WO1994023936A1

WO1994023936A1 - Flat laminated plate molding method in photohardening molding method

Info

Publication number: WO1994023936A1
Application number: PCT/JP1993/000489
Authority: WO
Inventors: Jie Wei; Naoichiro Saito; Seiji Hayano
Original assignee: Cmet, Inc.
Priority date: 1993-04-15
Filing date: 1993-04-15
Publication date: 1994-10-27

Abstract

When a flat laminated plate is molded by a photohardening molding method in the present invention, a step of forming layers with unhardened portions left therein, by irradiating the layers with light in a spaced manner, and a step of hardening the unhardened portions while an upper layer is hardened, are used to form a flat laminated plate while offsetting the strain occurring due to the hardening operation. This enables a flat laminated plate the shape of which is faithful to a design to be molded without causing warpage to occur therein.

Description

One one

Description Laminated flat plate molding method in light curing molding

The present invention relates to a photo-curing molding method, and more particularly, to a laminated plate molding method in a photo-curing molding method capable of forming a flat plate without causing warpage.

Background art

In order to form a three-dimensional model or a three-dimensional image, light-curing molding is used.c In this light-curing molding, the lowest cross section of the stereoscopic image is usually formed on the surface of the liquid resin that cures when irradiated with light. First, a cross-section hardened layer corresponding to the lowermost cross-section is formed by irradiating light to a region corresponding to. After that, an uncured liquid resin is introduced on top of it, and this time, light is applied to the area corresponding to the cross section immediately above, and a cross-section hardened layer is laminated. By repeating this process, a stacked three-dimensional image is formed.

For example, when a flat plate such as a desk top plate is formed by using such a technique, as shown in FIG. 10, light is first radiated to the entire region 99 corresponding to the flat plate, and The bottom layer 24 is formed. Here, reference numeral 9 in the drawing denotes a scanning locus of light. Then, the uncured liquid resin is introduced, and the whole area is irradiated again to form a layer 25 thereon. (Here, 24 and 25 are separated from each other for clarity. , But actually stick). By repeating this, a laminated flat plate is formed.

However, when the laminated plate is formed by the photo-curing molding method, the end of the laminated plate P is easily distorted into an upwardly curved shape as shown in FIG. 11 (c). The reason is presumed as follows.

In this photocuring molding method, as shown in Fig. 11 (a) (26 in the figure indicates each irradiation area), only the upper hardened layer 25 is formed on the lower hardened layer 24. Instead, the upper hardened layer 25 needs to be integrated with the lower hardened layer 24. For this reason, the lower hardened layer 24, especially the upper surface side, is irradiated while being overlapped during the irradiation for forming the upper hardened layer 25 (the double irradiated area is indicated by reference numeral 26 a). For this reason, as shown in FIG. 11 (b), the upper side of one hardened layer hardens harder and shrinks accordingly. Since this tendency affects all layers, the laminated flat plate is likely to have an unintended and distorted shape in which both ends are curved upward (see Fig. 11 (c)).

Disclosure of the invention

Therefore, the present invention proposes a laminated plate forming method in a photo-curing molding method capable of forming a laminated plate having a shape faithful to the design without causing warpage.

(1) The first invention comprises a step of forming a layer leaving an uncured portion by irradiating separately when forming a laminated flat plate by a photocuring molding method, and a step of curing an upper layer thereof. And a step of curing the uncured portion, wherein a laminated flat plate is molded while canceling distortion caused by curing.

According to this method, a layer with an uncured portion is interposed, and the uncured portion is cured when the upper layer is formed, so that the shrinkage stress accompanying the curing is offset, and a flat plate with less distortion is formed. .

