JP6037910B2 - Tool path generation apparatus and method - Google Patents

Description

  The present invention relates to a tool path generation apparatus and method for generating a tool path for machining a pocket portion.

  The pocket portion is generally defined using a two-dimensional processing region shape and depth. For example, a tool path generation device as disclosed in Patent Document 1 and Patent Document 2 uses a closed loop path such as a trochoid path (hereinafter referred to as a closed loop path) in the processing progress direction in order to process such a pocket portion. A tool path that repeats while shifting is generated. According to such a tool path generation device, since the processing load on the tool can be suppressed, high-efficiency processing that effectively uses the blade length of the tool becomes possible.

Japanese Patent No. 3870021 Japanese Patent No. 4714348

  However, in the machining surface of the side wall of the pocket portion machined by the above tool path, the machining load on the tool is not uniform at each point on the machining surface, so the amount of bending of the tool is not uniform. However, there is a problem that unevenness of the processing trace is likely to remain. In particular, when a high-hardness material is processed using a larger number of blade lengths, the unevenness of the processing trace becomes remarkable. For this reason, it may be necessary to add finishing processing or intermediate finishing processing to remove unevenness of the processing trace, and there is a problem that processing preparation and processing time increase.

  This invention is made in view of the above, Comprising: It aims at obtaining the tool path | route production | generation apparatus and method which can suppress the unevenness | corrugation of the process trace of the side wall of a pocket part as much as possible.

In order to solve the above-described problems and achieve the object, the present invention provides a plurality of closed-loop first paths in which a tool is in contact with the side wall constituting the pocket part along the side wall in the machining progress direction of the pocket part. A tool path generation device that generates a tool path to be processed while being shifted, and is a pair of a first path and a second path for shifting the first path from the first path to be processed immediately before in the processing progress direction . The reworking section setting unit for setting a reworking section in a part on the side of the machining progress direction in the processing section of the side wall for each unit path, and the processing of one unit path or two continuous unit paths A unit path generation unit configured to set the first path so as to process the rework section twice, and connect the set first path and the second path to generate a unit path. And

  According to the present invention, a portion to be machined in a state where the tool deflection is large is set as a re-machining section, and a portion set in the re-machining section is first machined in a state where the tool deflection is large, Therefore, the unevenness of the processing trace on the side wall of the pocket portion can be suppressed as much as possible.

FIG. 1 is an overhead view of a pocket portion for explaining a technique according to a comparative example. FIG. 2 is a diagram illustrating a positional relationship between a tool and a workpiece when machining is performed using a tool path according to a comparative example. FIG. 3 is a diagram illustrating a positional relationship between a tool and a workpiece when machining is performed using a tool path according to a comparative example. FIG. 4 is a diagram for explaining a positional relationship between a tool and a workpiece when machining is performed by the tool path according to the comparative example. FIG. 5 is a diagram for explaining the positional relationship between a tool and a workpiece when machining is performed by the tool path according to the comparative example. FIG. 6 is a diagram for explaining the positional relationship between a tool and a workpiece when machining is performed by the tool path according to the comparative example. FIG. 7 is a diagram illustrating a change in the contact angle on the processing target shape SK when the comparative example is applied. FIG. 8 is a diagram illustrating a functional configuration of the tool path generation device according to the embodiment of the present invention. FIG. 9 is a diagram illustrating a hardware configuration example of the tool path generation device according to the embodiment of the present invention. FIG. 10 is a flowchart for explaining the operation of the tool path generation device according to the embodiment of the present invention. FIG. 11 is a diagram illustrating a processing boundary shape in an initial state. FIG. 12 is a diagram illustrating a processing unit path. FIG. 13 is a flowchart for explaining processing for generating a machining start side rework path. FIG. 14 is a diagram for explaining processing for generating a machining start side rework path. FIG. 15 is a diagram for explaining processing for generating a machining start side rework path. FIG. 16 is a flowchart for explaining processing for generating a machining end side reworking path. FIG. 17 is a diagram for explaining a process of generating a machining end side rework path. FIG. 18 is a diagram for explaining a process of generating the machining end side rework path. FIG. 19 is a flowchart illustrating a process for generating a non-machined part path. FIG. 20 is a diagram illustrating an example of a non-machined part path. FIG. 21 is a diagram illustrating an example of a unit route. FIG. 22 is a diagram illustrating a change in contact angle on the machining target shape SK when the embodiment of the present invention is applied. FIG. 23 is a diagram for explaining another example of the process for setting the machining start side rework path. FIG. 24 is a diagram for explaining another example of the process for setting the machining end side rework path.

  First, the technique (comparative example) compared with embodiment of this invention is demonstrated. FIG. 1 is an overhead view of a pocket portion for explaining a technique according to a comparative example.

  SL and SK each indicate a side wall of the pocket portion and are defined as processing target shapes. The radius of the tool used is rt. According to the comparative example, the tool has a “D” type closed loop path (first path) and a path for moving the “D” type closed loop path to the right side of the drawing along the machining target shapes SL and SK ( The tool path is configured such that a plurality of unit paths paired with (second path) are continuous. More specifically, for example, a path from the point P0 to the point P1 corresponds to the second path, and a “D” type path passing through the point Q0 with the point P1 as the start point and the end point corresponds to the first path. Let p be the step amount of the closed loop path (that is, the amount of movement of the second path), SB be the central axis that gathers points that are equidistant from SL and SK, and N the number of repetitions.

