WO2021117468A1 - Laminate molding device, and method for manufacturing laminate molded object - Google Patents

Laminate molding device, and method for manufacturing laminate molded object Download PDF

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Publication number
WO2021117468A1
WO2021117468A1 PCT/JP2020/043437 JP2020043437W WO2021117468A1 WO 2021117468 A1 WO2021117468 A1 WO 2021117468A1 JP 2020043437 W JP2020043437 W JP 2020043437W WO 2021117468 A1 WO2021117468 A1 WO 2021117468A1
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WO
WIPO (PCT)
Prior art keywords
molten bead
base material
laminated
temperature
bead
Prior art date
Application number
PCT/JP2020/043437
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French (fr)
Japanese (ja)
Inventor
卓矢 池田
敏超 薛
崇史 藤井
Original Assignee
三菱電機株式会社
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Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to JP2021563830A priority Critical patent/JPWO2021117468A1/ja
Publication of WO2021117468A1 publication Critical patent/WO2021117468A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/105—Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/16—Both compacting and sintering in successive or repeated steps
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y10/00—Processes of additive manufacturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y30/00—Apparatus for additive manufacturing; Details thereof or accessories therefor

Definitions

  • This disclosure relates to a laminated modeling device and a method for manufacturing a laminated model.
  • 3D printers for modeling metal materials
  • a laser, an arc, or an electron beam is used as a heat source to melt and solidify a metal powder or a metal wire, and the molten metal is laminated to manufacture a shaped object.
  • Patent Document 1 is a method for manufacturing a laminated model in which the temperature of the molten bead of the previous layer is observed, and when the temperature of the molten bead of the previous layer becomes equal to or lower than the allowable interpass temperature, the molten bead of the next layer is formed.
  • the method for manufacturing a laminated model disclosed in Patent Document 1 described above has a problem that cooling may take time depending on the shape and size of the laminated model, resulting in inferior modeling efficiency. Further, in order to manufacture in a short time, if the molten bead of the next layer is molded in a state where the temperature of the molten bead of the previous layer does not decrease, the molding may not be stable.
  • the present disclosure has been made in view of the above-mentioned actual conditions, and an object of the present disclosure is to provide a laminated modeling apparatus and a method for manufacturing a laminated model, which have excellent modeling efficiency and can form a stable laminated model.
  • the laminated molding apparatus forms a new molten bead on the base material forming the laminated model or the molten bead of the front layer formed on the base material, and forms a plurality of molten beads. It is provided with a melt heating unit to be laminated and a cooling unit provided separately from the melt heating unit to cool the molten bead of the front layer.
  • the figure which shows the laminated modeling apparatus which concerns on embodiment of this disclosure A block diagram showing a laminated modeling apparatus according to an embodiment of the present disclosure.
  • the laminated molding apparatus 100 includes an arc torch 10 for forming a molten bead MB, a preheating unit 20 for preheating the base plate BP, and an arc torch 10.
  • a cooling unit 30 for cooling the molten bead MB, a temperature sensor 40 for measuring the temperature of the base plate BP and the molten bead MB, a robot unit 50 for moving the arc torch 10, and a base plate BP are placed.
  • the base 60 is provided, and a control unit 70 that controls the arc torch 10, the preheating unit 20, and the cooling unit 30 based on the temperature measured by the temperature sensor 40.
  • the laminated modeling apparatus 100 manufactures a laminated model LM by laminating a molten bead MB on a base plate BP.
  • An example of the laminated model LM is shown in FIG.
  • This laminated model LM has a hollow tubular shape.
  • the base plate BP is an example of a base material.
  • the plane on which the base plate BP is placed on the base 60 is set as the xy plane, and the direction perpendicular to the xy plane is set as the z direction.
  • the xy plane is arranged horizontally, and the z direction is arranged in the vertical direction.
  • the arc torch 10 includes a tubular shield nozzle to which a shield gas is supplied, a contact tip 11 arranged inside the shield nozzle, and a modeling material supply unit for supplying the modeling material W. To be equipped. Under the control of the control unit 70, the arc torch 10 generates an arc while flowing a shield gas while supplying the modeling material W to melt and solidify the modeling material W, and the molten bead MB is laminated on the base plate BP. To form a laminated model LM. It is assumed that the heat input condition of the arc torch 10 is constant.
  • the shaping material W is a wire selected from metal materials including Inconel®, stainless steel, aluminum alloys and magnesium alloys.
  • Inconel is a superalloy based on nickel and to which one or more of iron, chromium, niobium and molybdenum are added.
  • the arc torch 10 is an example of a melt heating unit that forms a new molten bead MB on the preheated base plate BP or the molten bead MB of the front layer formed on the base plate BP.
  • the preheating unit 20 preheats the base plate BP forming the laminated model LM and the molten bead MB of the front layer formed on the base plate BP, and heats the laser oscillator and the laser oscillated by the laser oscillator.
  • a laser apparatus comprising a mirror or optical fiber for transmission and an optical system including a condensing lens for condensing the transmitted laser.
  • the laser oscillator a transmitter that oscillates a laser by irradiating an optical fiber having a rare earth element added to the core with excitation light may be used, or a transmitter using a YAG crystal may be used.
  • the laser device may be one that irradiates an excimer laser or a CO 2 laser.
  • the preheating unit 20 irradiates the laser at the planned formation position P on the base plate BP to form a new molten bead MB, and preheats the planned formation position P.
  • the planned formation position P includes a position immediately below forming the molten bead MB and a front position in the modeling direction D1 in which the arc torch 10 relatively moves.
  • the preheating position is too far from the forming portion MB1 of the molten bead MB, the temperature of the preheated portion is lowered, and the effect of the preheating is reduced.
  • the preheating portion 20 is arranged directly above the forming portion MB1 of the molten bead MB or in front of the arc torch 10 in the molding direction D1 of the molten bead MB. Further, it is desirable that the preheating unit 20 preheats the planned formation position P in which the molten bead MB can be formed in 0.7 seconds or less in front of the molding direction D1 in which the arc torch 10 relatively moves. Since the speed at which the arc torch 10 moves during modeling is often 50 to 150 cm / min, if the molten bead MB is formed within 0.7 seconds after preheating, the temperature of the preheated portion is reached. The decrease can be sufficiently suppressed.
  • the preheating unit 20 can heat the base plate BP pinpointly by the laser and can minimize the preheating of the base plate BP, the heat effect after the laminated molding is reduced, and the laminated model LM It is also possible to suppress thermal deformation and coarsening of crystal grains.
  • a cathode point is formed in the vicinity of the arc, and there is also an advantage that the arc is stabilized. Further, if the preheating amount becomes too large, the width of the molten bead MB becomes large, so it is desirable to keep the preheating amount within a certain range.
  • the preheating unit 20 heats the base plate MB to a preheating temperature equal to or higher than the first reference value and equal to or lower than the second reference value, which is larger than the first reference value.
  • the first reference value and the second reference value are determined by the combination of the materials of the base plate MB and the modeling material W.
  • the melting temperature of the base plate MB of the preheating unit 20 is higher than the melting temperature of the modeling material W.
  • the preheating unit 20 may preheat the base plate MB at a temperature higher than the difference between the melting temperature of the base plate MB and the melting temperature of the modeling material W at the time of modeling the first layer L1.
  • the first reference value is set to 150 ° C and the second reference value is set to 350 ° C, a stable molten bead MB can be formed. It is valid.
  • the preheating unit 20 sets the temperature of the molten bead MB in the front layer to be equal to or higher than the third reference value and equal to or lower than the fourth reference value to be greater than the third reference value. Preheat to.
  • the arc torch 10 does not allow the new molten bead MB formed by melting the modeling material W to hang down, and a new molten bead MB is stably formed. Determined by temperature. Further, preheating an aluminum alloy or a copper alloy having high thermal conductivity is effective in suppressing internal defects.
  • the molten metal solidifies quickly, so if it is not preheated, the air or shield gas that has entered the voids inside the molten bead MB will solidify before it escapes from the molten metal. .. Therefore, by preheating, the solidification of the molten metal can be delayed, which leads to the suppression of internal defects. It is desirable to preheat both the aluminum alloy and the copper alloy to 100 ° C. or higher.
  • the cooling unit 30 cools the molten bead MB in the front layer formed by the arc torch 10 by blowing a refrigerant, and has a nozzle having a refrigerant flow path and a regulator for controlling the flow rate of the refrigerant. Specifically, the cooling unit 30 sets the planned formation position P for forming the molten bead MB of the next layer on the molten bead MB of the previous layer to be equal to or greater than the third reference value and greater than or equal to the third reference value to be less than or equal to the fourth reference value. Cool to the temperature of. Further, as shown in FIG.
  • the cooling unit 30 sprays the refrigerant at an angle with respect to the stacking direction of the laminated model LM when viewed from the molding direction D1 of the molten bead MB.
  • the refrigerant is sprayed in a direction parallel to the stacking direction of the laminated model LM, only the upper surface of the laminated model LM is concentrated and cooled.
  • the heat capacity of the modeled portion is smaller than that of the base plate BP, so that heat tends to be accumulated in the modeled portion. Therefore, efficient cooling is possible by cooling the molded portion with a large area from the side surface. Further, by providing the cooling portion 30 at an angle, it becomes difficult to interfere with the laminated model LM.
  • the narrow angle ⁇ formed by the stacking direction D2 of the laminated model LM and the direction D3 of blowing the refrigerant from the cooling unit 30 is 20 ° or more and 70 ° or less. If the narrow angle ⁇ is less than 20 °, the cooling efficiency deteriorates, and if the narrow angle ⁇ is larger than 70 °, the shield gas is disturbed and stable modeling becomes difficult.
  • the arc torch 10 is integrated with the cooling unit 30, it may be installed separately, or a plurality of cooling units may be provided on both sides of the molten bead MB.
  • the refrigerant is selected according to the modeling material W, and liquid nitrogen or cooling gas is used. If the refrigerant sprayed from the cooling unit 30 affects the shield gas of the arc torch 10 and becomes unstable, the molten bead MB may be defective. Therefore, it is preferably installed at a position away from the arc torch 10. .. When the flow rates of the shield gas and the refrigerant supplied from the cooling unit 30 are the same, it is desirable that the cooling unit 30 is installed behind the arc torch 10 in the forming direction D1 of the molten bead MB as shown in FIG. , It is more desirable to install the arc torch 10 at a position separated by 3 times or more the distance between the contact tip 11 and the modeling portion MB1.
  • the flow of the shield gas is faster than that of the refrigerant, and the shielding property of the molten bead MB can be ensured.
  • the cooling unit 30 is arranged at a position where the refrigerant does not directly hit the shield gas, the shielding property is less likely to deteriorate, so that the flow rate of the refrigerant can be increased.
  • the refrigerant it is preferable to use an inert gas containing argon gas or nitrogen gas. Deterioration of the shielding property can be suppressed by the above-mentioned measures, but the refrigerant may hinder the shielding property depending on the shape of the modeled object or the like. Therefore, by using an inert gas as the refrigerant, oxidation of the molten bead MB can be suppressed.
  • the temperature sensor 40 measures the temperature of the planned formation position P on the base plate BP and the planned formation position P for forming the molten bead MB of the next layer on the molten bead MB of the previous layer. is there.
  • the temperature sensor 40 may be any as long as it can measure the temperature of the base plate BP and the molten bead MB, and a contact sensor, a thermography, an infrared temperature sensor, or the like can be used. Since the laminated molten bead MB has a high temperature, a non-contact type sensor such as a thermography or an infrared temperature sensor is preferably used.
  • Thermography is particularly preferable because it is possible to measure the temperature distribution of the entire base plate BP and the molten bead MB formed on the base plate BP.
  • the temperature at the planned formation position P is extracted from the overall temperature distribution.
  • the robot unit 50 is an articulated robot, and under the control of the control unit 70, the arc torch 10, the preheating unit 20, and the cooling unit 30 are moved in the x, y, and z directions.
  • the robot unit 50 can move the arc torch 10, the preheating unit 20, and the cooling unit 30 three-dimensionally, and the posture and position of the arc torch 10 are controlled by the control unit 70, so that the arc torch 10 can be arbitrarily moved. You can move to any position with the posture of.
  • the base 60 is provided with a turntable and is placed around a rotation axis AX extending in the z direction to rotate the base plate BP.
  • the laminated model LM having a tubular shape can be easily modeled.
  • the control unit 70 includes a CPU (Central Processing Unit) 71 that executes a program, a ROM (Read Only Memory) 72 that stores the program, and a RAM (Random Access Memory) 73 that is used as a work area for executing the program.
  • the arc torch 10, the preheating unit 20, the cooling unit 30, and the robot unit 50 are controlled based on the temperature measured by the temperature sensor 40 by executing the program stored in the ROM 72.
  • the ROM 72 contains data indicating a first reference value and a second reference value, which are reference values of the temperature preheated by the preheating unit 20, for each combination of the materials of the base plate BP and the modeling material W, and the modeling material. For each material of W, data showing a third reference value and a fourth reference value, which are reference values of the temperature at which the molten bead MB is cooled by the cooling unit 30, is stored.
  • the control unit 70 acquires the shape data of the laminated model LM to be formed, and as shown in FIG. 6, the control unit 70 divides the laminated model LM into a plurality of layers and represents the shape of each layer, the first layer L1 and the second layer. L2, ... nth layer Ln ... Generates layer shape data of the k-1th layer Lk-1 and the kth layer Lk. Further, the control unit 70 generates position data of the contact tip 11 of the arc torch 10 based on each layer shape data. The position data includes data indicating the height Hn and data indicating the distance Rn from the rotation axis AX for each nth layer. The generated layer shape data and position data are stored in the RAM 73.
  • control unit 70 acquires the material data of the base plate BP and the material data of the modeling material W, and based on the material data of the base plate BP and the material data of the modeling material W, the preheating unit 20 causes the base plate BP to move.
  • the first reference value and the second reference value which are the reference values of the temperature to be preheated, are determined.
  • control unit 70 determines a third reference value and a fourth reference value, which are reference values of the temperature at which the molten bead MB is cooled by the cooling unit 30, based on the material data of the modeling material W.
  • the control unit 70 acquires the temperature data of the planned formation position P on the base plate BP measured by the temperature sensor 40. Next, when the control unit 70 determines that the measured temperature is not equal to or higher than the first reference value, the control unit 70 controls the preheating unit 20 to preheat the planned formation position P on the base plate BP. When the control unit 70 determines that the measured temperature is not equal to or lower than the second reference value, the control unit 70 controls the cooling unit 30 to blow the refrigerant onto the base plate BP to cool the base plate BP.