(2) Further, the second invention is a laminated flat plate molding method in the photocuring molding method according to the first invention, wherein a beam is applied to the entire surface of a plane portion of the liquid resin corresponding to the laminated flat plate. Irradiating without gaps to form a first cured layer, and leaving an uncured part by irradiating the flat part of the liquid resin introduced on the first cured layer with a beam separately A second cured layer is formed, and shrinkage stress is caused by dual irradiation of the beam irradiation for forming the first cured layer and the beam irradiation for forming the second cured layer on the upper part of the first cured layer. Forming a first hardened layer contraction stress acting portion acting on the third hardened layer by irradiating the flat portion of the liquid resin introduced on the second hardened layer with no gap. Forming step By curing the liquid resin in the uncured portion of the second cured layer without replenishing the liquid resin from the outside, the second cured layer has a contraction stress that offsets the contraction stress of the contraction stress acting portion of the first cured layer. Forming a second hardened layer shrinkage stress acting portion acting on the second hardened layer.

According to this method, the first hardened layer formed on the first hardened layer has a reduced contraction stress acting portion. One —

The shrinkage stress and the shrinkage stress of the second hardened layer contraction stress acting portion formed in the second hardened layer are canceled out, and a flat plate with less distortion is formed.

(3) Further, the third invention is a laminated flat plate molding method in the photocuring molding method according to the second invention, wherein the scanning locus of the beam when forming the second cured layer and the first By making the scanning trajectory of the beam different when forming the third hardened layer, the first hardened layer acts on the first hardened layer contraction stress and the second hardened layer in the second hardened layer. (2) It is characterized in that the hardened layer contraction stress acting portion is formed at a position off the same vertical line.

According to this method, as in the second aspect, the contraction stress of the first hardened layer contraction stress acting portion and the contraction stress of the second cured layer contraction stress acting portion are offset, and a flat plate with less distortion is formed. You.

(4) Further, the fourth invention is a laminated flat plate molding method in the photocuring molding method according to the first invention, wherein a path adjacent to a plane portion of the liquid resin corresponding to the laminated flat plate is provided. Forming a first hardened layer by scanning the beam along a lattice-shaped path where the beam trajectory does not overlap; and forming the first hardened layer with respect to the planar portion of the liquid resin introduced on the first hardened layer. Forming a second hardened layer by scanning the beam along a grid-like path that is finer than in the case of the hardened layer and does not overlap the beam trajectory in adjacent paths; and forming a second hardened layer on the second hardened layer. Forming a third cured layer by scanning the beam along a lattice-shaped path in which the beam trajectory overlaps the path adjacent to the plane portion in the introduced liquid resin. Before irradiation The beams are irradiated multiple times at appropriate places of the plurality of cured layers to form a multiple irradiation stress acting portion where a contraction stress acts, and the beam is not irradiated to the appropriate places of the plurality of cured layers. The remaining liquid resin is cured without replenishment of the liquid resin from the outside to form a non-irradiation shrinkage stress acting portion on which a contraction stress acting on the multiple irradiation stress acting portion is offset.

According to this method, the contraction stress of the multiple irradiation stress acting portion and the contraction stress of the non-irradiation contraction stress acting portion cancel each other, and a flat plate with little distortion is formed.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an enlarged cross-sectional view taken along line a-a of the laminate in the first embodiment shown in FIG. One one

It is the figure which matched the action figure of a force, and the figure showing the state of cancellation of contraction stress.

FIG. 2 is a schematic diagram of a method of forming a laminate by a photocuring molding method.

FIG. 3 is a diagram showing a laminated plate and a beam scanning method for each layer of the laminated plate.

FIG. 4 is a diagram showing a beam scanning method of the laminated plate of the second embodiment and each layer of the laminated plate (FIG. 5 is an enlarged sectional view of the laminated plate of FIG. FIG. 7 is a diagram corresponding to a diagram showing a state of cancellation of contraction stress.

FIG. 6 is a diagram correspondingly showing an enlarged cross-sectional view taken along the line c-c of the laminated plate of FIG. 4, a diagram showing the action of contraction stress, and a diagram showing the state of cancellation of contraction stress.

