JP6626788B2 - Control data generation method, information processing device, machine tool, and program - Google Patents

Description

  The present invention relates to a method for generating control data in additive manufacturing technology.

  Conventionally, additive manufacturing technology (Additive manufacturing) is known. Additive manufacturing technology refers to the process of creating an object from a three-dimensional numerical representation by attaching a material. Additive manufacturing techniques are often realized by stacking layers on top of each other, as opposed to absent manufacturing methods. The definition of such additional manufacturing technology is made in ASTM F2792- 12a (Standard Terminology for Additive Manufacturing Technologies) of ASTM International, which is a private standard setting organization for industrial standards. The additional manufacturing technology is also called “3D printer”.

  Patent Literature 1 discloses a method of generating a tool path in an additive manufacturing process using a powder bed method.

  Also, as shown in Patent Document 2, computer aided manufacturing (CAM) is known. The CAM is software that is used for manufacturing a product, and performs processing such as creation of an NC program for machining, using shape data created by CAD (computer-aided design) as input data.

JP 2015-199197 A JP 2003-005811 A

  The technique of Patent Document 1 is directed to a powder bed method. This method is suitable for a method in which thin layers are stacked one by one. On the other hand, in the form of irradiating a laser while discharging powder from a nozzle to build up on the material surface, modeling can be performed more freely. However, it is more difficult to determine how to make the tool path of the nozzle that can move three-dimensionally than in the case of solidifying layer by layer (only considering movement in a plane).

  The present invention has been made in view of the above problems, and has as its object to provide a method of generating control data (typically, a nozzle path) that enables a user to generate a desired shape in an additional manufacturing technique. Another object of the present invention is to provide an information processing apparatus for generating control data, a machine tool capable of implementing the additional manufacturing technology, and a program for generating control data.

  According to an aspect of the present invention, a control data generation method is a control data generation method for manufacturing a product having a specified shape by an additional manufacturing technology. The control data includes the path of the nozzle that supplies the material. The control data generation method includes a step of determining a cutting path for cutting a specified shape with a tool, and a step of determining a nozzle path by reproducing the cutting path in a direction going back in time. .

  According to another aspect of the present invention, an information processing apparatus generates control data for manufacturing a product having a specified shape by an additional manufacturing technology. The control data includes the path of the nozzle that supplies the material. The information processing apparatus includes a first determination unit that determines a cutting path for cutting a specified shape with a tool, and a second determination unit that determines a nozzle path by reproducing the cutting path in a direction going back in time. And a determination unit.

  According to yet another aspect of the present invention, a machine tool is capable of performing additional manufacturing techniques. The machine tool includes a control unit that generates control data for manufacturing a product having a specified shape using the additional manufacturing technology. The control data includes the path of the nozzle that supplies the material. The control unit includes a first determination unit that determines a cutting path for cutting the designated shape with a tool, and a second determination unit that determines a nozzle path by reproducing the cutting path in a direction going back in time. And a decision unit.

  According to still another aspect of the present invention, a program is used to generate control data for manufacturing a product having a specified shape by an additional manufacturing technology. The control data includes the path of the nozzle that supplies the material. The program stores a step of determining a cutting path for cutting a specified shape with a tool and a step of determining a nozzle path by reproducing the cutting path in a direction going back in time. Of the information processing apparatus.

  According to the above invention, it is possible to determine a nozzle path (moving path) that enables a user to generate a desired shape in the additional manufacturing technology.

5 is a flowchart for explaining how to create a tool path for a nozzle. FIG. 3 is a diagram for explaining a flow of processing executed in the machine tool. It is a schematic diagram for explaining appearance and internal structure of machine tool 1 for manufacturing a composite material. It is a figure showing the state where the additional manufacturing device was attached to the main shaft. FIG. 3 is a diagram illustrating a state in which a tool holder is attached to a main shaft. FIG. 2 is a diagram illustrating an outline of a hardware configuration of a machine tool. It is also for explaining the simulation of the removal processing. It is a figure showing the process of manufacturing a cylindrical semi-finished product by additive manufacturing by moving a nozzle along a tool path. FIG. 2 is a functional block diagram for describing a functional configuration of an operating system.

  Hereinafter, as an example of the additional manufacturing method in the additional manufacturing technology, a directional energy deposition method (directed energy deposition) is used. Note that control data described later is used at the time of additional manufacturing. Specifically, the control data is data for manufacturing a product having a specified shape by an additional manufacturing technology.

