JP4258571B2 - Manufacturing method and manufacturing apparatus for three-dimensional shaped object - Google Patents

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus for a three-dimensional shaped object in which an inorganic or organic powder material is irradiated with a light beam.

  Conventionally, a light beam is irradiated onto a powder layer formed of an inorganic or organic powder material, the powder layer is melted to form a hardened layer, and a new powder layer is formed on the hardened layer to emit a light beam. A method of manufacturing a three-dimensional shaped object by repeating irradiation and forming a hardened layer is known.

  Further, in the process of repeating the formation of the powder layer and the hardened layer, there is a manufacturing method that improves the processing accuracy of the three-dimensional shaped object by irradiating the light layer after heating the powder layer to a temperature close to the sintering temperature. It is known (see, for example, Patent Document 1).

  In addition, a manufacturing method is known in which the surface of a model is cut while the powder layer and the hardened layer are formed to form a three-dimensional model, and the processing accuracy of the three-dimensional model is improved. (For example, refer to Patent Document 2).

However, in the manufacturing method as shown in Patent Document 1, since the three-dimensional shaped object remains sintered, the processing accuracy is insufficient. In the manufacturing method shown in Patent Document 2, Since the three-dimensional shaped object is sintered and cut when it is in a high temperature state, the processing accuracy may be deteriorated if the three-dimensional shaped object is cooled to normal temperature and contracted.
JP-T-1-502890 JP 2002-115004 A

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a manufacturing method with high processing accuracy of a three-dimensional shaped object.

In order to achieve the above object, the invention of claim 1 includes a powder layer forming step of forming a powder layer by supplying an inorganic or organic powder material to a modeling plate, and a light beam at a predetermined portion of the powder layer. And a curing step of forming a cured layer by sintering or melting and curing the powder layer, and repeating the powder layer forming step and the curing step to integrate a plurality of cured layers. In the process of forming a three-dimensional shaped object by repeating the removing step of removing the surface and inner surface of the shaped object at least once in the middle of formation, the removing step comprises a predetermined cooling means for forming the modeling plate. And a removal finishing step performed after the cooling step, wherein the cooling step measures the temperature of the entire upper surface of the modeled object being modeled and is cooled to a predetermined temperature. Comprising the step of determining whether, shifted to the removing finishing step when cooled to the predetermined temperature, the during the curing step includes a heating step of heating the shaping plate by a predetermined heating means, the A heating process is performed after heating to a predetermined temperature, and further includes a correction process for correcting the machining position of the NC program for performing the removal process.
(I) Before modeling of the three-dimensional shaped object, creation of a plurality of reference points serving as reference positions for the removal finishing process on the modeling plate, and position detection of the reference points are performed.
(Ii) The position of the reference point is detected again before the removing step in the middle of forming the modeled object, the position of the reference point detected before the modeling, and the position of the reference point detected before the removing step The position is corrected based on the measurement difference .

According to a second aspect of the present invention, there is provided a powder layer forming step of forming a powder layer by supplying an inorganic or organic powder material to the modeling plate, and irradiating a predetermined portion of the powder layer with a light beam to form the powder layer. A step of sintering or melt-curing to form a cured layer, and repeating the powder layer forming step and the curing step to form a modeled object in which a plurality of cured layers are integrated. In the method of modeling the three-dimensional shaped object by repeating the removal process for removing the surface and the inner surface of the object at least once, the removing process is a cooling process for cooling the modeling plate by a predetermined cooling means; A removal finishing step performed after this cooling step,
The cooling step has a step of measuring the temperature of the entire upper surface of the modeled object under modeling and judging whether it has been cooled to a predetermined temperature, and when it is cooled to the predetermined temperature, And a heating step of heating the atmosphere around the three-dimensional shaped object by a predetermined heating means during the curing step, and performing the curing step after heating to a predetermined temperature by the heating step, the removing step A correction step of correcting the machining position of the NC program for performing the correction,
(I) Before modeling of the three-dimensional shaped object, creation of a plurality of reference points serving as reference positions for the removal finishing process on the modeling plate, and position detection of the reference points are performed.
(Ii) The position of the reference point is detected again before the removing step in the middle of forming the modeled object, the position of the reference point detected before the modeling, and the position of the reference point detected before the removing step The position is corrected based on the measurement difference .

