JP5406166B2 - Tool path generation device, tool path generation method and program therefor - Google Patents

Description

  The present invention relates to a tool path generation device, a tool path generation method, and a program therefor for cutting a workpiece using a rotary cutting tool.

  As background art of this technical field, there is JP-A-2005-74569 (Patent Document 1). In this publication, “not only the chatter vibration limit of the machining tool but also the chatter vibration limit of the workpiece is obtained, and based on this, the machining conditions and NC path are generated. Also, the chatter vibration limit of the workpiece is finite. If the cutting is difficult or the machining conditions are not high enough, the workpiece is divided into multiple sections and a chatter vibration limit chart is created for each section. In addition, we examined whether cutting is possible even with the original workpiece, and if the cutting is difficult or the cutting conditions are not high enough, The dimensions of the workpiece in the state can also be automatically corrected from the original design dimensions ”(see summary).

JP-A-2005-74569

  Patent Document 1 describes a method of setting machining conditions with high machining efficiency within a range in which chatter vibration does not occur. The machining conditions to be set are the rotation speed, feed speed, radial cutting depth and axial cutting depth. However, depending on the shape of the region to be processed, there is a case where processing is performed with a radial cutting depth smaller than the radial cutting depth set in Patent Document 1. For example, this is a case where the maximum cutting width in the tool radial direction of the region to be processed is not an integral multiple of the set radial cutting depth. In this case, the actual machining efficiency is lower than the machining efficiency under the machining conditions set in Patent Document 1.

  An object of this invention is to produce | generate a tool path with high machining efficiency, irrespective of the shape of a to-be-processed area | region.

In order to solve the above problems, for example, the configuration described in the claims is adopted.
The present application includes a plurality of means for solving the above-described problems. To give an example, a tool path generation device that generates a tool path for contouring a workpiece with a rotary cutting tool, A data input unit that inputs data necessary for generation; a machining condition setting unit that sets machining conditions; and a tool path generation unit that generates a tool path based on the set machining conditions, the machining condition setting unit In a tool path for contour machining, the radial cutting depth is such that the radial cutting depth is an integral fraction of the maximum radial cutting width of the work area to be machined at the machining height. The depth is set, and the value of the axial cut depth is changed according to the set radial cut depth.

  Another example is a tool path generation method for generating a tool path for contouring a workpiece with a rotary cutting tool, the step of inputting data necessary for generating the tool path, and machining with the tool path. A step of calculating a cross-sectional area to be processed divided for each height when the area to be processed by the rotary cutting tool, and a radial cutting depth in the calculated cross-sectional area of the processed cross-sectional area Setting the radial cutting depth to be an integral fraction of the maximum radial cutting width, changing the axial cutting depth according to the set radial cutting depth, and A step of generating a tool path based on the set radial cutting depth and axial cutting depth is provided.

  Another example is a program for generating a tool path for contouring a workpiece with a rotary cutting tool into a computer, the step of inputting data necessary for generating the tool path, and machining with the tool path. A step of calculating a cross-sectional area to be processed divided for each height when the region to be processed is processed by the rotary cutting tool, and a radial cutting depth in the calculated cross-sectional area is the cross-sectional area to be processed A step of setting the radial cutting depth so as to be an integral fraction of the maximum radial cutting width, and a step of changing the value of the axial cutting depth according to the set radial cutting depth; The step of generating a tool path based on the set radial cutting depth and axial cutting depth is executed.