  • control unit 70 determines that the measured temperature is equal to or higher than the first reference value and is equal to or lower than the second reference value, the control unit 70 controls the arc torch 10 and the base 60 to melt at the planned formation position P of the first layer L1. Form a bead MB.
  • control unit 70 when the control unit 70 forms the molten bead MB of the nth layer Ln, the control unit 70 obtains the temperature data of the planned formation position P in the molten bead MB of the n-1th layer Ln-1 measured by the temperature sensor 40. get. Next, when the control unit 70 determines that the measured temperature is not equal to or higher than the third reference value, the control unit 70 controls the preheating unit 20 to set the planned formation position P of the n-1 layer Ln-1 in the molten bead MB. Preheat.
  • control unit 70 determines that the measured temperature is not equal to or lower than the fourth reference value
  • the control unit 70 controls the cooling unit 30 to blow the refrigerant onto the molten bead MB to cool the molten bead MB.
  • the control unit 70 determines that the measured temperature is equal to or higher than the third reference value and equal to or lower than the fourth reference value
  • the control unit 70 controls the arc torch 10 and the base 60 to melt at the planned formation position P of the nth layer Ln. Form a bead MB.
  • the laminated modeling process executed by the laminated modeling device 100 will be described with respect to an example in which the laminated modeling device 100 having the above configuration performs the laminated modeling of the laminated model LM shown in FIG.
  • the laminated modeling apparatus 100 starts the laminated modeling process shown in FIG. 7 in response to an instruction from the user to start the process.
  • the laminated modeling process executed by the laminated modeling apparatus 100 will be described with reference to a flowchart.
  • the control unit 70 of the laminated modeling device 100 acquires the shape data of the laminated model LM and stores it in the RAM 73 (step S101).
  • the control unit 70 describes the first layer L1, the second layer L2, ... The nth layer Ln ... The kth, which represents the shape of each layer obtained by dividing the laminated model LM shown in FIG. 6 into a plurality of layers.
  • the layer shape data of the -1 layer Lk-1 and the kth layer Lk are generated, and the position data of the arc torch 10 is generated based on each layer shape data (step S102).
  • the generated layer shape data and position data are stored in the RAM 73.
  • the control unit 70 acquires the material data of the modeling material W and the base plate BP and stores them in the RAM 73 (step S103).
  • the control unit 70 has a first reference value which is a reference value of the temperature at which the base plate BP is preheated by the preheating unit 20 based on the material data of the base plate BP and the material data of the modeling material W.
  • the second reference value is determined (step S104).
  • the first reference value is set to 150 ° C. and the second reference value is set to 350 ° C.
  • the control unit 70 determines a third reference value and a fourth reference value, which are reference values of the temperature at which the molten bead MB is cooled by the cooling unit 30, based on the material data of the modeling material W ( Step S105).
  • control unit 70 executes the first layer modeling process shown in FIG. 8 for forming the molten bead MB of the first layer L1 on the base plate BP.
  • the control unit 70 controls the robot unit 50 and moves the arc torch 10 to the planned formation position P based on the position data of the arc torch 10 (step S201).
  • the control unit 70 controls the robot unit 50 to move the contact tip 11 of the arc torch 10 in the vicinity of the base plate BP and at a distance R1 from the rotation axis AX.
  • the control unit 70 acquires the temperature data of the planned formation position P on the base plate BP measured by the temperature sensor 40 (step S202).
  • the control unit 70 determines whether or not the measured temperature is equal to or higher than the first reference value (step S203).
  • step S203; No When it is determined that the measured temperature is not equal to or higher than the first reference value (step S203; No), the control unit 70 controls the preheating unit 20 to preheat the planned formation position P on the base plate BP (step S203; No). Step S204). Then, the process returns to step S202.
  • step S203 When it is determined that the measured temperature is equal to or higher than the first reference value (step S203; Yes), the control unit 70 determines whether or not the measured temperature is equal to or lower than the second reference value (step S205). ). When it is determined that the measured temperature is not equal to or lower than the second reference value (step S205; No), the control unit 70 controls the cooling unit 30 to blow the refrigerant onto the base plate BP to cool the base plate BP (step S206). .. Then, the process returns to step S202.
  • step S205 When it is determined that the measured temperature is equal to or lower than the second reference value (step S205; Yes), the control unit 70 controls the base 60 to rotate the base plate BP by a reference angle (step S207). Next, the control unit 70 controls the modeling material supply unit of the arc torch 10 to supply the modeling material W to form the molten bead MB of the first layer L1 (step S208). Next, the control unit 70 determines whether or not all the formation of the molten bead MB of the first layer L1 is completed (step S209). Here, it is determined whether or not the base plate is rotated by 360 ° by the base 60. If it is determined that the process has not been completed (step S209; No), the process returns to step S202. When it is determined that the process is completed (step S209; Yes), the first layer modeling process is completed, and the process returns to the laminated modeling process shown in FIG. 7 (step S106).
  • control unit 70 executes the nth layer modeling process shown in FIG. 10 for forming the molten bead MB of the nth layer Ln.
  • n is a natural number of 2 or more and k or less.
  • the control unit 70 controls the robot unit 50 to move the arc torch 10 to the planned formation position P based on the position data of the arc torch 10 (step S302).
  • the control unit 70 controls the robot unit 50 to move the contact tip 11 of the arc torch 10 from the base plate BP to the height H2 and the distance R2 from the rotation axis AX. ..
  • the control unit 70 acquires the temperature data of the planned formation position P in the molten bead MB of the n-1th layer Ln-1 measured by the temperature sensor 40 (step S303).
  • step S304 determines whether or not the measured temperature is equal to or higher than the third reference value.
  • step S304 determines whether or not the measured temperature is equal to or higher than the third reference value.
  • step S305 the control unit 70 controls the preheating unit 20 to form the planned formation position P in the molten bead MB of the first layer L1. Is preheated (step S305). Then, the process returns to step S303.
  • step S304 When it is determined that the measured temperature is equal to or higher than the third reference value (step S304; Yes), the control unit 70 determines whether or not the measured temperature is equal to or lower than the fourth reference value (step S306). ). When it is determined that the measured temperature is not equal to or lower than the fourth reference value (step S306; No), the control unit 70 controls the cooling unit 30 to blow the refrigerant onto the molten bead MB to cool it (step S307). .. Then, the process returns to step S303.
  • control unit 70 controls the base 60 to rotate the base plate BP by a reference angle (step S308).
  • control unit 70 controls the modeling material supply unit of the arc torch 10 to supply the modeling material W to form the molten bead MB of the second layer L2 (step S309).
  • control unit 70 determines whether or not the formation of the molten bead MB of the nth layer Ln is completed (step S310). Here, here, it is determined whether or not the formation of the molten bead MB of the second layer L2 is completed based on whether or not the base plate is rotated by 360 ° by the base 60. If it is determined that the process has not been completed (step S310; No), the process returns to step S303.
  • step S311 the control unit 70 determines that the layer modeling process for all the layers has been completed (step S311; Yes)
  • the control unit 70 ends the nth layer modeling process and returns to the layered modeling process shown in FIG. 7 (step S107).
  • the laminated modeling process is completed.
  • the laminated model LM shown in FIG. 3 is completed.
  • the preheating unit 20 is controlled so that the planned formation position P on the base plate BP is set to the first reference value or more.
  • the amount of heat required to bring the base plate BP to the melting temperature or higher is reduced, and the amount of heat input by the arc torch 10 can be reduced.
  • the base plate BP and the molten bead MB are joined by the molten portion MP1 without overlapping.
  • a stable molten bead MB can be formed with an arc current of 90 A and a molding speed of 50 cm / min, and the molding width is 2.5 mm or more and 3.0 mm or less. Can be narrowed down to. This is because the amount of heat for forming the molten bead MB is insufficient without preheating, but the preheating makes it possible to form under the molding conditions in which the base plate BP does not melt. At this time, the melt width Wm1 is the same as or close to the molding width of the molten bead MB.
  • the molten bead MB in the front layer when the temperature of the molten bead MB in the front layer is lowered even in the second and subsequent layers, the molten bead can be formed under the condition that the heat input is small by preheating the molten bead MB in the front layer, and the cooling rate becomes high. It is possible to suppress the influence of heat storage. Therefore, continuous laminated modeling becomes possible, and laminated modeling with high modeling efficiency becomes possible.
  • the minimum molding width without preheating is 4 mm.
  • the cooling unit 30 sprays a refrigerant onto the molten bead MB in the front layer formed by the arc torch 10 to cool the molten bead MB to a temperature equal to or higher than the third reference value and lower than the fourth reference value.
  • a new molten bead MB of the second layer L2 is formed on the molten bead MB of the first layer L1 which is the front layer, it is possible to prevent the molten bead MB of the second layer from dripping.
  • a stable laminated model LM can be formed. Further, as the molten bead MB is laminated, the cooling condition changes every moment due to changes in heat storage and heat capacity, but by controlling the temperature of the molten bead MB in the previous layer, the new molten bead MB is melted. Since the state is stable, continuous modeling is possible, and the modeling speed can be increased.
  • the overlap OL is just in the state, the molten bead MB has an unstable shape, and the bonding strength between the base plate BP and the molten bead MB is also reduced.
  • the thermophysical properties of Inconel and stainless steel are different, so that they cannot be modeled well under the conditions of ordinary laminated molding of the same type of metal.
  • the melting temperature of the stainless steel of the base plate BP is 200 ° C. higher than the melting temperature of the Inconel of the modeling material W, so that the melting width Wm2 of the base plate BP is small. Is the cause. Therefore, as shown in FIG.
  • the first layer of the laminated molding using stainless steel for the base plate BP and Inconel for the modeling material W is laminated and molded under the condition of a large amount of heat input, and the molten portion of the base plate BP is formed. It is necessary to widen the melting width Wm3 of MP3. However, under the condition of large heat input, the width of the molten bead MB becomes large, and the target range in which the laminated molding can be performed becomes narrow.
  • an arc current of 150 A and a molding speed of about 50 cm / min are the minimum required for stable first layer molding. Only modeling with a modeling width of 5 mm or more is possible.
  • a new molten bead MB is formed on the molten bead MB of the previous layer. Therefore, the temperature of the molten bead MB in the front layer when molding a new molten bead MB affects the shape stability of the molding of the new molten bead MB. If the temperature of the molten bead MB of the first layer L1 which is the front layer is high, a new molten bead MB of the second layer L2 hangs down as shown in FIG.
  • the molten bead MB when the molten bead MB is at a high temperature and is laminated in multiple layers, heat is stored, and the temperature of the portion where a new molten bead MB is formed is often increased. As the heat is stored, the molten bead MB hangs down, making it difficult to form a stable molten bead MB.
  • the arc torch 10 includes a modeling material supply unit for supplying the modeling material W
  • the arc torch 10 may be capable of forming a laminated model by laminating molten beads on the base plate BP.
  • the arc torch 10 may be a method in which the modeling material is supplied from the outside without providing the modeling material supply unit.
  • the control unit 70 controls the preheating unit 20 and the cooling unit 30 by feedback control based on the temperature measured by the temperature sensor 40, and sets the target temperature at the position P where the base plate BP and the molten bead MB in the front layer are to be formed. May be adjusted to.
  • Feedback control includes proportional control, PI (Proportional-Integral) control and PID (Proportional-Integral-Differential) control.
  • the target temperature of the base plate BP is equal to or higher than the first reference value and lower than the second reference value, and the target temperature of the molten bead MB in the front layer is equal to or higher than the third reference value and lower than the fourth reference value. ..
  • the preheating unit 20 preheats the molten bead MB in the front layer has been described, but the preheating unit 20 removes the film formed on the molten bead MB in the front layer. May be good.
  • alumina which is a strong oxide film, is formed on the surface of the molten bead MB.
  • the melting temperature of this oxide film is about 3000 ° C., which is much higher than the melting temperature of aluminum or an aluminum alloy of about 600 ° C.
  • the preheating unit 20 irradiates the laser at the position P where the molten bead MB of the front layer is to be formed, and pinpointly removes the oxide film of aluminum or the aluminum alloy, so that the molten bead MB of only a normal arc is formed. A stable molten bead MB can be formed.
  • the cooling unit 30 sprays a refrigerant on the molten bead MB in the front layer to cool it once, and then the preheating unit 20 irradiates the laser to blow off the oxide film of aluminum or an aluminum alloy.
  • aluminum has a lower latent heat than iron and copper, the molding width becomes wider when a wide range of heat is heated.
  • the temperature is 100 ° C. or higher and 200 ° C. or lower. Further, it is preferable that the heating range is in the vicinity of the modeling portion and the width of the preheating is 1 mm or less.
  • the heat input condition of the arc torch 10 is constant.
  • the arc current is relatively increased and the molten bead MB is formed and formed under the heat input condition higher than the reference heat input amount.
  • the arc current is relatively small and the molten bead MB is formed under the heat input condition lower than the reference heat input amount, so that stable modeling becomes possible.
  • the preheating unit 20 only needs to be able to preheat the base plate BP and the molten bead MB in the front layer, and is a hot plate.
  • a heat gun, an induction heating device, and the like may be provided. By doing so, the laminated modeling apparatus 100 can have a simpler structure.
  • the laminated modeling device 100 includes the arc torch 10, the preheating unit 20, and the cooling unit 30 has been described, but the laminated modeling device 100 includes at least the arc torch 10 and the cooling unit 30. Just do it. This makes it possible to prevent the molten bead MB from dripping. Further, it is possible to reduce the influence of heat storage when forming a new molten bead MB. Therefore, by cooling the molten bead MB by the cooling unit 30, the influence of heat storage is reduced, and the molten bead MB can be continuously formed. Therefore, the molding speed becomes high, and efficient laminated molding becomes possible. In addition, the laminated modeling apparatus 100 can have a simpler structure.
  • the melt heating unit only needs to be able to form the molten bead MB, and the molding material W is melted by a laser or an electron beam to melt the molten bead MB. May be formed.
  • the modeling material W is a powder material or a wire selected from a metal material including Inconel, stainless steel, an aluminum alloy, and a magnesium alloy.
  • the modeling material W is not limited as long as it can form a laminated model LM, and the modeling material W may be any material that melts with heat and solidifies when cooled, and is made of metal, ceramics, glass, and metal. It may be one material selected from the group containing a resin, or a material obtained by mixing a plurality of materials.