<A. Introduction>
In the directional energy deposition method, the discharge direction of the material powder (powder) is preferably set to the direction of gravity as much as possible. The path for the nozzle that discharges the powder (hereinafter, also referred to as “tool path Pn”) is obtained by selecting a shape that can be perpendicular to the direction of gravity. The tool path Pn (moving path, processing path) can be obtained from the shape of the final product to be manufactured, as described later. Conventionally, the optimum value is determined by trial and error (tri & error).

  In the present application, an original method is provided as one of the methods for deterministically determining control data such as the tool path Pn by omitting such a trial and error process.

<B. Process principle>
The laser melts the metal powder and the substrate. In this way, the metal powder is sprayed onto the base material, and the volume is increased while being fused. It is better to stack powder in the direction of gravity (restriction).

  If the temperature is not higher than the melting point of the material, the material powder will not melt. The substrate is cooled and solidified as soon as possible so as not to be overheated. That is, it is necessary to apply heat and immediately after that, apply a cooling effect. The powder (liquid) discharged from the nozzle adheres and fuses to the base material and is radiated from the melting point as radiant heat. At the same time, the temperature of the melting point decreases due to heat conduction due to the temperature difference generated in the material. It is cooled by the two actions radiated from the surface, and as a result, it is solidified (solidified).

  Specifically, a laser beam, a gas for a metal powder and a carrier, and a gas for a shield are discharged from the tip of the nozzle while moving the nozzle for discharging the powder in a predetermined direction. As a result, a melting point is formed on the surface of the work, and as a result, the metal powder is deposited.

<C. Parameters in Process>
It is said that there are about 19 parameters related to the process of forming an object by additive manufacturing technology. Typical parameters are the feed speed of the nozzle for discharging the powder, laser scanning for melting the powder (scanning to increase the area to be melted), supply amount of powder per unit time, and laser unit time. Output per hit and the like.

  When a control program of the additional manufacturing apparatus is operated by putting specific numerical values into such parameters, one process in the additional manufacturing technology is obtained. However, a desired result is not always obtained. However, the combination of parameters is not unlimited. By repeating trial and error, it is possible to bring the process closer to the desired result. The criteria for determining whether the process is successful or unsuccessful include various factors such as the strength of the product (result) and the fineness of the metal structure of the product.

  The above process results in a shape close to the final product (also called "near net shape"). In order to improve the surface roughness and dimensional accuracy of the semi-finished product, cutting and grinding by a conventional method may be required.

  What is manufactured by the additional manufacturing technology is not limited to one having a fixed shape. There are cases where parameters are dynamically changed, such as adjusting the laser output (energy) according to the shape (also referred to as “dynamically additive control”).

<D. Requirements>
The powder supply device is mounted on a conventionally known machine tool (for example, a 5-axis machine tool), and the movement of the nozzle and the supply of the powder are synchronously moved. In the machine tool according to the present embodiment, at what speed the nozzle is moved in the space, how much powder is ejected from the nozzle, and how much output laser is irradiated to melt the powder Can all be computer-controlled along the time axis.

  Before determining the laser output (intensity), the powder supply amount, and the like, it is necessary to determine a tool path Pn (nozzle path) (first requirement). It is very important in the first stage to create a tool path Pn in which the nozzle moves so as to form a three-dimensional contour. After determining the tool path Pn, the powder supply amount and the laser output are determined. If the supply amount of the powder is large, it is necessary to increase the laser intensity so that the melting and solidification of the powder does not become insufficient. When the supply amount of the powder is small and the laser is strong, the powder evaporates, so that the laser intensity needs to be reduced.

  Thus, based on the generated tool path Pn, the powder supply amount and the laser output are determined so as to be synchronized (parameter optimization method (second requirement)).

  Some powders do not adhere to the substrate unless the temperature is too high. On the other hand, if the temperature is too high, the crystal grains of the metal formed when the molten powder solidifies become large, which may cause a problem in the strength of the product. Therefore, it is necessary to optimize the temperature (specifically, laser output) at which the powder is adhered in order to properly adhere the powder to the base material and increase the strength of the product. Furthermore, since the cooling rate of the substrate to which the powder is attached also affects the strength of the product, it is necessary to optimize the cooling rate. (Third requirement). Specifically, under the conditions determined by the second requirement, in order to satisfy predetermined quality as a final product, it is necessary to perform control in consideration of a heat transfer phenomenon (evolution process).

<E. Approach>
(1) First Approach A tool path Pn (nozzle path) is generated based on geometric processing.