  ADVANTAGE OF THE INVENTION According to this invention, the tool path generation | occurrence | production apparatus and tool path generation | occurrence | production which can increase the axial direction cutting depth by equalizing radial direction cutting depth, and generate | occur | produce the tool path | route of contour processing with high machining efficiency. A method can be provided.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a block diagram of the tool path | route production | generation apparatus of the Example of this invention. It is an example of a figure explaining a processed field. It is an example of a figure explaining contour line processing. It is a flowchart explaining the process of the process condition setting part of the Example of this invention. It is a figure explaining the relationship between the axial direction cutting depth in the case of contour-line processing of an inclined surface, and the radial direction maximum cutting width of a to-be-processed cross-sectional area. It is a flowchart explaining the process of the radial direction cutting depth calculating part of the Example of this invention. It is an example of the figure explaining the calculation method of the radial direction maximum cutting width. It is a figure explaining the method of calculating an axial direction cutting depth from a radial direction cutting depth in the axial direction cutting depth calculating part of the Example of this invention. It illustrates a tool path generated by the tool path generating device according to this example of a certain workpiece sectional area V _n. It illustrates a tool path generated by conventional methods in the processed cross section region V _n in FIG. It is a figure which shows the process using the tool path | route produced | generated by the tool path | route production | generation apparatus by a present Example. It is a figure which shows the process using the tool path | route produced | generated by the conventional method. It is a figure explaining the effect of the machining efficiency improvement by the tool path | route produced | generated by the tool path | route production | generation apparatus by a present Example.

Embodiments of the present invention will be described below with reference to the drawings.
In the present embodiment, an example of a tool path generation device that creates a tool path will be described.

FIG. 1 is a configuration diagram of a tool path generation apparatus according to the present embodiment.
The tool path generation device includes a data input unit 101, a machining condition setting unit 102, a cross-sectional area calculation unit 103, a radial cutting depth calculation unit 104, an axial cutting depth calculation unit 105, a tool path generation unit 106, a tool A route output unit 107 is provided.

  The data input unit 101 is a means for inputting tool information, work material information, shape information, machining condition information, machining pattern information, and the like. Data may be input via a pointing device such as a keyboard or a mouse, or an input device such as a numeric keypad. Alternatively, it may be performed via a media device such as a CD, DVD, or MO, or a storage device such as an HDD or a flash memory.

  The machining condition setting unit 102 includes a work area calculation unit 103, a radial cutting depth calculation unit 104, and an axial cutting depth calculation unit 105. Based on the machining conditions input by the data input unit 101, Set the feed speed.

The processed cross-sectional area calculation unit 103 calculates a processed cross-sectional area V _n of the processed area V surrounded by the range of the heights Z _{n to} Z _n−1 . However, the to-be-processed area | region V is an area | region processed with the said created tool path | route shown to Fig.2 (a), and is a difference area | region of a raw material shape and a target shape, or its part. Z _n is the height of the tool tip when machining the _n-th workpiece cross-sectional area V _n shown in FIG. 2 (b).

Radial cutting depth calculating unit 104, the workpiece area when contouring, to calculate the radial depth of cut Rd _n at any of the processed cross section region V _n.

Axial cutting depth calculating unit 105, the the tool radial cuts Rd _n calculated in sets actual axial depth of cut Ad _n.

  The tool path generation unit 106 generates a tool path for the work area V using the machining conditions set by the radial cutting depth calculation unit 104 and the axial cutting depth calculation unit 105.

  The tool path output unit 107 outputs the tool path generated by the tool path generation unit 106. Data may be output to a file having an appropriate file format. In addition, data may be transmitted to a control device of another computer or machine tool via a network.

Next, data input by the data input unit 101 will be described.
The tool information includes dimensions, number of blades, tool shape, vibration characteristics, and the like. The dimension is a numerical value such as a tool diameter or a blade length. The number of blades is the number of cutting edges of the tool. For example, in the case of an end mill, the tool shape is flat, ball, bull nose, taper, or the like. The vibration characteristics are frequency response data of the tool or work material, and are numerical parameters such as mode mass, spring constant, damping ratio, vibration amplitude and phase data for each frequency, and the like.
The work material information is, for example, a cutting force coefficient. The cutting force coefficient is a cutting force per unit cutting cross-sectional area (= (axial cutting depth) × (cutting thickness)), and is preferably a value for each of the axial direction, circumferential direction, and radial direction of the tool. .
The shape information is, for example, material shape data of the work material or intermediate shape after pre-processing and target shape data after processing. Moreover, the shape data of a to-be-processed area | region may be sufficient.
The cutting condition information includes a reference axial direction cutting depth, a reference radial direction cutting depth, a rotational speed, a feed rate, a machining pattern, and the like. The axial cutting depth is the depth at which the tool cuts into the work material in the tool axial direction, and the radial cutting depth is the tool cut into the work material in a direction perpendicular to the tool traveling direction. Is the depth. The rotation speed is the rotation speed of the tool spindle. The feed speed is a relative movement speed of the tool and the work material. The machining pattern is a movement pattern of a tool such as a zigzag or a spiral.

