JP3446733B2 - Method and apparatus for manufacturing three-dimensional shaped object - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional shaped article manufacturing method and apparatus for producing a three-dimensional shaped article by sintering and curing a powder material with a light beam.

[0002]

2. Description of the Related Art There is a method of manufacturing a three-dimensional shaped object known as a stereolithography method. As shown in FIG. 18 (a), the manufacturing method disclosed in Japanese Patent No. 2620353 is performed by irradiating a predetermined portion of a layer of an inorganic or organic powder material with a light beam L to sinter the powder at that portion. By doing so, a sintered layer 11 is formed, a new layer 10 of powder material is coated on the sintered layer 11, and the light beam L is applied to a predetermined portion of the powder layer 10.
Is repeatedly irradiated to sinter the powder at the relevant position to form a new sintered layer 11 integrated with the lower sintered layer 11 to stack and integrate a plurality of sintered layers. And a cross-sectional shape data of each layer generated by slicing a model, which is design data (CAD data) of the three-dimensional shaped object, into a desired layer thickness. Since the light beam L is irradiated on the basis of the laser beam, it is possible to manufacture a three-dimensional shaped object having an arbitrary shape without using a so-called CAM device, and it is possible to rapidly produce a desired shape as compared with a manufacturing method such as cutting. A shaped object can be obtained.

[0003]

By the way, as shown in FIG. 20, unnecessary powder 15 adheres to the periphery of the portion where the light beam L is irradiated and sintered and hardened due to the heat transferred. The attached powder is a surface layer 1 having a low density.
6 is formed into a molded article.

In Japanese Patent Laid-Open No. 2000-73108, a step on the outer surface caused by stacking the sintered layers 11 (see FIG. 18).
(see (b)) has been shown to be removed, but simply removing this step can leave the low-density surface layer 16 as shown in FIG. 18 (c), and obtain a smooth surface. Can not.

Further, unless a sintered body having a sufficient density (low porosity) is formed in the sintering step, even if the step is removed, pores appear on the surface after the removal and a smooth surface cannot be obtained. .

Further, when finishing the removal of the low-density surface layer after completing the modeled object, the shape of the modeled object is limited by the working tool. For example, when cutting a deep rib or the like, a small-diameter tool may not be able to be machined due to the limited tool length, so a separate process such as electric discharge machining is required, which causes problems in terms of time and cost. Many.

The present invention has been made in view of the above points, and an object of the present invention is to manufacture a three-dimensional shaped object capable of smoothly finishing the surface of the object regardless of its shape at low cost. A method and an apparatus therefor are provided.

[0008]

SUMMARY OF THE INVENTION In the method for producing a three-dimensional shaped object according to the present invention, however, a layer of inorganic or organic powder material is irradiated with a light beam at a predetermined position to sinter the powder at that position. To form a sintered layer, coat a new layer of powder material on this sintered layer, and irradiate a light beam at a predetermined location to sinter the powder at that location to sinter the lower layer. When forming a powder sintered part in which multiple sintered layers are laminated and integrated by repeatedly forming a new sintered layer integrated with a layer, a powder sintered part that is a three-dimensional shaped object
The surface of the product is sintered at a high density, and the process of removing the surface part and / or unnecessary parts of the modeled object created up to that time after forming the sintered layer is performed multiple times during the process of creating the sintered layer. And remove the high density part by the removing process.
It is characterized by making it possible.

[0009]

The removing step can be performed by cutting or laser.

Immediately before the removing step, the object to be removed is irradiated with a light beam to soften the object to be removed, and immediately after the removing step, the part where the object to be removed is removed is irradiated with a light beam for melt hardening or heat treatment. You may do it.

Further, it is also preferable to carry out the removal work in the removal process at the same time as the removal work of the unsintered powder around the powder-sintered part which is a three-dimensional shaped object and the scraps generated in the removal work. May be removed immediately before the removal step.

When performing the above-mentioned removal, a resin or a brazing material may be poured into the removed portion and the removed portion immediately after the removing step, and then the next layer of powder material may be formed and sintered.