  According to the comparative example, first, a point Bi (i = 0, 1, 2,... N) on the central axis SB is calculated. The interval between the points Bi is a step amount p. According to the comparative example, as will be described next, the process of generating a unit route is repeated. Note that j is a counter variable that takes values from 0 to N-1.

  According to the comparative example, in the process of generating the unit path, the closest points Kj and Kj + 1 on the machining target shape SK and the nearest points Lj and Lj + 1 on the machining target shape SL for the points Bj and Bj + 1 are calculated. Then, a point Pj and a point Pj + 1 obtained by offsetting the points Kj and Kj + 1 by the tool radius rt in the directions of the points Bj and Bj + 1 are calculated. Similarly, a point Qj and a point Qj + 1 are calculated by offsetting the point Lj and the point Lj + 1 by the tool radius rt in the direction of the point Bj and the point Bj + 1, respectively. A path from the point Pj to the point Pj + 1, a semicircular circular arc path from the point Pj + 1 to the point Qj + 1, with the radius rc1 from the point Bj + 1 to the point Pj + 1 as the center, and from the point Qj + 1 A path toward the point Qj and a path from the point Qj toward the point Pj are generated and combined to generate one closed loop path.

  In the path generated by the above procedure, the path between the point Pj to the point Pj + 1 to the point Qj + 1 to the point Qj is a portion to be cut into the workpiece (processed part path), and the path between the point Qj to the point Pj + 1 is processed. This is a portion that is not cut into the material (non-processed portion path).

  2-6 is a figure explaining the positional relationship between the tool and a workpiece at the time of processing by the tool path concerning the comparative example mentioned above.

  FIG. 2 shows a positional relationship in a state where the center position of the tool is located at the point Pi. The tool is in contact with the machining target shape SK at the point Ki. From here, the tool moves toward the point Pi + 1, so that the tool cuts into the machining material and the side wall defined by the machining target shape SK is machined. The rotation direction of the tool is assumed to be clockwise as viewed from the upper side of the paper as indicated by the arrow in the figure.

  FIG. 3 shows the positional relationship when the center position of the tool is located at the point Pi + 1. The tool is in contact with the machining target shape SK at the position of the point Ki + 1. Further, since the tool is cut into the work material, the contact angle between the tool and the work material (the angle range of the portion where the tool and the work material are in contact with the tool center) is Fi + 1.

  When the direction of rotation of the tool is the direction indicated by the arrow in FIG. 2, the tool blade is trying to push the workpiece to the machining target shape side at the part where the tool and the workpiece are in contact. An opposite force (force in the M direction in FIG. 3) that attempts to separate from the target shape is applied. This force causes the tool to bend in a direction away from the machining target shape, and as a result, uncut material is generated with respect to the machining target shape.

  FIG. 4 shows a positional relationship in a state in which the tool passes through the path from the point Pi + 1 to the point Qi + 1, the point Qi, and the point Pi + 1 and returns to the position of the point Pi + 1 again. In the state shown in FIG. 4, the contact range between the tool and the work material (the contact range between the uncut portion and the tool in the case of FIG. 3) is the contact between the tool and the work material in FIG. It will be small enough compared to the range you are doing.

  FIG. 5 shows the positional relationship when the tool is cut into the workpiece material up to point Pi + 2, and FIG. 6 shows that the tool passes through the path from point Pi + 2 to point Qi + 2, point Qi + 1, point Pi + 2, and again at point Pi + 2. The positional relationship in the state where it returned to the position is shown. In the states shown in FIGS. 5 and 6, the same positional relationship as in the states shown in FIGS. 3 and 4 is repeated.

  FIG. 7 is a diagram illustrating a change in the contact angle on the processing target shape SK when the comparative example is applied. As shown in the figure, it is understood that the contact angle changes discontinuously when attention is paid to the change in the contact angle along the processing target shape SK. Since the amount of deflection of the tool also changes in accordance with the change in the contact angle, according to the comparative example, the result is that unevenness of the processing trace is formed on the processing surface.

  According to the embodiment of the present invention, it is possible to suppress unevenness of the machining trace generated on the side wall by suppressing the fluctuation of the contact angle between the tool and the workpiece in the machining on the machining target shape. Embodiments of a tool path generation apparatus and method according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment.
FIG. 8 is a diagram illustrating a functional configuration of the tool path generation device according to the embodiment of the present invention. The tool path generation device 100 includes a data input unit 1, a tool path generation unit 2, a path definition data storage unit 10, and a tool path storage unit 16. The tool path generation unit 2 includes a machining boundary shape generation unit 3, a machining unit path generation unit 4, a machining start side rework path generation unit 5, a non-machining part path generation unit 6, a path output unit 7, a machining end side re-generation. Machining path generation unit 8, machining boundary shape update unit 9, machining boundary shape storage unit 11, machining unit path storage unit 12, machining start side rework path storage unit 13, non-machining part path storage unit 14, and machining end side rework A route storage unit 15 is provided.