According to a third aspect of the present invention, there is provided a powder layer forming step of supplying an inorganic or organic powder material to a modeling plate to form a powder layer, and irradiating a predetermined portion of the powder layer with a light beam to form the powder layer. A step of sintering or melt-curing to form a cured layer, and repeating the powder layer forming step and the curing step to form a modeled object in which a plurality of cured layers are integrated. In the method of modeling a three-dimensional shaped object by repeating the removing step for removing the surface and the inner surface of the object at least once, the removing step is a cooling for cooling the atmosphere around the shaped object by a predetermined cooling means. And a finishing process performed after the cooling step, wherein the cooling step measures the temperature of the entire top surface of the modeled object being modeled and determines whether it has been cooled to a predetermined temperature. Has up, moves to the removing finishing step when cooled to the predetermined temperature, the during the curing step includes a heating step of heating the shaping plate by a predetermined heating means, predetermined by the heating step of the curing process rows that are in after heating to a temperature, further comprising a correction step for correcting the working position of the NC program for performing the removing step, the correction process,
(I) Before modeling of the three-dimensional shaped object, creation of a plurality of reference points serving as reference positions for the removal finishing process on the modeling plate, and position detection of the reference points are performed.
(Ii) The position of the reference point is detected again before the removing step in the middle of forming the modeled object, the position of the reference point detected before the modeling, and the position of the reference point detected before the removing step The position is corrected based on the measurement difference .

The invention of claim 4 is a powder layer forming step of forming a powder layer by supplying an inorganic or organic powder material to a modeling plate, and irradiating a predetermined portion of the powder layer with a light beam to form the powder layer. A step of sintering or melt-curing to form a cured layer, and repeating the powder layer forming step and the curing step to form a modeled object in which a plurality of cured layers are integrated. In the method of modeling a three-dimensional shaped object by repeating the removing step for removing the surface and the inner surface of the object at least once, the removing step is a cooling for cooling the atmosphere around the shaped object by a predetermined cooling means. And a finishing process performed after the cooling step, wherein the cooling step measures the temperature of the entire top surface of the modeled object being modeled and determines whether it has been cooled to a predetermined temperature. Has up, moves to the removing finishing step when cooled to the predetermined temperature, the during the curing step includes a heating step of heating the atmosphere surrounding the three-dimensionally shaped object by predetermined heating means , have rows curing step after heating to a predetermined temperature by the heating step, further comprising a correction step for correcting the working position of the NC program for performing the removing step, the correction process,
(I) Before modeling of the three-dimensional shaped object, creation of a plurality of reference points serving as reference positions for the removal finishing process on the modeling plate, and position detection of the reference points are performed.
(Ii) The position of the reference point is detected again before the removing step in the middle of forming the modeled object, the position of the reference point detected before the modeling, and the position of the reference point detected before the removing step The position is corrected based on the measurement difference .

The invention of claim 5, Oite to as you Keru said heating engineering to the production method of three-dimensionally shaped object according to claim 3 or claim 4, the temperature of the entire upper surface of a molded article in molding were measured, A step of determining whether or not a predetermined temperature has been reached.

According to a sixth aspect of the invention, in both or either one of claims 1 to Keru Contact to the production method of three-dimensionally shaped object according to any one of claims 5 wherein the heating and cooling steps, the removing finishing Instead of the temperature of the entire upper surface, the temperature of a predetermined portion of the modeled object is measured by a temperature sensor attached to the main shaft of the removing means for processing .

  The invention of claim 7 is the method for producing a three-dimensional shaped article according to any one of claims 1 to 6, wherein the cooling step includes a step of cooling the shaped article.

According to an eighth aspect of the present invention, there is provided a powder layer forming means for forming a powder layer by supplying an inorganic or organic powder material to the modeling plate, and irradiating a predetermined portion of the powder layer with a light beam to form the powder layer. A curing means for forming a cured layer by sintering or melt-curing; and a removing means for cutting and removing the surface and the inside of the surface of the three-dimensionally shaped object, and forming the powder layer; In the manufacturing apparatus for producing a three-dimensional shaped object by repeating the removal at least once by the removing means during the formation of a shaped object in which a plurality of hardened layers are integrated by repeating the formation, the removal Before the removing operation by means , cooling means for cooling the atmosphere around the modeled object and / or the modeling plate, and cooling the temperature of the entire upper surface of the modeled object to a predetermined temperature; and Model Further comprising a heating means for heating both or one of the surrounding atmosphere and the shaping plate, and correcting means for correcting the machining position of the NC program for the removal, wherein the correction means,
(I) Before modeling the three-dimensional shaped object, create a plurality of reference points serving as reference positions for removal finishing processing on the modeling plate, and detect the positions of the reference points.
(Ii) The position of the reference point is detected again before the removal during the formation of the modeled object, and the position of the reference point detected before the modeling and the position of the reference point detected before the removal The position is corrected based on the measurement difference .

According to the invention of claim 1, since the shaped article is cooled and the thermal contraction of the shaped article is stabilized, the removal finishing process is performed. Therefore, the shrinkage of the shaped article after the removal finishing process is reduced. Processing accuracy is improved. Further, since the curing process is performed after the temperature of the modeled object rises, the irradiation energy of the light beam may be small, and the sintering can be performed efficiently. In addition, since the deviation of the reference point of the removal finishing process is corrected during modeling, the processing accuracy is improved.