Immediately after the formation of the sintered layer or immediately after the removal step, the shape and position of the modeled object formed so far are measured, and based on the measurement result, the light beam for forming the next sintered layer is measured. It is also preferable to correct the irradiation path data and the removal processing path data of the removed portion in the next removal step. .

The unsintered powder may be solidified before the removing step. In this case, the unsintered powder may be frozen or a resin or a brazing material may be used.

The apparatus for producing a three-dimensional shaped object according to the present invention comprises a powder layer forming means for forming a layer of an inorganic or organic powder material, and a predetermined portion of the powder layer irradiated with a light beam. And a means for adjusting the relative distance between the sintered layer forming means and the sintered layer, and the surface portion of the modeled object and / or It is characterized in that it comprises a removing means for removing an unnecessary portion.

It is also possible to provide a means for eliminating the unsintered powder and scraps generated in the removing step by the removing means, and this removing means has a powder layer forming means or an XY drive mechanism. It is possible to suitably use the one that performs the exclusion work along the cross-sectional contour shape of the modeled object.

Further, immediately after the formation of the sintered layer or immediately after the removal step, the measuring means for measuring the shape and position of the modeled object formed so far, and the measuring means for measuring the sintered layer forming means based on the measurement result. It is also preferable to provide a correction means for correcting the operation, and in this case, the measurement means is X
A device having a Y drive mechanism and performing measurement along the cross-sectional contour shape of the modeled object can be suitably used.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to an example of an embodiment. FIG. 3 shows an apparatus for manufacturing a three-dimensional shaped object according to the present invention, in which the outer circumference is surrounded by a cylinder. The squeegee blade 21 smoothes the inorganic or organic powder material supplied onto the elevating table 20 that moves up and down in the space to form the powder layer 1 having a predetermined thickness Δt1.
Powder layer forming means 2 for forming 0 and laser oscillator 30
Sintered layer forming means 3 that sinters the powder to form the sintered layer 11 by irradiating the powder layer 10 with the laser beam output from the laser beam through the scanning optical system such as the galvanometer mirror 31.
The milling head 41 is provided on the base portion of the powder layer forming means 2 via an XY drive mechanism (preferably a linear motion linear motor drive in terms of speedup) 40 to form the removing means 4. .

As shown in FIG. 1, the manufacturing of the three-dimensional shaped article in this article is performed on the upper surface of the lifting table 20 which is an adjusting means for adjusting the relative distance between the sintered layer forming means and the sintered layer. First, by supplying an inorganic or organic powder material to the surface of the base 22 and smoothing it with the blade 21
The powder layer 10 of the first layer is formed, and a portion of the powder layer 10 to be cured is irradiated with a light beam (laser) L to sinter the powder and form a sintered layer 11 integrated with the base 22.

After that, the elevating table 20 is lowered a little and the inorganic or organic powder material is again supplied to the blade 2
The second powder layer 10 is formed by smoothing with 1, and a light beam (laser) is applied to the portion of the powder layer 10 to be cured.
L is irradiated to sinter the powder to form the sintered layer 11 integrated with the lower sintered layer 11.

By repeating the process of lowering the elevating table 20 to form a new powder layer 10 and irradiating it with a light beam to form a desired layer as the sintered layer 11, a desired three-dimensional shaped object is manufactured. For example, a spherical iron powder having an average particle diameter of about 20 μm as a powder material, a carbon dioxide laser as a light beam, and a thickness Δt1 of the powder layer 10 of 0.05 mm are preferable.

The light beam irradiation path is preliminarily defined by three-dimensional CAD.
Create from data. That is, similarly to the conventional one, the contour shape data of each cross section obtained by slicing the STL data generated from the three-dimensional CAD model at an equal pitch (here, 0.05 mm) is used. At this time, it is preferable to perform irradiation with a light beam so that at least the outermost surface of the three-dimensional shaped object can be sintered so as to have a high density (porosity of 5% or less). This is because even if the surface removal described later is performed by the removing means, if the exposed portion is porous, the surface after the removal processing will also be in a porous state. Therefore, as shown in FIG. The surface layer portion S and the inside N are divided, and the inside N is irradiated with a light beam under a sintering condition such that the inside N is porous, and the surface layer portion S is under the condition that the powder is almost melted to have a high density. In FIG. 5 (a), 12 indicates a high density portion, and 16 in the drawing is a low density surface layer formed by the above-mentioned adhered powder.