(2) Second approach The deposition of the material (metal) accompanying the movement of the nozzle is controlled. The movement of the machine, the shape (arrangement), and the material deposition are processed in association with each other. Note that the complex heat and mass transfer kinetics may be ignored.

(3) Third approach Add an improved model of the system to improve process control. In order to build a more complete control model of the system, a heat and mass transfer phenomena model is introduced.

  By adding the third approach to the first and second approaches, a better (more complete) technique can be achieved.

<F. Method>
(1) First, it is determined how to move the nozzle and how much powder should be supplied in synchronization with the movement of the nozzle.

  Processing in a normal machine tool is a subtractive processing opposite to additive manufacturing. The removal processing is typically metal cutting. In the removal processing, starting from a raw material (coarse material composed of a lump of metal or alloy), for example, when a cylindrical shape is to be formed, unnecessary portions are cut off with a tool and turned into chips.

  On the other hand, in the case of the additive manufacturing technique, the powder is sprayed on the base material while the nozzle is moved in a manner corresponding to a cylindrical shape, thereby forming the object.

  In the case of additive manufacturing, where to start supplying the powder in the space, how to move the nozzle, and how much powder to supply, are based on what the user actually wants to produce (items desired by the user). Need to decide.

  (2) FIG. 1 is a flowchart for explaining how to create a tool path Pn (nozzle path). Referring to FIG. 1, in step S1, a machine tool (typically, a numerical controller) executes a geometric process for generating a removal machining tool path. In step S2, the machine tool executes a simulation of the removal processing.

  In step S3, the machine tool reverses the arrangement of the tool paths (calculates a reverse path). In step S4, the machine tool optimizes the parameters of the additional manufacturing process (additional molding). In step S5, the machine tool generates an additional manufacturing processing program and an executable NC (Numerical Control) program.

  Further, between step S2 and step S4, as shown in step S6, the machine tool extracts a tool path and correlation data between time and position for material removal. In this way, data actually used in the control parameters of the additional manufacturing process is obtained from the removal processing simulation.

  (3) FIG. 2 is a diagram for explaining a flow of processing executed in the machine tool according to the present embodiment. FIG. 2 is also for explaining the simulation of the removal processing shown in step S2 of FIG. In the following, a case will be described in which a cylindrical semi-finished product is generated by the additional manufacturing technology.

  First, a user generates cylindrical shape data by CAD (computer-aided design). Thereafter, the shape data is used as input data to CAM (computer aided manufacturing). Thereby, a simulation at the time of cutting the cylinder can be executed. The CAM may be installed in the numerical control device of the machine tool, or may be installed in an information processing device that can communicate with the machine tool.

  Referring to FIG. 2, as shown in states (A) to (C), a virtual material (stock) is set, and this is cut off with a tool (end mill) along the determined cutting path. Contains only chips. In addition, since these processes are performed by CAM (software capable of three-dimensional simulation of metal cutting) which is generally distributed, actual processing is not performed.

  In the above simulation, since all the cylindrical semi-finished products are turned into chips, the simulation is not a necessary step in terms of making the final product by cutting. However, this simulation is significant in additive manufacturing technology. This will be described below.

  The above simulation process is stored in a memory of a computer (numerical control device). The amount of generated chips (i.e., the amount of metal removal) associated with the movement of the tool and the change in attitude is stored in the memory together with the tool movement path.

  Since the computer stores information until all the materials are exhausted, the computer reproduces the information in a temporally reverse direction. In this way, by rearranging the data in the reverse direction over time and arranging the data one by one, the relationship between the nozzle path and the removal amount can be understood. Eventually, it returns to its original shape.

  If the process of scraping and emptying the material is reproduced in the opposite direction (state (D)), the process returns to the original state. This corresponds to the case of the additive case that "when the powder is discharged into the space, the desired shape is finally obtained".

  The amount of chips removed is obtained by simulation. The amount (volume) of the overlapped area between the tool and the material can be determined.

  The tool path Pn is generated by the CAM. Usually, the optimal path is automatically set according to the shape.

  For a tool, feed speed and diameter (thickness) are important factors. The removal amount is determined based on the overlapping range of the tool and the material calculated from these pieces of information. The removal amount changes with time. The removal amount varies depending on “cutting conditions”. In the CAM, when a cutting amount (unit time) is set, a feed speed and the like are automatically determined. In the present embodiment, the supply amount of the powder is determined based on the removal amount of the chips.