  FIG. 9 is a diagram illustrating a hardware configuration example of the tool path generation device 100. As shown in FIG. 9, the tool path generation device 100 includes a CPU (Central Processing Unit) 101, a RAM (Random Access Memory) 102, a ROM (Read Only Memory) 103, an input device 104, and an output device 105. The CPU 101, RAM 102, ROM 103, input device 104, and output device 105 are connected to each other via a bus line.

  The CPU 101 executes a tool path generation program 106 that is a computer program. The output device 105 is a display device such as a liquid crystal monitor. The output device 105 displays output information for the user such as an operation screen based on an instruction from the CPU 101. The input device 104 includes a mouse and a keyboard. The input device 104 receives an operation for the tool path generation device 100 from the user. Operation information input to the input device 104 is sent to the CPU 101.

  The ROM 103 is a recording medium that stores the tool path generation program 106 in advance. The tool path generation program 106 is read from the ROM 103 and loaded into the RAM 102 via the bus line. The CPU 101 executes a tool path generation program 106 loaded in the RAM 102. Specifically, the tool path generation program 106 includes components (data input unit 1, machining boundary shape generation unit 3, machining unit path generation unit 4, machining start side rework path generation unit 5, non-machining part path generation unit. 6, a program module for realizing a path output unit 7, a machining end side reworking path generation unit 8 and a machining boundary shape update unit 9). In the tool path generation device 100, the CPU 101 reads the tool path generation program 106 from the ROM 103 and expands each program module in the program storage area in the RAM 102 in accordance with an instruction input from the input device 104 by the user. Further, the CPU 101 stores, in the RAM 102, the path definition data storage unit 10, the machining boundary shape storage unit 11, the machining unit path storage unit 12, the machining start side reworking path storage unit 13, and the non-machining based on the tool path generation program 106. The part path storage unit 14, the machining end side rework path storage unit 15, and the tool path storage unit 16 are secured. The CPU 101 can function as a corresponding component by executing the program module expanded in the RAM 102.

  Note that the tool path generation program 106 may be stored on a computer connected to a network such as the Internet, and downloaded to the RAM 102 by being downloaded via the network. The tool path generation program 106 may be provided or distributed via a network such as the Internet. In addition, the recording medium that stores the tool path generation program 106 in advance may be a recording medium other than the ROM 103 as long as it is a tangible recording medium that is not temporary. For example, a hard disk drive (HDD), a solid state drive (SSD), a CD-ROM, a DVD-ROM, or a removable memory device can be applied as a recording medium for storing the tool path generation program 106 in advance.

  The data input unit 1, the machining boundary shape generation unit 3, the machining unit path generation unit 4, the machining start side rework path generation unit 5, the non-machining part path generation unit 6, the path output unit 7, and the machining end side rework path The generation unit 8 and the machining boundary shape update unit 9 are assumed to be realized by software, but each of these components can be realized as hardware or a combination of hardware and software. Whether these components are implemented as hardware or software is determined based on design constraints imposed on the entire apparatus.

  FIG. 10 is a flowchart illustrating the operation of the tool path generation device 100 according to the embodiment of this invention.

  First, the data input unit 1 accepts input of path definition data describing conditions for generating a tool path that repeats while shifting the closed loop path (step S1). The path definition data includes the definition of the machining target shape, tool information, and tool path setting conditions. Specifically, the path definition data includes, for example, the setting of the tool radius rt, the machining target shapes SL and SK, the center axis SB, the closed loop path step amount p, and the closed loop path repetition number N. Further, the route definition data includes a contact angle setting value E. The contact angle setting value E will be clarified later. The data input unit 1 stores the received route definition data in the route definition data storage unit 10. Note that the route definition data input method is arbitrary. For example, route definition data may be created directly by the user by operating the input device 104, and the data input unit 1 may capture the created route definition data. Further, route definition data created in advance may be input via an external storage device (not shown).

  Subsequently, the machining boundary shape generation unit 3 generates the machining boundary shape in the initial state based on the route definition data stored in the route definition data storage unit 10 (step S2). The machining boundary shape generation unit 3 records the generated machining boundary shape in the initial state in the machining boundary shape data, and stores the machining boundary shape data in the machining boundary shape storage unit 11.

  FIG. 11 is a diagram illustrating a processing boundary shape in an initial state. The machining boundary shape generation unit 3 obtains the nearest point K0 on the machining target shape SK and the nearest point L0 on the machining target shape SL with respect to the starting point B0 on the center axis SB, and obtains the point K0 and the point L0 with the point B0 as the center. The arc on the processing region side to be connected is set as the initial processing boundary shape. In the embodiment of the present invention, as an example, the closed loop path includes a semicircular arc having a radius of (rb1-rt) on the machining progress direction side.

  Subsequently, the tool path generation unit 2 reads the repetition count N from the path definition data stored in the path definition data storage unit 10 and repeats it as preparation for repeating the generation of one round of path (ie, unit path). The counter variable i is initialized to 0 (step S3).