The formation of the powder layer 10 and irradiation of a light beam to form the sintered layer 11 is repeated, but the total thickness of the sintered layer 11 is, for example, a tool of the milling head 41. When the required value obtained from the length or the like is reached, the removing means 4 is once operated to cut the surface of the modeled object modeled up to that point. For example, if the tool (ball end mill) of the milling head 41 is capable of cutting with a diameter of 1 mm, an effective blade length of 3 mm and a depth of 3 mm, and the thickness Δt1 of the powder layer 10 is 0.05 mm, then 6
The removal means 4 is operated at the time when the 0 sintered layer 11 is formed.

As shown in FIG. 5, the low-density surface layer 16 of the powder adhering to the surface of the shaped article is removed by the cutting process by the removing means 4, and at the same time, the high-density portion 12 is ground, whereby the surface of the shaped article is cut. Then, the high-density portion 12 is entirely exposed. For this reason, the sintered layer 11 is more than the desired shape M.
To be a little larger.

The cutting route by the removing means 4 is created in advance from the three-dimensional CAD data, like the light beam irradiation route. At this time, the contour line machining is applied to determine the machining path, but the Z-direction pitch does not need to be particular about the stacking pitch at the time of sintering, and in the case of a gentle inclination, the Z-direction pitch is made finer and interpolated, Be prepared to get a smooth surface. When cutting with a ball end mill with a diameter of 1 mm, the cutting depth is 0.1 to 0.5 mm,
The feed speed is preferably 5 m / min to 50 m / min, and the tool rotation speed is preferably 20,000 rpm to 100,000 rpm.

At the time of removal by cutting, as shown in FIG. 6, a portion immediately before cutting is irradiated with a light beam (laser) L having a reduced energy density and heated to be softened. When the tool 44 cuts the softened portion, the cutting resistance is reduced, so that the cutting time can be shortened and the life of the tool 44 can be extended.

Further, as shown in FIG. 7, it is also preferable to increase the density by irradiating the portion immediately after the cutting with the light beam L to melt and harden or heat the portion.

In FIG. 8, the laser from the laser oscillator 30, which is the sintered layer forming means 3, is used for the optical fiber 3.
The irradiation head 35 for receiving and outputting through 6 is a removing means 4
Attached to the XY drive mechanism 40. Since the number of common parts increases, the number of parts can be reduced.

By the way, when the removal means 4 removes the surface of the shaped article and the unnecessary portion, the unsintered powder and the cutting scraps produced by the removal means 4 interfere with the removal work, and the next powder layer 1
At the time of forming 0, the cutting powder is caught on the blade 21 and the flat powder layer 10 cannot be formed,
The cutting waste may be caught between the blade 21 and the modeled object, and the blade 21 may stop. For this reason, FIG.
Also, as shown in FIG. 10A or FIG. 10B, for example, the suction nozzle 51 connected to the air pump 50 is attached to the tool 44.
It is advisable to dispose the green powder and cutting chips by suction at the same time as cutting so as to be removed by suction. In the case where the tool 44 is surrounded by the suction nozzle 51, as shown in FIG.
A spindle head can be suitably used as 4.

As shown in FIG. 11, only the unsintered powder may be sucked and removed before the cutting work, and the cutting debris may be sucked and removed at the same time as the cutting process. Since the powder does not mix, it becomes easy to reuse the unsintered powder.

By the way, if the unsintered powder is removed by suction, a large amount of powder is required when the powder layer 10 is further laminated after the removing step, and when the removing step is repeated a plurality of times, the unsintered powder is removed each time. The powder must be filled in the entire space excluding the binding powder, resulting in a large time loss.

For this reason, as shown in FIG. 12, a solidified portion 18 is formed by pouring a resin or a brazing material into the space where the unsintered powder has been removed, and solidifying the resin or brazing material. It may be formed on the upper surface of the upper sintered layer 11 and the solidified portion 18. The amount of powder used can be reduced.

