasing.

[0022] The calculation unit may calculate the breakability of the chips for all the tools indicated by the information stored in the storage unit, and the display unit may be configured to display a list of the breakability of the chips of each tool based on the information derived by the calculation unit.

[0023] In this aspect, a list of the breakability of the chips of each tool is displayed on the display unit. For this reason, even if the information derived by the calculation unit predicts that the chips will not break, it is possible to determine a tool with potential for improvement based on the list of the breakability of the tools displayed on the display unit. Therefore, an improvement in the breakability of the chips is expected.

[0024] The control device according to the present invention is provided in a prediction system for predicting the breakability of chips in cutting, and is a control device communicably connected to an input / output device, and includes a storage unit storing information on a workpiece and a tool in cutting, and among the workpiece and the tool indicated in the information stored in the storage unit, receives information on the workpiece to be machined and the tool to be used in the cutting selected by the input / output device, and a reception unit that receives information indicating the feed rate and the depth of cut in the cutting, a calculation unit that derives information for predicting whether the chip can be broken using the information received by the reception unit, and a communication unit that communicates with the input / output device so that the information for predicting whether the chip can be broken derived by the calculation unit is displayed on the display unit of the input / output device.

[0025] In the control device according to the present invention, the reception unit receives information on the workpiece to be machined and the tool to be used, and information indicating the feed rate and the depth of cut. Then, the calculation unit derives information for predicting whether the chip can be broken in the case of the workpiece, the tool, the feed rate, and the depth of cut indicated by the information received by the reception unit. The derived information is output from the communication unit, and this information is input to the input / output device. Based on the information displayed on the display unit of the input / output device, it becomes possible to determine whether the chip breaks. Also, even when it is predicted that the chip does not break, by changing at least one of the feed rate and the depth of cut, information regarding the break prediction can be obtained again. Therefore, it is possible to easily set the conditions for performing cutting.

[0026] The calculation unit may be configured to calculate the tensile strain generated in the chip by the cutting based on the initial curl radius and the chip thickness of the chip, and correct the tensile strain using the chamfer width or the cutting edge radius of the tool indicated by the information received by the reception unit, and the cutting thickness obtained from the nose radius of the tool, the side cutting edge angle of the tool, the feed rate, and the depth of cut indicated by the information received by the reception unit.

[0027] The calculation unit obtains the initial curl radius and rake angle in each cross-section from the cross-section in the direction perpendicular to the cross-cutting edge in the tool indicated by the information received by the reception unit and the cross-section of the bisector of the tip angle of the tool, and from the initial curl radius and rake angle in each obtained cross-section, the initial curl radius and rake angle in the direction of chip outflow during the cutting process are calculated by interpolation or extrapolation.

[0028] The communication unit may communicate with the input / output device so that an image representing the distribution of tensile strain generated in the chips by contour lines and representing the fracture boundary of the chips is displayed on the display unit in a coordinate system with the cutting conditions as the coordinate axes.

[0029] The communication unit may communicate with the input / output device so that the distribution of tensile strain generated in the chips is displayed on the display unit by one or more methods selected from color, shade of hue, and luminance.

[0030] The calculation unit may compare the distance from the cutting edge of the tool to the breaker apex with the chip thickness, and predict that the chip will not break when the chip thickness is larger.

[0031] When the chip thickness is large with respect to the breaker shape, the rigidity of the chip is too high and the chip does not enter the valley of the breaker. For this reason, the chip may not take the assumed shape along the breaker, and there is a risk that the prediction accuracy of the breakability will decrease. On the other hand, in this aspect, since the breakability is predicted by comparing the distance from the cutting edge of the cutting tool to the breaker apex with the chip thickness during cutting, it is possible to prevent the prediction accuracy from decreasing.

[0032] The calculation unit calculates the breakability of the chips for all the tools indicated by the information stored in the storage unit, and the communication unit may communicate with the input / output device so that a list of the breakability of the chips for each tool is displayed on the display unit based on the calculation result by the calculation unit.

[0033] The chip breakability prediction method according to the present invention receives information on a workpiece and a tool to be machined selected from the workpiece and the tool in the cutting process shown in the information stored in the storage unit, and receives information indicating the feed rate and the depth of cut in the cutting process, uses the received information to derive information for predicting whether the chip can be broken, and displays the derived information on a display unit.

[0034] In the chip breakability prediction method according to the present invention, information on the workpiece and the tool and information indicating the feed rate and the depth of cut are received, and the received information is used to derive information for predicting whether the chip can be broken. Since the derived information is displayed on the display unit, it is possible to determine whether the chip breaks from the information displayed on the display unit. Also, even when it is predicted that the chip does not break, information regarding the break prediction can be obtained again by changing at least one of the feed rate and the depth of cut. Therefore, it is possible to easily set the conditions for performing the cutting process.

[0035] In the chip breakability prediction method, the tensile strain generated in the chip by the cutting process may be calculated based on the initial curl radius and the chip thickness of the chip. In this case, the tensile strain may be corrected using the chamfer width or the cutting edge radius of the tool indicated by the received information, and the cutting thickness obtained from the nose radius of the tool, the side cutting edge angle of the tool, the feed rate, and the depth of cut indicated by the received information.

[0036] In the chip breakability prediction method, the initial curl radius and the rake angle in each cross section are obtained from the cross section perpendicular to the side cutting edge of the tool indicated by the received information and the cross section of the bisector of the tip angle of the tool, and the initial curl radius and the rake angle in the chip outflow direction in the cutting process are calculated by interpolation or extrapolation from the initial curl radius and the rake angle in each obtained cross section.

[0037] In the method for predicting chip breakability, the distance from the cutting edge of the cutting tool to the breaker apex may be compared with the chip thickness, and when the chip thickness is larger, it may be predicted that the chip will not break.

