JP2000218705A - Stereolithography - Google Patents

Abstract

(57) [Summary] An object of the present invention is to provide an apparatus for stereolithography with high precision in stereolithography. A squeegee passes through a flat portion of a modeling surface of a model, i.e., a plane approximately equal in height to a liquid surface, and applies a resin stuck to a rear end of the squeegee before applying an uncured resin to a modeling surface of a modeling model. After attaching and removing the squeegee from the flat surface, the height of the upper surface is approximately equal to the liquid level so that the squeegee passes through the modeling surface of the model at a predetermined distance from the standby position of the squeegee in the movement direction of the squeegee. Is achieved by arranging a plane part component equal to:

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical molding apparatus for producing a three-dimensional resin model by curing and laminating a photocurable resin by irradiating laser light, and more particularly to an apparatus for providing an optical molded article having excellent dimensional accuracy. About.

[0002]

2. Description of the Related Art An optical molding technique is known as a technique for creating a shape model from three-dimensional CAD data in a short time. As disclosed in Japanese Patent Publication No. 5-33901, CA
According to the contour data converted by cutting the shape data of D into a circle, the UV curing resin is irradiated with a UV laser,
The molding is performed by repeating the curing and laminating one layer.

[0003]

In stereolithography, after converting shape data into contour data, the resin liquid surface of the resin container is scanned with a laser beam in accordance with the contour data to expose and cure the photocurable resin. This operation is performed starting from the lowest layer of the contour line data, and is sequentially cured by exposure and laminated to form a shape model.

In stereolithography, a photocurable resin is cured and laminated at a predetermined pitch. In order to laminate at a predetermined pitch, it is necessary to apply an uncured resin with a constant thickness on the cured layer each time the layer is cured. For this reason,
The uncured resin is once thickly applied and the excess is scraped off with a squeegee.

However, the photocurable resin is viscous, and the photocurable resin sticks to the squeegee, and a desired uncured layer thickness to be defined by the squeegee cannot be obtained. In particular, at the end of the hardened layer or the narrow hardened portion where the squeegee encounters the same layer for the first time, there is a problem that the resin stuck to the rear side in the traveling direction of the squeegee adheres to the hardened portion due to the viscosity and swells. . This bulge is not flattened after the movement of the squeegee, and there is a problem that the uncured resin layer is locally formed thicker than a desired value. If the uncured resin layer is formed thicker, the surface accuracy of the molded product will be reduced, and that part will be cured thicker, so the next time the squeegee is moved, the squeegee will hit the cured layer, and the model being molded There is a problem of breaking.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a squeegee which passes through a flat surface of a model, that is, a liquid surface which is substantially equal in height, before the uncured resin is applied to the surface of the model. After the resin adhered to the rear end is adhered to and removed from the flat surface, the upper surface is located at a predetermined distance from the standby position of the squeegee in the direction of movement of the squeegee so that the squeegee passes through the modeling surface of the model. Is achieved by arranging a flat part constituting member whose height is substantially equal to the liquid level.

[0007]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view of the configuration of an optical shaping apparatus according to one embodiment of the present invention. The UV curable resin 1 is injected into a UV curable resin tank 2. The squeegee 3 is mounted on a slide rail 4 provided in parallel with the liquid surface of the UV curable resin 1, and the squeegee driving means 5 moves the squeegee 3 on the slide rail.
It is configured to be able to move in contact with the liquid surface of the V-cured resin 1. The photo-curing resin applying means includes a means 6 for sucking uncured photo-curing resin from the tank 2, a hose 7, and a small tank 8 for temporarily storing the sucked resin.
Has a nozzle 9 for discharging resin. The small tank 8 having the nozzle 9 is mounted on the slide rail 4 and moves prior to the movement of the squeegee 3, and discharges the uncured photocurable resin from the nozzle 9 and moves while applying.

[0010] Reference numeral 10 denotes a plane portion provided at a predetermined distance from the standby position of the squeegee 3 in the moving direction, and the plane height is substantially equal to the resin liquid level. Work table for stereolithography 1
The work table 1 is controlled by the work table Z-axis moving means 12 to move in the Z-axis (depth) direction in the UV-curable resin tank 2 while keeping the liquid level of the UV-curable resin 1 parallel. The UV laser light 13 is emitted to a laser oscillator 14 and is applied to a galvanomirror (X
(Axis, Y axis) 15 to the liquid surface of the UV curable resin 1.

The galvanomirror 15 is controlled by a galvanomirror control circuit 16 so that the laser beam 13 can scan the liquid surface of the UV curable resin 1. The squeegee driving means 5, the galvanomirror control circuit 16, and the worktable moving means 12 are controlled by a stereolithography system control circuit 17. The stereolithography system control circuit 17 operates the galvanomirrors 15 of the X and Y axes via the galvanomirror control circuit 16 according to the contour drawing data 18, and the laser beam 13 scans the liquid surface of the UV curable resin 1.

The portion of the UV curable resin 1 irradiated with the laser beam 13 is immediately cured. When one scan is completed,
The stereolithography system control circuit 17 reads the contour drawing data 18 ′ of the next layer, and sinks the work table 11 from the liquid surface of the UV-curable resin 1 further by the lamination pitch P via the work table Z-axis moving means 12.

