Information processing device, program, and method for calculating surface roughness

Abstract

To provide an information processing device that enables easy selection of parameters for oscillating cutting based on the surface roughness required for a workpiece in the turning cutting, particularly oscillating cutting.SOLUTION: An information processing device includes a processor. The processor acquires a parameter map in which values of multiple types of parameters related to swing cutting are linked to surface roughness of a workpiece, and causes a display device to display a relationship between a value of at least one of the multiple types of parameters in the parameter map and the surface roughness in the parameter map. By checking the relationship between the parameter value and the surface roughness displayed on the display device, an operator can intuitively select a parameter based on the surface roughness.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an information processing device, a program, and a method for calculating surface roughness used in processing related to the surface roughness of a workpiece in cutting processing. [Background technology]

[0002] Chip disposal is important to improve the productivity of machine tools, especially in turning. For example, when continuous chips are generated during turning, the chips may become entangled with the tool or workpiece. In such cases, it is necessary to interrupt the process to remove the chips, which reduces production efficiency. Furthermore, the chips may scratch the workpiece, resulting in a decrease in quality.

[0003] As a technique for avoiding such a situation, a rocking cutting technique has been disclosed in which the tool and the workpiece are rocked relatively in the machining feed direction to shred the chips (see, for example, Patent Document 1).

[0004] The frequency and amplitude of the oscillation command in oscillation cutting are parameters that are selected taking into consideration the required specifications of the workpiece to be machined, the machining conditions, the constraints of the machine performance, the servo control performance, etc. The parameters for oscillation cutting include, for example, the oscillation frequency magnification I and the oscillation amplitude magnification K.

[0005] Furthermore, as a means for determining parameters for orbital cutting, a technique has been proposed in which candidate parameters are presented to an operator according to the rotation speed or vibration frequency, and the operator is allowed to select one. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6636998 [Patent Document 2] Patent No. 5599523 [Patent Document 3] Patent No. 6843313 Summary of the Invention [Problem to be solved by the invention]

[0007] An example of the instructions on the drawing is surface roughness (arithmetic mean roughness Ra, maximum height roughness Rz, etc.). An example of the parameters for oscillation cutting is oscillation frequency magnification I and oscillation amplitude magnification K. In previous oscillation cutting, the relationship between the instructions on the drawing and the parameters for oscillation cutting was unclear, making it difficult for the worker to select the parameters.

[0008] An object of the present invention is to provide an information processing device that enables easy selection or setting of parameters in orbital cutting from surface roughness, or to provide a method for calculating surface roughness required to achieve this. [Means for solving the problem]

[0009] The information processing device of the present invention includes a processor, which acquires a parameter map in which values ​​of multiple types of parameters related to oscillatory cutting are linked to the surface roughness of the workpiece, and displays on a display device the relationship between the value of at least one of the multiple types of parameters in the parameter map and the surface roughness in the parameter map.

[0010] In addition, the information processing device of the present invention includes a processor, and is characterized in that the processor acquires a parameter map in which values ​​of multiple types of parameters related to oscillatory cutting are linked to the surface roughness of the workpiece, accepts a specified surface roughness of the workpiece, and acquires from the parameter map the values ​​of the parameters corresponding to the accepted specified surface roughness.

[0011] In the information processing device according to the present invention, the processor may obtain, from the parameter map, the value of the parameter associated with a surface roughness that is equal to or less than the received specified surface roughness and is closest to the specified surface roughness.

[0012] In the information processing device of the present invention, the multiple types of parameters may include a spindle phase Θ of the workpiece, a feed speed F of the tool, a shape of the tool cutting edge, a swing amplitude magnification K, and a swing frequency magnification I, and the surface roughness of the parameter map may be the surface roughness at the spindle phase Θ of the workpiece.

[0013] In the information processing device according to the present invention, the processor executes a creation process for creating the parameter map, The creation process includes: (i) setting values ​​of the spindle phase Θ, the feed rate F, the shape of the tool tip, the oscillation amplitude magnification K, and the oscillation frequency magnification I; (ii) From the following (Formula A), while sequentially changing the integrated spindle speed n (n is an integer equal to or greater than 0), obtain the command position Pz(n,Θ) of the tool tip at each spindle speed n in the spindle phase Θ; Pz(n,Θ)=(KF / 2)cos(I×(2πn+Θ)) -(KF / 2)+F×((2πn+Θ) / 2π)...(Formula A) (iii) calculating an intersection point where the shapes of the tool cutting edge at two command positions Pz(n, Θ) having adjacent values ​​of n intersect based on the shape of the tool cutting edge and each of the command positions Pz(n, Θ); (iv) acquiring a position of the machined surface in a spindle phase Θ generated by the tool tip so as to connect adjacent intersections, thereby acquiring a shape of the machined surface; (v) calculating the surface roughness at the spindle phase Θ based on the shape of the machined surface; and (vi) linking the values ​​of the feed rate F, the shape of the tool tip, the oscillation amplitude magnification K, and the oscillation frequency magnification I with the calculated surface roughness; (vii) creating the parameter map by varying at least one of the feed rate F, the shape of the tool cutting edge, the oscillation amplitude magnification K, and the oscillation frequency magnification I and repeating the processes (ii) to (vi) above.