[0038] When the chip thickness is large with respect to the breaker shape, the rigidity of the chip is too high and the chip does not enter the valley of the breaker. For this reason, the chip may not assume the assumed shape along the breaker, and there is a risk that the prediction accuracy of breakability will decrease. On the other hand, in this aspect, since the breakability is predicted by comparing the distance from the cutting edge of the cutting tool to the breaker apex with the chip thickness during cutting, it is possible to prevent the prediction accuracy from decreasing.

[0039] The method for predicting chip breakability according to the present invention receives, from an input / output device, information on a workpiece and a tool to be subjected to cutting selected from the workpiece and the tool in the cutting shown in the information stored in the storage unit, and also receives information indicating the feed rate and the depth of cut in the cutting from the input / output device, and derives information for predicting whether the chip can be broken in the case of the workpiece, tool, feed rate, and depth of cut indicated by the received information, and communicates with the input / output device so that the derived information is displayed on the display unit of the input / output device.

[0040] In the method for predicting chip breakability according to the present invention, information indicating a workpiece, a tool, a feed rate, and a depth of cut is received, and information for predicting whether the chip can be broken in the case of the workpiece, tool, feed rate, and depth of cut indicated by this information is derived. This derived information is displayed on the display unit by communication with the display unit of the input / output device. Based on this displayed information, it becomes possible to determine whether the chip breaks or not. Also, even when it is predicted that the chip does not break, information regarding the break prediction can be obtained again by changing at least one of the feed rate and the depth of cut. Therefore, it is possible to easily set the conditions for performing cutting.

Advantages of the Invention

[0041] As described above, according to the present invention, when performing cutting, it becomes possible to easily set the cutting conditions.

Brief Description of the Drawings

[0042]

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Embodiments for Carrying Out the Invention

[0043] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

[0044] (First Embodiment) As shown in FIG. 1, the chip breakability prediction device 10 according to the first embodiment includes a control unit 12 for performing arithmetic processing, a storage unit 14 for storing processing programs, data, etc., and an input / output unit 16 used for inputting and outputting information. The control unit 12 has a central processing unit (CPU; Central Processing Unit), and various operations are executed by this CPU. When performing an operation, the control unit 12 appropriately uses the information input from the input / output unit 16 and the information stored in the storage unit 14.

[0045] The storage unit 14 stores information on the workpiece in cutting (workpiece information 14a) and information on the tool (tool information 14b). The workpiece information 14a includes information such as the name of the workpiece, the value of the fracture strain, and the shear angle. The tool information 14b includes information such as the name of the holder, the name of the insert, and data representing the shape of the cross section of the insert in a predetermined direction.

[0046] In addition, the storage unit 14 may temporarily store information input through the input / output unit 16 and data and information used in the calculations by the arithmetic unit 12b described later.

[0047] The input / output unit 16 has a display unit 16a configured to display cutting conditions and calculation results. As shown in FIG. 2, the display screen 20 of the display unit 16a includes an input area 21 and a result output area 22. Information corresponding to operations on the input unit 16b such as a keyboard is input into the input area 21. Note that the input unit 16b may be integrally formed with the display unit 16a.

[0048] The input area 21 includes a column 21a for the workpiece, a column 21b for the holder shape, a column 21c for the insert shape, a column 21d for the cutting conditions, and a column 21e for the coolant conditions. In the column 21a for the workpiece, various workpieces are displayed in a pull-down format, and the workpiece to be machined can be selected from this list. The workpieces listed in the column 21a for the workpiece are obtained from the information on the workpiece stored in the storage unit 14. The information indicating the workpiece selected through the input / output unit 16 is input into the reception unit 12a described later.

[0049] In the column 21b for the holder shape, various holders are displayed in a pull-down format, and the holder to be used can be selected from this list. In addition, the side cutting edge angle and the cutting edge inclination angle can be manually input. The information indicating the side cutting edge angle and the cutting edge inclination angle is input into the reception unit 12a described later.

[0050] In the chip shape column 21c, various chips are displayed in a pull-down format, and the chip to be used can be selected from this list. The chips listed in the chip shape column 21c are obtained from the information indicating the tools stored in the storage unit 14. It is also possible to specify the tip radius and tip angle of the chip. The information indicating the chip selected in this column 21c and the information indicating the tip radius and tip angle of the chip specified in this column 21c are input to the reception unit 12a described later.

[0051] In the cutting condition column 21d, there are an input box 21d1 where the cutting speed, feed rate, and depth of cut can be input, and an adjustment column 21d2 arranged next to it. The feed rate is the feed per revolution, and the depth of cut is the depth of cut in the radial direction.

[0052] The numerical values of the cutting speed, feed rate, and depth of cut are input to the input box 21d1. However, for the feed rate and depth of cut, the numerical values input to the input box 21d1 can be finely adjusted by moving the slider displayed in the adjustment column 21d2. Note that the cutting speed is not used for calculating the tensile strain generated in the chips described later. Therefore, the input box 21d1 for the cutting speed can be omitted. The information regarding the feed rate and depth of cut input in this column 21d is input to the reception unit 12a described later.

[0053] In the coolant condition column 21e, an input is made as to whether or not to use coolant. Note that this input information may not be used for predicting chip breakage. Therefore, the coolant condition column 21e can be omitted.

[0054] In the result output area 22, there are included a contour map column 22a, a dividability column 22b, a division prediction value column 22c, a fracture boundary column 22d, and a tool candidate column 22e. The contour map image-displayed in the contour map column 22a is a contour map shown in a coordinate system with the cutting conditions as coordinate axes. In the contour map, the distribution of tensile strain generated in the chips is represented by contour lines, and the fracture boundary 22f of the chips is represented.