  • the laminated model LM is not limited as long as it has a shape that can be modeled by the laminated modeling device 100, and may be a component of a turbine or a jet engine. In this case, by moving the arc torch 10 by the robot unit 50 while rotating the base plate BP, it is possible to form a rotating component such as a turbine including a shape other than the rotational symmetry. Further, although an example in which the base plate BP is used as the base material has been described, the base material may be any base as long as it is a base for molding the laminated model LM, and the shape is not limited.
  • the base plate 60 may fix the base plate BP.
  • laminated modeling with high modeling efficiency becomes possible.

Abstract

A laminate molding device (100) is provided with a melt heating unit, and a cooling unit (30). The melt heating unit laminates molten beads (MB) in a plurality of layers by forming a new molten bead (MB) on a base material on which a laminate molded object (LM) is to be formed, or on a molten bead (MB) that has been formed on the base material. The cooling unit (30) is provided separately to the melt heating unit to cool the molten bead in the previous layer.

Description

積層造形装置および積層造形物の製造方法Laminated modeling equipment and manufacturing method of laminated modeled products
　この開示は、積層造形装置および積層造形物の製造方法に関する。 This disclosure relates to a laminated modeling device and a method for manufacturing a laminated model.
　生産数が少なく、複雑な形状の製品を生産する手段として、３Ｄプリンタのニーズが高まっており、特に、金属材料を造形する３Ｄプリンタの研究開発が盛んに行われている。金属材料を造形する３Ｄプリンタでは、レーザ、アークまたは電子ビームを熱源として金属粉体または金属ワイヤを溶融・凝固させ、溶融金属を積層し造形物を製造する。 The need for 3D printers is increasing as a means of producing products with a small number of production and complicated shapes, and in particular, research and development of 3D printers for modeling metal materials is being actively carried out. In a 3D printer for molding a metal material, a laser, an arc, or an electron beam is used as a heat source to melt and solidify a metal powder or a metal wire, and the molten metal is laminated to manufacture a shaped object.
　アークを用いた３Ｄプリンタでは、レーザを用いたものに比べ装置が安価であり、入熱量が多い。しかし、入熱量が多いため、冷却時間が短いと積層時の蓄熱により、溶融金属が垂れてしまい安定した造形ができないことがある。そこで、特許文献１は、溶融ビードの温度を観察し、前層の溶融ビードの温度が許容されるパス間温度以下になった際に、次層の溶融ビードを造形する積層造形物の製造方法を開示する。 A 3D printer using an arc is cheaper than a printer using a laser and has a large amount of heat input. However, since the amount of heat input is large, if the cooling time is short, the molten metal may hang down due to heat storage during lamination, and stable modeling may not be possible. Therefore, Patent Document 1 is a method for manufacturing a laminated model in which the temperature of the molten bead of the previous layer is observed, and when the temperature of the molten bead of the previous layer becomes equal to or lower than the allowable interpass temperature, the molten bead of the next layer is formed. To disclose.
特開２０１８－１６２５００号公報Japanese Unexamined Patent Publication No. 2018-162,500
　しかしながら、前述した特許文献１に開示された積層造形物の製造方法では、積層造形物の形状、大きさによって、冷却に時間がかかる場合があり、造形効率が劣るという問題がある。また、短い時間で製造するために、前層の溶融ビードの温度が下がらない状態で次層の溶融ビードを造形した場合、造形が安定しない虞がある。 However, the method for manufacturing a laminated model disclosed in Patent Document 1 described above has a problem that cooling may take time depending on the shape and size of the laminated model, resulting in inferior modeling efficiency. Further, in order to manufacture in a short time, if the molten bead of the next layer is molded in a state where the temperature of the molten bead of the previous layer does not decrease, the molding may not be stable.
　本開示は、上記実状に鑑みてなされたものであり、優れた造形効率を有し、安定した積層造形物を造形できる積層造形装置および積層造形物の製造方法を提供することを目的とする。 The present disclosure has been made in view of the above-mentioned actual conditions, and an object of the present disclosure is to provide a laminated modeling apparatus and a method for manufacturing a laminated model, which have excellent modeling efficiency and can form a stable laminated model.
　上記目的を達成するため、本開示に係る積層造形装置は、積層造形物を形成する基材または基材に形成された前層の溶融ビードに新たな溶融ビードを形成し、溶融ビードを複数層積層する溶融加熱部と、溶融加熱部とは別に設けられ、前層の溶融ビードを冷却する冷却部と、を備える。 In order to achieve the above object, the laminated molding apparatus according to the present disclosure forms a new molten bead on the base material forming the laminated model or the molten bead of the front layer formed on the base material, and forms a plurality of molten beads. It is provided with a melt heating unit to be laminated and a cooling unit provided separately from the melt heating unit to cool the molten bead of the front layer.
　本開示によれば、前層の溶融ビードを冷却することにより、優れた造形効率を有し、安定した積層造形物を造形することができる。 According to the present disclosure, by cooling the molten bead in the front layer, it is possible to form a stable laminated model having excellent modeling efficiency.
本開示の実施の形態に係る積層造形装置を示す図The figure which shows the laminated modeling apparatus which concerns on embodiment of this disclosure. 本開示の実施の形態に係る積層造形装置を示すブロック図A block diagram showing a laminated modeling apparatus according to an embodiment of the present disclosure. 本開示の実施の形態に係る積層造形物の一例を示す図The figure which shows an example of the laminated model | structure which concerns on embodiment of this disclosure. 本開示の実施の形態に係るアークトーチ、予備加熱部および冷却部を示す側面図Side view showing an arc torch, a preheating part and a cooling part according to the embodiment of the present disclosure. 本開示の実施の形態に係るアークトーチ、予備加熱部および冷却部を示す正面図Front view showing an arc torch, a preheating part and a cooling part according to the embodiment of the present disclosure. 本開示の実施の形態に係る積層造形物を複数の層に分割した各層の形状を示す図The figure which shows the shape of each layer which divided the laminated model | structure which concerns on embodiment of this disclosure into a plurality of layers. 本開示の実施の形態に係る積層造形処理を示すフローチャートA flowchart showing a laminated modeling process according to an embodiment of the present disclosure. 本開示の実施の形態に係る積層造形処理を示すフローチャートA flowchart showing a laminated modeling process according to an embodiment of the present disclosure. 本開示の実施の形態に係るベース板を示す図The figure which shows the base plate which concerns on embodiment of this disclosure. 本開示の実施の形態に係る積層造形処理を示すフローチャートA flowchart showing a laminated modeling process according to an embodiment of the present disclosure. 本開示の実施の形態に係る積層造形物の製造方法を説明する図The figure explaining the manufacturing method of the laminated molded article which concerns on embodiment of this disclosure. 本開示の実施の形態に係る積層造形物の製造方法を説明する図The figure explaining the manufacturing method of the laminated molded article which concerns on embodiment of this disclosure. 本開示の実施の形態に係る積層造形装置により形成された溶融ビードの拡大断面図Enlarged sectional view of the molten bead formed by the laminated molding apparatus according to the embodiment of the present disclosure. 本開示の実施の形態に係る積層造形装置により形成された溶融ビードの拡大断面図Enlarged sectional view of the molten bead formed by the laminated molding apparatus according to the embodiment of the present disclosure. 比較例に係る積層造形装置により形成された溶融ビードの拡大断面図Enlarged sectional view of the molten bead formed by the laminated molding apparatus according to the comparative example. 比較例に係る積層造形装置により形成された溶融ビードの拡大断面図Enlarged sectional view of the molten bead formed by the laminated molding apparatus according to the comparative example. 比較例に係る積層造形装置により形成された溶融ビードの拡大断面図Enlarged sectional view of the molten bead formed by the laminated molding apparatus according to the comparative example.
　以下、本開示の実施の形態に係る積層造形装置および積層造形物の製造方法について説明する。 Hereinafter, the laminated modeling apparatus and the manufacturing method of the laminated model according to the embodiment of the present disclosure will be described.
　本実施の形態に係る積層造形装置１００は、図１および図２に示すように、溶融ビードＭＢを形成するアークトーチ１０と、ベース板ＢＰを予備加熱する予備加熱部２０と、アークトーチ１０とは別に設けられ、溶融ビードＭＢを冷却する冷却部３０と、ベース板ＢＰおよび溶融ビードＭＢの温度を測定する温度センサ４０と、アークトーチ１０を移動するロボット部５０と、ベース板ＢＰが裁置される基台６０と、温度センサ４０により計測された温度に基づいて、アークトーチ１０、予備加熱部２０および冷却部３０を制御する制御部７０と、を備える。積層造形装置１００は、ベース板ＢＰに溶融ビードＭＢを積層して積層造形物ＬＭを製造するものである。積層造形物ＬＭの一例を図３に示す。この積層造形物ＬＭは、中空の筒状の形状を有する。また、ベース板ＢＰは、基材の一例である。 As shown in FIGS. 1 and 2, the laminated molding apparatus 100 according to the present embodiment includes an arc torch 10 for forming a molten bead MB, a preheating unit 20 for preheating the base plate BP, and an arc torch 10. Is separately provided, and a cooling unit 30 for cooling the molten bead MB, a temperature sensor 40 for measuring the temperature of the base plate BP and the molten bead MB, a robot unit 50 for moving the arc torch 10, and a base plate BP are placed. The base 60 is provided, and a control unit 70 that controls the arc torch 10, the preheating unit 20, and the cooling unit 30 based on the temperature measured by the temperature sensor 40. The laminated modeling apparatus 100 manufactures a laminated model LM by laminating a molten bead MB on a base plate BP. An example of the laminated model LM is shown in FIG. This laminated model LM has a hollow tubular shape. The base plate BP is an example of a base material.
　理解を容易にするために、相互に直交するｘｙｚ座標を設定し、適宜参照する。基台６０におけるベース板ＢＰが裁置される面をｘｙ平面、ｘｙ平面に垂直な方向をｚ方向、と設定する。なお、ｘｙ平面は、水平に配置され、ｚ方向は、垂直方向に配置される。 To facilitate understanding, set xyz coordinates that are orthogonal to each other and refer to them as appropriate. The plane on which the base plate BP is placed on the base 60 is set as the xy plane, and the direction perpendicular to the xy plane is set as the z direction. The xy plane is arranged horizontally, and the z direction is arranged in the vertical direction.
　アークトーチ１０は、図４に示すように、シールドガスが供給される筒状のシールドノズルと、シールドノズルの内部に配置されたコンタクトチップ１１と、造形材Ｗを供給する造形材供給部と、を備える。アークトーチ１０は、制御部７０の制御により、造形材Ｗを送給しつつ、シールドガスを流しながらアークを発生させて造形材Ｗを溶融及び固化し、ベース板ＢＰ上に溶融ビードＭＢを積層して積層造形物ＬＭを形成する。アークトーチ１０の入熱条件は、一定であるとする。造形材Ｗは、インコネル（登録商標）、ステンレス鋼、アルミニウム合金およびマグネシウム合金を含む金属材料から選択されるワイヤである。なお、インコネルは、ニッケルをベースとし、鉄、クロム、ニオブ、モリブデンのうち１または複数を添加した超合金である。アークトーチ１０は、予備加熱されたベース板ＢＰまたはベース板ＢＰに形成された前層の溶融ビードＭＢに新たな溶融ビードＭＢを形成する溶融加熱部の一例である。 As shown in FIG. 4, the arc torch 10 includes a tubular shield nozzle to which a shield gas is supplied, a contact tip 11 arranged inside the shield nozzle, and a modeling material supply unit for supplying the modeling material W. To be equipped. Under the control of the control unit 70, the arc torch 10 generates an arc while flowing a shield gas while supplying the modeling material W to melt and solidify the modeling material W, and the molten bead MB is laminated on the base plate BP. To form a laminated model LM. It is assumed that the heat input condition of the arc torch 10 is constant. The shaping material W is a wire selected from metal materials including Inconel®, stainless steel, aluminum alloys and magnesium alloys. Inconel is a superalloy based on nickel and to which one or more of iron, chromium, niobium and molybdenum are added. The arc torch 10 is an example of a melt heating unit that forms a new molten bead MB on the preheated base plate BP or the molten bead MB of the front layer formed on the base plate BP.
　予備加熱部２０は、積層造形物ＬＭを形成するベース板ＢＰおよびベース板ＢＰに形成された前層の溶融ビードＭＢを予備加熱するものであり、レーザ発振器と、レーザ発振器で発振されたレーザを伝送するミラーまたは光ファイバと、伝送されたレーザを集光する集光レンズを含む光学系と、を有するレーザ装置を備える。レーザ発振器は、コアに希土類を添加した光ファイバに励起光を照射してレーザ発振する発信器を用いてもよく、ＹＡＧ結晶を用いた発信器を用いてもよい。また、レーザ装置は、エキシマレーザまたはＣＯ２レーザを照射するものであってもよい。予備加熱部２０は、レーザをベース板ＢＰにおける新たな溶融ビードＭＢを形成する形成予定位置Ｐに照射し、形成予定位置Ｐを予備加熱する。形成予定位置Ｐは、溶融ビードＭＢを形成する直下、およびアークトーチ１０が相対的に移動する造形方向Ｄ１における前方の位置を含む。しかしながら、予備加熱する位置が溶融ビードＭＢの形成部ＭＢ１から離れすぎると、予備加熱した部分の温度が低下し、予備加熱の効果が小さくなってしまう。そのため、予備加熱部２０は溶融ビードＭＢの形成部ＭＢ１の直上、もしくは、溶融ビードＭＢの造形方向Ｄ１において、アークトーチ１０より前方に配置されることが好ましい。また、予備加熱部２０は、アークトーチ１０が相対的に移動する造形方向Ｄ１における前方で、０．７秒以下で溶融ビードＭＢを形成できる形成予定位置Ｐを予備加熱することが望ましい。造形する際のアークトーチ１０が移動する速度は、５０～１５０ｃｍ／ｍｉｎであることが多いため、予備加熱してから０．７秒以下で溶融ビードＭＢを形成すれば、予備加熱した部分の温度低下を十分に抑制することができる。 The preheating unit 20 preheats the base plate BP forming the laminated model LM and the molten bead MB of the front layer formed on the base plate BP, and heats the laser oscillator and the laser oscillated by the laser oscillator. A laser apparatus comprising a mirror or optical fiber for transmission and an optical system including a condensing lens for condensing the transmitted laser. As the laser oscillator, a transmitter that oscillates a laser by irradiating an optical fiber having a rare earth element added to the core with excitation light may be used, or a transmitter using a YAG crystal may be used. Further, the laser device may be one that irradiates an excimer laser or a CO 2 laser. The preheating unit 20 irradiates the laser at the planned formation position P on the base plate BP to form a new molten bead MB, and preheats the planned formation position P. The planned formation position P includes a position immediately below forming the molten bead MB and a front position in the modeling direction D1 in which the arc torch 10 relatively moves. However, if the preheating position is too far from the forming portion MB1 of the molten bead MB, the temperature of the preheated portion is lowered, and the effect of the preheating is reduced. Therefore, it is preferable that the preheating portion 20 is arranged directly above the forming portion MB1 of the molten bead MB or in front of the arc torch 10 in the molding direction D1 of the molten bead MB. Further, it is desirable that the preheating unit 20 preheats the planned formation position P in which the molten bead MB can be formed in 0.7 seconds or less in front of the molding direction D1 in which the arc torch 10 relatively moves. Since the speed at which the arc torch 10 moves during modeling is often 50 to 150 cm / min, if the molten bead MB is formed within 0.7 seconds after preheating, the temperature of the preheated portion is reached. The decrease can be sufficiently suppressed.