According to the invention of claim 2, since the shaped article is cooled and the thermal contraction of the shaped article is stabilized and the removal finishing process is performed, the shrinkage of the shaped article after the removal finishing process is reduced. Processing accuracy is improved. In addition, since the atmosphere around the modeled object is heated, the modeled object can be heated efficiently, and the curing process is performed after the temperature of the modeled object rises. Sintering can be performed efficiently. In addition, since the deviation of the reference point of the removal finishing process is corrected during modeling, the processing accuracy is improved.

According to the invention of claim 3, since the atmosphere around the modeled object is cooled, the modeled object can be cooled efficiently, and the removal finish processing is performed after the thermal shrinkage of the modeled object is stabilized. The shrinkage of the shaped object after the finishing process is reduced, and therefore the removal finishing process accuracy is improved. Further, since the curing process is performed after the temperature of the modeled object rises, the irradiation energy of the light beam may be small, and the sintering can be performed efficiently. In addition, since the deviation of the reference point of the removal finishing process is corrected during modeling, the processing accuracy is improved.

According to the invention of claim 4, since the atmosphere around the modeled object is cooled, the modeled object can be cooled efficiently, and the removal finish processing is performed after the thermal shrinkage of the modeled object is stabilized. The shrinkage of the shaped object after the finishing process is reduced, and therefore the removal finishing process accuracy is improved. In addition, since the atmosphere around the modeled object is heated, the modeled object can be heated efficiently, and the curing process is performed after the temperature of the modeled object rises. Sintering can be performed efficiently. In addition, since the deviation of the reference point of the removal finishing process is corrected during modeling, the processing accuracy is improved.

According to the invention of claim 5, since the measured temperature of the shaped object, pressurized heat may be expanded without excess or deficiency, efficiency of shaping is improved.

  According to the sixth aspect of the present invention, since the temperature of an arbitrary portion of the modeled object is measured, heating and cooling can be performed without excess or deficiency regardless of the shape of the modeled object, and the efficiency of modeling is improved.

  According to the seventh aspect of the present invention, since the molded article itself is cooled, the cooling can be performed efficiently.

According to the eighth aspect of the present invention, the shaped article is cooled by the cooling means, and the removal finishing process is performed after the thermal shrinkage is stabilized. Therefore, the shrinkage of the shaped article after the removal finishing process is reduced, and therefore the removal finishing process is performed. Processing accuracy is improved. Further, since the curing process is performed after the temperature of the modeled object is raised by the heating means, the irradiation energy of the light beam may be small and the sintering can be performed efficiently. In addition, since the deviation of the reference point of the removal finishing process is corrected during modeling, the processing accuracy is improved.

(First embodiment)
A method for manufacturing a three-dimensional shaped object according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a metal stereolithography machine used in the manufacturing method. The metal stereolithography machine 1 includes a modeling plate 22 on which a powder layer 21 of a metal powder 2 is laid, a lifting table 23 that holds the modeling plate 22 and moves up and down, and surrounds the outer periphery of the lifting table. A modeling tank 24 for holding the powder, a powder layer forming unit 3 for forming the powder layer 21 on the modeling plate 22, and a curing unit 4 for sintering or melting and curing the powder layer 21 with a light beam to form a cured layer 25. The cutting removal part 5 which cuts the molded article 11 and the control part (not shown) which controls operation | movement of the metal stereolithography machine 1 are provided.

  The powder layer forming unit 3 includes a powder tank 31 that supplies the metal powder 2, and a powder supply blade 32 that lays the powder layer 21 on the modeling plate 22 with the supplied metal powder 2. The curing unit 4 includes a light beam oscillator 41 that emits a light beam L, a condenser lens 42 that collects the light beam L, and a galvano mirror 43 that scans the collected light beam L onto the powder layer 21. And. The cutting removal unit 5 includes a cutting tool 51 that cuts the shaped article 11, a milling head 52 that holds the cutting tool 51, an XY drive unit 53 that moves the milling head 52 to a cutting position, and various cutting tools 51. And a tool magazine 54 for waiting. The metal powder 2 is, for example, a spherical iron powder having an average particle diameter of 20 μm, and the light beam is, for example, a carbon dioxide laser.

  Here, before explaining the manufacturing method in the present embodiment, a conventional manufacturing method in which the removal finishing process is performed without cooling the modeled object after laminating the hardened layers will be described. FIG. 12 shows the flow of the conventional manufacturing method, and FIG. 13 shows the operation thereof. The control unit supplies the metal powder 2 in the powder tank 31 by the powder supply blade 32 on the modeling plate 22 placed on the lifting table 23 to form the powder layer 21 (step S101) (FIG. 13 ( a)). This step S101 constitutes a powder layer forming process. Next, the light beam L is scanned by the galvano mirror 43 to an arbitrary portion of the powder layer 21 to sinter or melt-harden the metal powder 2 to form a hardened layer 25 integrated with the modeling plate 22 (step) S102) (see FIG. 13B). This step S102 constitutes a curing process. The irradiation path of the light beam L is determined based on contour shape data of each cross section obtained by slicing STL (Stereo Lithography) data generated from a three-dimensional CAD model at an equal pitch of, for example, 0.05 mm. This irradiation path is preferably such that at least the outermost surface of the three-dimensional shaped object has a high density with a porosity of 5% or less.