<G. Material deposition control>
(1) In the present embodiment, it is necessary to determine a nozzle moving speed, a laser output (power), and a powder supply amount as three important parameters among the above 19 parameters.

  The amount of chips (ie, the removal amount) accompanying the movement of the tool is determined. This amount has a correlation with the amount of powder supply accompanying the movement of the nozzle. The laser power required to melt the powder can be calculated based on the amount of chips.

  In the case of cutting, if the shape of the moving path is complicated or the moving path is not linear, the amount of generated chips significantly changes with the movement of the tool. On the other hand, in the case of additive manufacturing, it is difficult to change the powder supply amount instantaneously.

  Therefore, in the additional manufacturing, it is easier to manufacture a high quality product by changing the moving speed of the nozzle so that the supply amount of the powder is constant. That is, the moving speed of the nozzle is decreased when increasing the amount of powder deposited per unit area, and the moving speed of the nozzle is increased when decreasing the accumulated amount. As another solution, when generating the cutting information by the CAM, the moving speed and the path of the tool may be generated so that the generation amount of the chips becomes constant.

  (2) While controlling the powder flow rate, a constant flow is always obtained to control which position and how much powder is supplied. Once these are determined, the output of the laser is determined. The moving speed of the nozzle and the laser power can be freely switched in a short time. On the other hand, it is not easy to change the flow rate of the powder.

  As described above, the present embodiment focuses on the point that the volume of the solid material to be added coincides with the volume of the solid material removed in the simulation. That is, the removal amount of chips (chips) is defined as the additive powder supply amount. In the present embodiment, a powder supply amount that needs to be added along the tool path Pn in order to obtain a desired deposition amount is predicted. In addition, the laser power required to melt the powder to be deposited is predicted.

<H. Mounting etc.>
The above processing can be realized by adding a function (program module) to the CAM. That is, the program module is executed on the CAM operating system.

  As described above, such a program module is installed in a machine tool having a built-in numerical control device in which a CAM is installed, or in a computer capable of transferring data with a machine tool through communication or an external storage medium. There may be.

  An advantage is that a conventional CAM program for cutting can be used. That is, the CAM for cutting can be changed to the CAM for additional manufacturing only by adding a function (program module).

<I. Characteristic configuration>
(1) The control data generation method (or information processing device, machine tool, program) according to the present embodiment generates a path that has an original shape and cuts (removes) the shape from the CAM. Is reproduced in the reverse direction to generate a tool path Pn for additional manufacturing. The shape of the product is acquired as data, and a path (cutting path) virtually cut by the CAM is automatically or manually generated based on the data. In the control data generation method, a pass for additive manufacturing is generated by the reverse reproduction.

  As described above, a tool path Pn (additive tool path) is generated by a user creating a shape by CAD and processing CAD data (shape data) by CAM software.

  In the control data generation method according to the present embodiment, when the tool path Pn is determined, the supply amount of the powder, the moving speed of the nozzle, and the output (intensity, power) of the laser are determined by the program module. Specifically, in the method of generating the tool path Pn, the program module determines the control data (specifically, the value of the variable) based on the simulation result of the amount of chip removal. Note that the direction of the nozzle (the direction of powder discharge) is the direction of gravity (vertically downward).

(2) Determination of Tool Path Pn A configuration may be adopted in which the tool path Pn (path for additional manufacturing) is not merely a reverse direction (opposite path) with respect to a cutting path at the time of simulation in the CAM. . For example, when the additional manufacturing method is the directional energy deposition method, since the powder is ejected into the space, it is more stable to land on the work surface by ejecting the powder in the direction of gravity.

  More specifically, in the method of generating the tool path Pn according to the present embodiment, the tool path Pn (additive path) is generated such that the tip point (edge position) of the tool coincides with the laser irradiation position.

<J. Appearance and internal structure of machine tool>
FIG. 3 is a schematic diagram for explaining an external appearance and an internal structure of the machine tool 1 for manufacturing a composite material. Referring to FIG. 3, machine tool 1 includes operating system 11, splash guard 12, spindle head 13, spindle 14, rotating device 18, door 19, and table device 20.

  The table device 20 has a turntable 16 and a pedestal 17 that rotatably supports the turntable 16. The table device 20 is attached to the rotating device 18. Specifically, the pedestal 17 is fixed to the center of the rotating device 18.

  The operating system 11 is a numerical controller that plays the role of a conventional operation panel. The operating system 11 controls the overall operation of the machine tool 1 by executing a program or the like designed by the user. For example, the operating system 11 controls operations of the spindle head 13, the spindle 14, the rotating device 18, the door 19, the table device 20, and an additional manufacturing device 30 described later. The operating system 11 is a well-known system and will not be described in detail here.