[0055] The contour map shown in FIG. 2 has the feed rate on the horizontal axis and the depth of cut on the vertical axis. Note that the depth of cut may be on the horizontal axis and the feed rate may be on the vertical axis.

[0056] In the contour map, the ranges of the displayed feed rate and depth of cut are set so that the feed rate and depth of cut indicated by the information input in the input area 21 and received by the reception unit 12a described later are located at the center of the contour map. Further, the ranges of the displayed feed rate and depth of cut include at least the ranges predicted to be actually adjustable, and are determined so that ranges that do not become too large with respect to those ranges are displayed. Therefore, it is a contour map that makes it easy to judge the adjustment amount when adjusting the feed rate or the depth of cut.

[0057] In the contour map, a mark (a + mark in FIG. 2) indicating the feed rate and depth of cut input in the input area 21 and received by the reception unit 12a described later is displayed, and the fracture boundary 22f is displayed by a broken line. The fracture boundary 22f indicates the condition under which the tensile strain generated in the chips when the feed rate and the depth of cut are changed becomes the fracture strain ε c And the contour map shows the contour lines of the ratio of tensile strain to fracture strain. And the distribution of tensile strain is displayed such that the magnitudes of the ratios are divided for each predetermined value by one or more methods selected from color, hue shading, and luminance. Note that a difference value may be used instead of the ratio.

[0058] In the column 22b for cutability, a mark indicating whether the chips are predicted to be cut, not to be cut, or an intermediate value thereof is displayed based on the information derived by the arithmetic unit 12b described later. As a result, the cutability can be visually grasped.

[0059] In the column 22c for cutting prediction value, the value of the tensile strain ε in the case of the feed rate and the depth of cut input in the input area 21 and received by the reception unit 12a described later is numerically displayed. Also, in the column 22d for fracture boundary, the value of the fracture strain ε c is numerically displayed.

[0060] In the column 22e for tool candidates, a list of tools for which the chips are predicted to be cut is displayed based on the information derived by the arithmetic unit 12b described later. That is, for the workpiece material selected in the input area 21, the arithmetic unit 12b calculates whether the chips will be cut for all the tools included in the information stored in the storage unit 14. Therefore, by this calculation, all the tools are displayed in the column 22e for tool candidates so that those predicted to have high chip cutability are ranked higher. That is, the chip cutability of each tool is listed.

[0061] As shown in FIG. 1, the functions executed by the control unit 12 include a reception unit 12a, an arithmetic unit 12b, and a communication unit 12c. The reception unit 12a receives information on factors that affect whether the chips will be cut, such as cutting conditions. Specifically, the reception unit 12a receives information on the workpiece material and the tool selected in the input area 21 of the input / output unit 16 from the input / output unit 16. Also, the reception unit 12a receives information indicating the feed rate and the depth of cut input in the input area 21 of the input / output unit 16 from the input / output unit 16. That is, the reception unit 12a receives information on the workpiece material and the tool to be machined and the tool to be used, which are selected from the workpiece materials and tools shown in the workpiece material information 14a and the tool information 14b stored in the storage unit 14, and also receives information indicating the feed rate and the depth of cut in cutting.

[0062] The calculation unit 12b derives information for predicting whether the chip can be separated, using the information received by the reception unit 12a.

[0063] The communication unit 12c communicates with the input / output unit 16 so that the information for predicting whether the chip can be separated, derived by the calculation unit 12b, is displayed in the result output area 22 on the display screen 20 of the display unit 16a included in the input / output unit 16. The information for predicting whether the chip can be separated includes the information displayed in the contour map column 22a, the mark displayed in the separation possibility column 22b, the tensile strain value displayed in the separation prediction value column 22c, and the fracture strain value displayed in the fracture boundary column 22d.

[0064] Here, the derivation of the information for predicting whether the chip can be separated and the prediction determination of the separation possibility, performed by the calculation unit 12b, will be described in detail.

[0065] Whether the chip 30 (FIG. 3) can be separated can be predicted by comparing the tensile strain ε generated in the chip 30 during cutting with the fracture strain ε of the material used for cutting. c of the material used for cutting, and determining whether the tensile strain ε is greater than the fracture strain ε c of the material used for cutting by how much.

[0066] The tensile strain ε generated in the chip 30 is obtained by the following formula (1). Here, h is the chip thickness, and r 0 is the initial curl radius of the chip. That is, the tensile strain ε is calculated based on the initial curl radius r 0 of the chip 30 and the chip thickness h.

[0067]

Equation

[0068] The tensile strain ε may be replaced by a corrected tensile strain ε’ corrected by the following formulas (2) and (3). Here, t is the cut thickness, and b is the chamfer width or the cutting edge radius of curvature. That is, the tensile strain ε may be corrected by a relational expression indicating the ratio of the cut thickness t to the chamfer width or the cutting edge radius of curvature b. However, since A has an upper limit of 1, when the cut thickness t is larger than the chamfer width or the cutting edge radius of curvature b, A = 1.

[0069]

Number

[0070] In addition, in formula (2), the square of A is used, but instead, the first power or the third power of A may be used. As shown in FIG. 3, the chamfer width b is the width of the flat surface portion chamfered at the edge of the cutting edge. The cutting edge radius of curvature b is the radius of curvature at the edge of the cutting edge.

[0071] Since the chip thickness h is determined by the geometric relationship as shown in FIG. 4, it is calculated by the following formula (4). Here, t is the cut thickness, Φ is the shear angle, and α is the rake angle.