[0014] In the information processing device of the present invention, the value of the shape of the tool tip is a value of a nose R as a radius of the tool tip, and the processor may set the center of the nose R to the command position Pz(n, Θ).

[0015] In the information processing device of the present invention, the surface roughness of the parameter map may be a representative surface roughness obtained from the surface roughness at multiple spindle phases of the workpiece, and the representative surface roughness may be a maximum value, an average value, or a median value of the surface roughness at the multiple spindle phases.

[0016] The information processing device according to the present invention includes a processor used to calculate the surface roughness in a spindle phase Θ of a workpiece, The processor, (i) Obtain the values ​​of the spindle phase Θ, the feed rate F, the shape of the tool tip, the oscillation amplitude magnification K, and the oscillation frequency magnification I; (ii) Using the following (Formula A), the integrated spindle speed n (n is an integer equal to or greater than 0) is changed in sequence to obtain the command position Pz(n,Θ) of the tool tip at each spindle speed n in the spindle phase Θ, Pz(n,Θ)=(KF / 2)cos(I×(2πn+Θ)) -(KF / 2)+F×((2πn+Θ) / 2π)...(Formula A) (iii) calculating an intersection point where the shapes of the tool cutting edge at two command positions Pz(n, Θ) having adjacent values ​​of n intersect based on the shape of the tool cutting edge and each of the command positions Pz(n, Θ); (iv) acquiring a position of the machining surface in the spindle phase Θ generated by the tool tip so as to connect adjacent intersections, thereby acquiring a shape of the machining surface; (v) calculating the surface roughness at the spindle phase Θ based on the shape of the machined surface;

[0017] Further, a method for calculating surface roughness according to the present invention is a method for calculating a surface roughness in a spindle phase Θ of a workpiece using a computer, comprising the steps of: (i) acquiring values ​​of the spindle phase Θ, the feed rate F, the shape of the tool tip, the oscillation amplitude magnification K, and the oscillation frequency magnification I; (ii) obtaining a command position Pz(n, Θ) of the tool tip at each spindle speed n in the spindle phase Θ from the following (Formula A) while sequentially changing the integrated spindle speed n (n is an integer equal to or greater than 0); Pz(n,Θ)=(KF / 2)cos(I×(2πn+Θ)) -(KF / 2)+F×((2πn+Θ) / 2π)...(Formula A) (iii) calculating an intersection point where the shapes of the tool cutting edge at two command positions Pz(n, Θ) having adjacent values ​​of n intersect based on the shape of the tool cutting edge and each of the command positions Pz(n, Θ); (iv) acquiring a position of the machined surface in a spindle phase Θ generated by the tool tip so as to connect adjacent intersections, thereby acquiring a shape of the machined surface; (v) calculating the surface roughness at the spindle phase Θ based on the shape of the machined surface.

[0018] Further, the program according to the present invention is a program for causing a computer to execute a process for calculating a surface roughness in a spindle phase Θ of a workpiece, The process comprises: (i) obtaining values ​​of the spindle phase Θ, the feed rate F, the shape of the tool tip, the oscillation amplitude magnification K, and the oscillation frequency magnification I; (ii) From the following (Formula A), while sequentially changing the integrated spindle speed n (n is an integer equal to or greater than 0), obtain the command position Pz(n,Θ) of the tool tip at each spindle speed n in the spindle phase Θ; Pz(n,Θ)=(KF / 2)cos(I×(2πn+Θ)) -(KF / 2)+F×((2πn+Θ) / 2π)...(Formula A) (iii) calculating an intersection point where the shapes of the tool cutting edge at two command positions Pz(n, Θ) having adjacent values ​​of n intersect based on the shape of the tool cutting edge and each of the command positions Pz(n, Θ); (iv) acquiring a position of the machined surface in a spindle phase Θ generated by the tool tip so as to connect adjacent intersections, thereby acquiring a shape of the machined surface; (v) calculating the surface roughness at the spindle phase Θ based on the shape of the machined surface. Effect of the Invention

[0019] According to the present invention, regarding the orbital cutting, the operator can easily select the parameters of the orbital cutting that satisfy the drawing instruction (surface roughness). Also, regarding the orbital cutting, the parameters can be automatically selected or set from the surface roughness. [Brief description of the drawings]

[0020] [Figure 1] FIG. 4 is an explanatory diagram of calculation of a machined surface shape in the first embodiment. [Diagram 2] 10 is a flowchart showing a process according to the second embodiment. [Diagram 3] 13 is a diagram showing an example of surface roughness associated with each value of a variable parameter in the second embodiment. FIG. [Figure 4] FIG. 11 is a diagram showing an example of a display showing the relationship between variable parameters and surface roughness in the second embodiment. [Diagram 5] 13 is a flowchart showing a process according to a third embodiment. [Figure 6] FIG. 2 is a schematic block diagram of a machine tool and an external computer. [Figure 7] FIG. 2 is a diagram illustrating an example of a hardware configuration of an information processing device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] <Summary> Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment described herein.