  The spindle head 13 is attached to a cross rail (not shown). The spindle head 13 is provided so as to be slidable in an axial direction (X-axis direction) indicated by an arrow 901 and an axial direction (Y-axis direction) indicated by an arrow 902. A spindle 14 is attached to the spindle head 13.

  The main shaft 14 is provided slidably in the axial direction (Z-axis direction) indicated by the arrow 903. The main shaft 14 has a mechanism for mounting a tool holder to which a tool is attached at the tip.

  Examples of the tool holder include an additional manufacturing apparatus 30 (FIG. 4) for executing the additional manufacturing technique, and a tool holder (for example, a tool holder 40 having an end mill (see FIG. 4)) stored in a tool magazine (not shown). 5)). The tool holders other than the additional manufacturing device 30 are attached to the main shaft 14 by the automatic tool changing device 21 (FIG. 5).

  The tool magazine is arranged on the opposite side of the door 19 from the processing area (that is, on the inner side of the door 19 in FIG. 3). The “machining area” is a space (a space on the inner side of the machine tool 1) partitioned by the splash guard 12 and the door 19, and includes a spindle head 13, a spindle 14, a rotating device 18, a table device 20, and additional manufacturing. The space in which the device 30, the work, and the like are movably arranged.

  Each of the spindle head 13 and the spindle 14 is appropriately provided with a feed mechanism, a guide mechanism, a servomotor, and the like for enabling sliding movement. In the machine tool 1, the position of the tool attached to the tool holder can be freely changed in the XYZ space by combining the sliding movements of the spindle head 13 and the spindle 14.

  The rotating device 18 is provided so as to be rotatable around a central axis extending in the X-axis direction by driving a motor. Along with the rotation of the rotation device 18, the table device 20 rotates clockwise and counterclockwise (in the direction of the arrow 904) about the central axis.

  In the state shown in FIG. 3 which is a default state, the rotary table 16 of the table device 20 is provided rotatably around a central axis extending in the vertical (Z-axis) direction by driving a motor. Since the rotary table 16 is rotated in the direction of the arrow 904 by the rotary device 18, the center axis of rotation of the rotary table 16 changes while maintaining a state parallel to the YZ plane.

  The work is held on the rotary table 16 using a chuck or various jigs. At the time of cutting using a fixed tool, the work rotates in the clockwise and counterclockwise directions (in the direction of arrow 905) about the central axis as the rotary table 16 rotates.

  With the above configuration, the machine tool 1 can change the posture of a member such as a work set in the processing area.

  FIG. 4 is a diagram illustrating a state where the additional manufacturing apparatus 30 is attached to the main shaft 14. Referring to FIG. 4, additional manufacturing apparatus 30 includes a discharge unit 310, a mounting unit 320, and a hose unit 330.

  Although details will be described later, metal powder or the like is discharged from the tip 311 of the discharge unit 310. The attachment part 320 is a member for fixing the additional manufacturing device 30 to the main shaft 14. The hose section 330 is a supply path for powder or the like. The hose section 330 is provided for supplying powder or the like to the discharge section 310 via a mounting section 320 from a device (not shown) in which the powder or the like is stored.

  When the additional manufacturing device 30 is not used, the machine tool 1 stores the additional manufacturing device 30 in a holder 39 for the additional manufacturing device (see FIG. 5). The holder 39 is configured to be rotatable about a rotation axis while maintaining a state parallel to the XY plane in order to accommodate the additional manufacturing apparatus 30. That is, the holder 39 rotates around an axis parallel to the Z axis.

  FIG. 5 is a diagram illustrating a state where the tool holder 40 is attached to the main shaft 14. Referring to FIG. 5, operating system 11 performs control to open door 19, and then causes tool holder 40 to be attached to main shaft 14 by an automatic tool changer. The replacement of the tool holder 40 is performed with the additional manufacturing apparatus 30 stored in the holder 39.

<K. Hardware Configuration>
FIG. 6 is a diagram illustrating an outline of a hardware configuration of the machine tool 1. Referring to FIG. 6, a machine tool 1 includes an operating system 11, a spindle head 13, a spindle 14, a rotating device 18, a table device 20, an automatic tool changing device 21, a tool magazine 22, and additional manufacturing. And an apparatus 30.