[0072]

Number

[0073] The cutting thickness t is geometrically determined from the cutting conditions and the tool posture. First, when the depth of cut d is larger than the nose radius R (see Fig. 5) (the case shown in Fig. 6), the cutting thickness t is obtained by Equation (5) using the feed rate f and the side cutting edge angle θ. Also, when the value of a obtained by Equation (6) using the depth of cut d and the nose radius R is negative, since the cutting thickness t becomes the same value as the depth of cut d, Equation (7) is used. Note that when the value of a obtained by Equation (6) is negative, it is the case shown in Fig. 7. In other cases, that is, when the depth of cut d is smaller than the nose radius R and the value of a obtained by Equation (6) is positive, the cutting thickness t is obtained by Equation (8). Note that when using Equation (8), it is the case shown in Fig. 8, and the side cutting edge angle θ becomes irrelevant, and the cutting thickness t is determined by the nose radius R, the depth of cut d, and the feed rate f.

[0074]

Number

[0075] The rake angle α is obtained from the cross-sectional shape data in a predetermined direction of the chip stored in the storage unit 14. The rake angle α is not constant at any part of the rake face. For this reason, as the rake angle α, the rake angle α in the cross-section along the outflow direction θd (Fig. 5) of the chips 30 is adopted. For this reason, the rake angle α in the cross-section along this direction θd is derived by the arithmetic unit 12b and temporarily stored in the storage unit 14.

[0076] The outflow direction θd of the chips 30 can be calculated using Colwell's approximate formula assuming that the chips 30 flow out in a direction perpendicular to the straight line connecting both ends of the chip in contact with the workpiece (both ends in the circumferential direction of the nose). That is, if the depth of cut d, the feed rate f, and the nose radius R of the chip are determined, as shown in Fig. 5, the outflow direction θd of the chips 30 can be calculated from these geometric relationships.

[0077] The storage unit 14 stores the rake angle α1 in the cross section in the direction θ1 perpendicular to the cross cutting edge and the rake angle α2 in the cross section in the direction θ2 along the bisector of the tip angle of the chip. Therefore, using these rake angles α1 and α2, the rake angle α in the outflow direction θd according to the cutting conditions is obtained by interpolation or extrapolation (see Fig. 9). In Fig. 9, θ2 on the horizontal axis corresponds to the direction along the bisector of the tip angle of the chip, and θ1 corresponds to the direction perpendicular to the cross cutting edge.

[0078] Also, the breaker shape is derived in the same way. That is, the storage unit 14 stores data indicating the breaker shape in a predetermined direction. This predetermined direction is the direction θ1 perpendicular to the cross cutting edge and the direction θ2 along the bisector of the tip angle of the chip. Then, the calculation unit 12b determines the breaker shape β1, β2 (or the initial curl radius r of the chip) in the two directions θ1, θ2 stored in the storage unit 14 0 ) from the data, and the breaker shape β (or the initial curl radius r of the chip) in the chip outflow direction θd according to the cutting conditions is obtained by interpolation or extrapolation. 0 )

[0079] As shown in Fig. 10, the rake angles α1 and α2 are obtained by the gradient (or the gradient of the flat part) when the rake face 27 is linearly approximated and the distance from the cutting edge position (the value of the intercept when the cutting edge position is the origin position) in the cross section in the corresponding direction on the rake face 27 of the chip. Also, the breaker shapes β1, β2 are obtained by the gradient (or the gradient of the flat part) when the breaker slope 28 of the chip is linearly approximated in the cross section in the corresponding direction on the breaker slope 28 of the chip.

[0080] The shear angle Φ is obtained by performing a cutting test and is stored in the storage unit 14. An example of the cutting speed, the cutting thickness t, and the rake angle α used in this cutting test is shown in Table 1. The storage unit 14 stores information indicating the shear angle Φ, including data of the shear angle Φ obtained from cutting tests performed under other conditions.

[0081]

Table 1

[0082] In the cutting test, the thickness of the obtained chips 30 is measured. By substituting the measured chip thickness into the chip thickness h in Equation (4), the shear angle Φ can be obtained. An example of the chip thickness and the calculated shear angle obtained from the cutting test of the work material S45C is shown in Table 2.

[0083]

Table 2

[0084] The initial curl radius r of the chip 30 0 varies in the calculation method depending on whether the chip conforms to the parallel type or the clamp type shown in Figs. 11(a) and 11(b). In the parallel type shown in Fig. 11(a), since the breaker slope 28 is small, the chip 30 contacts the tip 32 portion on the rake face 27 and the apex 29 of the breaker. Therefore, the initial curl radius r 0 is geometrically calculated as the radius of the arc that contacts the tip 32 and the apex 29 of the breaker. On the other hand, in the clamp type shown in Fig. 11(b), the chip 30 contacts the tip 32 portion on the rake face 27 and the breaker slope 28. Therefore, the initial curl radius r 0 is geometrically calculated as the radius of the arc that contacts the tip 32 and the breaker slope 28. Note that the shape of the breaker is used to determine whether it is the parallel type or the clamp type.

[0085] Also, as with the rake angle α, as the initial curl radius, the initial curl radius r 0 in the chip outflow direction θd corresponding to the cutting conditions is used. That is, the storage unit 14 stores the initial curl radius r1 (see Fig. 9) in the cross-section in the direction θ1 perpendicular to the cross-cutting edge and the initial curl radius r2 (see Fig. 9) in the cross-section in the direction θ2 along the bisector of the tip angle of the chip. Then, using these initial curl radii r1 and r2, the initial curl radius r in the outflow direction θd corresponding to the cutting conditions0 is obtained by interpolation or extrapolation.