FIG. 7 is a perspective view showing a beam scanning method and an irradiation area of the first layer of the laminate of the third embodiment.

FIG. 8 is a perspective view showing a beam scanning method of the second layer and an irradiation region. FIG. 9 is a perspective view showing a beam scanning method of the third layer and an irradiation region. FIG. 10 is a perspective view showing a beam scanning method in a conventional molding method.

FIG. 11 is a diagram in which an enlarged cross-sectional view of the laminated plate by the conventional molding method, an action diagram of the contraction stress, and a diagram showing a state in which the contraction stress is offset are associated with each other.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, as a first embodiment of the present invention, a case where a laminated flat plate 12 shown in FIG. 3A is formed will be described as an example.

First, the three-dimensional shape of the laminated flat plate 12 is designed using a three-dimensional CAD system. As a result, the three-dimensional CAD system defines the three-dimensional shape information of the laminated plate 12. Then, the shape of the cross section when the laminated flat plate 12 is horizontally sliced with a certain thickness is defined. By irradiating the surface of the liquid resin with laser light based on this cross-sectional shape, a laminated surface is formed.

In the photo-curing molding method, as shown in FIG. 2, the surface of a liquid photo-curable resin 8 is irradiated with a powerful laser beam 9 to cure the resin 8 in the irradiated area. It is intended to create a three-dimensional cured resin image by stacking multiple layers of resin. The resulting shape is determined by the trajectory of beam 9.

That is, as schematically shown in FIG. 2, the photo-curable resin filled in the tank 8 A portion of the surface is solidified by applying a spot of the laser beam 9 to the surface of the laser beam and moving the laser beam 9 two-dimensionally by the scanner 10. Thereafter, the solidified material is settled from the liquid surface by the thickness of one layer by the stage 11, and a single liquid resin 8 is introduced onto the solidified portion. Next, the liquid portion is similarly solidified. This solidified image is laminated and integrated on the lower solidified image. This is repeated one after another.

In this case, the laser beam 9 can be freely scanned on the liquid surface by the scanner 10.

In the present embodiment, the inside of the outline of the cross-sectional shape is irradiated based on the data of the three-dimensional CAD system, and three layers are laminated to form a laminated flat plate 12. The spot shape of the laser beam 9 used is circular and the diameter is 0.5 mm. As shown in FIG. 1 (a), the laser beam 9 can reach the liquid resin 8 in a parabolic manner to a depth of about 7 times the thickness of one layer (however, in FIG. The resin 8 is not shown in the figure, and the areas irradiated by the laser beam 9 are indicated by reference numerals 4, 5, and 7.) o

The laminated flat plate 12 shown in FIG. 3A is a laminated flat plate having a thickness of 0.6 mm, for example, and is formed in a three-layer structure including 0.2 mm layers.

First, the beam 9 is scanned by the scanner 10 on the surface of the liquid resin 8 corresponding to the inside of the contour based on the cross-sectional shape information of the first layer 1 of the laminated plate 12 as shown in FIG. 3 (b). Is done. That is, the inside of the contour is run in a folded shape in parallel to the X direction in FIG. 3 (b). At this time, the interval between the centers of the beams 9 is 0.8 times the diameter, and is actually 0.4 mm. Therefore, the beams 8 are irradiated while overlapping each other by 0.1 mm. Therefore, the entire surface of the first layer 1 is irradiated without any gap.

The _c- beam 9 whose irradiation state on the cross section in the Y direction of the first layer 1 of the laminated flat plate 12 is shown in FIG. 1 reaches the liquid resin 8 in a parabolic manner, and the irradiation area 4 is formed in the resin 8. Form. The beam 9 irradiates the entire first layer in a thickness range of 0.2 mm, and the area 4 immediately starts polymerization and is hardened by laser light stimulation. Normally, when a certain amount of the liquid resin 8 hardens, the volume of the hardened resin 8 decreases and shrinks. Power, then, first In the layer, since the periphery is filled with the liquid resin 8, distortion is unlikely to occur.