  Until the powder layer forming step and the curing step are repeated, the cured layer 25 is laminated, and the number of layers of the cured layer 25 reaches the number N of layers obtained from the effective blade length of the cutting tool 51 that cuts the surface of the molded article 11. The stacking is repeated (steps S101 to S104). The number N of layers is, for example, a ball end mill capable of cutting with a cutting tool 51 having a diameter of 1 mm, an effective blade length of 3 mm, and a depth of 3 mm. If the thickness of the powder layer is 0.05 mm, the layers are stacked. The powder layer has 50 layers with a thickness of 2.5 mm. When the number of hardened layers 25 reaches the determined total number N, the control unit moves the milling head 52 by the XY driving unit 53 and removes the surface of the modeled object 11 by the cutting tool 51 (step S105) (FIG. 5). 13 (c)). This step S105 constitutes a removal finishing process. In this way, the formation of the hardened layer 25 and the removal of the surface of the modeled object 11 are repeated until the modeling of the three-dimensional modeled model is completed (steps S106 and S107). The removal finishing process is to remove the low-density surface layer from the powder adhering to the surface of the modeled object, but the high-density part is completely exposed on the surface of the modeled object by grinding to the high-density part. In this case, the hardened layer is made slightly larger than the desired shape.

  In the curing step, the molded article 11 is heated and stored by receiving energy from the light beam L. The metal powder 2 and the modeled object 11 in the portion irradiated with the light beam L locally rise to a temperature of 1000 ° C. or higher. The model 11 is cooled by radiation or convection, but stores heat inside the model. Furthermore, the molded article 11 is surrounded by the metal powder 2, and the metal powder 2 is easy to store heat because of its low thermal conductivity. FIG. 14 shows the temperature history of the model 11 during modeling. The temperature of the shaped object rises by irradiation with a light beam during the curing process, and heat is dissipated during the powder layer forming process, but the temperature decreases only slightly due to heat storage, and while the cured layer is laminated, The temperature continues to rise. And it becomes a removal finishing process with a high temperature state, and it cools during a removal finishing process.

Thus, in the conventional manufacturing method, since the removal finishing process is performed in a state where the temperature of the modeled object after the curing process is high, the modeled object is processed in a thermally expanded state, and when the modeled object returns to room temperature, Shrinkage and processing accuracy deteriorates. For example, if the length of the model is 100 mm and the temperature is 100 ° C., and the linear expansion coefficient is 1.0 × 10 ^−5, which is the same as steel, the heat shrinkage of the model is 25 ° C. The dimensional difference when returning is 100 × 1.0 × 10 ⁻⁵ × (100−25) = 0.075 mm, which is an unacceptably large amount when the modeled object is a mold.

  In order to solve the problems of the conventional method as described above, in this embodiment, the modeling plate is cooled in order to lower the temperature of the modeled object during the removal finishing process and improve the dimensional accuracy of the removal finishing process. . The cooling state of the shaped object in the present embodiment is shown in FIG. The elevating table 23 has a refrigerant circuit 6 therein, and the refrigerant circuit 6 is connected to a cooling temperature adjusting device 62 by a refrigerant pipe 61, and the cooling temperature adjusting device 62 circulates the refrigerant through the refrigerant circuit 6 to move the elevating table 23. Cooling. The cooling temperature adjusting device 62 measures the temperature of the modeling plate 22 by the plate temperature sensor 63, and cools the modeling plate 22 to a predetermined temperature in order to cool the modeled object.

  FIG. 3 shows the flow of this manufacturing method, and FIG. 4 shows the temperature history of the molded article at that time. The control unit repeats the powder layer forming process and the curing process until the number of hardened layers reaches a predetermined number N (steps S1 to S4). When the number of layers reaches N, the temperature of the modeling plate 22 is, for example, The elevating table 23 is cooled by the cooling temperature adjusting device 62 until the temperature drops to a predetermined temperature of 25 ° C., and the temperature is adjusted to a predetermined temperature (steps S5 to S7). Steps S5 to S7 constitute a cooling process. When the temperature is lowered to a predetermined temperature, the removal finishing process is started while continuing the temperature adjustment (step S8). When the removal finishing is finished, the cooling is stopped and the temperature adjustment is finished (step S9). In this way, the formation of the hardened layer 25 and the cutting of the surface of the modeled object 11 are repeated until the modeling of the three-dimensional modeled model is completed (steps S10 and S11). Thus, since the removal finishing process is performed after the shaped article 11 is cooled, the thermal shrinkage after the shaping of the shaped article 11 is small, and the processing error is reduced.

