JPH07304103A - Optical shaping apparatus - Google Patents

Abstract

PURPOSE:To reduce the build-up of the resin soln. on the cured layer formed on a base plate when the base plate is raised in the resin soln. CONSTITUTION:A plurality of holes 2 are provided to a base plate 1 on which a cured layer 25 must be formed so as to pierce the base plate along the rising and falling direction (shown by an arrow A) of the base plate 1. By this constitution, when the base plate 1 is raised, the cured layer 25 and the resin soln. present above the base plate 1 flow through the holes 2 as shown by an arrow B to flow under the base plate 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical modeling apparatus for hierarchically curing a photocurable resin material (hereinafter referred to as a resin liquid) to form a three-dimensional molded article having a desired arbitrary shape, and more particularly, The present invention relates to an optical modeling apparatus that improves the shape accuracy of a three-dimensional molded object.

[0002]

2. Description of the Related Art Conventionally, as a technique relating to an optical modeling apparatus, there is a three-dimensional shape forming method described in Japanese Patent Laid-Open No. 63-141724. FIG. 6 is a perspective view of an apparatus for carrying out the above conventional forming method, in which 11 is a laser device, 12 is a laser beam, and 13 is an optical modulator. The laser beam 12 is intensity-modulated by the optical modulator 13, and the lens 1
A polygon (rotating polygonal mirror) 17 is scanned through 5 and 16, and the resin liquid 20 is irradiated with the light by an fθ lens 18 through a scanning reflecting mirror 19. The main scanning by the polygon 17 and the sub-scanning by the sub-scanning base 21 are performed, and after the exposure and curing of one layer is completed on the base plate 22, the base plate supporting portion 23 is lowered to the vicinity of the bottom of the accommodating container 24, and the base plate The upper surface of the cured product 25 formed on the surface 22 is uniformly covered with the resin liquid 20. After that, the base plate 22 is lifted to a position where the upper surface of the cured product 25 is one layer deep from the surface of the resin liquid 20 and waits until the surface of the resin liquid 20 becomes flat. After the surface becomes flat, the movement of the sub-scanning table 21 and the modulation of the optical modulator 13 according to the shape data are started to expose the next layer.
Hereinafter, the same procedure is repeated to form a three-dimensional object in the content container 24 filled with the resin liquid 20.

Next, the principle of the three-dimensional shape forming method using the above apparatus will be described with reference to FIG. FIG. 7 shows a process of supplying the resin liquid 20 for forming the second layer onto the already-exposed and cured first cured layer 25a. FIG. 7A shows the first
This shows the time of forming the hardened layer 25a, and the surface of the first hardened layer 25a and the uncured resin liquid 20 are at the same height. By lowering the base plate 22 from this state, the resin liquid 26 of the second layer is moved along with the lowering of the base plate 22 so that the first hardened layer 25a.
Supplied on. However, when the surface tension of the resin liquid 26 is high, as shown in FIG. 7B, the supply is insufficient even if the base plate 22 is lowered by one layer. Therefore,
By continuing to lower the bubbles at a speed that does not pull in the bubbles, the second layer resin liquid 26 is supplied toward the central portion on the first cured layer 25a, as shown in FIG. 7C. Eventually, the second layer resin liquid 26 supplied from the end of the first cured layer 25a merges near the center of the first cured layer 25a,
The entire surface of the first hardened layer 25a is covered, as shown in FIG.
Through the flow shown in (d), it eventually becomes flat. After this,
As shown in FIG. 7E, by raising the base plate 22 to a position corresponding to the layer thickness of the second layer, it is possible to form a thin resin layer 26 on the entire surface of the first cured layer 25a. it can.

However, the resin liquid such as modified polyurethane methacrylate and epoxy acrylate used in the above three-dimensional shape forming method has a relatively high viscosity, and even if an attempt is made to form a thin resin liquid layer as described above, the resin liquid layer is actually The state does not become flat as shown in FIG. 7E, but as shown in FIG. 8, the ridge is thicker than the desired layer thickness when the second cured layer is formed on the first cured layer 25a and the base 22. 27a
Is formed. This occurs not only in the first cured layer 25a but also in the resin liquid layer when the next layer is formed on the pre-cured layer. That is, as shown in FIG. 9, the resin layer 20 from the first hardening layer 25a and the base plate 22 caused by the raising operation of the base plate 22 shown in FIG. 7D to FIG. The discharging motion indicated by the arrow B is governed by Newton's viscosity law, and the higher the viscosity of the resin liquid 20 or the wider the friction area in contact with the resin liquid 20, the slower it becomes compared to the rising speed of the base plate 22. As a result, as shown in FIG. 8, a thick bulge 27a is formed without being completely discharged.