[0022] The first embodiment described below relates to a "method of calculating surface roughness" for calculating the surface roughness at an arbitrary spindle phase Θ of a workpiece from parameters of oscillating cutting (see FIG. 1).

[0023] In the second embodiment, a "parameter map" is created in which the values ​​of multiple types of parameters related to swing cutting are linked to the surface roughness of the workpiece using the "surface roughness calculation method" of the first embodiment (see Figs. 2 and 3). In the second embodiment, the relationship between the value of at least one of the multiple types of parameters in the parameter map and the surface roughness in the parameter map is displayed on a display device (see Fig. 4).

[0024] In the third embodiment, the "parameter map" of the second embodiment is used to acquire parameter values ​​for orbital cutting that correspond to a specified surface roughness (for example, a surface roughness command: a surface roughness specified in a drawing) (see FIG. 5). Furthermore, the acquired parameter values ​​for orbital cutting may be manually or automatically set in a numerical control device of a machine tool to perform machining of a workpiece.

[0025] The first to third embodiments are all realized using an information processing device. The information processing device may be a numerical control device for a machine tool, or may be a computer (such as a personal computer) independent of the machine tool. For example, when an independent computer is used, at least one of the first to third embodiments is executed in the computer to realize a simulation related to surface roughness. The information processing device may also be configured by combining the numerical control device for the machine tool with an external computer (such as a personal computer) that is capable of communicating with the numerical control device.

[0026] 6 is a functional block diagram showing an example of the system. The system includes a machine tool 10 and an external computer 112. The machine tool 10 includes a numerical control device 12 and a machining unit 14. The numerical control device 12 includes a processor 20, a storage device 22, a display device 23, and an input device 24. The machining unit 14 includes a tool 26.

[0027] The external computer 112 includes a processor 120 , a storage device 122 , a display device 123 , and an input device 124 .

[0028] The processor 20, 120 may be configured to include at least one of a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), and an FPGA (Field Programmable Gate Array). The display device 23, 123 may be, for example, a liquid crystal display, an organic EL (Electro Luminescence) display, etc. The input device 24, 124 may be a keyboard, a mouse, a touch panel, etc. The hardware configuration of the further information processing device (numerical control device 12, external computer 112) will be described later with reference to FIG. 7. Hereinafter, the numerical control device will also be simply referred to as a control device.

[0029] The display processing in the first to third embodiments, for example the display showing the relationship between the parameter value and the surface roughness in the second embodiment (see Figure 4), may be performed on either the display device 23 of the numerical control device 12 or the display device 123 of the external computer 112, or may be performed on both.

[0030] The parameters of the swing cutting are, for example, the workpiece spindle phase Θ, the tool feed rate F, the spindle speed command S, the shape of the tool cutting edge, the swing amplitude magnification K, and the swing frequency magnification I. The spindle phase Θ is a value indicating the outer periphery position of the workpiece, and takes a value of 0≦Θ<2π. The tool feed rate F, the spindle speed command S, and the shape of the tool cutting edge are generally referred to as machining conditions or tool information, but in this specification they may be referred to as swing cutting parameters. Note that, for example, instead of the swing amplitude magnification K, parameters that can be converted between them may be used, such as giving the swing amplitude in physical unit amount [m].

[0031] The parameter map described below may be created in advance and stored in a storage device, or may be created when needed. "Acquiring a parameter map" refers to both acquiring a parameter map created in advance and creating and acquiring a parameter map when it becomes necessary.

[0032] <First embodiment: Calculation of surface roughness based on parameters of orbital cutting> The control device of the machine tool executes swing cutting, which performs cutting while moving the tool relatively to the workpiece. Here, an embodiment will be described in which the control device calculates the surface roughness from swing cutting parameters.

[0033] In this embodiment, the feed rate F [mm / rev] and spindle speed command S [rpm] are used as the machining conditions, the nose R [mm] of the tool (hereinafter simply referred to as nose R) is used as the tool information, and the oscillation amplitude magnification K and the oscillation frequency magnification I are used as the oscillation cutting parameters. Also, in this embodiment, the control device sets the nose R center of the tool as the position to be controlled, and performs position control so that the command position and the nose R center coincide.

[0034] It is sufficient that the relationship between the control target position and the cutting edge shape of the tool is known, and it is not necessary that the center of nose R is the control target position. In this embodiment, the case where machining and swinging are performed in the Z-axis direction will be described, but the same implementation is possible regardless of the machining direction.