[0086] In the above manner, the tensile strain ε is derived from Equation (1). On the other hand, the chip fracture strain ε c can be obtained by performing cutting tests while gradually changing the conditions. In the storage unit 14, the fracture strain ε c obtained for each workpiece by the cutting test is stored. That is, in the storage unit 14, the fracture strain ε c obtained by the cutting test performed while changing the cutting conditions (depth of cut d and feed rate f) is stored in association with the workpiece.

[0087] FIG. 12 shows an example when it is determined whether the chip 30 is broken. This example is an example of the result when S45C is used as the workpiece. When the chip 30 is not broken, it is marked as "×", when a partially broken chip 30 with 10 or more turns connected is generated, it is marked as "Δ", and when it is broken within 10 turns, it is marked as "〇".

[0088] Regarding the tensile strain ε of the chip 30 calculated in each cutting test, when it is determined that the chip 30 is broken (when it is marked as "〇"), the value when the tensile strain ε is the smallest is defined as the chip fracture strain ε c . The values of the chip fracture strain ε c for each workpiece are stored in the storage unit 14 in association with the name of the workpiece.

[0089] As described above, the tensile strain ε is calculated according to Equation (1) and compared with the fracture strain ε c to predict the breakability. However, as shown in FIG. 13, when the chip thickness h is greater than the distance L from the cutting edge 32 to the breaker apex 29, that is, h > L ··· Equation (9) is satisfied, the arithmetic unit 12b outputs information indicating that it is predicted that the chip 30 will not break. That is, the tensile strain ε and the fracture strain εc In the prediction of breakability by comparison with [something not specified in the original, assumed to be a reference value], the smaller the distance L from the cutting edge 32 to the apex 29 of the breaker, the easier it is to break. However, in reality, if the breaker is too small, as shown in Fig. 13, the chips 30 will pass through the breaker without being bent by the breaker, and the chips 30 will not break. In order to improve the predictability of breakability in such a case, the prediction of breakability when Equation (9) holds is also added.

[0090] Next, a method for predicting the breakability of the chips 30 using the chip breakability prediction device 10 according to the first embodiment will be described with reference to Fig. 14.

[0091] To perform cutting on the workpiece, it is necessary to set cutting conditions. To set the cutting conditions, the chip breakability prediction device 10 is used. The user inputs the necessary information into the input / output unit 16 using the chip breakability prediction device 10, outputs the prediction result of the chip breakability, and determines the cutting conditions according to this prediction result.

[0092] First, the user selects the workpiece to be processed in the workpiece column 21a of the input area 21 in the input / output unit 16, and selects the holder and insert to be used in the holder shape column 21b and the insert shape column 21c (step ST11). As a result, information regarding the selected workpiece and tool is extracted from the information regarding the workpiece and tool stored in the storage unit 14 and input into the reception unit 12a. At this time, if the user inputs values for the cross cutting edge angle, cutting edge inclination angle, nose radius R, and tip angle, this information is also input into the reception unit 12a.

[0093] In addition, the user inputs the cutting speed, feed rate f, and depth of cut d in the cutting condition column 21d (step ST12). These pieces of information are also input to the reception unit 12a. Note that the values of these cutting conditions are provisional values, and if it is predicted that the chips 30 will not be broken, the cutting conditions will be input again. Also, the holder and the chip may be changed according to the prediction result.

[0094] When the information necessary for cutting is input to the reception unit 12a, the calculation unit 12b uses the information received by the reception unit 12a to derive information for predicting whether the chips 30 can be broken. Specifically, the calculation unit 12b first calculates the cutting thickness t using any one of Equation (5), Equation (7), and Equation (8) according to the magnitude relationship between the depth of cut d and the nose radius R (step ST13).

[0095] In addition, the calculation unit 12b obtains the chip outflow direction θd using the depth of cut d, the feed rate f, and the nose radius R of the chip (step ST14). The chip outflow direction θd is calculated using, for example, Colwell's approximate formula stored in the storage unit 14. Using the calculated chip outflow direction θd, the rake angles α1 and α2 stored in the storage unit 14, and the initial curl radii r1 and r2 of the chips, the calculation unit 12b calculates the rake angle α and the initial curl radius r of the chips in the direction θd. 0 (Steps ST15 and ST16).

[0096] Subsequently, the calculation unit 12b substitutes the cutting thickness t obtained in step ST13, the rake angle α obtained in step ST15, and the shear angle Φ stored in the storage unit 14 into Equation (4) to calculate the chip thickness h (step ST17). In addition, the calculation unit 12b substitutes the initial curl radius r obtained in step ST16 and the chip thickness h obtained in step ST17 into Equation (1) to derive the tensile strain ε (step ST18). 0

[0097] At this time, when it is determined that the chamfer width or the cutting edge radius b of the selected chip is relatively large with respect to the cutting thickness t, the corrected tensile strain ε' calculated by Equation (2) is alternatively used as the tensile strain ε in Equation (1) (step ST19).

[0098] The value of the derived tensile strain ε (or corrected tensile strain ε') is displayed in the fracture prediction value column 22c in the result output area 22 of the input / output unit 16. Also, the fracture strain ε c The value of is displayed in the fracture boundary column 22d in the result output area 22 of the input / output unit 16 (step ST20).

[0099] Then, the arithmetic unit 12b determines the breakability of the chip 30 by comparing the tensile strain ε (or corrected tensile strain ε') derived in step ST18 with the fracture strain ε c stored in the storage unit 14 (step ST21).

[0100] The communication unit 12c communicates with the input / output unit 16. As a result, based on the comparison result with the fracture strain ε c marks such as ○, △, and × are displayed in the breakability column 22b in the result output area 22 of the input / output unit 16 (step ST22). For example, when the value of the tensile strain ε (or corrected tensile strain ε') is greater than a predetermined value compared to the fracture strain ε c a "○" is displayed. That is, in this case, a result indicating that the chip is predicted to break is displayed.