  Subsequently, the processing unit path generation unit 4 is based on the path definition data stored in the path definition data storage unit 10 and the counter variable i, and the path of the portion cut into the processing material in the path for one round ( A processing unit path) is generated (step S4). The processing unit path generation unit 4 records the generated processing unit path in the processing unit path data, and stores the processing unit path data in the processing unit path storage unit 12. In addition, when the old machining start side rework path data generated last time (when the counter variable is i-1) exists in the machining part path storage unit 12, the old machining start side rework path data is deleted. In addition, new machining start side rework path data is stored.

  The method for generating the machining part path is the same as that in the comparative example. FIG. 12 is a diagram illustrating a processing unit path. The machining unit path generation unit 4 pays attention to the points Bi and Bi + 1 that are two points that are continuous at an interval of the step amount p on the central axis SB. The machining unit path generation unit 4 then sets the nearest point on the machining target shape SK for the point Pi and the point Bi + 1, which is a position offset from the closest point on the machining target shape SK to the point Bi by the tool radius rt toward the central axis SB. Point Pi + 1, which is a position offset from the contact by the tool radius rt toward the center axis SB, Point Qi, which is a position offset from the closest point on the machining target shape SL relative to the point Bi by the tool radius rt toward the center axis SB, Then, a point Qi + 1, which is a position offset from the closest point on the machining target shape SL with respect to the point Bi + 1 by the tool radius rt toward the central axis SB, is obtained. And the process part path | route production | generation part 4 makes the process path | route TPCi the path | route which passes along the point Pi, the point Pi + 1, the point Qi + 1, and the point Qi in this order. Of the paths constituting the machining part path, the paths between the points Pi to Pi + 1 and the paths between the points Qi + 1 to Qi are straight lines, and the paths between the points Pi + 1 to Qi + 1 are determined in advance. It is a curved line (here, as described above, a semicircular arc).

  Subsequently, the machining start side rework route generation unit 5 performs machining based on the route definition data stored in the route definition data storage unit 10 and the machining boundary shape data stored in the machining boundary shape storage unit 11. On the side of the part path on the side where the cutting of the machining material is started, a path (a machining start side reworking path) of a part for reworking the machining target shape is generated (step S5). The machining start side rework path generation unit 5 records the generated machining start side rework path in the machining start side rework path data, and stores the machining start side rework path data in the machining start side rework path storage unit 13. Store.

  FIG. 13 is a flowchart for explaining the process of step S5 in more detail. 14 and 15 are diagrams for explaining the processing in step S5.

  First, the machining start side rework path generation unit 5 calculates a contact angle Fi + 1 at a point Pi + 1 between the tool and the work material (step S21). In FIG. 14, the path between the point Pi and the point Pi + 1 is a path (a path for processing the second processing section) where the cutting of the processing material starts while processing the side wall. The point Ki + 1 is a contact point between the tool located at the point Pi + 1 and the machining target shape SK. The process of step S21 is as follows, for example. That is, the intersection Ai + 1 between the circle of the tool outline and the machining boundary shape is calculated at the point Pi + 1. Then, the angle between the vector from point Pi + 1 to point Ai + 1 and the vector from point Pi + 1 to point Ki + 1 is calculated. The calculated angle is the contact angle Fi + 1.

  Subsequently, the machining start side rework path generation unit 5 determines whether or not the contact angle Fi + 1 is larger than the contact angle setting value E (step S22). The contact angle setting value E is described in the route definition data. When the contact angle Fi + 1 is smaller than the contact angle setting value E (step S22, No), the machining start side rework path generation unit 5 does not set the machining start side rework path (step S23) and ends the operation. . If the machining start side rework path is not set, nothing is stored in the machining start side rework path storage unit 13 and the previous time (when the counter variable is i-1) is stored in the machining start side rework path storage unit 13. When the generated old machining start side rework path data exists, the old machining start side rework path data is deleted.

  When the contact angle Fi + 1 is larger than the contact angle setting value E (step S22, Yes), the machining start side reworking path generation unit 5 is on the path from the point Pi to the point Pi + 1 as shown in FIG. A point Pi ′ at which the contact angle between the tool and the workpiece is equal to the contact angle setting value E is calculated (step S24). Then, the machining start side rework path generation unit 5 sets a path from the point Pi ′ to the point Pi + 1 as the machining start side rework path (step S25). That is, by this process, the machining start side rework path generation unit 5 sets a section from the point Pi ′ to the point Pi + 1 as a section in which reworking is performed. The process of calculating the point Pi ′ is realized by, for example, exploring by evaluating the contact angle at the point on the path from the point Pi to the point Pi + 1 by the calculation shown in the same procedure as step S21.

  Subsequently, the machining start side rework path generation unit 5 records the machining start side rework path in the machining start side rework path data, and uses the machining start side rework path data in which the machining start side rework path is recorded. The process is stored in the machining start side rework path storage unit 13 (step S26), and the operation ends. In the process of step S26, if old machining start side reworking path data generated last time (when the counter variable is i-1) exists in the machining start side reworking path storage unit 13, it is old. The machining start side rework path data is deleted and new machining start side rework path data is stored.

  As described above, the machining start side rework path generation unit 5 performs the machining progress direction side (that is, the right side of the drawing) in the section (section from the point Pi to the point Pi + 1) for machining the side wall defined by the machining target shape SK. ) Is set as a section to be reworked (a section from the point Pi ′ to the point Pi + 1). In addition, the process start side rework path | route production | generation part 5 sets the area where a contact angle exceeds the contact angle setting value E to the area to reprocess.