  Next, a first modification of the manufacturing method in the present embodiment will be described with reference to FIG. In the present modification, the vicinity of the hardened layer of the model is cooled. FIG. 5 shows the cooling state of the shaped object in this modification. After the curing process is completed, the heat radiation block 65 having the heat radiation fins 64 is placed on the molded article 11, and the heat radiation block 65 is cooled by the air blown from the cooling fan 66. The control unit measures the temperatures of the heat dissipation block 65 and the modeling plate 22 by the temperature measuring device 68 based on the detection signals from the block temperature sensor 67 and the plate temperature sensor 63, respectively. When the working plate 22 is cooled to a predetermined temperature, a removal finishing process is performed. Since the heat dissipation block 65 cools the vicinity immediately after the shaped object is sintered, the cooling can be performed efficiently. Further, the cooling by the heat radiation block 65 may be performed together with the cooling by the lifting table 23 described above. Furthermore, it can cool efficiently.

  Next, a second modification of the manufacturing method in the present embodiment will be described. In this modification, the three-dimensional shaped object is cooled by cooling the atmosphere around the three-dimensional shaped object. In order to cool the atmosphere, for example, the atmosphere of an inert gas in a chamber surrounding the powder layer is cooled, or the cooled inert gas is blown into the powder layer. Since the three-dimensional shaped object is cooled from the surroundings, it can be efficiently cooled.

(Second Embodiment)
Next, a method for manufacturing a three-dimensional shaped object according to the second embodiment of the present invention will be described with reference to the drawings. The heating state of the shaped object in the present embodiment is shown in FIG. In this embodiment, in addition to the cooling of the modeled object in the first embodiment, the modeled object is heated before the curing step. The elevating table 23 has a heater 69 along with the refrigerant circuit 6 therein. The heating / cooling device 62 a cools the lift table 23 by the refrigerant circuit 6 and heats the lift table 23 by the heater 69.

  FIG. 7 shows the flow of the manufacturing method, and FIG. 8 shows the temperature history of the three-dimensional shaped object in the manufacturing method. When manufacturing a three-dimensional shaped object, the control unit first heats the lifting table 23 with the heater 69 disposed on the lifting table 23, and the modeling plate 22 is heated to a predetermined temperature of, for example, 200 ° C. The temperature is raised and the temperature is adjusted to a predetermined temperature or higher (steps S21 to S23). Steps S21 and S23 constitute a heating process. When the modeling plate 22 is heated to a predetermined temperature, the cured layer is laminated by repeating the formation of the powder layer 21 and sintering or melt curing while continuing the temperature adjustment (steps S24 to S27). Since the molded article 11 is heated, the powder layer 21 is easily sintered or melt-cured. Then, after the number of hardened layers reaches the predetermined number N, heating is stopped and the temperature adjustment is finished (step S28), and the removal finish processing of the shaped article 11 is performed as in the first embodiment. Perform (Steps S29 to S35).

  In this manufacturing method, the modeling object is heated by, for example, installing an infrared heater above the powder layer, directly heating the three-dimensional modeled object with infrared rays, or blowing heated inert gas into the powder layer. You may carry out by heating the atmosphere around a shape molded article. A three-dimensional shaped object can be heated efficiently.

(Third embodiment)
Next, the manufacturing method of the three-dimensional shape molded article which concerns on the 3rd Embodiment of this invention is demonstrated with reference to FIG. FIG. 9 shows the configuration of a metal stereolithography machine used in the manufacturing method. In the present embodiment, in the heating process and the cooling process, there is a step of measuring the temperature of the modeled object and determining whether the predetermined temperature has been reached. The metal stereolithography machine 1 includes an infrared radiation thermometer 71 in addition to the configuration of the metal stereolithography machine in the first embodiment. In the heating process and the cooling process, the control unit measures the temperature of the entire upper surface of the modeled article 11 with the infrared radiation thermometer 71, and shifts from the heating process to the powder layer forming process and from the cooling process to the deletion finishing process. Determine migration. Since the temperature of the molded article 11 is measured, the heating process and the cooling process can be performed efficiently.

  Next, a modification of the manufacturing method will be described with reference to FIG. In this modification, the temperature of the predetermined part of the modeled object is measured instead of measuring the temperature of the entire upper surface of the modeled object. FIG. 10A shows the operation in which the local temperature sensor is waiting in the tool magazine in this modification, and FIGS. 10B and 10C show the temperature at an arbitrary position of the modeled object by the local temperature sensor. The operation | movement which is measuring is shown. The metal stereolithography machine of this modification includes a local temperature sensor 72 that can be attached to the milling head 52. The local temperature sensor 72 may be a contact type such as a thermocouple or a thermistor, or a non-contact type such as an infrared radiation thermometer. The portion where the milling head 52 holds the cutting tool 51 is a collet type, and the local temperature sensor 72 has an axis having the same diameter as the cutting tool 51, so the milling head 52 holds the local temperature sensor 72. can do.