[0101] Also, the arithmetic unit 12b derives the tensile strain ε (or corrected tensile strain ε') in the same manner not only for the selected cutting depth d and feed rate f but also for the cutting depth d and feed rate f within a predetermined range including these values. That is, the arithmetic unit 12b derives information for predicting the breakability of the chip for each case when the cutting conditions are changed within the range of the feed rate and cutting depth shown in the contour map. Also, the arithmetic unit 12b extracts the fracture strain ε c for the cases of the cutting depth d and feed rate f within these ranges.

[0102] Then, the communication unit 12c outputs information for creating a contour map of the tensile strain ε (or corrected tensile strain ε') in the case of the cutting amount d and feed rate f within this predetermined range. Further, the communication unit 12c communicates with the input / output unit 16 so that an image of the contour map is displayed on the display screen 20 of the display unit 16a in the input / output unit 16 (step ST23). Then, the contour map is displayed on the display screen 20 of the display unit 16a. In the image of this contour map, the fracture strain ε at each cutting amount d and feed rate f c is also displayed. That is, based on the information derived by the arithmetic unit 12b, the communication unit 12c communicates with the input / output unit 16 so that an image representing the distribution of the tensile strain ε generated in the chips by contour lines and representing the fracture boundary 22f of the chips is displayed on the display unit 16a of the input / output unit 16 in a coordinate system with the cutting conditions as the coordinate axes.

[0103] Also, for all the tools included in the tool information 14b stored in the storage unit 14 for the selected workpiece, the arithmetic unit 12b compares the tensile strain ε (or corrected tensile strain ε') with the fracture strain ε c to calculate whether the chips 30 will break in each case of the tools. As a result, all the registered tools are listed in the tool candidate column 22e in the order in which it is determined that the chips are likely to break (step ST24).

[0104] If it is determined that the chips 30 will break under the input cutting conditions, the user may perform cutting of the workpiece under the input cutting conditions. On the other hand, if it is determined that the chips 30 will not break under the input cutting conditions, the cutting conditions may be changed to those predicted to cause breakage from among the displayed contour maps. Alternatively, the cutting conditions may be changed and the prediction of chip breakability may be performed again. Alternatively, the cutting of the workpiece may be performed by changing to the tools displayed in the tool candidates.

[0105] Next, an example of the fragmentation prediction results obtained from cutting tests with different depths of cut d and feed rates f will be introduced. Fig. 15 shows a contour map obtained by the chip fragmentation prediction device 10, with symbols (○△×) indicating the fragmentation states of the chips shown in Fig. 12 superimposed on it. As such, the prediction results roughly match the experimental results. Note that as the depth of cut decreases from around 1.2 mm, the areas determined to be fragmented curve smoothly because the chip outflow angle changes rapidly for depths of cut d less than the nose radius R (1.2 mm) of the tool. However, since the method using the breaker shape (initial curl radius r 0 ) and the rake angle α in the chip outflow direction θd is adopted, it can be seen that the fragmentation of the chips can be predicted.

[0106] Figs. 16(a) to (c) show the prediction results when the tensile strain ε is replaced by the corrected tensile strain ε’. When the chamfer width b is relatively large, the prediction results regarding fragmentability deviate. However, it can be seen that the prediction accuracy is improved by replacing the tensile strain ε with the corrected tensile strain ε’. Also, it can be seen that the case with the correction value using A 2 has a higher prediction accuracy than the case with the correction value using A or A 3 .

[0107] Also, Fig. 17 shows the prediction results when the tensile strain ε is replaced by the corrected tensile strain ε’. Fig. 17 shows an actual chip photograph, a contour map based on the tensile strain ε, and a contour map based on the corrected tensile strain ε’. For example, in the test example No. 4, although chip 30 is not fragmented, the fragmentation prediction based on the tensile strain ε predicts fragmentation, while the fragmentation prediction based on the corrected tensile strain ε’ predicts non-fragmentation. Therefore, it can be seen that the prediction accuracy is improved by replacing the tensile strain ε with the corrected tensile strain ε’.

[0108] FIG. 18 shows an example of the result when the arithmetic unit 12b outputs information predicting that the chips 30 will not be broken when the chip thickness h is greater than the distance L from the cutting edge 32 to the apex 29 of the breaker. In the upper right part of the figure, it is the area indicating that it will not be broken. On the other hand, for the ○△× obtained from the experimental results, they are shown as △ within the said area, and it can be said that it has been predicted that the chips 30 will become too thick and will not be broken.

[0109] Also, FIG. 19 is also an example of the result when the chip thickness h is greater than the distance L from the cutting edge 32 to the breaker apex 29. It is the result when the tool is changed, and the chip photograph is also shown together. It can be seen that the chip photograph and the prediction result match.

[0110] As described above, in the chip breakability prediction device 10 according to the present embodiment, the reception unit 12a receives information regarding the workpiece and the tool, and information indicating the feed rate and the depth of cut. Then, the arithmetic unit 12b derives information for predicting whether the chips 30 can be broken in the case of the workpiece, the tool, the feed rate f, and the depth of cut d indicated by the information received by the reception unit 12a. Since this derived information is displayed on the display unit 16a, it becomes possible to determine whether the chips 30 will be broken from the information displayed on the display unit 16a. Also, even when it is predicted that the chips 30 will not be broken, by changing at least one of the feed rate f and the depth of cut d, information regarding the break prediction can be obtained again. Therefore, it is possible to easily set the conditions when performing cutting.

[0111] Also, in the present embodiment, when the chamfer width of the tool or the cutting edge radius b is relatively large with respect to the cut thickness t, the tensile strain ε is replaced by the corrected tensile strain ε'. That is, since the influence on the tensile strain ε of the chips 30 is considered according to the size of the chamfer width of the tool or the cutting edge radius b, the break prediction performance of the chips 30 can be further improved.