[0035] This embodiment is mainly realized by the following procedure. First, a plurality of command positions at an arbitrary spindle phase are calculated. Next, for each command position, the intersection point where the cutting edge shape of the tool intersects with the adjacent command position is calculated. After that, for each command position, the cutting edge shape is considered only between the intersection points with the adjacent command position to calculate the shape of the machined surface. Finally, the surface roughness is calculated from the shape of the machined surface. These steps will be described in detail below.

[0036] First, we will show how to calculate the command position Pz(n, Θ) [mm] (command position at any spindle phase Θ) during oscillating cutting at the integrated spindle rotation speed n from the start of machining of the target object for which the shape of the machined surface is to be estimated.

[0037] The command position Pz(t) [mm] during oscillating cutting at a certain time t can be expressed by formula (1) using the integrated spindle angle Ps(t) [rad] from the start of machining. For convenience, the start point of the cutting path for calculating the machining surface for Pz(n, Θ) and Pz(t) is set to 0. Note that F [mm / rev] is the feed rate, S [rpm] is the spindle speed command, K is the oscillation amplitude magnification, and I is the oscillation frequency magnification.

[0038] Pz(t) = (KF / 2) cos(πSIt / 30) -(KF / 2)+F×Ps(t) / 2π ···(1)

[0039] On the other hand, if the start time of the oscillation cutting is t=0, Ps(t) can be expressed by equation (2) using the spindle angular velocity ωs [rad / s].

[0040] Ps(t) = ωs × t =2πn+Θ (n=0,1,2,…) ···(2)

[0041] Note that Θ [rad] is the spindle phase (apparent spindle angle) expressed as 0≦Θ<2π, and Θ = 0 at time t = 0. n is the integrated number of spindle rotations from the start time of oscillation cutting, t = 0, and is 0 or an integer with decimal points rounded down.

[0042] In addition, the spindle angular velocity ωs [rad / s] can be expressed by equation (3) through a simple unit conversion from [rpm].

[0043] ωs=πS / 30 (3)

[0044] Therefore, from equations (2) and (3), when time t is expressed as a function of n and Θ, equation (4) is obtained.

[0045] t=(2πn+Θ) / ωs=(60πn+30Θ) / (πS) ···(4)

[0046] Therefore, by substituting equation (4) into equation (2) and then substituting the result into equation (1), Pz(t) can be expressed by equation (5) using n and Θ.

[0047] Pz(n,Θ)=(KF / 2)cos(I×(2πn+Θ)) -(KF / 2)+F×((2πn+Θ) / 2π) ···(5)

[0048] Next, a method for calculating the shape of the machining surface by calculating the intersection point where the tool cutting edge shape intersects with each command position and the adjacent command position will be described. As will be described with reference to Fig. 1, in this embodiment, machining in the positive direction of the Z axis is assumed on a lathe configured with X and Z axes, and the tool cutting edge faces downward along the X axis. Note that a workpiece is not shown in Fig. 1.

[0049] Figure 1 shows the command positions of the X-axis and Z-axis at a certain spindle phase Θ. By fixing Θ in equation (5) as the command position of the Z-axis at a certain spindle phase Θ and sequentially changing n from 0, the command positions during machining are calculated as shown in Z(0), Z(1), Z(2), Z(3), Z(4), and Z(5) in Figure 1(a). When implementing with a computer program, it is more preferable to delete duplicate command positions if they exist and assign subscripts in ascending order in the machining direction, and in Figure 1, the subscripts are reassigned in ascending order in the machining direction (from left to right on the paper).

[0050] Next, for each command position, the intersection point where the tool cutting edge shape intersects with the adjacent command position is calculated. Figure 1 shows the case where the cutting depth is less than or equal to the nose R and the distance between adjacent points is less than or equal to the nose R. In this case, the intersection point is the midpoint between the adjacent points, so for example, the intersection point of Z(2) and Z(3) can be calculated as (Z(2) + Z(3)) / 2. Figure 1(b) shows the result of drawing a straight line parallel to the X-axis that passes through the intersection point. Note that even in cases other than the above, because the shape of the tool cutting edge is known, it is easily possible to calculate the intersection point between adjacent command points based on the shape of the tool cutting edge.

[0051] Next, at each command position, the shape of the machining surface is calculated by considering the cutting edge shape only between the intersections with adjacent command positions. Specifically, as shown in Fig. 1(c), the part corresponding to the machining surface generated by the nose R is drawn only between the adjacent intersections with the command position as the center. As for the end points, since there are no intersections in one direction, it is sufficient to draw only the tool shape (nose R in this embodiment) in the direction where there are no intersections.

[0052] Finally, the surface roughness is calculated based on the shape of the machined surface calculated from the above. For example, surface roughness such as the arithmetic mean roughness Ra and maximum height Ry specified in JIS B 0601 can be calculated based on the calculated shape of the machined surface. Note that the entire stroke of machining is not required to calculate the surface roughness, so it is of course possible to calculate the surface roughness by focusing on an area of ​​the calculated shape of the machined surface where the shape of the machined surface at the end points does not need to be considered (for example, area A in Figure 1(c)).