FIG. 3 is an example of a flowchart illustrating a method for setting the radial cutting depth and the axial cutting depth by the machining condition setting unit 102 in the tool path generation device according to the present embodiment. In this flowchart, the n-th how to set the radial depth of cut Rd _n and axial depth of cut Ad _n with respect to the processed cross section region V _n will be described.

First processing condition setting unit 102 in step S201 sets the initial height Z _0. The initial height Z ₀ is the height of the highest position in the work area V. In step S202, the machining condition setting unit 102 sets the value of the axial cutting depth Ad _n as the axial cutting depth Ad _set set by the data input unit 101. In step S203, the machining condition setting unit 102 calculates a processed cross _- sectional area height Z _n = Z _n−1 −Ad _n that is offset by Ad _n from the height Z _{n−1 of the} previous processed cross-sectional area. .
In step S204, the processed cross section region calculation section 103 slicing the processed region V height Z _n and Z _n-1 of the cross section, the area of the range surrounded by height Z _n to Z _n-1 to be Extracted as a machining cross-sectional area V _n . In step S205, the to-be-processed cross-sectional area calculation unit 103 determines whether or not the extracted cross-sectional area to be processed V _n exists. If not, the processing condition setting for the processed area V ends. When the cross-sectional area V _{n to} be processed exists, the process proceeds to step S206.
Step S206 is the radial cutting depth calculating unit 104 calculates the radial depth of cut Rd _n as the radial depth of cut in the processed cross section region V _n is equalized. In step S207, the axial cutting depth calculating unit 105 calculates the axial depth of cut Ad _n corresponding to the set radial depth of cut Rd _n in step S206.
In step S208, when machining the inclined surface as shown in FIG. 4 for example, the machining condition setting unit 102 changes the maximum cutting width in the radial direction of the cross-sectional area V _n to be machined when the axial cutting depth is changed. Judging that the change in the radial cutting depth Rd _n or the axial cutting depth Ad _n falls within a predetermined range, it is judged appropriate, and the set radial cutting depth Rd _n and axial cutting depth are set. Steps S203 to S207 are repeated until Ad _n becomes appropriate. In addition, by setting an allowable value for the volume of the uncut portion or the uncut height from the target finish shape, the radial cutting depth is within a range where the volume or height of the uncut portion falls within the set allowable value. The case _where the product of Rd _n and the axial cutting depth Ad _n is maximized may be determined as appropriate.
Step S208 processing condition setting unit 102 when the radial depth of cut Rd _n and axial depth of cut Ad _n were appropriate in the n = n + 1 in step S209, the next workpiece section area V _n Steps S202 to S208 are repeated for ₊₁ . Thus, dividing the processed region V some to be processed cross section region can be set in the radial direction depth of cut Rd _n and axial depth of cut Ad _n to each of the processed cross section each area.

Incidentally, the step S201~S203 defines the processed cross section region V _n in the order from the top of the processing region V, has described how to continue to set the processing conditions, the processing condition setting unit 102 is initialized in step S201 The height Z ₀ is defined as the lowest position in the processing region V, and the processing condition setting unit 102 sets the processing cross-sectional region height Z _n = Z _n-1 + Ad _n in step S203 to be below the processing region V. From the above, the cross-sectional area V _n to be processed may be defined.