Regarding the suction nozzle 51 in the excluding means composed of the air pump 50 and the suction nozzle 51, which removes the unsintered powder prior to the removing step,
As shown in FIG. 13, when it is attached to the drive part of the blade 21 in the powder layer forming means 2, it is possible to remove the unsintered powder in the entire area and a dedicated drive mechanism for the suction nozzle 51 is required. Therefore, the device configuration can be simplified.

Further, as shown in FIG. 14, the suction nozzle 5
When 1 is attached to the dedicated XY drive mechanism 55 or the XY drive mechanism 40 in the removing means 4, the suction nozzle 51 can be moved along the cross-sectional contour line shape of the modeled object.

The unsintered powder is not removed by suction immediately before the removing step, but is sprayed with liquid nitrogen or the like (at the same time, a gas containing moisture is sprayed if necessary). May be solidified, or resin or brazing material may be poured to solidify, and the removing means 4 may be operated in this state. Since the cutting dust does not enter the unsintered powder, it is possible to easily remove the cutting dust.

The one shown in FIG. 15 shows one provided with a measuring means 6 for measuring the shape and position of the modeled object immediately after sintering or immediately after removal processing. The irradiation accuracy of the light beam and the processing accuracy of the removal processing can be measured on-machine. By feeding back the measurement results and comparing the measurement data (position coordinate data) with the CAD data, the modeling accuracy can be improved. In addition to being able to calculate, by correcting the next light beam irradiation path data or the next removal processing path data based on the comparison result, it is possible to perform more accurate modeling.

When the measuring means 6 is, for example, a piezoelectric contact sensor, the XY drive mechanism 4 in the removing means 4 is used.
When the measuring means 6 is provided at 0, measurement can be performed without requiring a dedicated drive mechanism for the measuring means 6.

As the measuring means 6, an image pickup means such as a CCD camera may be used. The image pickup means is moved so that the point to be measured becomes the center of the image, and the displacement amount is measured from the number of pixels displaced from the image center and the point to be measured in the modeled object.

In each of the above examples, the removal means 4 is one that removes by cutting, but in addition to this, the removal may be performed by a high-power laser. For example, if a Q-switched YAG laser having a peak output of 10 kW or more is used, the low-density surface layer 16 on the surface of the modeled object can be instantly evaporated and removed. Further, the removed portion is not limited to the surface portion of the modeled object, and if the originally unneeded part has to be modeled for the sake of modeling, this unnecessary part can be removed.

[0041]

As described above, according to the method for producing a three-dimensional shaped object of the present invention, by irradiating a predetermined portion of the layer of the inorganic or organic powder material with a light beam and sintering the powder at the corresponding portion. Forming a sintered layer, coating a new layer of powder material on this sintered layer, irradiating a light beam at a predetermined location to sinter the powder at the relevant location, and integrate it with the lower sintered layer. By repeating the formation of a new sintered layer, the surface of the powder sintered part, which is a three-dimensional shaped object, is created in order to create a powder sintered part in which multiple sintered layers are laminated and integrated. High density
In addition to sintering, the process of removing the surface part and / or unnecessary part of the modeled object created up to that time after the formation of the sintered layer is inserted into the process of creating the sintered layer multiple times .
Since the high density portion is exposed by the removing step , that is, the formation of a sintered layer in which the surface is sintered at high density
High density by removing the surface and / or unnecessary parts of the model
Because the exposed part is repeatedly performed, the surface roughness of the surface is high without being restricted by the drill length etc. for finishing.
You can comb it to get a nice finish.

[0042]

[0043]

Immediately before the removal step, if the removal target portion is irradiated with a light beam to soften the removal target portion, the cutting resistance can be lowered when the removal is performed by cutting. The tool life can be improved.

Further, if the light beam for melt hardening or heat treatment is irradiated to the portion where the portion to be removed is removed immediately after the removing step, the surface density can be improved.

When removing the unsintered powder around the powder-sintered part, which is a three-dimensional shaped object, and the scraps generated during the removing operation, the cutting scraps can be treated at the same time as the removing operation in the removing step. Therefore, it is possible to prevent the cutting chips from exerting a bad influence upon forming the next powder layer. The removal of the unsintered powder may be performed immediately before the removal step. In this case, since the unsintered powder and the cutting waste can be treated separately, it is easy to reuse the unsintered powder. .