  The operating system 11 has a CPU (Central Processing Unit) 91, a memory 92, a communication IF (InterFace) 93, a display 94, and operation keys 95.

  The CPU 91 controls the operation of each unit of the machine tool 1 via the communication IF 93 by executing various programs stored in the memory 92. The display 94 displays various types of information on the machine tool 1 so that the user of the machine tool 1 can visually recognize the information. The operation keys 95 receive various inputs (for example, inputs for starting processing) by the user.

  Specifically, the memory 92 of the operating system 11 stores a CAM and a program module for executing the additional manufacturing technique using the above-described reverse reproduction. The quasi-final product or the final product is manufactured by the operating system 11 executing a process according to the instruction from the user.

<L. Details>
Hereinafter, a case in which a cylindrical semi-finished product is generated by the additional manufacturing technology will be described. 7 corresponds to the states (A) to (C) in FIG. 2, and FIG. 8 corresponds to the state (D) in FIG. 7 and 8 differ from FIG. 2 in which a cylindrical semi-finished product is manufactured in that a cylindrical semi-finished product is manufactured.

(1) Simulation of Removal Processing FIG. 7 is also for explaining a simulation of removal processing. That is, FIG. 7 is a diagram for explaining the simulation in the CAM.

  Referring to FIG. 7, in state (A), cylindrical material 500 (virtual material) is cut by about one-third from the upper end according to the cutting conditions (including the cutting path) determined by the CAM. It shows the state when it is done. The path Ps represents the path of the tip of the virtual tool 600 (for example, an end mill) until the start of cutting. In other words, the path Ps represents a path until the tip of the tool 600 contacts the upper end of the material 500. The path Pta represents a part of the cutting path Pt (see state (C) in FIG. 7). That is, the path Pta indicates a path of a portion where the tool 600 has already moved among the cutting paths Pt determined by the CAM.

  The state (B) represents a state when cutting has further progressed from the state (A). Specifically, the state (B) shows a state when the material 500 is cut by about two-thirds from the upper end. The path Ptb represents a part of the cutting path Pt. That is, the path Ptb indicates a path of a portion where the tool 600 has already moved in the cutting path Pt.

  State (C) represents a state when cutting has further progressed from state (B). Specifically, the state (C) represents a state when the entire material 500 has been cut. As described above, the cylindrical material 500 is completely shaved off by the tool 600, and as a result, the material 500 disappears.

  The operating system 11 of the machine tool 1 determines the amount of chips (removal amount per unit time) that is removed when the tool 600 is moved along the above-described cutting path Pt by the position of the tool 600 (the cutting path Pt). And the feed speed of the tool 600 and the like. Note that the feed speed of the tool 600 can also be determined by CAM. Further, the removal amount is a value calculated by the simulation using the CAM as described above.

(2) Manufacturing Process of Semi-Final Product by Additional Manufacturing The operating system 11 executes a program module for executing the additional manufacturing technology using the above-described reverse reproduction to generate control data including the tool path Pn. Specifically, as described above, the operating system 11 reproduces the cutting path Pt (see the state (C) in FIG. 7) in a direction going back in time, so that the cylinder (material) as the designated shape is reproduced. (Same shape as 500) is determined. At the same time, the operating system 11 also determines control data values such as the amount of powder supplied and the output of the laser.

  FIG. 8 is a diagram illustrating a process of manufacturing a cylindrical semi-finished product 700 by additional manufacturing by moving a nozzle (more specifically, the additional manufacturing device 30) along the tool path Pn.

  The state (A) shows the state when the intermediate body 700A having a height of about one third of the cylinder as the designated shape is generated by moving the additional manufacturing apparatus 30 along the tool path Pn. Represents. In the state (B), by moving the additional manufacturing apparatus 30 further along the tool path Pn than in the state (A), the intermediate body 700B having a height of about two thirds of the cylinder as the designated shape is obtained. It represents the state when it was created.

  The state (C) represents a state immediately after the manufacture of the cylindrical semi-finished product 700 is completed by moving the additional manufacturing apparatus 30 further along the tool path Pn than the state (B).

  As described above, the operating system 11 determines the tool path Pn, which is the path of the nozzle, by reproducing the cutting path Pt in a temporally backward direction. Thereafter, the operating system 11 generates the semi-finished product having the specified shape by the machine tool 1 by moving the nozzle along the determined tool path Pn.

<M. Functional configuration>
FIG. 9 is a functional block diagram for explaining a functional configuration of the operating system 11. Referring to FIG. 9, operating system 11 as a control device (controller) of machine tool 1 includes simulation execution unit 110, control data generation unit 120, additional manufacturing control unit 130, and cutting path determination unit 140. Prepare.