A new layer of an uncured UV-curable resin is placed on the already-cured layer. Thereafter, by moving the squeegee 3, the uncured resin portion applied thicker than the prescribed liquid level is removed. At this time, since the squeegee 3 passes over the flat member 10 and removes the resin adhering to the rear side of the squeegee 3 onto the flat member, and then passes over the hardened layer serving as a modeling model, the squeegee 3 has an extra amount on the hardened layer. The resin can be applied evenly without causing the adhesion of the resin. FIG. 2 shows a state in which the worktable 7 is sunk by P after the n-th layer is cured, and an uncured resin layer 19 is applied thereon.

FIG. 3 shows a state in which the surplus resin 19 is scraped off while the squeegee 3 is moved when the conventional flat member 10 is not provided. Although the squeegee 3 scrapes off the surplus resin 19 of the applied uncured resin, the resin clinging 20 is large behind the movement of the squeegee 3. For this reason, as shown in FIG. 4, the uncured resin is thickly applied to the narrow portion 21 or the end 22 of the hardened layer on the application bottom surface. As a result, as shown in FIG. 5, a portion to be cured with a predetermined thickness (the reference line 23) has an excessively thick portion, which causes a problem of a decrease in dimensional accuracy. In a thick part, there is also a problem that the squeegee 3 collides at the time of squeegee operation in the next layer and breaks the model being formed.

FIG. 6 is a view showing a state of application of a resin when the planar member of the present invention is arranged. The resin adhering to the rear side of the squeegee 3 is that the squeegee 3
When the squeegee 3 passes through the squeegee 3, it adheres to the flat member (indicated by 24) and is removed from the rear side.

As shown in FIG. 7, the hardened layer on the bottom surface of the coating is applied flat even in the narrow portion 21 or the end portion 22, so that it is possible to prevent the uncured resin from being applied thickly. After the uncured resin is applied in a predetermined thickness in this way, a laser is scanned according to the contour data of the next layer to cure the applied UV-cured resin.

As shown in FIG. 8, the cured surface is flat, has good dimensional accuracy, and has no fear of squeegee hitting. By repeating this operation, it is possible to form a shape model with high accuracy as if thin sheets having contour lines are stacked.

[0016]

According to the present invention, it is possible to suppress the swelling of the resin caused by the transfer and adhesion of the resin adhered to the rear portion of the squeegee to the end of the cured layer. Thereby, the dimensional accuracy of the surface of the stereolithography model can be improved. Also, hit the thickened squeegee,
The problem of breaking the model during modeling can also be avoided.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view of an optical shaping apparatus according to an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of the optical shaping apparatus according to the embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view of a portion that is a problem in the related art.

FIG. 4 is a cross-sectional view illustrating a phenomenon that causes a problem in the related art.

FIG. 5 is a cross-sectional view illustrating a shape in which accuracy is poor in the related art.

FIG. 6 is a sectional view showing a problem solving part according to an embodiment of the present invention.

FIG. 7 is a sectional view for explaining a state of solving a problem according to the embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a state in which modeling is performed with high accuracy according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... UV curable resin, 2 ... UV curable resin tank, 3 ... Squeegee, 4 ... Slide rail, 5 ... Squeegee drive means, 6
... resin sucking means, 7 ... hose, 8 ... small tank, 9 ... resin discharge nozzle, 10 ... flat member, 11 ... work table, 12 ... Z-axis moving means, 13 ... optical laser light, 14 ... laser oscillator, 15 ... Galvano mirror, 16 ... Galvano mirror control circuit, 17 ... Stereolithography system control circuit, 18 ...
Contour drawing data, 19: excess resin, 20: resin clinging, 21: narrow portion of cured layer, 22: end of cured layer, 23: reference line, 24: resin adhered to flat member.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiro Endo 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Multimedia Systems Development Division of Hitachi, Ltd. (72) Inventor Masayuki Muranaka Kanda, Surugadai, Chiyoda-ku, Tokyo 6-chome F-term in Hitachi, Ltd. (reference) 4F213 AA44 WA25 WA86 WB01 WL05 WL12 WL34 WL87 WL92 WL93

Claims (1)

[Claims] A laser light oscillating means and ON / O of the laser light
FF switch means, means for converging the laser light, means for planar scanning of the laser light, a photocurable resin container, a work table provided to sink in the photocurable resin container, and a liquid surface of the photocurable resin container A coating means for moving the squeegee to apply the photocurable resin and a control means for controlling them, storing the photocurable resin in the photocurable resin container, and forming the converged laser light into the light according to shape data. Irradiation and scanning are performed on the liquid surface of the cured resin, the photocured resin is exposed and cured on a work table, and an uncured photocurable resin is applied on the cured layer in a layered manner by the application means, and the uncured resin is applied. In an optical shaping apparatus for forming a shape model by successively laminating layers by exposure and curing repeatedly, the height of the upper surface is substantially at a position separated from the standby position of the squeegee by a predetermined distance in the moving direction of the squeegee. Optical shaping apparatus characterized by being configured to arrange the flat part forming element is equal to the.