In the case of performing the above-mentioned removal, if a resin or a brazing material is poured into the removed portion and the removed portion immediately after the removing step, and then a layer of the next powder material is formed and sintered,
The amount of powder used can be reduced.

Immediately after the formation of the sintered layer or immediately after the removal step, the shape and position of the modeled object formed so far are measured, and based on the measurement result, the light beam for forming the next sintered layer is measured. By correcting the irradiation path data and the removal processing path data of the part to be removed in the next removing step, more accurate modeling can be performed.

The unsintered powder may be solidified before the removing step. In this case, the unsintered powder may be frozen or a resin or a brazing material may be used. When solidified in this manner, only cutting chips can be easily removed without the need for refilling with powder or the like.

The apparatus for producing a three-dimensional shaped object according to the present invention comprises a powder layer forming means for forming a layer of an inorganic or organic powder material, and a predetermined portion of the powder layer irradiated with a light beam to a corresponding portion. And a means for adjusting the relative distance between the sintered layer forming means and the sintered layer, and the surface portion of the modeled object and / or Since the removal means for removing the unnecessary portion is provided, the surface roughness after modeling can be improved, and the above manufacturing method can be carried out easily.

The effect of scraps can be avoided by providing the removing means for removing the unsintered powder and scraps generated in the removing step by the removing means.

Immediately after the formation of the sintered layer or immediately after the removal step, a measuring means for measuring the shape and position of the modeled object formed so far, and an XY drive mechanism are provided to obtain the cross-sectional contour shape of the modeled object. By providing a correction unit that corrects the operation of the sintered layer forming unit based on the measurement result of the above-described measuring unit that performs measurement along with, it is possible to easily obtain a highly accurate modeled object. Become.

[Brief description of drawings]

FIG. 1 is an operation explanatory diagram according to an example of an embodiment of the present invention.

FIG. 2 is a block diagram of the above.

FIG. 3 is a schematic perspective view of the above.

FIG. 4 is an explanatory diagram related to the surface high density portion of the above.

5 (a) and 5 (b) are cross-sectional views showing the same removing step as above.

FIG. 6 is a perspective view showing an operation of another example of the above.

FIG. 7 is a perspective view showing an operation of still another example of the same.

FIG. 8 is a schematic perspective view of another example.

FIG. 9 is a schematic perspective view of still another example.

10 (a) and 10 (b) are schematic cross-sectional views each showing an example of an excluding means.

11A and 11B are schematic cross-sectional views showing the operation of another example of the excluding means.

12 (a) and 12 (b) are schematic cross-sectional views showing a process after the exclusion process.

FIG. 13 is a schematic cross-sectional view showing still another example of the excluding means.

FIG. 14 is a schematic perspective view showing another example of the excluding means.

FIG. 15 is a schematic perspective view of an example including measuring means.

16 (a) and 16 (b) are cross-sectional views showing the same operation.

FIG. 17 is a schematic perspective view showing another example of measuring means.

FIG. 18 (a) is a cross-sectional view illustrating adhesion of powder during formation of a sintered layer, (b) is a cross-sectional view showing a low-density surface layer, (c).
[Fig. 3] is a cross-sectional view when only a step is removed.

[Explanation of symbols]

L light beam 4 Removal means 10 powder layer 11 Sintered layer

Front page continued (72) Inventor Hirohiko Togeyama 1048, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Isao Fuwa, 1048, Kadoma, Kadoma City, Osaka Prefecture (72) Inventor Ei Master, 1048, Kadoma, Kadoma, Osaka Prefecture, Matsushita Electric Works Co., Ltd. (56) Reference JP 2000-73108 (JP, A) JP 3-183530 (JP, A) JP 9-109269 (JP, A) Special Table 9-511705 (JP, A) Patent 2620353 (JP, B2) International Publication 97/024217 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) B22F 1/00 -7/08 B29C 67/00-67/24 B23K 26/00-26/18

Claims (16)