  Similar to the cutting tool 51, the local temperature sensor 72 is placed in the tool magazine 54. The control unit attaches the local temperature sensor 72 to the milling head 52 during the cooling process or the heating process, and moves the local temperature sensor 72 to an arbitrary position of the molded article 11 by the XY driving unit 53 to measure the temperature. As a location to be measured, for example, the center of gravity of each cross section, the point farthest from the contour line, and the like are set from the cross section contour shape data of the CAD data of the three-dimensional shaped object. Since the temperature of the location according to the shape of the three-dimensional shaped object to be modeled can be measured and the state of cooling or heating can be detected, cooling and heating can be performed efficiently without excess or deficiency.

(Fourth embodiment)
Next, the manufacturing method of the three-dimensional shape molded article which concerns on the 4th Embodiment of this invention is demonstrated with reference to FIG. In the modeling of a three-dimensional modeled object, since heating and cooling are repeated during modeling, the modeled object, the modeling plate, and the lifting table repeat thermal expansion and contraction, which may shift the reference point for modeling. Therefore, in the present embodiment, a reference point serving as a reference position for the removal finishing process is created on the modeling plate by a cutting tool before modeling the three-dimensional modeled object. FIGS. 11A to 11F show operations of the reference point creation and removal finishing process in the present embodiment. First, as shown in FIG. 11A, before the three-dimensional shaped object is formed, the control unit moves the milling head 52 to a predetermined position and removes it to the forming plate 22 by the cutting tool 51. For example, a + -shaped reference point 8 is formed as a reference position for finishing, and the reference point 8 is detected by a CCD camera 81 attached to the milling head 52 as shown in FIG. Remember.

Next, as shown in FIG. 11 (c), the control unit laminates a predetermined number of hardened layers, and then, as shown in FIG. 11 (d), unsintered so that the reference point 8 can be seen during cooling. The metal powder 2 is sucked by a suction machine 82. Next, as shown in FIG. 11E, the control unit 9 detects the reference point 8 by the CCD camera 81, compares it with the first stored position data, and performs the removal finishing process based on the difference. (Numerical Control) The machining position of the program is corrected. This correction operation constitutes a correction process. The controller 9, the milling head 52, and the CCD camera 81 constitute correction means. Next, as shown in FIG. 11 (f), the removal finish processing of the shaped article 11 is performed by the corrected NC program. Since the machining position is corrected before the removal finish machining, the machining accuracy is improved. The correction of the processing position may be performed not only for the removal finishing processing program but also for the program that scans the light beam. Since the scanning position of the light beam is corrected, the positional accuracy of sintering is improved.

(Fifth embodiment)
Next, a method for manufacturing a three-dimensional shaped object according to the fifth embodiment of the present invention will be described. In the present embodiment, unlike the manufacturing methods in the first to fourth embodiments, the cooling standby before the removal finishing process is not performed by measuring the temperature, but the standby time is calculated from the manufacturing conditions and waited. . The temperature of the three-dimensional shaped object during cooling after the curing process depends on the material properties such as the metal powder type, particle size, light beam energy absorption rate and thermal conductivity, light beam irradiation conditions, and cooling conditions. Can be predicted based on. Further, in addition to the above-described factors, the cooling temperature is largely caused by the heating amount by the light beam after the previous removal finishing process and the heat storage amount of the modeled object.

  In order to calculate the waiting time, the area S of the hardened layer formed after the previous removal finishing process is used as an index representing the heating amount by the light beam after the previous removal finishing process, and the heat storage amount of the modeled object is calculated. Using the volume V that has been shaped so far as an index to represent, the area S and the volume V are used as variables, and an equation based on the above-described material characteristics of the metal powder and the waiting time T = f (S, V) are tested. Derived from data. Then, after the curing process, the apparatus waits for the waiting time T calculated by this equation. By calculating from the calculation formula, the standby time can be easily determined without measuring the temperature. Further, the waiting time in the heating process after the removal finishing process may be calculated by adding a heating amount or the like to a factor to derive the waiting time. The waiting time during the heating process can be easily determined without measuring the temperature.

  In addition, this invention is not restricted to the structure of the said various embodiment, A various deformation | transformation is possible in the range which does not change the meaning of invention. For example, the composition of the metal powder is not limited to the configuration of the above embodiment, and may be an organic powder material.