Therefore, in order to eliminate the bulge 27a, most of the optical modeling apparatuses currently on the market, as shown in FIG. 10, are sweeping means which move in the direction of arrow C so as to flatten the bulged liquid surface. 28 (hereinafter referred to as a squeegee) is provided.

[0006]

However, the squeegee 28
The conventional device provided with has the following problems. That is, since the squeegee 28 sweeps the raised liquid surface, a phenomenon 29 of the resin liquid 27a wrapping behind the squeegee 28 occurs as the squeegee 28 moves in the direction of arrow C, and a new rise 27b is generated. That is, it could not be an effective measure. That is, the swelling 27b formed on the first cured layer 25a (pre-cured layer) and the base plate 22 cannot be eliminated only by the configuration shown in FIGS. 7 to 10, which significantly deteriorates the accuracy of the cured product 25. There was a problem of making it.

The present invention has been made in view of the above problems in the prior art, and provides an optical modeling apparatus capable of significantly reducing the rise of the resin liquid formed on the pre-cured layer and the base plate. The purpose is to

[0008]

In order to solve the above-mentioned problems, the invention according to claim 1 is directed to a surface of a liquid photo-curable resin material in which an ultraviolet laser beam is applied on the basis of sectional shape data obtained by slicing a desired three-dimensional shape. And a liquid surface sweeping means for irradiating a portion to form a hardened layer on the base plate, a means for raising and lowering the base plate to introduce a photo-curable resin material onto the hardened layer, and a base surface sweeping means. In an optical forming apparatus for sequentially forming the cured product on a plate, the base plate is
The photocurable resin material can flow through the base plate in the vertical direction of the base plate.

Further, according to the invention of claim 2, the base plate is constituted by a combined body which can be divided / removed / rejoined.

[0010]

[Action]

[Operation of Claim 1] By providing the base plate with a plurality of holes and the like, when the resin liquid flows through the base plate, the friction area perpendicular to the vertical direction of the base plate decreases. As a result, the flow resistance acting on the resin liquid is reduced, and the flow velocity of the motion of the resin liquid discharged from the pre-cured layer and the base plate is increased, and as a result, the resin liquid rises 27 after the base plate is lifted.
a and 27b (see FIG. 8) are significantly reduced.

[Operation of Claim 2] The base plate can be formed by removing a portion of the base plate formed by the combined body of the small pieces other than the place where the cured product is formed, and a gap is formed in the combined portion of the combined body. Is formed, and the same effect as in claim 1 is obtained.

[0012]

Embodiment 1 FIGS. 1 and 2 show a main part of Embodiment 1 of the present invention. FIG. 1 is a sectional view showing a state in which a base plate is lowered after forming a first curing on the base plate. FIG. 3 is a cross-sectional view showing a state in which the base plate is lifted from the state of FIG. 1 to form a resin layer having a desired thickness on the first cured layer. The basic structure is the same as that of the conventional apparatus (FIGS. 6 to 10) except for the structure of the base plate in the present embodiment and the second and third embodiments described later, and therefore, the illustration except for the main part of the present embodiment is omitted. While omitting, the same numbers are given to the same components and the description thereof is omitted.

In the figure, reference numeral 1 denotes a base plate, which is fixed to a support member 23 and is vertically movable in a resin liquid 20 filled in a container 24. The base 1 is provided with a plurality of holes 2 along the vertical direction (arrow A direction) of the base plate 1 and the support member 23. The hole can be formed by a polygonal cylindrical hole, a cylindrical hole, an elliptic cylindrical hole, a polygonal conical hole, a conical hole, an elliptical conical hole, or the like, and the shape of the contact surface with the first hardened layer formed on the base plate 1 is formed. It is desirable to provide as many as possible without deteriorating. Also,
The base plate 1 can be configured by using a porous member, a porous ceramic member, a pumice plate, or the like, and the base plate 1 is effective in the resin liquid 20 having a relatively low viscosity.