FIG. 5 is an example of a flowchart for explaining the radial cutting depth setting method (step S206) in the radial cutting depth calculation unit 104. In step S401, based on the machining pattern set by the data input unit 101 calculates the radial maximum cutting width W _n at the time of processing the processed cross section region V _n. The maximum radial cutting width W _n is the maximum width in the pick feed direction of the region to be processed. For example, as shown in FIG. 6, in the case of a zigzag where the machining pattern is pick-feeded in the X direction, the difference between the maximum value and the minimum value of the X coordinate is set as the radial maximum cutting width W _n for the region removed by the contour processing. .
In step S402, it calculates the processing number N _n is the number of times that pick feed radially when processing the processed cross section region V _n shown in FIG. 2 (b). The number of machining times N _n is an integer value obtained by dividing the maximum radial cutting width W _n by the radial cutting depth Rd _{set set} by the data input unit 101 and rounded up to the first decimal place. In step S403, it sets the radial depth of cut Rd _n radial maximum cutting width W _n as a value divided by N _n. Thus, to the processing region V _n, uniform radial depth of cut Rd _n is set.
In step S402, the number of times of processing N _n may not be an integer obtained by rounding up W _n / Rd _set , but may be an integer value obtained by rounding off to the first decimal place. However, if the Rd _n is greater than the diameter of the tool in step S403, it is desirable to use the ceiling of the processing number N _n.

FIG. 7 is an example of a diagram illustrating an axial cutting depth setting method (step S207) in the axial cutting depth calculation unit 105. Fig. 7 is a stability limit diagram of chatter vibration. The horizontal axis indicates the radial cut depth, the vertical axis indicates the axial cut depth, the lower part of the plotted line is the stable region, and the upper part is chattered. This is an unstable region where vibration occurs. Axis of the in stability limit diagram, the radial cutting depth calculating unit 104 to be processed the maximum axial depth of cut without chattering against radial depth of cut Rd _n set in (step 206) cross-sectional area V _n Set as direction cut depth Ad _n .

Incidentally, the axial depth of cut Ad _n is not the maximum axial depth of cut of not chatter vibrations in the set radial depth of cut Rd _n, the safety factor S is provided, the maximum axial depth of cut of not chattering A value obtained by multiplying 1 / S may be used.

The stability limit diagram of FIG. 7 can be obtained by analysis, for example, there is a solution in the frequency domain of Altintas et al. Alternatively, a method of evaluating the divergence of vibration by integrating the equation of motion in the time domain may be used. In either case, it is necessary to use the vibration characteristics and cutting force coefficient of the tool or work material input by the data input unit 101. Further, the stability limit diagram as shown in FIG. 7 may be obtained from the experimental results of evaluating the occurrence of chatter vibration by performing a machining test while changing the radial cut depth and the axial cut depth.
Further, the setting is not limited to the above-described chatter vibration stability limit, and the axial cutting depth Ad _n may be set. For example, the product of the axial cutting depth Ad _n and the radial cutting depth Rd _n is the set axial cutting depth Ad _set and the radial cutting so that the machining efficiency is constant when the feed rate is constant. The axial cutting depth Ad _n may be set to be equal to the product of the depth Rd _set .

FIG. 8 is an example of a diagram illustrating a tool path generated by the tool path generation apparatus according to the present embodiment in a certain cross-sectional area V _n , and FIG. 9 is a conventional method in the cross-sectional area V _{n to} be processed It is an example of the figure explaining the tool path by. As shown in FIG. 8, the tool path generated by the tool path generating device according to this embodiment, since the radial direction depth of cut Rd _n in the processed cross section region V _n becomes equal, the processed cross section region V _n of the height Z _n changed, it is possible to increase the axial depth of cut Ad _n. On the other hand, the tool path according to the conventional method shown in FIG. 9, since the radial depth of cut Rd _n unequal, axially depth of cut Ad _n the radial depth of cut maximum value of Rd _n (= Rd _set) It is necessary to set a corresponding value, and the machining efficiency is low in the tool path in the portion of Rd _where the radial cutting depth Rdn is small.