  Subsequent to the process of step S5, the processes of step S6 to step S7 are executed. For the sake of clarity, the process of step S8 will be described before the processes of step S6 to step S7.

  In step S <b> 8, the machining end side re-machining path generation unit 8 is based on the path definition data stored in the path definition data storage unit 10 and the machining boundary shape data stored in the machining boundary shape storage unit 11. Then, on the side of the machining portion path on the side where the cutting of the machining material is completed, a path of a part for reworking the machining target shape (machining end side remachining path) is generated (step S8). The processing end side rework path generation unit 8 records the generated processing end side rework path in the processing end side rework path data, and stores the processing end side rework path data in the processing end side rework path storage unit 15. Store.

  FIG. 16 is a flowchart for explaining the process of step S8 in more detail. FIGS. 17 and 18 are diagrams for explaining the processing in step S8.

  First, the machining end side rework path generation unit 8 calculates a contact angle Gi + 1 at a point Qi + 1 between the tool and the work material (step S31). In FIG. 17, the path from the point Qi + 1 to the point Qi is a path (cutting path for the first machining section) where the cutting of the workpiece is completed while the side wall is being machined. Point Li + 1 is a contact point between the tool located at Qi + 1 and the machining target shape SL. The process of step S31 is as follows, for example. That is, at the point Qi + 1, the intersection of the tool contour circle and the machining boundary shape is obtained. Then, an angle between the vector from the point Qi + 1 to the obtained intersection and the vector from the point Qi + 1 to the point Li + 1 is calculated. The calculated angle is the contact angle Gi + 1.

  Subsequently, the processing end side rework path generation unit 8 determines whether or not the contact angle Gi + 1 is larger than the contact angle setting value E (step S32). When the contact angle Gi + 1 is smaller than the contact angle setting value E (step S32, No), the machining end side rework path generation unit 8 ends the operation without setting the machining end side rework path (step S33). . If the machining end side rework path is not set, nothing is stored in the machining end side rework path storage unit 15 and the last time in the machining end side rework path storage unit 15 (when the counter variable is i-1). When the generated old machining end side rework path data is stored, the old machining end side rework path data is deleted.

  When the contact angle Gi + 1 is larger than the contact angle set value E (step S32, Yes), the processing end side reworking path generation unit 8 is on the path from the point Qi + 1 to the point Qi as shown in FIG. A point Qi ′ at which the contact angle between the tool and the workpiece is equal to the contact angle setting value E is calculated (step S34). Then, the machining end side rework path generation unit 8 sets the path from the point Qi + 1 to the point Qi ′ as the machining end side rework path (step S35). The process for obtaining the point Qi 'is realized by the same method as the process for obtaining the point Pi' (step S24), for example.

  Subsequently, the processing end side rework path generation unit 8 records the processing end side rework path in the processing end side rework path data, and stores the recorded processing end side rework path data in the processing end side rework path. The data is stored in the unit 15 (step S36), and the operation is terminated. In the process of step S36, when old machining end side reworking path data is stored in the machining end side reworking path storage unit 15, the old machining end side reworking path data is deleted. New machining end side rework path data is stored.

  As described above, the machining end side re-machining path generation unit 8 performs the machining progress direction side (that is, the right side of the drawing) in the section (the section from the point Qi + 1 to the point Qi) for machining the side wall defined by the machining target shape SL. ) Is set as a section to be reworked (a section from the point Qi + 1 to the point Qi ′). Note that the machining end side rework path generation unit 8 sets a section where the contact angle exceeds the contact angle setting value E as a section to be reworked.

  Subsequent to the processing in step S5, the non-machined part path generation unit 6 determines that the tool is a machining material based on the storage content of the machining start side reworking path storage unit 13 and the storage content of the machining end side reworking path storage unit 15. A path (a non-machined part path) of a part that is not cut is generated (step S6). The non-machined part path generation unit 6 records the generated non-machined part path in the non-machined part path data, and stores the non-machined part path data in the non-machined part path storage unit 14.

  FIG. 19 is a flowchart for explaining the process of step S6 in more detail. FIG. 20 is a diagram illustrating an example of a non-machined part path generated by the process of step S6. In FIG. 20, a path TPSi between the point Pi ′ and the point Pi + 1 is a machining start side rework path. A path TPEi-1 between the points Qi and Qi-1 'is a machining end side reworking path. The machining end side rework path TPEi-1 was generated last time (when the counter variable is i-1).

  The non-machining part path generation unit 6 first determines whether or not the machining end side rework path data is stored in the machining end side rework path storage unit 15 (step S41). When the machining end side rework path data is stored in the machining end side rework path storage unit 15 (step S41, Yes), the non-machining part path generation unit 6 determines the end point Qi-1 of the machining end side rework path. 'Is set as the start point of the non-machined part path (step S42). When the machining end side rework path data is not stored in the machining end side rework path storage unit 15 (No in step S41), the non-machining part path generation unit 6 sets the point Qi as the start point of the non-machining part path. (Step S43).