The perspective view of the metal stereolithography processing machine used for the manufacturing method which concerns on the 1st Embodiment of this invention. The figure which shows the cooling state of the molded article in the manufacturing method. The flowchart of the manufacturing method. The figure showing the temperature history of the molded article in the manufacturing method. The figure which shows the cooling state of the molded article in the modification of the manufacturing method. The figure which shows the heating state of the molded article in the manufacturing method which concerns on the 2nd Embodiment of this invention. The flowchart of the manufacturing method. The figure showing the temperature history of the molded article in the manufacturing method. The perspective view of the metal stereolithography machine used for the manufacturing method which concerns on the 3rd Embodiment of this invention. (A) thru | or (c) is a figure explaining the modification of the manufacturing method in time series. (A) thru | or (f) is a figure explaining the manufacturing method which concerns on the 4th Embodiment of this invention in time series. The flowchart of the conventional manufacturing method. (A) thru | or (c) is a figure explaining the manufacturing method in time series. The figure showing the temperature history of the molded article in the manufacturing method.

Explanation of symbols

1 Metal stereolithography machine (manufacturing equipment)
11 Modeled objects (three-dimensional modeled objects)
2 Metal powder (powder material)
21 Powder layer 22 Modeling plate 25 Hardened layer 3 Powder layer forming part (powder layer forming means)
4 Curing part (curing means)
5 Cutting removal part (removal means)
52 Milling head (spindle)
6 Refrigerant circuit (cooling means)
61 Refrigerant piping (cooling means)
62 Cooling temperature adjusting device (cooling means)
64 Radiation fins (cooling means)
65 Heat dissipation block (cooling means)
66 Cooling fan (cooling means)
69 Heater (heating means)
72 Local temperature sensor (temperature sensor)
8 Reference point L Light beam

Claims (8)