FIG. 10 is an example of a diagram illustrating machining using a tool path generated by the tool path generation apparatus according to the present embodiment, and FIG. 11 is an example of a diagram illustrating machining on a tool path according to a conventional method. As shown in FIG. 10, in the tool path in the present embodiment, the axial cutting depth Ad _n for each cross-sectional area V _{n to} be processed is not necessarily a constant value. In particular, since the radial maximum width of cut W _n radial cuts in a small partial-depth Rd _{The set} of the processed cross section region V _n is small, the axial depth of cut Ad _n is large. On the other hand, in the tool path by the conventional method shown in FIG. 11, the axial cutting depth Ad _n is a constant value corresponding to Rd _set .

FIG. 12 is a diagram for explaining the effect of improving the machining efficiency by the tool path generated by the tool path generating apparatus according to the present embodiment. If the feed speed of the tool is constant, the processing efficiency is the axial depth of cut Ad _n and radial depth of cut product of Rd _n. Radial cutting depth calculating unit 104 be set to equalize the radial depth of cut Rd _n in (step 206), since the axial depth of cut Ad _n machining efficiency if constant is the same, the tool according to the conventional method The machining efficiency in the path corresponds to the area of the region 1201. Since the machining efficiency in the tool path generated by the tool path generation apparatus according to the present embodiment corresponds to the area of the area 1202, the machining efficiency is improved by the area of the area 1203 which is the difference between the area 1201 and the area 1202.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be stored in a recording device such as a memory, a hard disk, an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

DESCRIPTION OF SYMBOLS 101 Data input part 102 Machining condition setting part 103 Work area area calculation part 104 Radial direction cutting depth calculation part 105 Axial direction cutting depth calculation part 106 Tool path generation part 107 Tool path output part 1201 Machining efficiency by conventional method 1202 Machining efficiency when the embodiment is applied 1203 Increase in machining efficiency when the embodiment is applied.

Claims (15)