  Subsequent to the process of step S42 or the process of step S43, the non-machined part path generation unit 6 determines whether or not the machining start side rework path data is stored in the machining start side rework path storage unit 13 ( Step S44). When the machining start side rework path data is stored in the machining start side rework path storage unit 13 (Yes in step S44), the non-machined part path generation unit 6 sets the starting point Pi ′ of the machining start side rework path. The end point of the non-machined part path is set (step S45). If the machining start side rework path data is not stored in the machining start side rework path storage unit 13 (No in step S44), the non-machined part path generation unit 6 sets the point Pi + 1 as the end point of the non-machined part path. (Step S46).

  After the process of step S45 or the process of step S46, the non-machined part path generation unit 6 creates a path from the set start point to the set end point so that the tool does not cut into the work material. (Step S47). By the process of step S48, the path from the point Qi-1 'to the point Pi', the path from the point Qi to the point Pi 'without passing through the point Qi-1', or the point Qi-1 'through Pi' The path from the point Qi to the point Pi + 1 without passing through any of the points Qi-1 ′ and Pi ′ without setting the path to the point Pi + 1 is set as the non-machined part path. FIG. 20 shows a case where the path TPNi from the point Qi-1 ′ to the point Pi ′ is set as the non-machined part path. In FIG. 20, a route indicated by a dotted line, that is, a route TPCi from the point Pi to the point Qi through the point Pi ′ and the point Qi + 1 indicates a machining part route.

  Subsequently, the non-machined part path generation unit 6 records the non-machined part path in the non-machined part path data, and stores the non-machined part path data in which the non-machined part path is recorded in the non-machined part path storage unit 14. (Step S48), the operation is terminated. In the process of step S48, when there is old non-machined part path data generated in the previous time (when the counter variable is i-1) stored in the non-machined part path storage unit 14, The old non-machined part path data is deleted.

  Following the processing of step S6, the path output unit 7 includes the machining unit path storage unit 12, the machining end side reworking path storage unit 15, the non-machining unit path storage unit 14, and the machining start side reworking path storage unit 13. The route data is read from the storage unit storing the data in the order of the storage unit, and the route data for one round is generated by combining the read route data in the read order (step S7). . The path output unit 7 outputs the generated path data for one round to the tool path storage unit 16.

  FIG. 21 is a diagram illustrating examples of unit paths generated when the value of the counter variable is i and when the value of the counter variable is i + 1. In both cases, it is assumed that both the machining start side path data and the machining end side path data are generated and stored in the corresponding storage units. As shown in the figure, a path starting from point Pi, passing through point Pi ′, point Pi + 1, point Qi + 1, point Qi ′, point Qi, point Qi−1 ′ and point Pi ′ in this order, and point Pi + 1 as the end point Is a unit path when the value of the counter variable is i. Further, the path starting from the point Pi + 1, passing through the point Pi + 1 ′, the point Pi + 2, the point Qi + 2, the point Qi + 1, the point Qi ′, and the point Pi + 1 ′ in this order and the point Pi + 2 as the end point has a counter variable value i + 1. This is a unit route in some cases. That is, the path from the point Pi ′ set to the rework path at the start of machining to the point Pi + 1 is machined twice in total when the path for one round when the value of the counter variable is i is machined. The Similarly, the path from the point Pi + 1 ′ to the point Pi + 2 set as the rework path at the start of machining is processed twice in total when the path for one round when the value of the counter variable is i + 1 is machined. Is done. Further, the path from the point Qi + 1 to the point Qi ′ set as the rework path at the end of machining is when the path for one round when the value of the counter variable is i is machined and the value of the counter variable is i + 1. In some cases, the processing is performed twice in total when the path for one round is processed.

  As described above, the path output unit 7 sets the closed loop path so that the section set as the section to be reprocessed is processed twice by processing one unit path or two continuous unit paths. The path output unit 7 connects the closed loop path and the path for shifting the closed loop path to generate a unit path.

  FIG. 22 is a diagram showing a change in the contact angle on the machining target shape SK when the embodiment of the present application is applied. As shown in the drawing, the contact angle in the section of Ki ′ to Ki + 1 reaches Fi + 1 beyond the contact angle setting value E in the first machining. Thereafter, the contact angle is suppressed to a value sufficiently smaller than the contact angle setting value E at the time of reworking. That is, the contact angle when the processing target shape SK is finally processed is suppressed to be smaller than the contact angle setting value E. The same applies to the machining target shape SL. Thereby, the process which suppressed the bending of the tool on a process target shape will be performed, As a result, the unevenness | corrugation by the process trace of a side wall will become small compared with a comparative example.

  Following the process of step S7, the process of step S8 described above is executed. Then, the tool path generation unit 2 increments the counter variable i by 1 (step S9).

  Subsequently, the tool path generation unit 2 determines whether or not the value of the counter variable i is smaller than the number of repetitions N set by the path definition data (Step S10). When the value of the counter variable i is not smaller than the number of repetitions N (step S10, No), the operation ends. When the value of the counter variable i is smaller than the repetition number N (step S10, Yes), the machining boundary shape update unit 9 includes the route definition data stored in the route definition data storage unit 10 and the machining unit route storage unit 12. The machining boundary shape data is created again based on the machining part path data stored in the machining part, and the machining boundary shape data stored in the machining part path storage unit 12 is updated with the newly created machining boundary shape data. (Step S11). New machining boundary shape data is generated by removing a region machined by the tool along the machining unit path from the machining boundary shape recorded in the old machining boundary shape data. After the process of step S11, the process of step S4 is executed.