　予備加熱部２０は、レーザにより、ベース板ＢＰをピンポイントで加熱でき、ベース板ＢＰの予熱を最小限に抑えることが可能なため、積層造形後の熱影響が小さくなり、積層造形物ＬＭの熱変形および結晶粒の粗大化を抑えることも可能である。予備加熱部２０が、レーザを照射することにより、陰極点がアーク近傍に形成され、アークが安定するというメリットも挙げられる。また、予熱量が多くなりすぎると、溶融ビードＭＢの幅が大きくなってしまうため、予熱量は一定の範囲に収めることが望ましい。このため、予備加熱部２０は、第１の基準値以上、第１の基準値より大きい第２の基準値以下の予熱温度にベース板ＭＢを加熱する。第１の基準値および第２の基準値は、ベース板ＭＢと造形材Ｗの材質の組み合わせにより決定される。ベース板ＭＢと造形材Ｗとが異なる場合において、予備加熱部２０は、ベース板ＭＢの溶融温度が造形材Ｗの溶融温度より高いことが望ましい。このようにすることで、ベース板ＭＢに安定して積層造形物ＬＭを形成できる。また、予備加熱部２０は、第１層Ｌ１の造形時に、ベース板ＭＢの溶融温度と造形材Ｗの溶融温度との差より高い温度で、ベース板ＭＢを予備加熱するとよい。例えば、ベース板ＭＢにステンレス鋼、造形材Ｗにインコネルを使用する場合、第１の基準値を１５０℃、第２の基準値を３５０℃に設定すると、安定した溶融ビードＭＢを形成するのに有効である。また、予備加熱部２０は、前層の溶融ビードＭＢの温度が下がった場合、前層の溶融ビードＭＢを第３の基準値以上、第３の基準値より大きい第４の基準値以下の温度に予備加熱する。第３の基準値および第４の基準値は、アークトーチ１０により、造形材Ｗを溶融して形成された新たな溶融ビードＭＢが垂れ落ちず、安定して新たな溶融ビードＭＢが形成される温度に決定される。また、熱伝導の高いアルミニウム合金または銅合金を予備加熱することは、内部欠陥の抑制に有効である。熱伝導の高い金属の場合、溶融した金属が凝固するのが速いため、予備加熱しない場合、溶融ビードＭＢの内部の空隙に入った空気またはシールドガスが溶融した金属から抜ける前に凝固してしまう。そのため、予備加熱することで、溶融した金属の凝固を遅らせることができ、内部欠陥の抑制に繋がる。アルミニウム合金、銅合金共に、１００℃以上に予備加熱することが望ましい。 Since the preheating unit 20 can heat the base plate BP pinpointly by the laser and can minimize the preheating of the base plate BP, the heat effect after the laminated molding is reduced, and the laminated model LM It is also possible to suppress thermal deformation and coarsening of crystal grains. By irradiating the preheating unit 20 with a laser, a cathode point is formed in the vicinity of the arc, and there is also an advantage that the arc is stabilized. Further, if the preheating amount becomes too large, the width of the molten bead MB becomes large, so it is desirable to keep the preheating amount within a certain range. Therefore, the preheating unit 20 heats the base plate MB to a preheating temperature equal to or higher than the first reference value and equal to or lower than the second reference value, which is larger than the first reference value. The first reference value and the second reference value are determined by the combination of the materials of the base plate MB and the modeling material W. When the base plate MB and the modeling material W are different, it is desirable that the melting temperature of the base plate MB of the preheating unit 20 is higher than the melting temperature of the modeling material W. By doing so, the laminated model LM can be stably formed on the base plate MB. Further, the preheating unit 20 may preheat the base plate MB at a temperature higher than the difference between the melting temperature of the base plate MB and the melting temperature of the modeling material W at the time of modeling the first layer L1. For example, when stainless steel is used for the base plate MB and Inconel is used for the modeling material W, if the first reference value is set to 150 ° C and the second reference value is set to 350 ° C, a stable molten bead MB can be formed. It is valid. Further, when the temperature of the molten bead MB in the front layer is lowered, the preheating unit 20 sets the temperature of the molten bead MB in the front layer to be equal to or higher than the third reference value and equal to or lower than the fourth reference value to be greater than the third reference value. Preheat to. As for the third reference value and the fourth reference value, the arc torch 10 does not allow the new molten bead MB formed by melting the modeling material W to hang down, and a new molten bead MB is stably formed. Determined by temperature. Further, preheating an aluminum alloy or a copper alloy having high thermal conductivity is effective in suppressing internal defects. In the case of a metal with high thermal conductivity, the molten metal solidifies quickly, so if it is not preheated, the air or shield gas that has entered the voids inside the molten bead MB will solidify before it escapes from the molten metal. .. Therefore, by preheating, the solidification of the molten metal can be delayed, which leads to the suppression of internal defects. It is desirable to preheat both the aluminum alloy and the copper alloy to 100 ° C. or higher.
　冷却部３０は、アークトーチ１０により形成された前層の溶融ビードＭＢに冷媒を吹き付けて冷却するものであり、冷媒流路を有するノズルと、冷媒の流量を制御するレギュレータと、を有する。詳細には、冷却部３０は、前層の溶融ビードＭＢに次層の溶融ビードＭＢを形成する形成予定位置Ｐを第３の基準値以上、第３の基準値より大きい第４の基準値以下の温度に冷却する。また、冷却部３０は、図５に示すように、溶融ビードＭＢの造形方向Ｄ１から見て、積層造形物ＬＭの積層方向に対し、角度をつけて冷媒を吹き付けることが望ましい。積層造形物ＬＭの積層方向と平行の向きに冷媒を吹き付ける場合、積層造形物ＬＭの上面のみが集中して冷却される。しかし、金属造形物の場合、造形した部分がベース板ＢＰに比べて熱容量が小さいため、造形している部分に熱が溜まりやすい。そのため、造形した部分を側面から大きい面積で冷却することで、効率的に冷却が可能である。また、冷却部３０に角度を設けることで、積層造形物ＬＭと干渉しにくくなる。積層造形物ＬＭの積層方向Ｄ２と、冷却部３０から冷媒を吹き付ける方向Ｄ３と、の為す狭角θは、２０°以上７０°以下であることが望ましい。狭角θが２０°未満の場合、冷却効率が悪くなり、狭角θが７０°より大きい角度になると、シールドガスが乱れ、安定した造形が難しくなる。アークトーチ１０は、冷却部３０と一体となっているが、別々で設置しても良いし、溶融ビードＭＢの両サイドに複数の冷却部を設けても良い。 The cooling unit 30 cools the molten bead MB in the front layer formed by the arc torch 10 by blowing a refrigerant, and has a nozzle having a refrigerant flow path and a regulator for controlling the flow rate of the refrigerant. Specifically, the cooling unit 30 sets the planned formation position P for forming the molten bead MB of the next layer on the molten bead MB of the previous layer to be equal to or greater than the third reference value and greater than or equal to the third reference value to be less than or equal to the fourth reference value. Cool to the temperature of. Further, as shown in FIG. 5, it is desirable that the cooling unit 30 sprays the refrigerant at an angle with respect to the stacking direction of the laminated model LM when viewed from the molding direction D1 of the molten bead MB. When the refrigerant is sprayed in a direction parallel to the stacking direction of the laminated model LM, only the upper surface of the laminated model LM is concentrated and cooled. However, in the case of a metal model, the heat capacity of the modeled portion is smaller than that of the base plate BP, so that heat tends to be accumulated in the modeled portion. Therefore, efficient cooling is possible by cooling the molded portion with a large area from the side surface. Further, by providing the cooling portion 30 at an angle, it becomes difficult to interfere with the laminated model LM. It is desirable that the narrow angle θ formed by the stacking direction D2 of the laminated model LM and the direction D3 of blowing the refrigerant from the cooling unit 30 is 20 ° or more and 70 ° or less. If the narrow angle θ is less than 20 °, the cooling efficiency deteriorates, and if the narrow angle θ is larger than 70 °, the shield gas is disturbed and stable modeling becomes difficult. Although the arc torch 10 is integrated with the cooling unit 30, it may be installed separately, or a plurality of cooling units may be provided on both sides of the molten bead MB.
　冷媒は、造形材Ｗに応じて選択され、液体窒素または冷却ガスが用いられる。冷却部３０から吹き付けられた冷媒によって、アークトーチ１０のシールドガスに影響を与え不安定になると、溶融ビードＭＢに欠陥が生じる虞があるため、好ましくは、アークトーチ１０から離れた位置に設置する。シールドガスと冷却部３０から供給する冷媒の流量が同一の場合、冷却部３０は、図４に示すように、溶融ビードＭＢの造形方向Ｄ１において、アークトーチ１０から後方に設置されることが望ましく、アークトーチ１０のコンタクトチップ１１と造形部ＭＢ１の距離の３倍以上離れた位置に設置することがより望ましい。そうすることにより、シールドガスの方が冷媒より流れが速くなり、溶融ビードＭＢのシールド性を確保できる。また、シールドガスに冷媒が直接当たらない位置に冷却部３０を配置すると、シールド性が悪化しにくいため、冷媒の流量を上げることが可能である。冷媒には、アルゴンガスまたは窒素ガスを含む不活性ガスを使用することが好ましい。上記のような工夫により、シールド性の悪化を抑制できるが、造形物の形状などにより、冷媒がシールド性を妨げる可能性がある。そのため、冷媒に不活性ガスを使用することで、溶融ビードＭＢの酸化を抑制できる。 The refrigerant is selected according to the modeling material W, and liquid nitrogen or cooling gas is used. If the refrigerant sprayed from the cooling unit 30 affects the shield gas of the arc torch 10 and becomes unstable, the molten bead MB may be defective. Therefore, it is preferably installed at a position away from the arc torch 10. .. When the flow rates of the shield gas and the refrigerant supplied from the cooling unit 30 are the same, it is desirable that the cooling unit 30 is installed behind the arc torch 10 in the forming direction D1 of the molten bead MB as shown in FIG. , It is more desirable to install the arc torch 10 at a position separated by 3 times or more the distance between the contact tip 11 and the modeling portion MB1. By doing so, the flow of the shield gas is faster than that of the refrigerant, and the shielding property of the molten bead MB can be ensured. Further, if the cooling unit 30 is arranged at a position where the refrigerant does not directly hit the shield gas, the shielding property is less likely to deteriorate, so that the flow rate of the refrigerant can be increased. As the refrigerant, it is preferable to use an inert gas containing argon gas or nitrogen gas. Deterioration of the shielding property can be suppressed by the above-mentioned measures, but the refrigerant may hinder the shielding property depending on the shape of the modeled object or the like. Therefore, by using an inert gas as the refrigerant, oxidation of the molten bead MB can be suppressed.
　図１および図２に戻って、温度センサ４０は、ベース板ＢＰにおける形成予定位置Ｐおよび前層の溶融ビードＭＢに次層の溶融ビードＭＢを形成する形成予定位置Ｐの温度を計測するものである。温度センサ４０は、ベース板ＢＰおよび溶融ビードＭＢの温度を測定可能なものであればよく、接触式センサ、サーモグラフィー（Thermography）、赤外線温度センサなどを用いることができる。積層された溶融ビードＭＢは高温であることから、好ましくは、サーモグラフィー、赤外線温度センサなどの非接触式のセンサを用いる。サーモグラフィーを用いると、ベース板ＢＰおよびベース板ＢＰに形成された溶融ビードＭＢ全体の温度分布を計測することができるので特に好ましい。全体の温度分布を計測した場合、全体の温度分布から形成予定位置Ｐの温度を抽出する。 Returning to FIGS. 1 and 2, the temperature sensor 40 measures the temperature of the planned formation position P on the base plate BP and the planned formation position P for forming the molten bead MB of the next layer on the molten bead MB of the previous layer. is there. The temperature sensor 40 may be any as long as it can measure the temperature of the base plate BP and the molten bead MB, and a contact sensor, a thermography, an infrared temperature sensor, or the like can be used. Since the laminated molten bead MB has a high temperature, a non-contact type sensor such as a thermography or an infrared temperature sensor is preferably used. Thermography is particularly preferable because it is possible to measure the temperature distribution of the entire base plate BP and the molten bead MB formed on the base plate BP. When the overall temperature distribution is measured, the temperature at the planned formation position P is extracted from the overall temperature distribution.
　ロボット部５０は、多関節ロボットであり、制御部７０の制御により、アークトーチ１０、予備加熱部２０および冷却部３０を、ｘ方向、ｙ方向およびｚ方向に移動するものである。ロボット部５０は、アークトーチ１０、予備加熱部２０および冷却部３０を３次元的に移動可能であり、アークトーチ１０の姿勢及び位置を制御部７０により制御されることにより、アークトーチ１０を任意の姿勢で、任意の位置に移動することができる。 The robot unit 50 is an articulated robot, and under the control of the control unit 70, the arc torch 10, the preheating unit 20, and the cooling unit 30 are moved in the x, y, and z directions. The robot unit 50 can move the arc torch 10, the preheating unit 20, and the cooling unit 30 three-dimensionally, and the posture and position of the arc torch 10 are controlled by the control unit 70, so that the arc torch 10 can be arbitrarily moved. You can move to any position with the posture of.
　基台６０は、ターンテーブルを備え、ｚ方向に延びる回転軸ＡＸを中心に裁置されベース板ＢＰを回転するものである。これにより、筒状の形状を有す積層造形物ＬＭを容易に造形することができる。 The base 60 is provided with a turntable and is placed around a rotation axis AX extending in the z direction to rotate the base plate BP. As a result, the laminated model LM having a tubular shape can be easily modeled.