[0112] In addition, in this embodiment, in the result output area 22 of the display unit 16a, a contour map, a determination possibility, a fracture prediction value, and a fracture boundary 22f are displayed, but it is not limited thereto. For example, only the contour map may be displayed, or only the determination possibility may be displayed, or only the fracture prediction value and the fracture boundary 22f may be displayed. Also, the display of the tool candidate may be omitted.

[0113] Further, in this embodiment, a process of substituting the tensile strain ε with the corrected tensile strain ε' is performed. However, when it is known that the cutting thickness t is equal to or less than the chamfer width or the cutting edge radius b, this process may be omitted.

[0114] Also, in this embodiment, the calculation unit 12b calculates the initial curl radius r 0 and the rake angle α in the chip outflow direction θd due to cutting, and performs a calculation for predicting the fracturability using the calculated initial curl radius r 0 and the rake angle α. However, it is not limited thereto. That is, although the prediction accuracy decreases, the initial curl radius r 0 and the rake angle α in the chip outflow direction θd may not be derived.

[0115] (Second Embodiment) As shown in FIG. 20, the second embodiment is a control device 41 provided in a prediction system 40 for predicting the fracturability of chips in cutting. Here, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0116] The control device 41 is communicably connected to an input / output device 42 via, for example, a computer network NW. The control device 41 includes a control unit 12 for performing arithmetic processing and a storage unit 14 for storing processing programs, data, and the like.

[0117] The input / output device 42 includes a display unit 16a having a display screen 20 and an input unit 16b such as a keyboard. The display unit 16a is configured to display cutting conditions and calculation results. The display screen 20 of the display unit 16a includes an input area 21 and a result output area 22, similar to the display screen 20 (see FIG. 2) of the first embodiment. Information input by an operation of the input unit 16b is displayed in the input area 21. This input information is temporarily stored in the storage unit 14 of the control device 41 via, for example, a computer network NW. Note that the input unit 16b may be integrally configured with the display unit 16a.

[0118] The storage unit 14 stores information regarding the workpiece in cutting (workpiece information 14a) and information regarding the tool (tool information 14b). Also, information transmitted from the input / output device 42 and data and information used in calculations by the calculation unit 12b may be temporarily stored in the storage unit 14.

[0119] The functions executed by the control unit 12 include a reception unit 12a, a calculation unit 12b, and a communication unit 12c. The communication unit 12c transmits necessary information to the input / output device 42 so that the workpiece and tool indicated by the information stored in the storage unit 14 are displayed on the display screen 20 of the input / output device 42.

[0120] When performing calculations, the control unit 12 uses the information stored in the storage unit 14 and the information output from the input / output device 42 and temporarily stored in the storage unit 14 via the computer network NW.

[0121] The reception unit 12a receives information from the input / output device 42 regarding factors that affect whether chips will be segmented, such as cutting conditions. Specifically, information regarding the workpiece and tool that match the workpiece and tool selected in the input area 21 of the input / output device 42 is input to the reception unit 12a from the storage unit 14. Further, information indicating the feed rate f and the depth of cut d input in the input area 21 of the input / output device 42 is input to the reception unit 12a from the input / output device 42. That is, the reception unit 12a receives information regarding the workpiece to be machined and the tool to be used, which are the objects of the cutting process selected in the input / output device 42, among the workpiece and tool indicated by the information stored in the storage unit 14, and also receives information indicating the feed rate f and the depth of cut d in the cutting process.

[0122] The calculation unit 12b derives information for predicting whether the chips will be segmented using the information received by the reception unit 12a.

[0123] The communication unit 12c communicates with the input / output device 42 so that the information for predicting whether the chips will be segmented, derived by the calculation unit 12b, is displayed in the result output area 22 on the display screen 20 of the display unit 16a of the input / output device 42.

[0124] In the control device 41 according to the second embodiment, among the control steps shown in FIG. 14, steps ST13 to ST19 and ST21 are performed. Further, the control device 41 communicates with the input / output device 42 so that steps ST20 and ST22 to 24 are performed in the input / output device 42.

[0125] Although the description of other configurations, operations, and effects is omitted, the description of the first embodiment can be incorporated into the second embodiment.

[0126] (Other Embodiments) It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The present invention is not limited to the above-described embodiments, and various changes, improvements, etc. are possible without departing from the spirit thereof.

Description of Reference Numerals

[0127] 10: Disconnection prediction device 12a: Reception unit 12b: Calculation unit 12c: Communication unit 14: Storage unit 16a: Display unit 22f: Fracture boundary 29: Breaker vertex 32: Cutting edge 40: Prediction system 41: Control device 42: Input / output device L: Distance b: Chip width or cutting edge radius of curvature d: Depth of cut f: Feed rate h: Thickness r 0 : Initial curl radius t: Cutting thickness Φ: Shear angle α: Rake angle θd: Chip outflow direction

Claims

1. A storage unit storing information on a workpiece and a tool in machining; a reception unit that receives information on a workpiece to be machined and a tool to be used, which are selected from the workpiece and the tool indicated in the information stored in the storage unit, and also receives information indicating a feed rate and a depth of cut in the machining; a calculation unit that derives information for predicting whether chips can be broken using the information received by the reception unit; and a display unit that displays the information for predicting whether the chips can be broken, which is derived by the calculation unit. A chip breakability prediction device.