[0053] In addition, since the machined surface created by oscillating cutting has a certain periodicity that differs from that of normal machining, it is more preferable to use a length that is an integer multiple of the periodicity generated on the machined surface as the reference length when calculating the surface roughness.

[0054] <Second embodiment: Outputting the relationship between parameters and surface roughness> Next, an embodiment will be described in which a parameter map is created in which the values ​​of multiple types of parameters related to oscillating cutting are linked to the surface roughness of the workpiece, and the relationship between the values ​​of the multiple types of parameters and the surface roughness in the parameter map is displayed on a display device. In this embodiment, a parameter map is created in which two of the parameters for oscillating cutting are set to fixed values ​​and the other two parameters are set to variable values. This embodiment allows the operator to select parameters more easily than in the past.

[0055] FIG. 2 is a flowchart showing the processing of this embodiment. In step S11, the control device acquires the type of fixed parameters and their values. In step S12, the control device acquires the type of variable parameters and their value ranges. In step S13, the control device acquires information about the shape of the tool tip. In step S14, the control device calculates the surface roughness corresponding to the fixed parameter values ​​and each value within the range of the variable parameters. In step S15, the control device outputs the surface roughness for each parameter value (the result of step S14) to an external device with respect to the output of the relationship between the variable parameters and the surface roughness. The order of steps S11 to S13 is not particularly limited, but it is preferable that they be the processing order shown in FIG. 2. Details of each process will be described below.

[0056] In step S11, the types and values ​​of two fixed parameters selected by an external device or an operator are obtained.

[0057] In step S12, the types of two variable parameters selected by the external device or the worker and the value ranges set for each variable parameter by the external device or the worker are acquired.

[0058] In step S13, information on the shape of the tool cutting edge set by an external device or an operator is acquired. Here, the external device may measure the shape of the tool cutting edge by some automated means, or the operator may set it from a screen (e.g., an input device such as a touch panel).

[0059] In step S14, a theoretical value of arithmetic mean roughness Ra is calculated as the surface roughness corresponding to one combination of the values ​​of the fixed parameters and the variable parameters. Here, the use of arithmetic mean roughness Ra as the surface roughness is merely an example, and any index capable of quantitatively evaluating the surface roughness, such as maximum height roughness Rz or root mean square roughness Rq, may be used. Then, the value of the variable parameter is changed, and a surface roughness corresponding to another combination of the values ​​of the fixed parameters and the variable parameters is calculated. This is repeated to obtain a surface roughness for each of a plurality of combinations of the values ​​of the fixed parameters and the variable parameters.

[0060] In step S15, the result of calculation in step S14 regarding the relationship between the variable parameters and the surface roughness is output to an external device.

[0061] Hereinafter, this embodiment will be described with specific numerical examples. In this example, the feed rate F and the spindle speed command S are used as fixed parameters. The nose R is set as the tool shape. As variable parameters, the oscillation frequency magnification I is set in the range of 0.2 to 2.0, and the oscillation amplitude magnification K is set in the range of 0.2 to 2.0.

[0062] In this example, we will assume that finishing is performed and that the machined surface depends only on the nose R. However, it is of course possible to calculate the surface roughness taking into account the tool shape other than the nose R portion, and the results of this calculation may be used.

[0063] In step S14 (calculation of surface roughness for each parameter), the oscillation frequency magnification I is changed in increments of 0.2, and the oscillation amplitude magnification K is changed in increments of 0.2, for example, to obtain the calculation results shown in FIG.

[0064] For example, in the above formula (5), values ​​are input for each of the spindle phase Θ, feed rate F, oscillation frequency magnification I, and oscillation amplitude magnification K, and each command position Pz(n,Θ) [mm] at that spindle phase Θ is found, from which the shape of the machined surface is calculated using the nose R, and the surface roughness is calculated based on the calculated shape of the machined surface. By updating at least one of the oscillation frequency magnification I and the oscillation amplitude magnification K and repeating the calculation of the surface roughness, the calculation results shown in Figure 3 can be obtained. In other words, the surface roughness for each combination of the value of the oscillation frequency magnification I and the value of the oscillation amplitude magnification K can be obtained as shown in Figure 3.

[0065] In step S15 (output of relationship between variable parameters and surface roughness), the calculation results of surface roughness for each parameter (results of step S14) are output externally. Fig. 4 shows an example of the calculation results of Fig. 3 being graphically output as a three-dimensional bar graph, using an LCD display as an example of an external device. Although there are no particular limitations, it is advisable to illustrate the surface roughness calculated in the calculation of surface roughness for each parameter (step S14) with a color map associated with an arbitrary color. By checking the relationship between the parameter values ​​displayed on the display device (such as an LCD display) and the surface roughness, the worker can intuitively select parameters from the surface roughness.

[0066] In the above embodiment, the calculation of the surface roughness for each parameter (step S14) and the output of the relationship between the variable parameter and the surface roughness (step S15) show results related to a single surface roughness evaluation index. However, it is of course possible to display multiple surface roughness indexes, such as the arithmetic mean roughness Ra and the maximum height roughness Rz, using at least one graph.