Next, when the stage 11 is lowered to lower the first layer 1 by the thickness of one layer (0.2 mm), a new resin 8 is introduced onto the first layer 1. As shown in FIG. 3B, a beam 9 is scanned on the surface of the resin 8 in parallel with the X direction based on the cross-sectional shape information of the second layer 2. At this time, the center of the beam 9 is scanned in a folded shape inside the contour at an interval of 1.5 times the diameter. That is, the distance between the centers of the adjacent beams 9 is 0.75 mm, and the beams 9 are radiated at a distance without overlapping. As a result, as shown in the sectional view in the Y direction of FIG. 1, the irradiation area 5 by the beam 9 is formed in a band shape. The resin 8 in the beam irradiation area 5 in the second layer is immediately polymerized and hardened.

As shown in FIG. 1, the depth of the laser beam of this beam 9 reaches about 1.7 times the layer thickness. Therefore, the laser beam of the beam 9 of the second layer 2 is partially irradiated to a depth of about 70% above the already hardened first layer. In such a double irradiation area 4a, the resin that has been cured once is polymerized by receiving light stimulation again. C Therefore, the degree of polymerization of the resin is increased in this part 4a. However, unlike the first hardening, the resin is not replenished from the surrounding area, so it hardens and shrinks by pulling the surrounding area. That is, as shown in FIG. 1 (b), a stress that contracts on the upper surface acts on the entire first layer 1 to cause upward warpage at both ends. Although this arrow illustrates the Y direction, contraction stress is actually acting in all directions around the arrow.

At the same time, an uncured portion 6 is formed between the irradiation regions 5 in a band shape having a half width (0.25 mm) of the diameter of the beam 9.

Next, the second layer 2 is further lowered by the stage 11 to introduce a new liquid resin 8. The beam 10 is scanned by the scanner 10 in parallel to the X direction on the surface of the liquid resin 8 based on the cross-sectional shape information of the third layer 3. The scanning method in the third layer 3 is the same as that in the first layer 1. That is, the beam 9 irradiates the entire surface without any gap while overlapping each other by 0.1 mm. By this irradiation, an irradiation area 7 as shown in FIG. 1 is formed. Beam 9 reaches over this layer thickness --

Therefore, the entire third layer 3 is cured by this irradiation.

Further, since this beam 9 reaches about 70% above the second layer 2, a double irradiation area 5 a is partially formed above the irradiation area 5 of the second layer 2. In the double irradiation region 5a, as in the case of the first layer 1, the polymerization proceeds further, so that a contraction stress acts on this region 5a.

Further, the uncured portion 6 of the second layer 2 is newly irradiated by this irradiation, and an irradiation area 6a is formed in the second layer. In this irradiation area 6a, the liquid resin 8 is immediately cured. In this region 6a, no strain stress is generated during curing because the liquid resin 8 in the region 6b of the uncured portion 6 that has not been irradiated this time is still present.c However, the beam 9 is still unirradiated. In 6b, the polymerization proceeds slowly but hardens due to the surrounding polymerization stimulus. There is not enough resin 8 in this part 6b and it is not refilled. Therefore, at the time of hardening, the surrounding hardened parts are strongly pulled to try to polymerize. That is, strong contraction stress acts on the uncured portion 6b.