　制御部７０は、プログラムを実行するＣＰＵ（Central Processing Unit）７１と、プログラムを記憶するＲＯＭ（Read Only Memory）７２と、プログラムを実行するための作業領域として用いられるＲＡＭ（Random Access Memory）７３と、を有し、ＲＯＭ７２に記憶したプログラムを実行することにより、温度センサ４０により測定された温度に基づいて、アークトーチ１０、予備加熱部２０、冷却部３０およびロボット部５０を制御する。ＲＯＭ７２は、ベース板ＢＰと造形材Ｗの材質の組み合わせ毎に、予備加熱部２０により予備加熱される温度の基準値である第１の基準値および第２の基準値を示すデータ、および造形材Ｗの材質毎に、冷却部３０により溶融ビードＭＢが冷却される温度の基準値である第３の基準値および第４の基準値を示すデータを記憶する。 The control unit 70 includes a CPU (Central Processing Unit) 71 that executes a program, a ROM (Read Only Memory) 72 that stores the program, and a RAM (Random Access Memory) 73 that is used as a work area for executing the program. The arc torch 10, the preheating unit 20, the cooling unit 30, and the robot unit 50 are controlled based on the temperature measured by the temperature sensor 40 by executing the program stored in the ROM 72. The ROM 72 contains data indicating a first reference value and a second reference value, which are reference values of the temperature preheated by the preheating unit 20, for each combination of the materials of the base plate BP and the modeling material W, and the modeling material. For each material of W, data showing a third reference value and a fourth reference value, which are reference values of the temperature at which the molten bead MB is cooled by the cooling unit 30, is stored.
　制御部７０は、形成予定の積層造形物ＬＭの形状データを取得し、図６に示すように、積層造形物ＬＭを複数の層に分割した各層の形状を表す第１層Ｌ１、第２層Ｌ２、・・・第ｎ層Ｌｎ・・・第ｋ－１層Ｌｋ－１、第ｋ層Ｌｋの層形状データを生成する。また、制御部７０は、各層形状データに基づいてアークトーチ１０のコンタクトチップ１１の位置データを生成する。位置データは、各第ｎ層毎に高さＨｎを示すデータと回転軸ＡＸからの距離Ｒｎを示すデータを含む。生成された層形状データおよび位置データは、ＲＡＭ７３に格納される。また、制御部７０は、ベース板ＢＰの材質データおよび造形材Ｗの材質データを取得し、ベース板ＢＰの材質データおよび造形材Ｗの材質データに基づいて、予備加熱部２０によりベース板ＢＰが予備加熱される温度の基準値である第１の基準値および第２の基準値を決定する。また、制御部７０は、造形材Ｗの材質データに基づいて、冷却部３０により溶融ビードＭＢが冷却される温度の基準値である第３の基準値および第４の基準値を決定する。 The control unit 70 acquires the shape data of the laminated model LM to be formed, and as shown in FIG. 6, the control unit 70 divides the laminated model LM into a plurality of layers and represents the shape of each layer, the first layer L1 and the second layer. L2, ... nth layer Ln ... Generates layer shape data of the k-1th layer Lk-1 and the kth layer Lk. Further, the control unit 70 generates position data of the contact tip 11 of the arc torch 10 based on each layer shape data. The position data includes data indicating the height Hn and data indicating the distance Rn from the rotation axis AX for each nth layer. The generated layer shape data and position data are stored in the RAM 73. Further, the control unit 70 acquires the material data of the base plate BP and the material data of the modeling material W, and based on the material data of the base plate BP and the material data of the modeling material W, the preheating unit 20 causes the base plate BP to move. The first reference value and the second reference value, which are the reference values of the temperature to be preheated, are determined. Further, the control unit 70 determines a third reference value and a fourth reference value, which are reference values of the temperature at which the molten bead MB is cooled by the cooling unit 30, based on the material data of the modeling material W.
　また、制御部７０は、第１層Ｌ１の溶融ビードＭＢを形成する場合、温度センサ４０により測定されたベース板ＢＰにおける形成予定位置Ｐの温度のデータを取得する。つぎに、制御部７０は、測定した温度が第１の基準値以上でないと判定すると、予備加熱部２０を制御して、ベース板ＢＰにおける形成予定位置Ｐを予備加熱する。制御部７０は、測定した温度が第２の基準値以下でないと判定すると、冷却部３０を制御して、ベース板ＢＰに冷媒を吹き付けて冷却する。制御部７０は、測定した温度が第１の基準値以上第２の基準値以下であると判定すると、アークトーチ１０および基台６０を制御して、第１層Ｌ１の形成予定位置Ｐに溶融ビードＭＢを形成する。 Further, when forming the molten bead MB of the first layer L1, the control unit 70 acquires the temperature data of the planned formation position P on the base plate BP measured by the temperature sensor 40. Next, when the control unit 70 determines that the measured temperature is not equal to or higher than the first reference value, the control unit 70 controls the preheating unit 20 to preheat the planned formation position P on the base plate BP. When the control unit 70 determines that the measured temperature is not equal to or lower than the second reference value, the control unit 70 controls the cooling unit 30 to blow the refrigerant onto the base plate BP to cool the base plate BP. When the control unit 70 determines that the measured temperature is equal to or higher than the first reference value and is equal to or lower than the second reference value, the control unit 70 controls the arc torch 10 and the base 60 to melt at the planned formation position P of the first layer L1. Form a bead MB.
　つぎに、制御部７０は、第ｎ層Ｌｎの溶融ビードＭＢを形成する場合、温度センサ４０により測定された第ｎ－１層Ｌｎ－１の溶融ビードＭＢにおける形成予定位置Ｐの温度のデータを取得する。つぎに、制御部７０は、測定した温度が第３の基準値以上でないと判定すると、予備加熱部２０を制御して、第ｎ－１層Ｌｎ－１の溶融ビードＭＢにおける形成予定位置Ｐを予備加熱する。制御部７０は、測定した温度が第４の基準値以下でないと判定すると、冷却部３０を制御して、溶融ビードＭＢに冷媒を吹き付けて冷却する。制御部７０は、測定した温度が第３の基準値以上第４の基準値以下であると判定すると、アークトーチ１０および基台６０を制御して、第ｎ層Ｌｎの形成予定位置Ｐに溶融ビードＭＢを形成する。 Next, when the control unit 70 forms the molten bead MB of the nth layer Ln, the control unit 70 obtains the temperature data of the planned formation position P in the molten bead MB of the n-1th layer Ln-1 measured by the temperature sensor 40. get. Next, when the control unit 70 determines that the measured temperature is not equal to or higher than the third reference value, the control unit 70 controls the preheating unit 20 to set the planned formation position P of the n-1 layer Ln-1 in the molten bead MB. Preheat. When the control unit 70 determines that the measured temperature is not equal to or lower than the fourth reference value, the control unit 70 controls the cooling unit 30 to blow the refrigerant onto the molten bead MB to cool the molten bead MB. When the control unit 70 determines that the measured temperature is equal to or higher than the third reference value and equal to or lower than the fourth reference value, the control unit 70 controls the arc torch 10 and the base 60 to melt at the planned formation position P of the nth layer Ln. Form a bead MB.
　つぎに、以上の構成を有する積層造形装置１００が、図３に示す積層造形物ＬＭを積層造形する例について、積層造形装置１００が実行する積層造形処理を説明する。 Next, the laminated modeling process executed by the laminated modeling device 100 will be described with respect to an example in which the laminated modeling device 100 having the above configuration performs the laminated modeling of the laminated model LM shown in FIG.
　積層造形装置１００は、ユーザによる処理を開始させる指示に応答し、図７に示す積層造形処理を開始する。以下、積層造形装置１００が実行する積層造形処理をフローチャートを用いて説明する。 The laminated modeling apparatus 100 starts the laminated modeling process shown in FIG. 7 in response to an instruction from the user to start the process. Hereinafter, the laminated modeling process executed by the laminated modeling apparatus 100 will be described with reference to a flowchart.
　積層造形処理が開始されると、積層造形装置１００の制御部７０は、積層造形物ＬＭの形状データを取得し、ＲＡＭ７３に格納する（ステップＳ１０１）。つぎに、制御部７０は、図６に示す積層造形物ＬＭを複数の層に分割した各層の形状を表す第１層Ｌ１、第２層Ｌ２、・・・第ｎ層Ｌｎ・・・第ｋ－１層Ｌｋ－１、第ｋ層Ｌｋの層形状データを生成し、各層形状データに基づいてアークトーチ１０の位置データを生成する（ステップＳ１０２）。生成された層形状データおよび位置データは、ＲＡＭ７３に格納される。 When the laminated modeling process is started, the control unit 70 of the laminated modeling device 100 acquires the shape data of the laminated model LM and stores it in the RAM 73 (step S101). Next, the control unit 70 describes the first layer L1, the second layer L2, ... The nth layer Ln ... The kth, which represents the shape of each layer obtained by dividing the laminated model LM shown in FIG. 6 into a plurality of layers. The layer shape data of the -1 layer Lk-1 and the kth layer Lk are generated, and the position data of the arc torch 10 is generated based on each layer shape data (step S102). The generated layer shape data and position data are stored in the RAM 73.
　つぎに、制御部７０は、造形材Ｗおよびベース板ＢＰの材質データを取得し、ＲＡＭ７３に格納する（ステップＳ１０３）。つぎに、制御部７０は、ベース板ＢＰの材質データおよび造形材Ｗの材質データに基づいて、予備加熱部２０によりベース板ＢＰが予備加熱される温度の基準値である第１の基準値および第２の基準値を決定する（ステップＳ１０４）。ベース板ＢＰにステンレス鋼、造形材Ｗにインコネルを使用する場合、第１の基準値を１５０℃、第２の基準値を３５０℃に設定する。つぎに、制御部７０は、造形材Ｗの材質データに基づいて、冷却部３０により溶融ビードＭＢが冷却される温度の基準値である第３の基準値および第４の基準値を決定する（ステップＳ１０５）。 Next, the control unit 70 acquires the material data of the modeling material W and the base plate BP and stores them in the RAM 73 (step S103). Next, the control unit 70 has a first reference value which is a reference value of the temperature at which the base plate BP is preheated by the preheating unit 20 based on the material data of the base plate BP and the material data of the modeling material W. The second reference value is determined (step S104). When stainless steel is used for the base plate BP and Inconel is used for the modeling material W, the first reference value is set to 150 ° C. and the second reference value is set to 350 ° C. Next, the control unit 70 determines a third reference value and a fourth reference value, which are reference values of the temperature at which the molten bead MB is cooled by the cooling unit 30, based on the material data of the modeling material W ( Step S105).
　つぎに、制御部７０は、ベース板ＢＰに第１層Ｌ１の溶融ビードＭＢを形成する図８に示す第１層造形処理を実行する。 Next, the control unit 70 executes the first layer modeling process shown in FIG. 8 for forming the molten bead MB of the first layer L1 on the base plate BP.
　第１層造形処理が開始されると、制御部７０は、ロボット部５０を制御して、アークトーチ１０の位置データに基づいて、アークトーチ１０を形成予定位置Ｐに移動する（ステップＳ２０１）。ここでは、図９に示すように、制御部７０は、ロボット部５０を制御して、アークトーチ１０のコンタクトチップ１１をベース板ＢＰの近傍、且つ回転軸ＡＸからの距離Ｒ１に移動する。つぎに、制御部７０は、温度センサ４０により測定されたベース板ＢＰにおける形成予定位置Ｐの温度のデータを取得する（ステップＳ２０２）。つぎに、制御部７０は、測定した温度が第１の基準値以上であるか否かを判定する（ステップＳ２０３）。測定した温度が第１の基準値以上でないと判定されると（ステップＳ２０３；Ｎｏ）、制御部７０は、予備加熱部２０を制御して、ベース板ＢＰにおける形成予定位置Ｐを予備加熱する（ステップＳ２０４）。その後、ステップＳ２０２に戻る。 When the first layer modeling process is started, the control unit 70 controls the robot unit 50 and moves the arc torch 10 to the planned formation position P based on the position data of the arc torch 10 (step S201). Here, as shown in FIG. 9, the control unit 70 controls the robot unit 50 to move the contact tip 11 of the arc torch 10 in the vicinity of the base plate BP and at a distance R1 from the rotation axis AX. Next, the control unit 70 acquires the temperature data of the planned formation position P on the base plate BP measured by the temperature sensor 40 (step S202). Next, the control unit 70 determines whether or not the measured temperature is equal to or higher than the first reference value (step S203). When it is determined that the measured temperature is not equal to or higher than the first reference value (step S203; No), the control unit 70 controls the preheating unit 20 to preheat the planned formation position P on the base plate BP (step S203; No). Step S204). Then, the process returns to step S202.
　測定した温度が第１の基準値以上であると判定されると（ステップＳ２０３；Ｙｅｓ）、制御部７０は、測定した温度が第２の基準値以下であるか否かを判定する（ステップＳ２０５）。測定した温度が第２の基準値以下でないと判定されると（ステップＳ２０５；Ｎｏ）、制御部７０は、冷却部３０を制御して、ベース板ＢＰに冷媒を吹き付けて冷却する（ステップＳ２０６）。その後、ステップＳ２０２に戻る。 When it is determined that the measured temperature is equal to or higher than the first reference value (step S203; Yes), the control unit 70 determines whether or not the measured temperature is equal to or lower than the second reference value (step S205). ). When it is determined that the measured temperature is not equal to or lower than the second reference value (step S205; No), the control unit 70 controls the cooling unit 30 to blow the refrigerant onto the base plate BP to cool the base plate BP (step S206). .. Then, the process returns to step S202.
　測定した温度が第２の基準値以下であると判定されると（ステップＳ２０５；Ｙｅｓ）、制御部７０は、基台６０を制御して、ベース板ＢＰを基準角度回転する（ステップＳ２０７）。つぎに、制御部７０は、アークトーチ１０の造形材供給部を制御して、造形材Ｗを供給し、第１層Ｌ１の溶融ビードＭＢを形成する（ステップＳ２０８）。つぎに、制御部７０は、第１層Ｌ１の溶融ビードＭＢの形成が全て終了したか否かを判定する（ステップＳ２０９）。ここでは、基台６０によりベース板が３６０°回転したか否かにより判定する。終了していないと判定されると（ステップＳ２０９；Ｎｏ）、ステップＳ２０２に戻る。終了したと判定すると（ステップＳ２０９；Ｙｅｓ）、第１層造形処理を終了し、図７に示す積層造形処理に戻る（ステップＳ１０６）。 When it is determined that the measured temperature is equal to or lower than the second reference value (step S205; Yes), the control unit 70 controls the base 60 to rotate the base plate BP by a reference angle (step S207). Next, the control unit 70 controls the modeling material supply unit of the arc torch 10 to supply the modeling material W to form the molten bead MB of the first layer L1 (step S208). Next, the control unit 70 determines whether or not all the formation of the molten bead MB of the first layer L1 is completed (step S209). Here, it is determined whether or not the base plate is rotated by 360 ° by the base 60. If it is determined that the process has not been completed (step S209; No), the process returns to step S202. When it is determined that the process is completed (step S209; Yes), the first layer modeling process is completed, and the process returns to the laminated modeling process shown in FIG. 7 (step S106).