[0067] In the above embodiment, there are two variable parameters and two fixed parameters, but this is not necessarily the case. For example, if there are three variable parameters, it is also possible to display them in three dimensions using sample points. All parameters may be variable, and an animation may be added to the three-dimensional display to make all four parameter values ​​variable, and the result may be output. Naturally, it is also possible to output one parameter as a variable parameter.

[0068] The method of displaying the relationship between the variable parameters and surface roughness (step S15) in an external device is not limited to that described here, and any method that can express the relationship between the variable parameters and surface roughness, such as using paper output via a printer, may be used.

[0069] In addition, in an external device, the selection of parameters for oscillating cutting may be assisted by superimposing and displaying the output result of the relationship output between the variable parameters and surface roughness (step S15) on whether or not chips are broken during oscillating cutting.

[0070] In this embodiment, a parameter map related to the surface roughness at a certain spindle phase Θ of the workpiece is created. Here, by changing the value of the spindle phase Θ, a parameter map related to the surface roughness at a different spindle phase Θ can be created. In this way, by acquiring parameter maps at multiple spindle phases of the workpiece, multiple surface roughnesses associated with the same condition (same parameter value) can be acquired. In addition, the maximum value, minimum value, average value, median value, etc. of multiple surface roughnesses associated with the same condition (same parameter value) can be acquired as a representative surface roughness. A parameter map related to the surface roughness of the entire workpiece can also be created by linking the parameter value to the corresponding representative surface roughness for each of multiple conditions (parameter values).

[0071] <Third embodiment: Acquisition of parameters corresponding to surface roughness> Next, an embodiment for acquiring the parameter values ​​of the orbital cutting corresponding to the surface roughness command (surface roughness specified in the drawing) will be described. In this embodiment, by acquiring the parameters corresponding to the surface roughness, a function for automatically determining the operating conditions of the orbital cutting is provided.

[0072] FIG. 5 shows a flow chart in this embodiment. In step S21, the control device acquires a command value of surface roughness required for calculating cutting conditions from an external device. In step S22, the control device acquires information on the shape of the tool cutting edge from an input from an external device or an operator. In step S23, the control device selects parameters for swing cutting from the acquisition result of the surface roughness command in step S21 and the acquisition result of the shape of the tool cutting edge in step S22 with respect to the selection of swing parameters. In step S24, the control device outputs the selection result of the swing parameters in step S23 to the external device with respect to the output of parameters. Note that there is no particular limitation on the order of processing in step S21 (acquisition of surface roughness command) and step S22 (acquisition of tool information), but it is preferable to follow the processing order shown in FIG. 5. Details of each process will be described below.

[0073] In step S21, a spindle speed command S, a feed rate F, and a surface roughness command value RA are acquired from an external device in accordance with an NC program such as the following (Command 1).

[0074] G01 Z100 S1000 F0.12 RA3.2...(Instruction 1)

[0075] Note that (Command 1) is just one example, and it is naturally possible to specify cutting conditions by methods other than those described above, and it is sufficient to obtain parameters equivalent to the spindle speed command S, feed rate F, and surface roughness command value RA required for selecting parameters for swing cutting. It is not necessary to specify the parameters in the NC program, and it is naturally possible to set them in advance on a setting screen, for example.

[0076] In step S22, information about the tool is obtained from an external device. Specifically, information necessary for calculating the surface roughness, such as the nose R of the tool and the cutting edge shape of the tool, which are given as examples in the first embodiment, is obtained.

[0077] In step S23, the oscillation frequency magnification I and the oscillation amplitude magnification K, which are parameters for oscillation cutting, are determined from the information obtained in step S21 (obtaining the surface roughness command) and step S22 (obtaining the tool shape). Note that the oscillation frequency magnification I and the oscillation amplitude magnification K are merely examples, and it is of course possible to determine the oscillation frequency and the oscillation amplitude.

[0078] Here, an example of a method for determining specific parameters in step S23 (selection of oscillation parameters) will be described. First, by calculating the surface roughness when the oscillation frequency magnification I and the oscillation amplitude magnification K are made variable by the method of the second embodiment, for example, a data set (parameter map) of Fig. 3 is obtained. Next, among the surface roughnesses Ra in the data set (parameter map) of Fig. 3, the surface roughness Ra with the smallest difference from the surface roughness command value RA is found, and the parameters of the oscillation cutting conditions linked to that surface roughness Ra (oscillation amplitude magnification K, oscillation frequency magnification I) are determined as the parameters of oscillation cutting.

[0079] The method using the parameter map is one example of step S23 (selection of oscillation parameters), and the above method is not necessarily required as long as the operation described in step S23 can be realized by any means. For example, it is naturally possible to calculate the surface roughness each time while sequentially changing the oscillation frequency magnification I and the oscillation amplitude magnification K, and when the surface roughness falls below the surface roughness command value RA, to output the oscillation frequency magnification I and the oscillation amplitude magnification K in step S23 (selection of oscillation parameters).