  In the above description, the case where the tool path is generated so that the closed loop path is in contact with each of the two side walls (SK and SL) constituting the pocket portion has been described. However, the number of side walls with which the closed loop path is in contact is as follows. There may be one. In that case, the tool path generation device 100 shifts the first path, which is a closed-loop path, from the closed-loop path as if the re-machining section set as the section for processing the side wall is set to the machining target shape SK. The second path may be processed twice. Further, the tool path generation device 100 may process the re-machining section twice with the first path and the first path belonging to the next unit path as in the case of the machining target shape SL.

  In addition, the two side walls of the pocket portion in contact with the closed loop path are described as being arranged in parallel to each other, but the arrangement of the two side walls of the pocket portion in contact with the closed loop path may not be parallel. In that case, the size of the closed loop path may be sequentially changed for each unit path.

  As described above, according to the embodiment of the present invention, the tool path generation device 100 starts machining by setting a re-machining section in a part on the machining progress direction side of the machining section of the side wall for each unit path. Side rework path generation unit 5 and process end side rework path generation unit 8 and a first path that is a closed loop path so as to process a rework section twice by machining one unit path or two consecutive unit paths And a path output unit 7 for generating a unit path by connecting the first path and a second path for shifting the first path along the side wall in the machining progress direction side. Thus, according to the embodiment of the present invention, the rework section is first machined in a state where the deflection of the tool is large, and then reworked in a state where the deflection of the tool is smaller than the first. The surface can suppress unevenness of the processing trace remaining on the side wall as compared with the comparative example in which the reworking section is not provided. That is, it is possible to suppress the unevenness of the processing trace on the side wall of the pocket portion as much as possible.

  In addition, the machining start side rework path generation unit 5 sets a machining start side reworking section to a machining section where one side wall is machined and starts cutting into the workpiece material, and the machining end side reworking is performed. The path generation unit 8 sets a machining end side reworking section to a machining section in which another side wall is machined and which finishes cutting into the machining material. The path output unit 7 uses the first path of the next unit path after the machining by the first path after the machining start side remachining section is machined by the second path and the machining end side remachining section is machined by the first path. The first route is set so as to be processed. Thereby, according to embodiment of this invention, while being able to process the two side walls which comprise a pocket part simultaneously, the unevenness | corrugation of the process trace which remains on the said two side walls can be suppressed.

  Further, the machining start side rework path generation unit 5 and the machining end side rework path generation unit 8 set a section where the contact angle between the tool and the workpiece material exceeds a preset value as a rework section. Thereby, according to embodiment of this invention, since the contact angle of a tool can be restrained to below a predetermined value in a side wall, the unevenness | corrugation of the process trace which remains in a side wall can be suppressed compared with a comparative example.

  Note that the tool path generation device 100 may be configured so that the user can specify whether or not machining traces need to be suppressed. For example, the data input unit 1 can accept input of route definition data in which attribute information indicating whether or not machining traces need to be suppressed is described. When the attribute information indicating that it is necessary to suppress the machining trace is input, the machining start side rework path generation unit 5 executes a series of processes shown in FIG. 8 executes a series of processes shown in FIG. When attribute information indicating that it is not necessary to suppress the machining trace is input, the machining start side rework path generation unit 5 does not execute the setting of the machining start side rework path, and generates the machining end side rework path. The unit 8 does not execute the machining end side reworking path. Note that the tool path generation device 100 may be configured such that the setting of whether or not machining traces need to be suppressed can be set separately (that is, independently) for the machining target shape SK and the machining target shape SL. .

  Further, the section of the rework path (the work start side rework path and / or the work end side rework path) may be simply calculated as follows. That is, as shown in FIG. 23, the machining start side re-machining path generation unit 5 sets the position Pi returned from the point Pi + 1 to the point Pi side by a predetermined distance l on the path from the point Pi to the point Pi + 1. The path from the point Pi ′ to the point Pi + 1 is defined as a machining start side rework path. Further, as shown in FIG. 24, the processing end side reworking path generation unit 8 sets a point Qi on the path from the point Qi + 1 to the point Qi by a predetermined distance m on the path from the point Qi + 1 to the point Qi. The path from the point Qi + 1 to the point Qi ′ is taken as the machining end side rework path.

  Here, the distance l and the distance m are described and input in the route definition data, for example. By enabling the user to set the distance l and the distance m, the user can confirm the width of the unevenness of the machining trace as a machining result, and can directly specify the rework section by the distance accordingly. Intuitive adjustment is possible according to

  Further, the machining start side rework path generation unit 5 and the machining end side rework path generation unit 8 may calculate the distance l and the distance m based on the tool radius rt, respectively. For example, the machining start side rework path generation unit 5 and the machining end side rework path generation unit 8 calculate the distance l and the distance m so that the distance l and the distance m increase as the tool radius rt increases. The relationship between the tool radius rt and the distance l and the distance m may be a proportional relationship. Thereby, the operation | movement which changes a rework area in response to the tool radius rt is easily implement | achieved.