2. The calculation unit: calculates tensile strain generated in the chips by machining based on an initial curl radius and a chip thickness of the chips; and is configured to correct the tensile strain using a chamfer width or a cutting edge radius of the tool indicated by the information received by the reception unit, and a cutting thickness obtained from a nose radius of the tool, a side cutting edge angle of the tool, the feed rate, and the depth of cut indicated by the information received by the reception unit. The chip breakability prediction device according to claim 1.

3. The calculation unit: obtains an initial curl radius and a rake angle in each cross section from a cross section perpendicular to a side cutting edge of the tool indicated by the information received by the reception unit and a cross section of a bisector of the tip angle of the tool; and is configured to calculate an initial curl radius and a rake angle in the chip outflow direction by machining from the initial curl radius and the rake angle in each obtained cross section by interpolation or extrapolation. The chip breakability prediction device according to claim 1.

4. The display unit displays, as the information for predicting the chip breakability, an image representing a distribution of tensile strain generated in the chips by contour lines and representing a fracture boundary of the chips in a coordinate system having machining conditions as coordinate axes. The chip breakability prediction device according to claim 1.

5. The display unit displays the distribution of tensile strain generated in the chips by one or more methods selected from color, shade of hue, and luminance. The chip breakability prediction device according to claim 4.

6. The calculation unit compares a distance from a cutting edge of the tool to a breaker apex with a chip thickness, and predicts that the chips will not break when the chip thickness is larger. The chip breakability prediction device according to claim 1.

7. The calculation unit calculates the breakability of the chips for all the tools indicated by the information stored in the storage unit. The display unit displays a list of the breakabilities of the chips of each tool based on the information derived by the calculation unit. The chip breakability prediction device according to claim 1.

8. A control device provided in a prediction system for predicting the breakability of chips in cutting, and communicably connected to an input / output device, comprising: a storage unit storing information on the workpiece and the tool in cutting; a reception unit that receives information on the workpiece and the tool to be used, which are the objects of the cutting selected by the input / output device, among the information on the workpiece and the tool shown in the information stored in the storage unit, and also receives information indicating the feed rate and the depth of cut in the cutting; a calculation unit that derives information for predicting whether the chips can be broken using the information received by the reception unit; a communication unit that communicates with the input / output device so that the information for predicting whether the chips can be broken, derived by the calculation unit, is displayed on the display unit of the input / output device. Control device.

9. The calculation unit: calculates the tensile strain generated in the chips by cutting based on the initial curl radius and the chip thickness of the chips; is configured to correct the tensile strain using the chamfer width or the nose radius of the tool indicated by the information received by the reception unit, and the cutting thickness obtained from the nose radius of the tool, the side cutting edge angle of the tool, the feed rate, and the depth of cut indicated by the information received by the reception unit. The control device according to claim 8.

10. The calculation unit: acquires the initial curl radius and the rake angle in each cross-section from the cross-section perpendicular to the side cutting edge of the tool indicated by the information received by the reception unit and the cross-section of the bisector of the tip angle of the tool; is configured to calculate the initial curl radius and the rake angle in the chip outflow direction by cutting from the initial curl radius and the rake angle in each of the acquired cross-sections by interpolation or extrapolation. The control device according to claim 8.

11. The communication unit communicates with the input / output device so that an image representing the distribution of the tensile strain generated in the chips by contour lines and representing the fracture boundary of the chips is displayed on the display unit in a coordinate system with the cutting conditions as coordinate axes. The control device according to claim 8.

12. The communication unit communicates with the input / output device such that the distribution of tensile strain generated in the chips is displayed on the display unit by one or more methods selected from color, shade of hue, and luminance. The control device according to claim 11.

13. The arithmetic unit compares the distance from the cutting edge of the tool to the breaker apex with the chip thickness, and predicts that the chip will not break when the chip thickness is larger. The control device according to claim 8.

14. The arithmetic unit calculates the breakability of chips for all the tools indicated by the information stored in the storage unit. The communication unit communicates with the input / output device such that a list of the breakability of chips for each tool is displayed on the display unit based on the calculation result by the arithmetic unit. The control device according to claim 8.

15. Receive information regarding the workpiece and the tool to be machined selected from the workpiece and the tool in the cutting process indicated in the information stored in the storage unit, and receive information indicating the feed rate and the depth of cut in the cutting process. Using the received information, derive information for predicting whether the chip can be broken. Display the derived information on the display unit. Chip breakability prediction method.

16. Calculate the tensile strain generated in the chips by the cutting process based on the initial curl radius and the chip thickness of the chips. Correct the tensile strain using the chamfer width or the cutting edge radius of the tool indicated by the received information, and the cutting thickness obtained from the nose radius of the tool, the side cutting edge angle of the tool, the feed rate, and the depth of cut indicated by the received information. The chip breakability prediction method according to claim 15.

17. Obtain the initial curl radius and the rake angle at each cross-section from the cross-section perpendicular to the side cutting edge of the tool indicated by the received information and the cross-section of the bisector of the tip angle of the tool. Calculate the initial curl radius and the rake angle in the chip outflow direction by the cutting process from the initial curl radius and the rake angle at each of the obtained cross-sections by interpolation or extrapolation. The chip breakability prediction method according to claim 15.

18. Compare the distance from the cutting edge of the cutting tool to the breaker apex with the chip thickness, and predict that the chip will not break when the chip thickness is larger. The chip breakability prediction method according to claim 15.

19. Receive information regarding the workpiece and the tool to be used, which are selected from the workpiece and the tool in the cutting process shown in the information stored in the storage unit, from the input / output device, and receive information indicating the feed rate and the depth of cut in the cutting process from the input / output device. Derive information for predicting whether the chips can be broken in the case of the workpiece, tool, feed rate, and depth of cut indicated by the received information. Communicate with the input / output device so that the derived information is displayed on the display unit of the input / output device. Chip breakability prediction method.

Images