  The control data generation unit 120 includes a tool path determination unit 121, a powder supply amount determination unit 122, and a laser power determination unit 123.

  The cutting path determination unit 140 determines a cutting path based on the CAD data. The cutting path determination unit 140 may automatically determine the cutting path based on the CAD data, or may determine the cutting path based on a user input (manual operation). The cutting path determination unit 140 may have any configuration as long as it can uniquely determine a cutting path.

  The simulation execution unit 110 performs a cutting simulation based on the CAD data. Specifically, the simulation execution unit 110 executes a simulation of cutting along the set cutting path.

  By executing the simulation, information such as the cutting path, the amount of chip removal, and the feed speed of the tool can be obtained. The simulation execution unit 110 sends these simulation results to the control data generation unit 120.

  The control data generation unit 120 generates control data for manufacturing a product having a shape (designated shape) based on CAD data by additional manufacturing. The tool path determination unit 121 determines a tool path Pn that is a path of the nozzle (specifically, the additional manufacturing apparatus 30) at the time of additional manufacturing by reproducing the cutting path in a direction going back in time.

  The powder supply amount determination unit 122 determines the powder supply amount. Specifically, the powder supply amount determination unit 122 determines the supply amount of the powder at each position on the tool path Pn. Note that typically, the powder supply amount determination unit 122 determines a constant supply amount at each position on the tool path Pn.

  The laser power determination unit 123 determines the output of the laser. Specifically, the laser power determination unit 123 determines the laser output at each position on the tool path Pn.

  The control data generator 120 sends the generated control data to the additional manufacturing controller 130. The additional production control unit 130 controls the operation of the additional production device 30, the rotation angle of the turntable 16, the rotation angle of the rotation device 18, and the like based on the control data. As a result, a semi-finished product having substantially the same shape as the shape indicated by the CAD data is generated. Further, a final product (a product having the same shape as the CAD data) can be obtained by subjecting the semi-final product to surface processing such as polishing using a tool in the processing area of the machine tool 1.

  Note that a series of processing of the control data generation unit 120 is realized by the operating system 11 (specifically, a processor) executing a program embedded in the CAM. More specifically, a series of processes of the control data generation unit 120 are realized by the processor executing an application program configured to be executable (operable) on the CAM system. On the other hand, the cutting path determination unit 140 and the simulation execution unit 110 are realized by the processor executing a CAM body (a program other than the embedded application).

<N. Summary>
The characteristic configuration of the above-described control data generation method is extracted as follows.

  (1) The control data generation method is a method for generating control data for manufacturing a product having a specified shape by the additional manufacturing technology. The control data includes a nozzle path (tool path Pn) for discharging a material (powder). The control data generation method includes a step of determining a cutting path for cutting a specified shape with a tool, and a step of determining a nozzle path by reproducing the cutting path in a direction going back in time. .

  According to the above-described method, it is possible to determine a nozzle path that can generate a shape (a desired shape) specified by a user in the additional manufacturing technology.

  (2) The control data generation method includes a step of determining a moving speed of the nozzle, a discharge amount of the material, and an output of a laser for irradiating the material when performing the additional manufacturing technology along the path of the nozzle. In addition. This determines not only the path of the nozzle, but also the moving speed of the nozzle, the discharge amount of the material, and the output of the laser for irradiating the material.

  (3) The step of determining the cutting path includes the step of calculating the amount of the material removed from the shape specified by the cutting along the cutting path. The moving speed of the nozzle, the discharge amount of the material, and the output of the laser are determined based on the amount of the removed material.

  (4) In the step of determining the path of the nozzle, the path of the nozzle is determined so that the laser irradiation position coincides with the position of the cutting edge of the tool in the cutting path.

  (5) The cutting path is generated by the CAM. The nozzle path is determined by a program installed in the CAM.

<O. Modification>
In the above description, as an example of the machine tool, a 5-axis processing machine having the function of an additional manufacturing technology (that is, a 3D printer) has been described as an example, but the machine tool is limited to a 5-axis processing machine. is not. The machine tool may be any removal processing machine (for example, a 4-axis processing machine) having the function of the additional manufacturing technology.

  In the above description, the additional manufacturing process (additional molding) for discharging powder is described as an example. However, the various processes described above can also be applied to an additional manufacturing process in which a wire is fed.