A tool path generation device that generates a tool path for contouring a workpiece with a rotary cutting tool,
A data input unit that inputs data necessary for tool path generation, a machining condition setting unit that sets machining conditions, and a tool path generation unit that generates a tool path based on the set machining conditions,
The processing condition setting unit includes a processing cross-sectional area calculation unit that calculates a processing cross-sectional area divided for each height when processing an area processed by the tool path with the rotary cutting tool, and the calculation A radial cutting depth calculation unit that sets a radial cutting depth so that a radial cutting depth in a cross-sectional area to be processed is an integer fraction of a maximum cutting width in the radial direction of the cross-sectional area to be processed; A tool path generation device comprising: an axial cutting depth calculator that changes a value of an axial cutting depth according to a set radial cutting depth. The tool path generation device according to claim 1,
The data input unit has a function of inputting a reference value of a radial cutting depth, and the radial cutting depth calculation unit is configured to determine the radial cutting depth in any machining of the cross-sectional area to be processed. A tool path generation device, characterized in that it is set to a radial cutting depth that can be machined with the same number of machining operations as when machining with a reference value. The tool path generation device according to claim 1 or 2,
The data input unit has a function of inputting a vibration frequency response characteristic of the rotary tool or the workpiece, and the axial depth-of-cut calculation unit analyzes a stability limit of chatter vibration, and arbitrarily selects the workpiece. In machining a cross-sectional area, the axial cutting depth is set from the analysis result to an axial cutting depth that does not chatter at the radial cutting depth set by the radial cutting depth calculation unit. A tool path generation device. The tool path generation device according to claim 3,
The axial cutting depth calculator calculates the axial cutting depth based on the analysis result in the radial cutting depth set by the radial cutting depth calculator in the processing of the arbitrary cross-sectional area to be processed. A tool path generation device characterized in that it is set to a maximum axial depth of cut that does not cause chatter vibration. The tool path generation device according to claim 1 or 2,
The axial cut depth calculator sets the axial cut depth so that the product of the radial cut depth and the axial cut depth is constant in machining at an arbitrary height. Route generator. A tool path generation method for generating a tool path for contouring a workpiece with a rotary cutting tool,
Entering the data required for tool path generation;
Calculating a cross-sectional area to be processed divided for each height when the area to be processed by the tool path is processed by the rotary cutting tool;
Setting the radial cutting depth so that the calculated radial cutting depth in the cross-sectional area to be processed is an integral fraction of the maximum radial cutting width of the cross-sectional area to be processed;
Changing the value of the axial cutting depth according to the set radial cutting depth;
A tool path generation method comprising the step of generating a tool path based on the set radial cutting depth and axial cutting depth. The tool path generation method according to claim 6,
The step of inputting the data has a function of inputting a reference value of the radial cutting depth,
The step of setting the radial cut depth is set to a radial cut depth that can be machined with the same number of machining operations as when machining with the reference value of the radial cut depth in machining of any of the cross-sectional areas to be machined. A tool path generation method characterized by: The tool path generation method according to claim 6 or 7,
The step of inputting the data has a function of inputting a vibration frequency response characteristic of the rotary tool or the workpiece,
The step of setting the axial depth of cut analyzes the stability limit of chatter vibration, and in the machining of the arbitrary cross-sectional area to be machined, the axial depth of cut is calculated from the analysis result and the radial direction depth of cut is calculated. A tool path generation method characterized by setting an axial cutting depth at which no chatter vibration occurs at a radial cutting depth set by a section. The tool path generation method according to claim 8,
In the step of setting the axial cutting depth, in the machining of the arbitrary cross-sectional area to be processed, the axial cutting depth is calculated from the analysis result, and the radial cutting depth set by the radial cutting depth calculator is determined. A tool path generation method characterized by setting the maximum axial depth of cut that does not cause chatter vibration. The tool path generation method according to claim 6 or 7,
The step of setting the axial cutting depth is characterized by setting the axial cutting depth so that the product of the radial cutting depth and the axial cutting depth is constant in machining at an arbitrary height. Tool path generation method. A program for generating a tool path for contouring a workpiece with a rotary cutting tool on a computer,
A step of inputting data necessary for generating a tool path; a step of calculating a cross-sectional area to be machined divided for each height when the area to be machined by the tool path is machined by the rotary cutting tool; Setting the radial cutting depth so that the radial cutting depth in the processed cross-sectional area is an integral fraction of the maximum radial cutting width of the processed cross-sectional area, and the set radial direction A program for executing a step of changing a value of an axial cutting depth according to a cutting depth and a step of generating a tool path based on the set radial cutting depth and the axial cutting depth. The program according to claim 11,
The step of inputting the data has a function of inputting a reference value of the radial cutting depth,
The step of setting the radial cut depth is set to a radial cut depth that can be machined with the same number of machining operations as when machining with the reference value of the radial cut depth in machining of any of the cross-sectional areas to be machined. The program characterized by doing. The program according to claim 11 or 12,
The step of inputting the data has a function of inputting a vibration frequency response characteristic of the rotary tool or the workpiece,
The step of setting the axial depth of cut analyzes the stability limit of chatter vibration, and in the machining of the arbitrary cross-sectional area to be machined, the axial depth of cut is calculated from the analysis result and the radial direction depth of cut is calculated. A program characterized in that it is set to an axial cut depth that does not chatter at the radial cut depth set in the section. The program according to claim 13,
In the step of setting the axial cutting depth, in the machining of the arbitrary cross-sectional area to be processed, the axial cutting depth is calculated from the analysis result, and the radial cutting depth set by the radial cutting depth calculator is determined. A program characterized in that it is set to the maximum axial depth of cut that does not cause chatter vibration. The program according to claim 11 or 12,
The step of setting the axial cutting depth is characterized by setting the axial cutting depth so that the product of the radial cutting depth and the axial cutting depth is constant in machining at an arbitrary height. Program to do.

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