[0080] In step S23 (selection of oscillation parameters), a method using the parameter map described above or a method of calculating the surface roughness while changing the oscillation frequency magnification I and the oscillation amplitude magnification K described above is preferable, but any other method may be used as long as it can realize the contents of step S23 by utilizing at least the relationship between the surface roughness command value RA and the oscillation cutting parameters.

[0081] In step S24 (output of parameters), the parameters of the oscillation cutting determined in step S23 (selection of oscillation parameters), for example, the oscillation frequency magnification I and the oscillation amplitude magnification K, are output to an external device.

[0082] According to this embodiment, by connecting the control device of the machine tool to an external device, the operator can easily perform machining with the desired surface roughness even in oscillating cutting, based on the machining conditions commanded in normal cutting processing and the surface roughness indication value on the drawing.

[0083] In the above embodiment, the parameters closest to the surface roughness command value RA are used, but in actual machining, the surface roughness command value RA generally only needs to be equal to or less than a designated value. Therefore, it is of course possible to select parameters for oscillating cutting that satisfy a preset condition, for example, making the oscillation frequency magnification I and the oscillation amplitude magnification K as small as possible, from among those that are equal to or less than the surface roughness command value RA.

[0084] In addition, by combining this with information indicating whether chips can be chopped in oscillating cutting, as described in the prior art, for example, in Patent Document 3, parameters for oscillating cutting that satisfy the constraints on the surface roughness command value RA and enable chipping of chips may be selected.

[0085] In addition, in this embodiment, the parameter maps described in the second embodiment are used to determine the oscillating cutting parameters corresponding to the surface roughness command value RA, the feed rate F, and the spindle speed command S, but the oscillating cutting parameters may be determined using other parameter maps, etc.

[0086] <Information processing device> The information processing device of the above embodiment is configured using, for example, a computer. The information processing device may be configured as, for example, a single computer or a system consisting of multiple computers linked to each other. As illustrated in FIG. 7, the computer that is the base of the information processing device has a circuit configuration in which, for example, a processor 1020, a memory (main storage device) 1030 such as a random access memory (RAM), a controller that controls an auxiliary storage device 1032 that is a non-volatile storage device such as a flash memory, an SSD (solid state drive), or an HDD (hard disk drive), an interface with various input / output devices 1040, a network interface 1050 that controls connection to a network, and the like are connected via a data transmission path such as a bus 1060. A program in which the processing contents are described is installed in the computer via a network or the like and stored in the auxiliary storage device 1032. The information processing device of this embodiment is configured by the processor 1020 executing the program stored in the auxiliary storage device 1032 using the memory 1030.

[0087] The above program can be provided via a network such as the Internet, or can be provided by storing it on a computer-readable recording medium such as an optical disk or a USB memory. [Explanation of symbols]

[0088] 10 machine tool, 12 numerical control device (information processing device), 14 machining section, 20 processor, 22 storage device, 23 display device, 24 input device, 26 tool, 112 external computer, 120 processor, 122 storage device, 123 display device, 124 input device, 1020 processor, 1030 memory, 1032 auxiliary storage device, 1040 input / output device, 1050 network interface, 1060 bus.

Claims

1. An information processing device, A processor is included. The processor, A parameter map is obtained in which the values ​​of multiple types of parameters related to the swing cutting are linked to the surface roughness of the workpiece, displaying on a display device a relationship between a value of at least one of the plurality of types of parameters in the parameter map and the surface roughness in the parameter map; Information processing device.

2. An information processing device, A processor is included. The processor, A parameter map is obtained in which the values ​​of multiple types of parameters related to the swing cutting are linked to the surface roughness of the workpiece, Accepting a specified surface roughness of the workpiece; obtaining, from the parameter map, a value of the parameter corresponding to the received specified surface roughness; Information processing device.

3. 3. The information processing device according to claim 2, The processor, obtain, from the parameter map, a value of the parameter associated with a surface roughness that is equal to or less than the received specified surface roughness and is closest to the specified surface roughness; Information processing device.

4. 4. An information processing device according to claim 1, The multiple types of parameters include a spindle phase Θ of the workpiece, a feed rate F of the tool, a shape of the tool tip, a swing amplitude magnification K, and a swing frequency magnification I, The surface roughness of the parameter map is the surface roughness at the spindle phase Θ of the workpiece. Information processing device.