A powder layer forming step of forming a powder layer by supplying an inorganic or organic powder material to the modeling plate, and irradiating a predetermined portion of the powder layer with a light beam to sinter or melt cure the powder layer A curing step for forming a cured layer, and by repeating the powder layer forming step and the curing step, the surface of the modeled object and the inside of the modeled object are formed in the middle of the formation of the modeled product in which a plurality of cured layers are integrated. In the method of modeling a three-dimensional shaped object by repeating the removing step to be removed at least once,
The removing step includes a cooling step of cooling the modeling plate by a predetermined cooling means, and a removal finishing step performed after the cooling step,
The cooling step has a step of measuring the temperature of the entire upper surface of the modeled object under modeling and judging whether it has been cooled to a predetermined temperature, and when it is cooled to the predetermined temperature, Migrate ,
During the curing step, including a heating step of heating the modeling plate by a predetermined heating means, and performing the curing step after heating to a predetermined temperature by this heating step,
The method further comprises a correction step of correcting the machining position of the NC program for performing the removal step,
(I) Before modeling of the three-dimensional shaped object, creation of a plurality of reference points serving as reference positions for the removal finishing process on the modeling plate, and position detection of the reference points are performed.
(Ii) The position of the reference point is detected again before the removing step in the middle of forming the modeled object, the position of the reference point detected before the modeling, and the position of the reference point detected before the removing step A method for manufacturing a three-dimensional shaped object, wherein the position is corrected based on the measurement difference . A powder layer forming step of forming a powder layer by supplying an inorganic or organic powder material to the modeling plate, and irradiating a predetermined portion of the powder layer with a light beam to sinter or melt cure the powder layer A curing step for forming a cured layer, and by repeating the powder layer forming step and the curing step, the surface of the modeled object and the inside of the modeled object are formed in the middle of the formation of the modeled product in which a plurality of cured layers are integrated. In the method of modeling a three-dimensional shaped object by repeating the removing step to be removed at least once,
The removing step includes a cooling step of cooling the modeling plate by a predetermined cooling means, and a removal finishing step performed after the cooling step,
The cooling step has a step of measuring the temperature of the entire upper surface of the modeled object under modeling and judging whether it has been cooled to a predetermined temperature, and when it is cooled to the predetermined temperature, Migrate ,
During the curing step, including a heating step of heating the atmosphere around the three-dimensional shaped object by a predetermined heating means, and performing the curing step after heating to a predetermined temperature by this heating step,
The method further comprises a correction step of correcting the machining position of the NC program for performing the removal step,
(I) Before modeling of the three-dimensional shaped object, creation of a plurality of reference points serving as reference positions for the removal finishing process on the modeling plate, and position detection of the reference points are performed.
(Ii) The position of the reference point is detected again before the removing step in the middle of forming the modeled object, the position of the reference point detected before the modeling, and the position of the reference point detected before the removing step A method for manufacturing a three-dimensional shaped object, wherein the position is corrected based on the measurement difference . A powder layer forming step of forming a powder layer by supplying an inorganic or organic powder material to the modeling plate, and irradiating a predetermined portion of the powder layer with a light beam to sinter or melt cure the powder layer A curing step for forming a cured layer, and by repeating the powder layer forming step and the curing step, the surface of the modeled object and the inside of the modeled object are formed in the middle of the formation of the modeled product in which a plurality of cured layers are integrated. In the method of modeling a three-dimensional shaped object by repeating the removing step to be removed at least once,
The removal step includes a cooling step of cooling the atmosphere around the modeled object by a predetermined cooling means, and a removal finishing step performed after the cooling step,
The cooling step has a step of measuring the temperature of the entire upper surface of the modeled object under modeling and judging whether it has been cooled to a predetermined temperature, and when it is cooled to the predetermined temperature, Migrate,
Wherein during the curing step includes a heating step of heating the shaping plate by a predetermined heating means, rows that have a curing step after heating to a predetermined temperature by the heating step,
The method further comprises a correction step of correcting the machining position of the NC program for performing the removal step,
(I) Before modeling of the three-dimensional shaped object, creation of a plurality of reference points serving as reference positions for the removal finishing process on the modeling plate, and position detection of the reference points are performed.
(Ii) The position of the reference point is detected again before the removing step in the middle of forming the modeled object, the position of the reference point detected before the modeling, and the position of the reference point detected before the removing step method for producing a three-dimensionally shaped object you characterized in that the position is corrected based on the measurement difference. A powder layer forming step of forming a powder layer by supplying an inorganic or organic powder material to the modeling plate, and irradiating a predetermined portion of the powder layer with a light beam to sinter or melt cure the powder layer A curing step for forming a cured layer, and by repeating the powder layer forming step and the curing step, the surface of the modeled object and the inside of the modeled object are formed in the middle of the formation of the modeled product in which a plurality of cured layers are integrated. In the method of modeling a three-dimensional shaped object by repeating the removing step to be removed at least once,
The removal step includes a cooling step of cooling the atmosphere around the modeled object by a predetermined cooling means, and a removal finishing step performed after the cooling step,
The cooling step has a step of measuring the temperature of the entire upper surface of the modeled object under modeling and judging whether it has been cooled to a predetermined temperature, and when it is cooled to the predetermined temperature, Migrate,
Wherein during the curing step includes a heating step of heating the atmosphere surrounding the three-dimensionally shaped object by predetermined heating means, rows that have a curing step after heating to a predetermined temperature by the heating step,
The method further comprises a correction step of correcting the machining position of the NC program for performing the removal step,
(I) Before modeling of the three-dimensional shaped object, creation of a plurality of reference points serving as reference positions for the removal finishing process on the modeling plate, and position detection of the reference points are performed.
(Ii) The position of the reference point is detected again before the removing step in the middle of forming the modeled object, the position of the reference point detected before the modeling, and the position of the reference point detected before the removing step method for producing a three-dimensionally shaped object you characterized in that the position is corrected based on the measurement difference.   5. The three-dimensional according to claim 3, wherein the heating step includes a step of measuring the temperature of the entire upper surface of the modeled object during modeling and determining whether or not a predetermined temperature is reached. A method of manufacturing a shaped object.   In both or any one of the heating step and the cooling step, a temperature sensor attached to a main shaft of a removing unit that performs the removal finishing process measures a temperature of a predetermined portion of the modeled object instead of the temperature of the entire upper surface. The method for producing a three-dimensional shaped article according to any one of claims 1 to 5, wherein   The said cooling process has a step which cools the said molded article, The manufacturing method of the three-dimensional shaped molded article as described in any one of Claim 1 thru | or 6 characterized by the above-mentioned. Powder layer forming means for forming a powder layer by supplying an inorganic or organic powder material to a modeling plate, and irradiating a predetermined portion of the powder layer with a light beam to sinter or melt cure the powder layer A curing means for forming a hardened layer; and a removing means for cutting and removing the surface and the inner surface of the three-dimensionally shaped object, and by repeating the formation of the powder layer and the formation of the hardened layer. In the process of forming a three-dimensional shaped object by repeating the removal at least once by the removing means during the formation of a three-dimensional object in which the cured layer is integrated,
Cooling means for cooling the atmosphere around the modeled object and / or the modeling plate before the removing operation by the removing unit, and cooling the temperature of the entire upper surface of the modeled object to a predetermined temperature ; ,
A heating means for heating the atmosphere around the modeled object and / or the modeling plate;
Correction means for correcting the machining position of the NC program to be removed, and the correction means,
(I) Before modeling the three-dimensional shaped object, create a plurality of reference points serving as reference positions for removal finishing processing on the modeling plate, and detect the positions of the reference points.
(Ii) The position of the reference point is detected again before the removal during the formation of the modeled object, and the position of the reference point detected before the modeling and the position of the reference point detected before the removal An apparatus for manufacturing a three-dimensional shaped object, wherein the position is corrected based on a measurement difference .

Images