[Operation] The first hardened layer 25 having a desired thickness and shape is formed on the base plate 1, and then the first hardened layer 25 is formed.
In order to introduce the resin liquid 20 onto the base plate 1, the container 2
4 Lower to the bottom. Next, as shown in FIG. 1, the base plate 1 is raised in the resin liquid 20 by the support member 23,
As shown in FIG. 2, the thickness of the second hardened layer to be formed next on the first hardened layer 25 is raised to a position of a depth L at which it can be formed. When the base plate 1 is raised, the resin liquid 20 exists so as to prevent the base plate 1 from rising in the conventional case.
Through without resistance, and flows to the lower side of the base plate 1 as indicated by arrow B.

[Effect] According to the present embodiment, the base plate 1 can be easily manufactured by making a hole in the base plate or using a porous member as the base plate. Furthermore, since the resin liquid 20 flows downward through the holes 2 when the base plate 1 is raised, it is possible to eliminate the swelling that occurs on the liquid surface of the resin liquid 20.

[0016]

[Embodiment 2] FIG. 3 is a perspective view showing an essential part of Embodiment 2 of the present invention. The base plate 3 of this embodiment is formed by connecting a large number of coarse spheres 4 in a flat plate shape, and is fixed to the support member 23. Holes 5 are formed between the coarse spheres 4, and the diameter of the coarse spheres 4 used in this embodiment is about φ1.0 to φ2.0 mm. Coarse sphere materials include metal, glass,
A thermoplastic resin or the like can be used.

[Operation] In the present embodiment, the base plate 3
By connecting the coarse spheres 4 of φ1.0 to φ2.0 mm in a flat plate shape, the surface forming the first hardened layer 25 becomes flat, and the contact surface of the first hardened layer 25 in contact with the base plate 3 becomes Does not get worse. Further, when the base plate 3 is raised in the resin liquid, the resin liquid passes through the gaps 5 between the coarse spheres 4 without resistance and flows downward of the base plate 3.

[Effect] The base plate 1 of the first embodiment has the hole 2
Since it is configured by providing, although it may be easily manufactured, there may be a case where the range in which the first hardened layer 25 is formed may be restricted. However, according to the present embodiment, the coarse spheres 4 are combined to form the base. Since it is the plate 3, a gap (hole) through which the resin liquid flows
Is smaller, and there is no restriction on the formation range of the first hardened layer 25.

[0019]

Third Embodiment FIGS. 4 and 5 show the essential parts of a third embodiment of the present invention, FIG. 4 is a perspective view, and FIG. 5 is a plan view of a base plate.
The base plate 6 of the present embodiment is formed in a flat plate shape by an assembly of small piece plates 8 whose opposing positions are joined by an adhesive 7 and is fixed to the support member 23. A gap 9 through which the resin liquid flows is formed between each small piece plate 8. Each small piece plate 8 can be divided, detached, and rejoined, and the size of the base plate 6 can be changed.

[Operation] In the present embodiment, the cured product 25
The base plate 6 is formed by joining the small piece plates 8 by the width of the range forming the. Therefore, when the base plate 6 rises, the resin liquid flows through the gap between the small piece plates 8 and the cured product 25
The portion of the base plate 6 that goes out is reduced, and the frictional resistance between the base plate 6 and the resin liquid is almost eliminated.

[Effect] According to the present embodiment, a flatter liquid surface can be formed on the pre-cured layer as compared with the first and second embodiments. Furthermore, since the small piece plate 8 can be arbitrarily divided, detached, and recombined according to the shape change of the cured product 25, a very versatile base plate 6 can be obtained.

In this embodiment, the case where the small piece plates 8 are joined by the adhesive 7 has been described. However, the small piece plate 8 is connected by providing a convex portion and a concave portion, which are fitted to opposite joining portions, respectively, or the small piece plate 8 is a magnet. It is also possible to adopt a configuration in which the pieces are adsorbed and coupled by magnetic force. In this case, a gap 9 is formed between each small piece plate 8 as in the present embodiment. Even with such coupling, the same operation and effect as those of the present embodiment can be obtained.