As a result, a contraction stress acts on the double irradiation area 5a on the upper side of the second layer 2, and a stronger contraction stress acts on the uncured portion 6b formed around the lower side. For this reason, the entire second layer 2 contracts as shown by the arrow in FIG. 1 (b), and as a result, tends to cause downward warpage. The arrow in Fig. 1 (b) illustrates the Y direction, but actually contracts in all directions. Therefore, the stress of the second layer 2 and the stress of the first layer 1 act to cancel each other. As a result, as a whole, the laminated flat plate 12 in which the warpage is offset is formed as shown in FIG. 1 (c). In the conventional irradiation method, which scans the entire surface of each of the layers 1, 2, and 3 at equal intervals without any gap, the upper part of each layer becomes a partially double irradiation area, and the layers 1, 2, and 3 Shrinkage stress was acting on the upper surface side. However, in this example, as is apparent from the cross-sectional view in the Y direction of the laminated flat plate 12 shown in FIG. 1, a contraction stress stronger than the contraction stress acting on the double irradiation regions 4a and 5a is observed. By interposing the layer 2 having the acting uncured portion 6b, the warpage of the first layer 1 having the double irradiation area 4a is offset by the warpage of the second layer 2 having the uncured portion 6b. Have been.

In this way, by forming the remote irradiation layer 2, a strong lower layer is formed. One one

As a result, an uncured portion 6b having a shrinking action is formed, and the shrinkage stress of the laminated layer 1 can be corrected and offset. In addition, this canceling effect acts in all directions, so that the entire shape of the laminated flat plate 12 does not warp.

Next, as a second embodiment of the present invention, a laminated flat plate 13 (see FIG. 4 (a)) formed by the irradiation method shown in FIG. 4 (b) will be described as an example. In this embodiment, as in the first embodiment, a laminated flat plate 13 formed by laminating three layers having a thickness of 0.2 mm is formed. The apparatus and the basic operation in the photocuring molding method are the same as those in the first embodiment. The scanning method of the force beam 9 is different.

First, as shown in FIG. 4 (b), similarly to the first embodiment, the inside of the cross section of the cross section of the first layer 14 based on the three-dimensional shape information is parallel to the X direction shown, and the irradiation interval is set to 9 beams. It is scanned back and forth as 0.8 times the diameter of. For this reason, the beam 9 is irradiated on the first layer 14 so that the entire surface has no gap and the scanned trajectories partially overlap (by 0.1 mm).

The irradiation state of the cross section of the first layer 14 of the laminated flat plate 13 in the Y direction is shown in FIGS. 5 (a) and 6 (a). The beam 9 reaches the liquid resin 8 in a parabolic manner, and forms an irradiation area 17 in the resin 8. This beam 9 irradiates the entire first layer in a range of 0.2 mm in thickness, and this area 17 starts polymerization immediately by light stimulation and _cures.c Normally, a certain amount of liquid resin 8 cures Then, the volume of the cured resin 8 decreases and shrinks. In the first layer 14, no distortion occurs because the periphery is filled with the liquid resin 8. Therefore, no stress acts on this layer 14.

Next, when the stage 11 is lowered to lower the first layer 14 by the thickness of one layer (0.2 mm), a new resin 8 is introduced onto the first layer 14. As shown in FIG. 4B, the surface of the resin 8 is further scanned with a beam 9 in parallel with the Y direction based on the cross-sectional shape information of the second layer 15. At this time, the inside of the contour is scanned in a folded shape so that the center of the beam 9 is spaced 1.5 times the diameter. That is, the distance between the centers of the adjacent beams 9 is 0.75 mm, and the beams 9 are irradiated at a distance without overlapping. As a result, Figs. 5 (a) and 6 ( One one

As shown in the second layer 15 in the Y-direction cross-sectional view of a), the irradiation area 18 by the beam 9 is formed in a band shape. The beam irradiation area 18 in the second layer 15 immediately overlaps and hardens.

In addition, as shown in FIG. 5 (a), the beam 9 irradiating the second layer 15 partially irradiates to a depth of about 70% above the already cured first layer 14 as shown in FIG. Will be done. In such a double irradiation area 17a, the once cured resin 8 is again photostimulated and polymerized. Therefore, in this portion 17a, the degree of polymerization of the resin 8 is increased. Therefore, as in the first embodiment, as shown in FIG. 5 (b), contraction stress acts in all directions on the double irradiation area 17a, that is, on the upper surface side of the first layer 14.