　つぎに、制御部７０は、第ｎ層Ｌｎの溶融ビードＭＢを形成する図１０に示す第ｎ層造形処理を実行する。なお、ｎは、２以上ｋ以下の自然数である。 Next, the control unit 70 executes the nth layer modeling process shown in FIG. 10 for forming the molten bead MB of the nth layer Ln. Note that n is a natural number of 2 or more and k or less.
　第ｎ層造形処理が開始されると、ｎ＝２に設定する（ステップＳ３０１）。つぎに、制御部７０は、ロボット部５０を制御して、アークトーチ１０の位置データに基づいて、アークトーチ１０を形成予定位置Ｐに移動する（ステップＳ３０２）。ここでは、図１１に示すように、制御部７０は、ロボット部５０を制御して、アークトーチ１０のコンタクトチップ１１をベース板ＢＰから高さＨ２、且つ回転軸ＡＸからの距離Ｒ２に移動する。制御部７０は、温度センサ４０により測定された第ｎ－１層Ｌｎ－１の溶融ビードＭＢにおける形成予定位置Ｐの温度のデータを取得する（ステップＳ３０３）。ここでは、ｎ＝２であるので、第１層Ｌ１の溶融ビードＭＢにおける形成予定位置Ｐの温度のデータを取得する。つぎに、制御部７０は、測定した温度が第３の基準値以上であるか否かを判定する（ステップＳ３０４）。測定した温度が第３の基準値以上でないと判定されると（ステップＳ３０４；Ｎｏ）、制御部７０は、予備加熱部２０を制御して、第１層Ｌ１の溶融ビードＭＢにおける形成予定位置Ｐを予備加熱する（ステップＳ３０５）。その後、ステップＳ３０３に戻る。 When the nth layer modeling process is started, n = 2 is set (step S301). Next, the control unit 70 controls the robot unit 50 to move the arc torch 10 to the planned formation position P based on the position data of the arc torch 10 (step S302). Here, as shown in FIG. 11, the control unit 70 controls the robot unit 50 to move the contact tip 11 of the arc torch 10 from the base plate BP to the height H2 and the distance R2 from the rotation axis AX. .. The control unit 70 acquires the temperature data of the planned formation position P in the molten bead MB of the n-1th layer Ln-1 measured by the temperature sensor 40 (step S303). Here, since n = 2, the temperature data of the planned formation position P in the molten bead MB of the first layer L1 is acquired. Next, the control unit 70 determines whether or not the measured temperature is equal to or higher than the third reference value (step S304). When it is determined that the measured temperature is not equal to or higher than the third reference value (step S304; No), the control unit 70 controls the preheating unit 20 to form the planned formation position P in the molten bead MB of the first layer L1. Is preheated (step S305). Then, the process returns to step S303.
　測定した温度が第３の基準値以上であると判定されると（ステップＳ３０４；Ｙｅｓ）、制御部７０は、測定した温度が第４の基準値以下であるか否かを判定する（ステップＳ３０６）。測定した温度が第４の基準値以下でないと判定されると（ステップＳ３０６；Ｎｏ）、制御部７０は、冷却部３０を制御して、溶融ビードＭＢに冷媒を吹き付けて冷却する（ステップＳ３０７）。その後、ステップＳ３０３に戻る。 When it is determined that the measured temperature is equal to or higher than the third reference value (step S304; Yes), the control unit 70 determines whether or not the measured temperature is equal to or lower than the fourth reference value (step S306). ). When it is determined that the measured temperature is not equal to or lower than the fourth reference value (step S306; No), the control unit 70 controls the cooling unit 30 to blow the refrigerant onto the molten bead MB to cool it (step S307). .. Then, the process returns to step S303.
　つぎに、制御部７０は、基台６０を制御して、ベース板ＢＰを基準角度回転する（ステップＳ３０８）。つぎに、制御部７０は、アークトーチ１０の造形材供給部を制御して、造形材Ｗを供給し、第２層Ｌ２の溶融ビードＭＢを形成する（ステップＳ３０９）。つぎに、制御部７０は、第ｎ層Ｌｎの溶融ビードＭＢの形成が終了したか否かを判定する（ステップＳ３１０）。ここでは、ここでは、基台６０によりベース板が３６０°回転したか否かにより、第２層Ｌ２の溶融ビードＭＢの形成が終了したか否かを判定する。終了していないと判定されると（ステップＳ３１０；Ｎｏ）、ステップＳ３０３に戻る。 Next, the control unit 70 controls the base 60 to rotate the base plate BP by a reference angle (step S308). Next, the control unit 70 controls the modeling material supply unit of the arc torch 10 to supply the modeling material W to form the molten bead MB of the second layer L2 (step S309). Next, the control unit 70 determines whether or not the formation of the molten bead MB of the nth layer Ln is completed (step S310). Here, here, it is determined whether or not the formation of the molten bead MB of the second layer L2 is completed based on whether or not the base plate is rotated by 360 ° by the base 60. If it is determined that the process has not been completed (step S310; No), the process returns to step S303.
　第ｎ層Ｌｎの溶融ビードＭＢの形成が終了したと判定すると（ステップＳ３１０；Ｙｅｓ）、全ての層の層造形処理が終了したか否かを判定する（ステップＳ３１１）。この例では、ｎ＝ｋであれば全ての層の層造形処理が終了したと判定する。制御部７０は、全ての層の層造形処理が終了していないと判定されると（ステップＳ３１１；Ｎｏ）、ｎをインクリメントし（ステップＳ３１２）、ステップＳ３０２に戻る。図１２に示すように、第ｎ－１層まで積層された状態で、ステップＳ３０２に戻ると、制御部７０は、ロボット部５０を制御して、アークトーチ１０のコンタクトチップ１１をベース板ＢＰから高さＨｎ、且つ回転軸ＡＸからの距離Ｒｎに移動し、ステップＳ３０３からステップＳ３１０を繰り返し、第ｎ層Ｌｎの溶融ビードＭＢの形成を実行する。制御部７０は、全ての層の層造形処理が終了したと判定すると（ステップＳ３１１；Ｙｅｓ）、第ｎ層造形処理を終了し、図７に示す積層造形処理に戻る（ステップＳ１０７）。その後、積層造形処理を終了する。これにより、図３に示す積層造形物ＬＭが完成する。 When it is determined that the formation of the molten bead MB of the nth layer Ln is completed (step S310; Yes), it is determined whether or not the layer forming process of all the layers is completed (step S311). In this example, if n = k, it is determined that the layer shaping process for all layers has been completed. When it is determined that the layer forming process of all the layers has not been completed (step S311; No), the control unit 70 increments n (step S312) and returns to step S302. As shown in FIG. 12, when returning to step S302 in a state where the n-1th layer is stacked, the control unit 70 controls the robot unit 50 to transfer the contact tip 11 of the arc torch 10 from the base plate BP. The height Hn and the distance Rn from the rotation axis AX are moved, and steps S303 to S310 are repeated to form the molten bead MB of the nth layer Ln. When the control unit 70 determines that the layer modeling process for all the layers has been completed (step S311; Yes), the control unit 70 ends the nth layer modeling process and returns to the layered modeling process shown in FIG. 7 (step S107). After that, the laminated modeling process is completed. As a result, the laminated model LM shown in FIG. 3 is completed.
　以上のように、本実施の形態の積層造形装置１００および積層造形物の製造方法によれば、予備加熱部２０を制御して、ベース板ＢＰにおける形成予定位置Ｐを第１の基準値以上第２の基準値以下の温度に予備加熱することで、ベース板ＢＰを溶融温度以上にするために必要な熱量が少なくなり、アークトーチ１０による入熱量を小さくすることも可能になる。これにより、図１３に示すように、ベース板ＢＰと溶融ビードＭＢが溶融部ＭＰ１によりオーバーラップなく接合される。実験の結果によれば、ベース板ＢＰを２５０℃に予備加熱することにより、アーク電流９０Ａ、造形速度５０ｃｍ／ｍｉｎで安定した溶融ビードＭＢが造形でき、造形幅を２．５ｍｍ以上３．０ｍｍ以下まで狭くすることが可能である。これは、予備加熱なしでは、溶融ビードＭＢを造形する熱量が足りないが、予備加熱することでベース板ＢＰが溶融しない造形条件で造形可能になったからである。このとき、溶融幅Ｗｍ１は、溶融ビードＭＢの造形幅と同じであるか造形幅に近い幅である。また、２層目以降でも前層の溶融ビードＭＢの温度が下がった場合、前層の溶融ビードＭＢを予熱することにより、入熱が小さい条件で溶融ビードが形成でき、冷却速度が速くなり、蓄熱の影響を抑えることが可能である。そのため、連続した積層造形が可能になり、造形効率の良い積層造形が可能になる。なお、予備加熱しない場合の造形幅は、最小で４ｍｍである。 As described above, according to the laminated modeling apparatus 100 and the manufacturing method of the laminated model of the present embodiment, the preheating unit 20 is controlled so that the planned formation position P on the base plate BP is set to the first reference value or more. By preheating to a temperature equal to or lower than the reference value of 2, the amount of heat required to bring the base plate BP to the melting temperature or higher is reduced, and the amount of heat input by the arc torch 10 can be reduced. As a result, as shown in FIG. 13, the base plate BP and the molten bead MB are joined by the molten portion MP1 without overlapping. According to the results of the experiment, by preheating the base plate BP to 250 ° C., a stable molten bead MB can be formed with an arc current of 90 A and a molding speed of 50 cm / min, and the molding width is 2.5 mm or more and 3.0 mm or less. Can be narrowed down to. This is because the amount of heat for forming the molten bead MB is insufficient without preheating, but the preheating makes it possible to form under the molding conditions in which the base plate BP does not melt. At this time, the melt width Wm1 is the same as or close to the molding width of the molten bead MB. Further, when the temperature of the molten bead MB in the front layer is lowered even in the second and subsequent layers, the molten bead can be formed under the condition that the heat input is small by preheating the molten bead MB in the front layer, and the cooling rate becomes high. It is possible to suppress the influence of heat storage. Therefore, continuous laminated modeling becomes possible, and laminated modeling with high modeling efficiency becomes possible. The minimum molding width without preheating is 4 mm.
　また、冷却部３０により、アークトーチ１０により形成された前層の溶融ビードＭＢに冷媒を吹き付けて第３の基準値以上第４の基準値以下の温度に冷却することで、図１４に示すように、前層である第１層Ｌ１の溶融ビードＭＢの上に新たな第２層Ｌ２の溶融ビードＭＢを形成する際に、第２層の溶融ビードＭＢが垂れ落ちることを防ぐことができる。また、新たな溶融ビードＭＢを形成する際に蓄熱の影響を小さくすることが可能である。これは、図６に示す第３層Ｌ３から第ｋ層Ｌｋの造形においても同様である。従って、溶融ビードＭＢを冷却部３０により冷却することで、蓄熱の影響が小さくなり、連続して溶融ビードＭＢを造形することが可能になる。そのため、造形速度が高くなり、効率の良い積層造形が可能になる。 Further, as shown in FIG. 14, the cooling unit 30 sprays a refrigerant onto the molten bead MB in the front layer formed by the arc torch 10 to cool the molten bead MB to a temperature equal to or higher than the third reference value and lower than the fourth reference value. In addition, when a new molten bead MB of the second layer L2 is formed on the molten bead MB of the first layer L1 which is the front layer, it is possible to prevent the molten bead MB of the second layer from dripping. Further, it is possible to reduce the influence of heat storage when forming a new molten bead MB. This also applies to the modeling of the third layer L3 to the kth layer Lk shown in FIG. Therefore, by cooling the molten bead MB by the cooling unit 30, the influence of heat storage is reduced, and the molten bead MB can be continuously formed. Therefore, the molding speed becomes high, and efficient laminated molding becomes possible.
　このように、新たな溶融ビードＭＢを形成する直下のベース板ＢＰおよび溶融ビードＭＢ温度を予備加熱もしくは冷却でコントロールすることにより、安定した積層造形物ＬＭを造形することができる。また、溶融ビードＭＢが積層されていくと、蓄熱および熱容量の変化などにより、冷却状況が刻々と変化するが、前層の溶融ビードＭＢの温度をコントロールすることにより、新たな溶融ビードＭＢの溶融状態が安定するため、連続した造形が可能になり、造形速度を早くすることも可能である。 In this way, by controlling the temperature of the base plate BP immediately below the molten bead MB and the molten bead MB MB forming a new molten bead MB by preheating or cooling, a stable laminated model LM can be formed. Further, as the molten bead MB is laminated, the cooling condition changes every moment due to changes in heat storage and heat capacity, but by controlling the temperature of the molten bead MB in the previous layer, the new molten bead MB is melted. Since the state is stable, continuous modeling is possible, and the modeling speed can be increased.