  Further, the machining start side rework path generation unit 5 and the machining end side rework path generation unit 8 may calculate the distance l and the distance m based on the step amount p, respectively. The relationship between the step amount p, the distance l, and the distance m may be, for example, a proportional relationship. As a result, it is possible to prevent a rework path in a range exceeding the step amount p from being set.

  Further, the machining start side rework path generation unit 5 and the machining end side rework path generation unit 8 may calculate the distance l and the distance m based on the tool radius rt and the step amount p, respectively. For example, the tool radius rt and the step amount p each have a proportional relationship with the distance l, and the tool radius rt and the step amount p have a proportional relationship with the distance m, respectively. The distance l and the distance m may be calculated.

  As described above, the tool path generation apparatus and method according to the present invention are suitable for application to a tool path generation apparatus and method for generating a tool path for machining a pocket portion.

  DESCRIPTION OF SYMBOLS 1 Data input part, 2 Tool path generation part, 3 Machining boundary shape generation part, 4 Machining part path generation part, 5 Machining side rework path generation part, 6 Non-machining part path generation part, 7 Path output part, 8 Machining End side rework path generation unit, 9 machining boundary shape update unit, 10 path definition data storage unit, 11 machining boundary shape storage unit, 12 machining unit path storage unit, 13 machining start side rework path storage unit, 14 non-machining unit Path storage unit, 15 machining end side re-machining path storage unit, 16 tool path storage unit, 100 tool path generation device, 101 CPU, 102 RAM, 103 ROM, 104 input device, 105 output device, 106 tool path generation program.

Claims (12)

A tool path generation device that generates a tool path for machining a plurality of closed-loop first paths in contact with the side wall constituting the pocket part while shifting the first path in the machining direction of the pocket part along the side wall,
The processing progress direction in the processing section of the side wall for each unit path that is a pair of the first path and the second path for shifting the first path from the first path processed immediately before in the processing progress direction. A rework section setting unit for setting a rework section on a part of the side,
The first path is set so that the rework section is machined twice by machining one unit path or two consecutive unit paths, and the set first path and the second path are connected to form a unit. A unit route generator for generating a route;
A tool path generation device comprising: The first path is a path in which the tool is in contact with each of the two side walls constituting the pocket portion, and is a first processing section for processing one of the two side walls. Including a first machining section that terminates the cutting into the machining area of
The second path includes a second processing section that processes the other of the two side walls and starts cutting into a processing area of the unit path,
The rework section setting unit sets a first rework section on the first work section and a second rework section on the second work section,
The unit path generation unit is configured to process the second rework section by the first path after processing by the second path, and the first rework section to be processed by the first unit path after processing by the first path. Setting the first path to be processed by one path;
The tool path generation device according to claim 1 characterized by things. The rework section setting unit sets a section where the contact angle between the tool and the work material exceeds a preset value as a rework section,
The tool path generation device according to claim 1 or 2, characterized by things. The reworking section setting unit sets a section of a set distance as a reworking section.
The tool path generation device according to claim 1 characterized by things. The reworking section setting unit sets a section of a set distance as a reworking section.
The tool path generation device according to claim 2 characterized by things. The set distance is set independently for the first machining section and the second machining section.
The tool path generation device according to claim 5 characterized by things. The rework section setting unit calculates the set distance according to a radius of the tool;
The tool path generation device according to any one of claims 4 to 6, characterized by the above. The rework section setting unit calculates the set distance according to a movement amount of the second path;
The tool path generation device according to any one of claims 4 to 6, characterized by the above. The rework section setting unit calculates the set distance according to a radius of the tool and a movement amount of the second path;
The tool path generation device according to any one of claims 4 to 6, characterized by the above. A tool path generating device generates a tool path for machining a plurality of closed loop first paths in which a tool is in contact with a side wall constituting a pocket part while shifting the first path along the side wall in the machining progress direction of the pocket part. ,
A unit in which the re-machining section setting unit included in the tool path generating device is a pair of a first path and a second path for shifting the first path from the first path to be machined immediately before in the machining progress direction. Setting a reworking section in a part of the machining progress direction side of the processing section of the side wall for each path;
The unit path generation unit provided in the tool path generation device sets the first path so as to process the rework section twice by processing one unit path or two continuous unit paths, and the set first path A second step of connecting one path and the second path to generate a unit path;
A method comprising the steps of: The first path is a path in which the tool is in contact with each of the two side walls constituting the pocket portion, and is a first processing section for processing one of the two side walls. Including a first machining section that terminates the cutting into the machining area of
The second path includes a second processing section that processes the other of the two side walls and starts cutting into a processing area of the unit path,
The first step is a step in which the rework section setting unit sets a first rework section on the first work section and a second rework section on the second work section,
In the second step, the unit path generation unit is configured to process the second rework section after the second path is processed by the first path, and the first rework section is processed after the first path is processed. A step of setting the first path so that the first path of the unit path is processed.
The method according to claim 10. The first step is a step in which the reworking section setting unit sets a section where the contact angle between the tool and the work material exceeds a preset value as a reworking section.
12. A method according to claim 10 or claim 11 characterized in that.

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