The present invention may be configured as follows for the purpose of flattening the liquid surface of the resin liquid formed on the pre-cured layer. Means for forming a cured layer on the base plate by irradiating the surface portion of the liquid photo-curable resin material with an ultraviolet laser beam based on the cross-sectional shape data obtained by slicing a desired three-dimensional structure, and moving the base plate up and down. A means for introducing a photocurable resin material onto the cured layer, and a liquid surface sweeping means, in an optical forming apparatus for sequentially laminating the cured product on the base plate, in the base plate It is configured by penetrating a plurality of holes along the vertical direction.
As a result, when the base plate rises, the resin liquid flows through the holes and flows below the base plate, and the resin liquid surface on the hardened layer becomes flat. The plurality of holes may be polygonal prismatic holes, cylindrical holes, elliptical cylindrical holes, polygonal conical holes, conical holes, or elliptical conical holes. Further, the base plate may be composed of a porous member, a porous ceramic member, or a pumice stone plate. Further, the base plate is formed by connecting a large number of coarse spheres in a flat plate shape,
A gap may be provided between the coarse spheres. The material of the coarse sphere is made of metal, glass, or thermoplastic resin. Further, the base plate is composed of a combined body formed by connecting a plurality of small pieces in a flat plate shape with a soft adhesive.
As a result, the small piece plate can be divided, detached, and recombined, and the size of the base plate corresponds to the size of the hardened layer.
The above-mentioned combined body is formed by connecting one of the facing portions of the small piece plate with a convex shape and the other with a concave shape, and combining the convex portion and the concave portion. Further, the combined body is configured by using the small piece plates as magnet pieces and connecting the small piece plates by magnetic force.

[0024]

As described above, according to the invention of claim 1, when the base plate is lifted in the resin liquid, the resin liquid flows downward through the plurality of holes of the base plate. It is possible to eliminate the swelling of the resin liquid above the specified value. Further, according to the invention of claim 2, the size of the base plate can be made to correspond to the size of the cured product by coupling / removing the small piece plates, and a gap is formed between the small piece plates. The same effect as that of the item 1 can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the main parts of the first embodiment of the present invention.

FIG. 3 is a perspective view showing a main part of a second embodiment of the present invention.

FIG. 4 is a perspective view showing a main part of a third embodiment of the present invention.

FIG. 5 is a plan view showing a base plate in Embodiment 3 of the present invention.

FIG. 6 is a perspective view showing a conventional optical modeling apparatus.

FIG. 7 is a diagram illustrating the principle of an optical modeling method.

FIG. 8 is an explanatory diagram showing a problem of the conventional technique.

FIG. 9 is an explanatory diagram showing a discharging movement of a resin liquid on a hardening layer in a conventional technique.

FIG. 10 is an explanatory diagram showing a problem of the conventional technique.

[Explanation of symbols]

 1, 3, 6 Base plate 2 Hole 4 Coarse sphere 5, 9 Gap 7 Adhesive 8 Small piece plate 20 Photocurable resin material (resin liquid) 25 First cured layer

Claims (2)

[Claims] 1. A means for irradiating a surface portion of a liquid photocurable resin material with an ultraviolet laser beam on the basis of sectional shape data obtained by slicing a desired three-dimensional structure to form a cured layer on a base plate, and the base. In the optical forming apparatus, which comprises means for moving a plate up and down to introduce a photo-curable resin material onto the cured layer, and liquid level sweeping means, and sequentially laminating and forming the cured product on the base plate, the base An optical modeling apparatus, characterized in that the plate is configured such that the photocurable resin material can flow through the base plate in a vertical direction of the base plate. 2. A means for irradiating a surface portion of a liquid photocurable resin material with an ultraviolet laser beam on the basis of sectional shape data obtained by slicing a desired three-dimensional structure to form a cured layer on a base plate, and the base. In the optical forming apparatus, which comprises means for raising and lowering a plate to introduce a photocurable resin material onto the cured layer, and liquid level sweeping means, and sequentially forming the cured product on the base plate, An optical modeling apparatus characterized in that a plate is composed of a combined body that can be divided, removed, and recombined.