　これに対して、予備加熱部２０および冷却部３０を有さない比較例の積層造形装置を用いる場合について説明する。インコネルを積層造形する場合、インコネルの材料コストが高いため、造形材Ｗはインコネルを使用するが、ベース板ＢＰにステンレス鋼を使用する場合などがある。この場合、入熱量が小さいと、図１５に示すように、ベース板ＢＰの溶融部ＭＰ２の溶融幅Ｗｍ２が小さく、溶融ビードＭＢの端部が、溶融ビードＭＢがベース板ＢＰの上にのっただけの状態であるオーバーラップＯＬになり、溶融ビードＭＢが不安定な形状になり、また、ベース板ＢＰと溶融ビードＭＢとの接合強度も小さくなる。これは、インコネルとステンレス鋼の熱物性が異なるため、通常の同種金属の積層造形する条件では、うまく造形できないためである。ベース板ＢＰにステンレス鋼、造形材Ｗにインコネルを用いる場合、ベース板ＢＰのステンレス鋼の溶融温度が造形材Ｗのインコネルの溶融温度に比べ２００℃高いため、ベース板ＢＰの溶融幅Ｗｍ２が小さくなることが原因である。そのため、図１６に示すように、ベース板ＢＰにステンレス鋼、造形材Ｗにインコネルを使用した積層造形の第１層には、入熱量の大きい条件で、積層造形し、ベース板ＢＰの溶融部ＭＰ３の溶融幅Ｗｍ３を広げる必要がある。しかしながら、入熱の大きい条件では、溶融ビードＭＢの幅が大きくなってしまい、積層造形できる対象範囲が狭くなってしまう。ベース板ＢＰにステンレス鋼、造形材Ｗにインコネルを使用した組み合わせの積層造形実験では、安定した初層の造形に、アーク電流１５０Ａ、造形速度５０ｃｍ／ｍｉｎ程度の入熱量が最低限必要であり、造形幅５ｍｍ以上の造形しかできない。 On the other hand, a case where a laminated modeling device of a comparative example having no preheating unit 20 and a cooling unit 30 is used will be described. In the case of laminating Inconel, since the material cost of Inconel is high, Inconel is used as the modeling material W, but stainless steel may be used for the base plate BP. In this case, when the amount of heat input is small, as shown in FIG. 15, the melting width Wm2 of the molten portion MP2 of the base plate BP is small, and the end of the molten bead MB is such that the molten bead MB is placed on the base plate BP. The overlap OL is just in the state, the molten bead MB has an unstable shape, and the bonding strength between the base plate BP and the molten bead MB is also reduced. This is because the thermophysical properties of Inconel and stainless steel are different, so that they cannot be modeled well under the conditions of ordinary laminated molding of the same type of metal. When stainless steel is used for the base plate BP and Inconel is used for the modeling material W, the melting temperature of the stainless steel of the base plate BP is 200 ° C. higher than the melting temperature of the Inconel of the modeling material W, so that the melting width Wm2 of the base plate BP is small. Is the cause. Therefore, as shown in FIG. 16, the first layer of the laminated molding using stainless steel for the base plate BP and Inconel for the modeling material W is laminated and molded under the condition of a large amount of heat input, and the molten portion of the base plate BP is formed. It is necessary to widen the melting width Wm3 of MP3. However, under the condition of large heat input, the width of the molten bead MB becomes large, and the target range in which the laminated molding can be performed becomes narrow. In a laminated molding experiment using stainless steel for the base plate BP and Inconel for the molding material W, an arc current of 150 A and a molding speed of about 50 cm / min are the minimum required for stable first layer molding. Only modeling with a modeling width of 5 mm or more is possible.
　また、２層目以降は、前層の溶融ビードＭＢの上に新たな溶融ビードＭＢを造形する。そのため、新たな溶融ビードＭＢを造形する際の、前層の溶融ビードＭＢの温度が新たな溶融ビードＭＢの造形の形状安定性に影響する。前層である第１層Ｌ１の溶融ビードＭＢの温度が高いと、図１７に示すように新たな第２層Ｌ２の溶融ビードＭＢが垂れてしまう。特に、溶融ビードＭＢが高温で、多層に積層していくと蓄熱し、徐々に新たな溶融ビードＭＢを造形する部位の温度が高くなってしまうことが多い。蓄熱していくと、溶融ビードＭＢが垂れ落ちてしまい、安定した溶融ビードＭＢの造形が難しくなる。 In addition, from the second layer onward, a new molten bead MB is formed on the molten bead MB of the previous layer. Therefore, the temperature of the molten bead MB in the front layer when molding a new molten bead MB affects the shape stability of the molding of the new molten bead MB. If the temperature of the molten bead MB of the first layer L1 which is the front layer is high, a new molten bead MB of the second layer L2 hangs down as shown in FIG. In particular, when the molten bead MB is at a high temperature and is laminated in multiple layers, heat is stored, and the temperature of the portion where a new molten bead MB is formed is often increased. As the heat is stored, the molten bead MB hangs down, making it difficult to form a stable molten bead MB.
　（変形例）
　上述の実施の形態では、アークトーチ１０が、造形材Ｗを供給する造形材供給部を備える例について説明した。アークトーチ１０は、ベース板ＢＰ上に溶融ビードを積層して積層造形物を形成することができればよい。例えば、アークトーチ１０は、造形材供給部を備えず、外部から造形材を供給する方式であってもよい。 (Modification example)
In the above-described embodiment, an example in which the arc torch 10 includes a modeling material supply unit for supplying the modeling material W has been described. The arc torch 10 may be capable of forming a laminated model by laminating molten beads on the base plate BP. For example, the arc torch 10 may be a method in which the modeling material is supplied from the outside without providing the modeling material supply unit.
　上述の実施の形態では、予備加熱部２０および冷却部３０が、第１の基準値以上第２の基準値以下または第３の基準値以上第４の基準値以下に温度を調整する例について説明した。制御部７０は、温度センサ４０により測定された温度に基づいて、フィードバック制御により予備加熱部２０および冷却部３０を制御し、ベース板ＢＰおよび前層の溶融ビードＭＢの形成予定位置Ｐを目標温度に調整してもよい。フィードバック制御は、比例制御、ＰＩ（Proportional-Integral）制御およびＰＩＤ（Proportional-Integral-Differential）制御を含む。なお、ベース板ＢＰの目標温度は、第１の基準値以上第２の基準値以下であり、前層の溶融ビードＭＢの目標温度は、第３の基準値以上第４の基準値以下である。 In the above-described embodiment, an example in which the preheating unit 20 and the cooling unit 30 adjust the temperature to the first reference value or more and the second reference value or less or the third reference value or more and the fourth reference value or less will be described. did. The control unit 70 controls the preheating unit 20 and the cooling unit 30 by feedback control based on the temperature measured by the temperature sensor 40, and sets the target temperature at the position P where the base plate BP and the molten bead MB in the front layer are to be formed. May be adjusted to. Feedback control includes proportional control, PI (Proportional-Integral) control and PID (Proportional-Integral-Differential) control. The target temperature of the base plate BP is equal to or higher than the first reference value and lower than the second reference value, and the target temperature of the molten bead MB in the front layer is equal to or higher than the third reference value and lower than the fourth reference value. ..
　上述の実施の形態では、予備加熱部２０が、前層の溶融ビードＭＢを予備加熱する例について説明したが、予備加熱部２０は、前層の溶融ビードＭＢに形成された被膜を除去してもよい。造形材Ｗにアルミニウムまたはアルミニウム合金を用いた場合、溶融ビードＭＢは、表面に強固な酸化被膜であるアルミナが形成される。この酸化被膜の溶融温度は約３０００℃で、アルミニウムまたはアルミニウム合金の溶融温度約６００℃に比べ、非常に高い。予備加熱部２０が、レーザを前層の溶融ビードＭＢの形成予定位置Ｐに照射し、アルミニウムまたはアルミニウム合金の酸化被膜をピンポイントで除去することにより、通常のアークだけの溶融ビードＭＢの形成より安定した溶融ビードＭＢが形成可能である。この場合、冷却部３０により、前層の溶融ビードＭＢに冷媒を吹き付けて一旦冷却し、その後、予備加熱部２０が、レーザを照射し、アルミニウムまたはアルミニウム合金の酸化被膜を吹き飛ばす。また、アルミニウムは鉄および銅に比べ潜熱が低いため、広範囲を加熱した場合、造形幅が広くなってしまう。そのため、アルミニウムまたはアルミニウム合金を予備加熱する場合、１００℃以上２００℃以下であることが望ましい。また、加熱する範囲を造形部近傍であって、予備加熱の幅は、１ｍｍ以下であることが好適である。 In the above-described embodiment, the example in which the preheating unit 20 preheats the molten bead MB in the front layer has been described, but the preheating unit 20 removes the film formed on the molten bead MB in the front layer. May be good. When aluminum or an aluminum alloy is used for the modeling material W, alumina, which is a strong oxide film, is formed on the surface of the molten bead MB. The melting temperature of this oxide film is about 3000 ° C., which is much higher than the melting temperature of aluminum or an aluminum alloy of about 600 ° C. The preheating unit 20 irradiates the laser at the position P where the molten bead MB of the front layer is to be formed, and pinpointly removes the oxide film of aluminum or the aluminum alloy, so that the molten bead MB of only a normal arc is formed. A stable molten bead MB can be formed. In this case, the cooling unit 30 sprays a refrigerant on the molten bead MB in the front layer to cool it once, and then the preheating unit 20 irradiates the laser to blow off the oxide film of aluminum or an aluminum alloy. Moreover, since aluminum has a lower latent heat than iron and copper, the molding width becomes wider when a wide range of heat is heated. Therefore, when preheating aluminum or an aluminum alloy, it is desirable that the temperature is 100 ° C. or higher and 200 ° C. or lower. Further, it is preferable that the heating range is in the vicinity of the modeling portion and the width of the preheating is 1 mm or less.
　上述の実施の形態では、アークトーチ１０の入熱条件は、一定である例について説明した。安定、かつ、効率の良い溶融ビードＭＢの造形には、溶融ビードＭＢ造形部のベース板ＢＰもしくは前層の溶融ビードＭＢの温度コントロールが重要である。そのため、溶融ビードＭＢ近傍の温度を温度センサ４０で測定し、その温度データを制御部７０にフィードバックし、アークトーチ１０の入熱条件を調整してもよい。入熱条件は、アーク電流により調整する。ベース板ＢＰまたは前層の溶融ビードＭＢにおける形成予定位置Ｐの温度が基準温度より低い場合、相対的にアーク電流を大きくし、基準入熱量より高い入熱条件で溶融ビードＭＢを形成し、形成予定位置Ｐの温度が基準温度より高い場合、相対的にアーク電流を小さくし基準入熱量より低い入熱条件で溶融ビードＭＢを形成することで、安定した造形が可能になる。 In the above-described embodiment, an example in which the heat input condition of the arc torch 10 is constant has been described. For stable and efficient molding of the molten bead MB, it is important to control the temperature of the base plate BP of the molten bead MB molding portion or the molten bead MB of the front layer. Therefore, the temperature near the molten bead MB may be measured by the temperature sensor 40, and the temperature data may be fed back to the control unit 70 to adjust the heat input conditions of the arc torch 10. The heat input conditions are adjusted by the arc current. When the temperature of the planned formation position P in the base plate BP or the molten bead MB of the front layer is lower than the reference temperature, the arc current is relatively increased and the molten bead MB is formed and formed under the heat input condition higher than the reference heat input amount. When the temperature of the planned position P is higher than the reference temperature, the arc current is relatively small and the molten bead MB is formed under the heat input condition lower than the reference heat input amount, so that stable modeling becomes possible.
　上述の実施の形態では、予備加熱部２０が、レーザ装置を備える例について説明したが、予備加熱部２０は、ベース板ＢＰおよび前層の溶融ビードＭＢを予備加熱することができればよく、ホットプレート、ヒートガン、誘導加熱装置などを備えてもよい。このようにすることで、積層造形装置１００をよりシンプルな構造にすることができる。 In the above-described embodiment, the example in which the preheating unit 20 is provided with the laser device has been described, but the preheating unit 20 only needs to be able to preheat the base plate BP and the molten bead MB in the front layer, and is a hot plate. , A heat gun, an induction heating device, and the like may be provided. By doing so, the laminated modeling apparatus 100 can have a simpler structure.
　上述の実施の形態では、積層造形装置１００が、アークトーチ１０、予備加熱部２０および冷却部３０を備える例について説明したが、積層造形装置１００は、少なくともアークトーチ１０および冷却部３０を備えればよい。これにより、溶融ビードＭＢが垂れ落ちることを防ぐことができる。また、新たな溶融ビードＭＢを形成する際に蓄熱の影響を小さくすることが可能である。従って、溶融ビードＭＢを冷却部３０により冷却することで、蓄熱の影響が小さくなり、連続して溶融ビードＭＢを造形することが可能になる。そのため、造形速度が高くなり、効率の良い積層造形が可能になる。また、積層造形装置１００をよりシンプルな構造にすることができる。 In the above-described embodiment, the example in which the laminated modeling device 100 includes the arc torch 10, the preheating unit 20, and the cooling unit 30 has been described, but the laminated modeling device 100 includes at least the arc torch 10 and the cooling unit 30. Just do it. This makes it possible to prevent the molten bead MB from dripping. Further, it is possible to reduce the influence of heat storage when forming a new molten bead MB. Therefore, by cooling the molten bead MB by the cooling unit 30, the influence of heat storage is reduced, and the molten bead MB can be continuously formed. Therefore, the molding speed becomes high, and efficient laminated molding becomes possible. In addition, the laminated modeling apparatus 100 can have a simpler structure.
　上述の実施の形態では、溶融加熱部としてアークトーチ１０を用いる例について説明したが、溶融加熱部は、溶融ビードＭＢを形成できればよく、レーザまたは電子線により造形材Ｗを溶融し、溶融ビードＭＢを形成するものであってもよい。 In the above-described embodiment, an example in which the arc torch 10 is used as the melt heating unit has been described. However, the melt heating unit only needs to be able to form the molten bead MB, and the molding material W is melted by a laser or an electron beam to melt the molten bead MB. May be formed.
　上述の実施の形態では、造形材Ｗが、インコネル、ステンレス鋼、アルミニウム合金およびマグネシウム合金を含む金属材料から選択される粉末材料またはワイヤである例について説明した。造形材Ｗは、積層造形物ＬＭを形成することができるものであれば限定されず、造形材Ｗは、熱で溶融し、冷却すると固化するものであればよく、金属、セラミックス、ガラス、および樹脂を含む群から選択される１つの材料または複数の材料を混合した材料などであってもよい。 In the above-described embodiment, an example in which the modeling material W is a powder material or a wire selected from a metal material including Inconel, stainless steel, an aluminum alloy, and a magnesium alloy has been described. The modeling material W is not limited as long as it can form a laminated model LM, and the modeling material W may be any material that melts with heat and solidifies when cooled, and is made of metal, ceramics, glass, and metal. It may be one material selected from the group containing a resin, or a material obtained by mixing a plurality of materials.