On the other hand, at the same time, as shown in Fig. 6 (a), the uncured part of the irradiation area 18 of the second layer 15 was strip-shaped with half the width of the beam 9 (0.25 mm). 19 is formed.

Next, a new liquid resin 8 is introduced on the second layer 15 as a third layer 16 c. The beam 9 is again applied to the third layer 16 in parallel with the X direction. The entire cross section is scanned at the same irradiation interval as 14. As shown in FIG. 5A, the third layer 16 is rapidly cured by this irradiation. Further, a double irradiation area 18a is formed in the second layer 15, and as in the first embodiment, the contraction stress in all directions shown in FIG. Works. As a result, the b section of the second layer 15 is warped upward, and as shown in FIG. 5C, the b section of the first layer 14 and the second layer 15 is combined. Try to cause upward warpage.

Further, as shown in FIG. 6 (a), the beam 9 also reaches the uncured portion 19, and the resin 8 is cured in the irradiation region 19a. The portion of the second layer, which is centered on the lower part of the uncured portion 19, has a portion 19b to which the beam 9 does not reach even when the third layer 16 is irradiated. In the uncured portion 19b, a shortage of the resin 8 occurs as in the first embodiment. That is, curing gradually proceeds in a state where there is no longer enough resin 8 capable of filling the uncured portion 19b. Therefore, as it hardens, it tries to harden while pulling the surrounding hardened area. In other words, as shown in Fig. 6 (b), strong contraction stress acts on this part 19b. -1 o-

Become. As a result, as shown in FIG. 6 (c), the C section including the first layer 14 and the second layer 15 tends to be warped downward.

As described above, in the first layer 14, the second layer 15 and the third layer 16, even when the scanning direction of the beam 9 in each layer is orthogonal, the uncured portion 19b is interposed by the remote irradiation. It is exactly the same that can be done. Accordingly, the effect of canceling or correcting the contraction stress by the uncured portion 19b can be obtained in the same manner. As a result, in the present embodiment, the upward warping stress generated in the section b of the laminated flat plate 13 and the downward warping stress generated in the section c cancel each other out, so that the warpage as a whole is reduced. No laminated plate 13 is formed.

Third embodiment>

Next, a case of manufacturing a laminated flat plate 20 shown in FIG. 9B will be described as a third embodiment. In this embodiment, as in the first and second embodiments, a laminated flat plate 20 formed by laminating three layers each having a layer thickness of 0.2 mm is manufactured. The apparatus and the basic operation in the photocuring molding method are the same as those of the above-mentioned embodiments, but the method of scanning the beam 9 is different.

First, as shown in Fig. 7 (a), the inside of the contour of the cross section of the first layer 21 based on the three-dimensional shape information is turned back at an interval of 2.0 times the diameter in parallel to the X direction shown in the figure. Is scanned. That is, the distance between the centers of the adjacent beams 9 is 1.0 mm, and as shown in FIG. 7 (b), the irradiation areas 21a by the respective beams 9 do not overlap each other and are spaced apart from each other. When it is irradiated, Further, thereafter, scanning is performed in a folded manner at the same irradiation interval in parallel with the Y direction in the figure. As a result, the beam 9 is irradiated in a band shape with a gap at the same interval (0.5 mm) as the diameter, forming a grid-shaped irradiation region 21a. In the irradiation area 21a, the resin 8 is rapidly _cured.c. And, between the lattice-shaped irradiation areas 21a, an uncured part 21b is formed at an interval corresponding to the diameter of the beam 9. Is done.