<P. Appendix>
(1) In the CAM, the tool orientation may or may not be the laser orientation. When shaving off, the chips fall down, so any angle may be used. However, when spraying the powder, it is preferable to set the powder in the direction of gravity.

  (2) If the removal amount is determined, the tool path Pn is determined. The removal amount is determined by the cutting depth (radial direction and axial direction) and the feed speed. The removal amount is determined by the user. Once the removal amount is determined, the tool path Pn, rotation speed, and the like are determined.

  (3) Once the powder flow rate is determined, the laser power is determined as a function of the energy that can melt the powder.

  (4) It is very difficult to perform cutting with a constant removal amount. Usually, the removal amount fluctuates while the moving speed of the tool is kept constant. However, it is difficult to change the amount of powder supplied in the same manner as such fluctuation. Therefore, the nozzle speed and the laser intensity are changed so as to have a constant value (the powder supply amount is constant). This is to cope with a change in the removal amount.

  (5) The relationship between the nozzle speed and the laser output differs depending on the situation. Therefore, what kind of control is to be performed in advance is programmed in advance. More specifically, data that has been correlated in advance is stored, and a program that performs control under optimum conditions according to the situation is prepared. Note that speed is easier to control than laser output.

  (6) Although the above embodiment uses directional energy deposition as an additional manufacturing method, it can be applied to other additional manufacturing methods such as a fused deposition modeling method.

  The embodiment disclosed this time is an exemplification, and is not limited to the above contents. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 machine tool, 11 operating system, 13 spindle head, 14 spindle, 16 rotary table, 17 pedestal, 18 rotary device, 21 automatic tool changer, 22 tool magazine, 30 additional manufacturing equipment, 39 holder, 40 tool holder, 92 memory , 110 simulation execution unit, 120 control data generation unit, 121 tool path determination unit, 122 powder supply amount determination unit, 123 laser power determination unit, 130 additional manufacturing control unit, 140 cutting path determination unit, 310 ejection unit, 311 tip , 320 Mounting part, 500 materials, 600 tools, 700 semi-finished products, 700A, 700B intermediate, Pn tool path, Ps, Pta, Ptb path, Pt cutting path.

Claims (8)

A method for generating control data for manufacturing a product by additive manufacturing technology,
The control data includes a path of a nozzle that supplies a material,
The method for generating the control data includes:
Determining a cutting path for cutting the shape to be generated by the additional manufacturing technology with a tool,
Determining a path of the nozzle so that the cutting path is reproduced in a direction going back in time. Definitive when performing the additional fabrication techniques along the path of the nozzle, the step of determining the moving speed of the nozzle, the supply amount of the material, at least one of the output of the laser irradiated to the material The method of generating control data according to claim 1, further comprising: Wherein said step of determining the cutting path comprises a step of calculating the amount of material removed from the pre-Symbol shape by cutting along the cutting path,
Wherein a moving speed, and the supply amount, at least one of the output of the laser is determined based on the amount of the removed material, the method of generating the control data according to claim 2.   4. The step of determining the path of the nozzle, wherein the path of the nozzle is determined such that the irradiation position of the laser coincides with the position of the cutting edge of the tool in the cutting path. 5. A method for generating control data according to the above. The cutting path is generated by CAM (Computer Aided Manufacturing),
The control data generation method according to claim 1, wherein the path of the nozzle is determined by a program incorporated in the CAM. An information processing apparatus for generating control data for manufacturing a product by additive manufacturing technology,
The control data includes a nozzle path for discharging the material,
The information processing device,
A first determination unit that determines a cutting path for cutting a shape to be generated by the additional manufacturing technology with a tool,
An information processing apparatus comprising: a second determination unit that determines the path of the nozzle by reproducing the cutting path in a direction going back in time. A machine tool capable of performing additional manufacturing technology,
A control unit including a control unit that generates control data for manufacturing a product by the additional manufacturing technology,
The control data includes a path of a nozzle that supplies a material,
The control unit includes:
A first determination unit that determines a cutting path for cutting a shape to be generated by the additional manufacturing technology with a tool,
A second determining unit that determines the path of the nozzle by reproducing the cutting path in a direction going back in time. A program for generating control data for manufacturing a product by additive manufacturing technology,
The control data includes a path of a nozzle that supplies a material,
The program is
Determining a cutting path for cutting the shape to be generated by the additional manufacturing technology with a tool,
Determining the path of the nozzle by reproducing the cutting path in a direction going back in time, thereby causing a processor of an information processing apparatus in which the program is stored to execute.