　上述の実施の形態では、積層造形物ＬＭが、中空の筒状の形状を有する例について説明した。積層造形物ＬＭは、積層造形装置１００により造形できる形状であれば限定されず、タービンまたはジェットエンジンの部品であってもよい。この場合、ベース板ＢＰを回転させながら、ロボット部５０によりアークトーチ１０を移動することにより、回転対称体以外の形状を含むタービンなどの回転部品を造形することができる。また、基材としてベース板ＢＰを用いる例について説明したが、基材は、積層造形物ＬＭを造形するベースとなるものであればよく、形状は限定されない。 In the above-described embodiment, an example in which the laminated model LM has a hollow tubular shape has been described. The laminated model LM is not limited as long as it has a shape that can be modeled by the laminated modeling device 100, and may be a component of a turbine or a jet engine. In this case, by moving the arc torch 10 by the robot unit 50 while rotating the base plate BP, it is possible to form a rotating component such as a turbine including a shape other than the rotational symmetry. Further, although an example in which the base plate BP is used as the base material has been described, the base material may be any base as long as it is a base for molding the laminated model LM, and the shape is not limited.
　上述の実施の形態では、基台６０が、回転軸ＡＸを中心として裁置されたベース板ＢＰを回転する例について説明した。基台６０は、ベース板ＢＰを固定してもよい。このようにすることで、積層造形物ＬＭが回転部品を除く形状を有する場合、造形効率の良い積層造形が可能になる。 In the above-described embodiment, an example in which the base 60 rotates the base plate BP placed around the rotation axis AX has been described. The base plate 60 may fix the base plate BP. By doing so, when the laminated modeled object LM has a shape excluding rotating parts, laminated modeling with high modeling efficiency becomes possible.
　本開示は、本開示の広義の精神と範囲を逸脱することなく、様々な実施の形態及び変形が可能とされるものである。また、上述した実施の形態は、この開示を説明するためのものであり、本開示の範囲を限定するものではない。すなわち、本開示の範囲は、実施の形態ではなく、特許請求の範囲によって示される。そして、特許請求の範囲内及びそれと同等の開示の意義の範囲内で施される様々な変形が、この開示の範囲内とみなされる。 The present disclosure allows for various embodiments and modifications without departing from the broad spirit and scope of the present disclosure. Moreover, the above-described embodiment is for explaining this disclosure, and does not limit the scope of the present disclosure. That is, the scope of the present disclosure is indicated by the scope of claims, not by the embodiment. And, various modifications made within the scope of claims and the equivalent meaning of disclosure are considered to be within the scope of this disclosure.
　本出願は、２０１９年１２月１２日に出願された、日本国特許出願特願２０１９－２２４３９６号に基づく。本明細書中に日本国特許出願特願２０１９－２２４３９６号の明細書、特許請求の範囲、図面全体を参照として取り込むものとする。 This application is based on Japanese Patent Application No. 2019-224396 filed on December 12, 2019. The specification, claims, and drawings of Japanese Patent Application No. 2019-224396 shall be incorporated into this specification as a reference.
１０　アークトーチ、１１　コンタクトチップ、２０　予備加熱部、３０　冷却部、４０　温度センサ、５０　ロボット部、６０　基台、７０　制御部、７１　ＣＰＵ、７２　ＲＯＭ、７３　ＲＡＭ、１００　積層造形装置、ＢＰ　ベース板、ＭＢ　溶融ビード、ＬＭ　積層造形物、Ｗ　造形材。 10 arc torch, 11 contact tip, 20 preheating part, 30 cooling part, 40 temperature sensor, 50 robot part, 60 base, 70 control part, 71 CPU, 72 ROM, 73 RAM, 100 laminated molding device, BP base plate , MB molten bead, LM laminated model, W model.

Claims (20)

  1. 　積層造形物を形成する基材または前記基材に形成された前層の溶融ビードに新たな溶融ビードを形成し、前記溶融ビードを複数層積層する溶融加熱部と、
    　前記溶融加熱部とは別に設けられ、前層の前記溶融ビードを冷却する冷却部と、
    　を備える、積層造形装置。     A melt heating unit in which a new melt bead is formed on a base material forming a laminated model or a melt bead of a front layer formed on the base material, and a plurality of layers of the melt bead are laminated.
    A cooling unit provided separately from the melting heating unit and cooling the molten bead in the front layer,
    A laminated modeling device.
  2. 　前記溶融ビードの形成部の直上、もしくは、前記溶融ビードの造形方向における前方に配置された予備加熱部を備え、
    　前記予備加熱部は、予備加熱してから０．７秒以下で前記溶融加熱部により前記溶融ビードが形成される形成予定位置を予備加熱する、
    　請求項１に記載の積層造形装置。     A preheating portion arranged directly above the formed portion of the molten bead or in front of the formed portion of the molten bead in the forming direction of the molten bead is provided.
    The preheating section preheats the position where the molten bead is formed by the melt heating section in 0.7 seconds or less after the preheating.
    The laminated modeling apparatus according to claim 1.
  3. 　前記冷却部は、前記溶融ビードの造形方向において、前記溶融加熱部より後方に設置される、
    　請求項１または２に記載の積層造形装置。     The cooling unit is installed behind the molten heating unit in the molding direction of the molten bead.
    The laminated modeling apparatus according to claim 1 or 2.
  4. 　前記冷却部は、前記積層造形物の側面を冷却できる位置であって、かつ、前記溶融ビードに供給されているシールドガスに冷媒が直接当たらない位置に設置される、
    　請求項１から３の何れか１項に記載の積層造形装置。     The cooling unit is installed at a position where the side surface of the laminated model can be cooled and at a position where the refrigerant does not directly hit the shield gas supplied to the molten bead.
    The laminated modeling apparatus according to any one of claims 1 to 3.
  5. 　前記積層造形物の積層方向と、前記冷却部から冷媒を吹き付ける方向と、の為す狭角は、２０°以上７０°以下である、
    　請求項１から４の何れか１項に記載の積層造形装置。     The narrow angle formed by the laminating direction of the laminated model and the direction of blowing the refrigerant from the cooling unit is 20 ° or more and 70 ° or less.
    The laminated modeling apparatus according to any one of claims 1 to 4.
  6. 　前記基材および前記基材に形成された前層の溶融ビードのうち少なくとも何れかにおける新たな溶融ビードを形成する形成予定位置の温度を測定する温度センサを備え、
    　前記冷却部は、前記温度センサにより測定された温度に基づいて、前記基材または前層の溶融ビードにおける新たな溶融ビードを形成する前記形成予定位置を冷却する、
    　請求項１から５の何れか１項に記載の積層造形装置。     A temperature sensor for measuring the temperature of a planned formation position for forming a new molten bead in at least one of the base material and the molten bead of the front layer formed on the base material is provided.
    The cooling unit cools the planned formation position in the molten bead of the base material or the front layer to form a new molten bead based on the temperature measured by the temperature sensor.
    The laminated modeling apparatus according to any one of claims 1 to 5.
  7. 　前記基材および前記基材に形成された前層の溶融ビードのうち少なくとも何れかにおける新たな溶融ビードを形成する形成予定位置の温度を測定する温度センサと、
    　前記基材および前記基材に形成された前層の溶融ビードのうち少なくとも何れかを予備加熱する予備加熱部と、を備え、
    　前記予備加熱部は、前記温度センサにより測定された温度に基づいて、前記基材または前層の溶融ビードにおける前記形成予定位置を予備加熱する、
    　請求項１から６の何れか１項に記載の積層造形装置。     A temperature sensor that measures the temperature of the position where a new molten bead is formed in at least one of the base material and the molten bead of the front layer formed on the base material, and a temperature sensor.
    A preheating portion for preheating at least one of the base material and the molten bead of the front layer formed on the base material is provided.
    The preheating unit preheats the planned formation position in the molten bead of the base material or the front layer based on the temperature measured by the temperature sensor.
    The laminated modeling apparatus according to any one of claims 1 to 6.
  8. 　前記温度センサにより測定された前記形成予定位置の温度に基づいて、前記溶融加熱部の入熱条件を制御して、前記溶融加熱部により新たな溶融ビードを形成する、
    　請求項７に記載の積層造形装置。     Based on the temperature of the planned formation position measured by the temperature sensor, the heat input condition of the melt heating unit is controlled, and a new molten bead is formed by the melt heating unit.
    The laminated modeling apparatus according to claim 7.
  9. 　前記予備加熱部は、レーザを前記基材または前層の溶融ビードに照射して予備加熱し、
    　前記溶融加熱部は、アークを用いて新たな溶融ビードを形成する、
    　請求項７または８に記載の積層造形装置。     The preheating unit irradiates the base material or the molten bead of the front layer with a laser to preheat the base material or the molten bead of the front layer.
    The melt heating section uses an arc to form a new melt bead.
    The laminated modeling apparatus according to claim 7 or 8.
  10. 　前記予備加熱部は、レーザを照射して前層の溶融ビードに形成された被膜を除去する、
    　請求項７から９の何れか１項に記載の積層造形装置。     The preheating portion irradiates a laser to remove the coating formed on the molten bead of the front layer.
    The laminated modeling apparatus according to any one of claims 7 to 9.
  11. 　積層造形物を形成する基材または前記基材に形成された前層の溶融ビードに新たな溶融ビードを形成し、前記溶融ビードを複数層積層する溶融加熱工程と、
    　前層の前記溶融ビードを冷却する冷却工程と、
    　を備える、積層造形物の製造方法。     A melt heating step of forming a new molten bead on a base material forming a laminated model or a molten bead of a front layer formed on the base material and laminating a plurality of layers of the molten bead.
    A cooling step for cooling the molten bead in the front layer and
    A method for manufacturing a laminated model.
  12. 　前記基材および前記基材に形成された前層の溶融ビードのうち少なくとも何れかにおける新たな溶融ビードを形成する形成予定位置の温度を測定する温度測定工程を備え、
    　前記冷却工程において、前記温度測定工程により測定された温度に基づいて、前記基材または前層の溶融ビードにおける新たな溶融ビードを形成する前記形成予定位置を冷却する、
    　請求項１１に記載の積層造形物の製造方法。     A temperature measuring step for measuring the temperature of a planned formation position for forming a new molten bead in at least one of the base material and the molten bead of the front layer formed on the base material is provided.
    In the cooling step, the planned formation position for forming a new molten bead in the molten bead of the base material or the front layer is cooled based on the temperature measured by the temperature measuring step.
    The method for manufacturing a laminated model according to claim 11.
  13. 　前記基材および前記基材に形成された前層の溶融ビードのうち少なくとも何れかにおける新たな溶融ビードを形成する形成予定位置の温度を測定する温度測定工程と、
    　前記基材および前記基材に形成された前層の溶融ビードのうち少なくとも何れかを予備加熱する予備加熱工程と、を備え、
    　前記予備加熱工程において、前記温度測定工程により測定された温度に基づいて、前記基材または前層の溶融ビードにおける前記形成予定位置を予備加熱する、
    　請求項１１または１２に記載の積層造形物の製造方法。     A temperature measuring step of measuring the temperature of the planned formation position for forming a new molten bead in at least one of the base material and the molten bead of the front layer formed on the base material,
    A preheating step of preheating at least one of the base material and the molten bead of the front layer formed on the base material is provided.
    In the preheating step, the planned formation position in the base material or the molten bead of the front layer is preheated based on the temperature measured by the temperature measuring step.
    The method for producing a laminated model according to claim 11 or 12.
  14. 　前記温度測定工程により測定された前記形成予定位置の温度に基づいて、前記溶融加熱工程における入熱条件を制御して、前記溶融加熱工程により新たな溶融ビードを形成する、
    　請求項１３に記載の積層造形物の製造方法。     Based on the temperature of the planned formation position measured by the temperature measuring step, the heat input conditions in the melting and heating step are controlled, and a new molten bead is formed by the melting and heating step.
    The method for manufacturing a laminated model according to claim 13.
  15. 　前記予備加熱工程において、レーザを前記基材または前層の溶融ビードに照射して予備加熱し、
    　前記溶融加熱工程において、アークを用いて新たな溶融ビードを形成する、
    　請求項１３または１４に記載の積層造形物の製造方法。     In the preheating step, the base material or the molten bead of the front layer is irradiated with a laser to preheat it.
    In the melt heating step, a new melt bead is formed by using an arc.
    The method for producing a laminated model according to claim 13 or 14.
  16. 　前記予備加熱工程において、レーザを照射して前層の溶融ビードに形成された被膜を除去する、
    　請求項１３から１５の何れか１項に記載の積層造形物の製造方法。     In the preheating step, a laser is irradiated to remove the coating formed on the molten bead of the front layer.
    The method for manufacturing a laminated model according to any one of claims 13 to 15.
  17. 　前記基材と前記積層造形物を形成する造形材とが異なる場合において、前記基材の溶融温度が前記造形材の溶融温度より高い、
    　請求項１３から１６の何れか１項に記載の積層造形物の製造方法。     When the base material and the modeling material forming the laminated model are different, the melting temperature of the base material is higher than the melting temperature of the modeling material.
    The method for manufacturing a laminated model according to any one of claims 13 to 16.
  18. 　前記予備加熱工程において、第１層の造形時に、前記基材の溶融温度と造形材の溶融温度との差より高い温度で、前記基材を予備加熱する、
    　請求項１７に記載の積層造形物の製造方法。     In the preheating step, at the time of molding the first layer, the base material is preheated at a temperature higher than the difference between the melting temperature of the base material and the melting temperature of the molding material.
    The method for manufacturing a laminated model according to claim 17.
  19. 　前記積層造形物がアルミニウムまたはアルミニウム合金により形成される、
    　請求項１１から１８の何れか１項に記載の積層造形物の製造方法。     The laminated model is formed of aluminum or an aluminum alloy.
    The method for manufacturing a laminated model according to any one of claims 11 to 18.
  20. 　予備加熱の幅は、１ｍｍ以下である、
    　請求項１９に記載の積層造形物の製造方法。     The width of preheating is 1 mm or less.
    The method for manufacturing a laminated model according to claim 19.
PCT/JP2020/043437 2019-12-12 2020-11-20 Laminate molding device, and method for manufacturing laminate molded object WO2021117468A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019002563A2 (en) * 2017-06-30 2019-01-03 Norsk Titanium As Solidification refinement and general phase transformation control through application of in situ gas jet impingement in metal additive manufacturing
JP2019081187A (en) * 2017-10-30 2019-05-30 株式会社神戸製鋼所 Method for manufacturing laminated shaped object
JP2019084553A (en) * 2017-11-06 2019-06-06 三菱重工コンプレッサ株式会社 Metal laminate molding method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019002563A2 (en) * 2017-06-30 2019-01-03 Norsk Titanium As Solidification refinement and general phase transformation control through application of in situ gas jet impingement in metal additive manufacturing
JP2019081187A (en) * 2017-10-30 2019-05-30 株式会社神戸製鋼所 Method for manufacturing laminated shaped object
JP2019084553A (en) * 2017-11-06 2019-06-06 三菱重工コンプレッサ株式会社 Metal laminate molding method

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