5. 5. The information processing device according to claim 4, The processor executes a creation process to create the parameter map; The creation process includes: (i) setting values ​​of a spindle phase Θ, a feed rate F, a shape of a tool tip, a swing amplitude magnification K, and a swing frequency magnification I; (ii) acquiring a command position Pz(n, Θ) of the tool tip at each spindle speed n in the spindle phase Θ from the following (Formula A) while sequentially changing the integrated spindle speed n (n is an integer equal to or greater than 0); Pz (n, Θ) = (KF / 2) cos (I x (2πn + Θ)) -(KF / 2)+F×((2πn+Θ) / 2π)...(Formula A) (iii) calculating an intersection point where the shapes of the tool cutting edge at two command positions Pz(n, Θ) having adjacent values ​​of n intersect based on the shape of the tool cutting edge and each of the command positions Pz(n, Θ); (iv) acquiring a position of the machining surface in a spindle phase Θ generated by the tool tip so as to connect adjacent intersections, thereby acquiring a shape of the machining surface; (v) calculating the surface roughness at the spindle phase Θ based on the shape of the machined surface; (vi) linking the values ​​of the feed rate F, the shape of the tool tip, the oscillation amplitude magnification K, and the oscillation frequency magnification I with the calculated surface roughness; (vii) creating the parameter map by changing at least one of the feed rate F, the shape of the tool cutting edge, the oscillation amplitude magnification K, and the oscillation frequency magnification I, and repeating the processes (ii) to (vi) above; Information processing device.

6. 6. The information processing device according to claim 5, The value of the shape of the tool tip is a value of a nose R as a radius of the tool tip, The processor, The center of the nose R is defined as the command position Pz(n, Θ). Information processing device.

7. 4. An information processing device according to claim 1, The surface roughness of the parameter map is a representative surface roughness obtained from surface roughnesses in a plurality of spindle phases of the workpiece, The representative surface roughness is a maximum value, an average value, or a median value of the surface roughness in the plurality of spindle phases. Information processing device.

8. An information processing device, A processor is included which is used to calculate the surface roughness at the spindle phase Θ of the workpiece, The processor, (i) acquiring values ​​of the spindle phase Θ, the feed rate F, the shape of the tool tip, the oscillation amplitude magnification K, and the oscillation frequency magnification I; (ii) From the following (Formula A), while sequentially changing the integrated spindle speed n (n is an integer equal to or greater than 0), obtain the command position Pz(n, Θ) of the tool tip at each spindle speed n in the spindle phase Θ; Pz (n, Θ) = (KF / 2) cos (I x (2πn + Θ)) -(KF / 2)+F×((2πn+Θ) / 2π)...(Formula A) (iii) calculating an intersection point where the shapes of the tool cutting edge at two command positions Pz(n, Θ) having adjacent values ​​of n intersect based on the shape of the tool cutting edge and each of the command positions Pz(n, Θ); (iv) acquiring a position of the machining surface in the spindle phase Θ generated by the tool tip so as to connect adjacent intersections, thereby acquiring a shape of the machining surface; (v) calculating the surface roughness at the spindle phase Θ based on the shape of the machined surface; Information processing device.

9. A method for calculating a surface roughness in a spindle phase Θ of a workpiece using a computer, comprising: (i) acquiring values ​​of a spindle phase Θ, a feed rate F, a shape of a tool tip, a swing amplitude magnification K, and a swing frequency magnification I; (ii) acquiring a command position Pz(n, Θ) of the tool tip at each spindle speed n in the spindle phase Θ from the following (Formula A) while sequentially changing the integrated spindle speed n (n is an integer equal to or greater than 0); Pz (n, Θ) = (KF / 2) cos (I x (2πn + Θ)) -(KF / 2)+F×((2πn+Θ) / 2π)...(Formula A) (iii) calculating an intersection point where the shapes of the tool cutting edge at two command positions Pz(n, Θ) having adjacent values ​​of n intersect based on the shape of the tool cutting edge and each of the command positions Pz(n, Θ); (iv) acquiring a position of the machining surface in a spindle phase Θ generated by the tool tip so as to connect adjacent intersections, thereby acquiring a shape of the machining surface; (v) calculating the surface roughness at the spindle phase Θ based on the shape of the machined surface; How to calculate surface roughness.

10. A program for causing a computer to execute a process for calculating a surface roughness in a spindle phase Θ of a workpiece, The process comprises: (i) obtaining values ​​of a spindle phase Θ, a feed rate F, a shape of a tool tip, a swing amplitude magnification K, and a swing frequency magnification I; (ii) acquiring a command position Pz(n, Θ) of the tool tip at each spindle speed n in the spindle phase Θ from the following (Formula A) while sequentially changing the integrated spindle speed n (n is an integer equal to or greater than 0); Pz (n, Θ) = (KF / 2) cos (I x (2πn + Θ)) -(KF / 2)+F×((2πn+Θ) / 2π)...(Formula A) (iii) calculating an intersection point where the shapes of the tool cutting edge at two command positions Pz(n, Θ) having adjacent values ​​of n intersect based on the shape of the tool cutting edge and each of the command positions Pz(n, Θ); (iv) acquiring a position of the machining surface in a spindle phase Θ generated by the tool tip so as to connect adjacent intersections, thereby acquiring a shape of the machining surface; (v) calculating the surface roughness at the spindle phase Θ based on the shape of the machined surface; program.

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