Next, the stage 11 is lowered, the first layer 21 is lowered by the thickness of one layer, and a new resin 8 is introduced on the first layer 21. The inside of the outline is illuminated based on the cross-sectional shape information of the second layer 22. In this irradiation, as shown in Fig. 8 (a), the irradiation interval was set to be 1.3 times the diameter of the beam 9 in parallel with the X direction, and turned back. Scanned. That is, scanning is performed so that the distance between the centers of the beams 9 is 0.65 mm. Further, the beam is scanned in a folded manner in parallel with the Y direction at the same irradiation interval. That is, in the second layer 22, as shown in FIG. 8 (b), the beam 9 has a diameter in both the X and Y directions. Irradiated in a band leaving 0.3 times the gap (0.15 mn) _c. As a result, an irradiated area 22 a is formed leaving a slight uncured portion 22 b. This area 2 Most of 2a is a double irradiation area, but since irradiation is performed in a state where the resin 8 can be replenished, the resin 8 cures without the action of shrinkage stress.

Due to the irradiation of the second layer 22, a double or triple irradiation region is also formed on the upper side of the first layer 21. In this double or triple irradiation area, though not shown, contraction stress acts on the surroundings as in the first and second embodiments. Further, in the uncured portion 2 1b of the first layer 21, the upper side is partially cured by the irradiation of the second layer 22, but is not irradiated mainly on the lower side of the second layer 22. In the portion where the resin 8 is located, shortage of the resin 8 occurs as in the first and second embodiments. That is, curing proceeds gradually in a state where there is no longer enough resin to fill the uncured portion. Therefore, as it cures, it tries to cure while pulling the surrounding cure zone. That is, a strong contraction stress acts partially on the lower side of the first layer 21. Since the effect of the lower contraction stress is greater than the upper contraction stress of the first layer 21, the first layer 21 will be subjected to a downward warping stress _c . When the stage 11 is lowered to lower the second layer 22 by one layer thickness (0.2 mm), a new resin 8 is introduced onto the second layer 22. As shown in FIG. 9A, the inside of the contour of the resin 8 is further illuminated on the surface of the resin 8 based on the cross-sectional shape information of the third layer 23. First, the irradiation of the third layer 23 is performed in a folded manner in parallel with the X direction with an irradiation interval of 1.1 times the diameter of the beam 9. That is, scanning is performed so that the distance between the centers of the beams 9 is 0.55 mm. Furthermore, scanning is performed in a folded shape at the same irradiation interval in parallel with the Y direction. That is, in the third layer 23, as shown in FIG. 9 (b), the beam 9 has a gap (0.05 mm) of 0.1 times the diameter in both the X and Y directions. Irradiated in a band. As a result, an irradiated area 23a is formed leaving a very small uncured portion 23b. Most of this area 23a is a double irradiation area, but irradiation with resin 8 is possible. --

Therefore, it cures without the action of shrinkage stress.

Due to the irradiation of the third layer 23, a double or triple irradiation area is also formed on the upper side of the second layer 22. In this double or triple irradiation area, although not shown, contraction stress acts on the surroundings as in the first and second embodiments. Further, in the uncured portion 2 2 b of the second layer 22, the upper portion of the uncured portion 2 2 b is partially cured by the irradiation of the third layer 23, but is not irradiated mainly around the lower side of the second layer 22. In the portion where the resin 8 is located, shortage of the resin 8 occurs as in the first and second embodiments. That is, a strong contraction stress acts partially on the lower side of the second layer 22. However, the contraction stress in this layer 22 has only a small effect on the whole laminated flat plate as compared with the first layer 21. This is because the uncured portion 22 b itself is small in the second layer 22, and the portion where light does not reach even by the irradiation of the third E ²³ is small. Therefore, unlike the first layer 21, the second layer 22 is warped upward. As a result, the first layer 21 acts to cancel or correct the warpage, and the laminated flat plate 20 having no warp as a whole is formed.

Thus, in the first layer 21, the second layer 22, and the third layer 23, even when the scanning direction of the beam 9 is orthogonal in each layer, the uncured portion 21b, 22 b can be interposed. Further, by changing the irradiation interval in each layer, the ratio of the uncured portion can be adjusted, and the degree of the action of the shrinkage stress can be adjusted.