(57) [Claims] 1. A sintered layer is formed by irradiating a predetermined portion of an inorganic or organic powder material layer with a light beam to sinter the powder at that portion, and a sintered material layer is formed on the sintered layer. By coating a new layer and irradiating a predetermined location with a light beam to sinter the powder at the relevant location to form a new sintered layer integrated with the lower sintered layer, a plurality of layers are repeatedly formed. When creating a powder-sintered part in which the above-mentioned sintered layers are integrated , the surface of the powder-sintered part, which is a three-dimensional shaped object, is highly dense.
In addition to sintering, the process of removing the surface part and / or unnecessary part of the modeled object created up to that time after the formation of the sintered layer is inserted into the process of creating the sintered layer multiple times .
A method for manufacturing a three-dimensional shaped object, which comprises exposing the high-density portion by the removing step . 2. The removing step is performed by cutting.
The method for manufacturing a three-dimensional shaped object according to claim 1 . 3. A laser is used for the removing step.
The method for producing a three-dimensional shaped object according to claim 1, which is characterized in that . ) 4. A light beam is applied to a portion to be removed immediately before the removing step.
Contractor characterized by irradiating the material to soften the part to be removed.
The method for producing a three-dimensional shaped object according to any one of claims 1 to 3 . 5. The part to be removed is removed immediately after the removing step.
Irradiate a part with a light beam for melt hardening or heat treatment
The method for producing a three-dimensional shaped object according to any one of claims 1 to 4, characterized in that . 6. A removal process and a tertiary process at the same time as the removal work.
The unsintered powder around the powder-sintered part, which is the original shape,
Characterized by removing the scraps generated during the removal work
The method for manufacturing a three-dimensional shaped object according to any one of claims 1 to 5 . 7. The unsintered powder is removed immediately before the removing step.
The method according to any one of claims 1 to 5, characterized in that
Manufacturing method of the three-dimensional shaped object. 8. The removing section and the removing section are paired immediately after the removing step.
Resin or brazing material and then the next powder material
The formation and the sintering of the layers are performed.
7. The method for producing a three-dimensional shaped object according to any one of items 7 . 9. Immediately after forming the sintered layer or directly after the removing step.
After that , measure the shape and position of the formed object
And for the formation of the next sintered layer based on the measurement results.
Light beam irradiation path data and removal target in the next removal process
The feature is that the removal processing route data of the part is corrected.
The method for manufacturing a three-dimensional shaped object according to any one of claims 1 to 8 . 10. The green powder is solidified before the removing step.
It is characterized by what is described in any one of Claims 1-9.
Manufacturing method of the three-dimensional shaped object. 11. Solidification of unsintered powder by freezing
The method for manufacturing a three-dimensional shaped object according to claim 10 . 12. An unsintered powder is solidified with a resin or a brazing material.
The method for producing a three-dimensional shaped object according to claim 10, wherein the three-dimensional shaped object is produced. 13. A layer of inorganic or organic powder material
Means for forming a powder layer and a predetermined portion of the powder layer
Irradiate a light beam to sinter the powder at the relevant location to form a sintered layer.
Formed sintered layer forming means, sintered layer forming means and sintered layer
And adjusting means for adjusting the relative distance of the
Removal means for removing the surface portion and / or unnecessary portion of the shaped article
Manufacturing of three-dimensional shaped objects characterized by being equipped with
Equipment . 14. A removal process using unsintered powder or removal means.
Attached to the powder layer forming means is an excluding means for eliminating the dust generated in
The three-dimensional shape according to claim 13, wherein the three-dimensional shape is provided.
Equipment for manufacturing shaped objects . 15. A step of removing the non-sintered powder or removing means.
Is equipped with a means for eliminating the dust generated in the
The removing means has an XY drive mechanism to change the cross-sectional contour shape of the modeled object.
Claims characterized by carrying out exclusion work
Item 13. A device for manufacturing a three-dimensional shaped object according to item 13 . 16. Immediately after the formation of the sintered layer or in the removal step
Immediately after that, measurement of the shape and position of the formed object
Based on the measurement means to perform and the measurement result by the measurement means
And a correction means for correcting the operation of the sintered layer forming means.
In both cases, the measuring means has an XY drive mechanism and
The feature is that the measurement is performed along the cross-sectional contour shape of
The apparatus for manufacturing a three-dimensional shaped object according to any one of claims 13 to 15, which is a characteristic .