The number of layers having an uncured portion and the number of layers having an uncured portion and a combination of the layers having no uncured portion with respect to a layer which has been irradiated entirely and have no uncured portion are determined by irradiation. Depends on scanning interval, direction setting, beam intensity, scanning speed, and other conditions. Therefore, in order to obtain a laminated flat plate having no warp, a plurality of irradiation layers may be required for one layer having an uncured portion, or vice versa. In addition, the layer having the uncured portion may be interposed alone or laminated and interposed.

As described above, according to the present invention, when forming a laminated flat plate by the light curing molding method, a new contraction stress is generated by interposing a layer having an uncured portion without being irradiated with a beam. However, due to this contraction stress, warpage due to the conventional contraction stress One —

The effects can be compensated and offset. For this reason, an accurate shape with little distortion can be formed.

Claims

The scope of the claims

(1) When forming a laminated plate by light curing molding method,

By irradiating at a distance, a step of forming a layer leaving an uncured portion and a step of curing the uncured portion at the time of curing the upper layer, offsetting the distortion caused by curing. A laminated flat plate molding method in a photo-hardening molding method, wherein a flat plate laminated while being formed is formed.

(2) The laminated flat plate molding method in the photocurable molding method according to (1), wherein the first curing is performed by irradiating a beam to the entire surface of the flat portion of the liquid resin corresponding to the laminated flat plate without any gap. Forming a layer;

By irradiating the beam separately to the flat portion of the liquid resin introduced on the first cured layer, a second cured layer leaving an uncured portion is formed, and the first cured layer is formed. A first hardened layer contraction stress acting portion where a shrinkage stress is applied is formed on the upper part of the layer by the double irradiation with the beam irradiation for forming the first hardened layer and the beam irradiation for forming the second hardened layer. The process of

Forming a third cured layer by irradiating a beam to the flat portion of the liquid resin introduced on the second cured layer without gaps, and forming an uncured part of the second cured layer. By curing the liquid resin in the portion without external supply of the liquid resin, the second cured layer acts on the second cured layer with a contraction stress acting on the first cured layer and a contraction stress offsetting the contraction stress on the portion. A laminated flat plate molding method in a light curing molding method, wherein a layer contraction stress acting portion is formed.

(3) The laminated flat plate molding method in the light curing molding method according to the above (2), wherein the scanning locus of a beam when forming the second cured layer and the first and third cured layers are formed. By making the beam scanning trajectory different, the first hardened layer contraction stress acting portion in the first hardened layer and the second hardened layer contraction stress acting portion in the second hardened layer are the same vertical. A laminated flat plate molding method in a light curing molding method, which is formed at a position off the line.

(4) A laminated flat plate molding method in the photocuring molding method according to (1), wherein a path adjacent to a plane portion of the liquid resin corresponding to the laminated flat plate is provided. Forming a first cured layer by scanning the beam along a lattice-like path where the beam trajectories do not overlap;

With respect to the planar portion of the liquid resin introduced on the first hardened layer, along a grid-like path where the eyes are finer than in the case of the first hardened layer and the beam trajectories do not overlap in adjacent paths. Forming a second cured layer by scanning the beam; and forming a second cured layer along a lattice-shaped path in which a beam trajectory overlaps with a path adjacent to the plane portion in the liquid resin introduced on the second cured layer. Forming a third cured layer by scanning the beam with

At the time of each of the beam irradiations, the beams are irradiated in multiple places at the appropriate positions of the plurality of cured layers to form a multiple irradiation stress acting portion where a contraction stress acts, and at the appropriate places of the plurality of cured layers. The liquid resin remaining without receiving the beam irradiation is cured without replenishment of the liquid resin from the outside, and the non-irradiation shrinkage stress acting portion where the shrinkage stress acting to cancel the shrinkage stress of the multiple irradiation stress acting portion acts. A laminated flat plate molding method in a photo-curing molding method characterized by being formed.