JP2002103457A - Stereo lithographic device and method for producing stereo lithographic product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely perform a stereo lithography and to shorten a time for lithography by efficiently changing the moving speed or the number of times of moving a squeegee in a section in which a gate structure is not existed by detecting the gate structure of the lithographic model by an EWS. SOLUTION: A method for producing a stereo lithographic product comprises the steps of receiving profile shape data 13 of a product from the EWS 1, and setting the minimum value/normal value of the moving speed of the squeegee or the maximum value/normal value of the number of times of moving when the gate structure A is existed in the profile shape data 13 of the product. In the case of moving the squeegee, on the gate structure A, the moving speed of the squeegee is set to the minimum value. In the gate structure A, the moving speed of the squeegee is set to the normal value. On the structure A, the number of times of moving the squeegee is set to the maximum value. In the structure A, the number of times of moving the squeegee is set to the minimum value.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical molding apparatus, and more particularly, to a method of exposing and curing a photocurable resin housed in a molding tank with laser light in accordance with product shape data. The present invention relates to a squeegee device and a squeegee method of an optical molding device for forming an uncured resin film having a thickness.

2. Description of the Related Art Generally, an optical shaping apparatus exposes a photo-curable resin filled in a shaping tank to laser light in accordance with shape data created by a three-dimensional CAD system.
The laser beam condensed on the liquid surface of the photocurable resin is exposed and cured according to the cross-sectional shape of the product, and is supported on a table located slightly below the liquid surface. When resin curing is completed for one cross-sectional shape, the elevator descends by a small amount, whereby uncured resin is filled on the cured resin layer and an uncured layer of uniform thickness is formed on the cured resin layer. Then, a new uncured resin film is formed on the already-cured resin by making the excess uncured resin on the already-cured resin layer uniform while scraping it off with a squeegee device. Then, the photocurable resin film is cured on the cured resin according to the next cross-sectional shape based on the scanning data on the next cross-sectional shape data, and is laminated on the cured resin. In this way, the resin is hardened according to each cross-sectional shape by repeating the resin hardening by scanning the laser beam according to the cross-sectional shape at each minute interval, the lowering of the elevator, and the scraping of the uncured resin by the squeegee. A three-dimensional laminate model of the product is created as a laminate of the cured resin thus obtained. In general, in the modeling of the three-dimensional stacked model, the moving speed and the number of times of movement of the squeegee are uniformly determined irrespective of the structure of the surface to be formed, for example, a structure having a weir structure. Although it is possible to set the movement speed and the number of movements, if the speed is increased or the number of movements is reduced, the liquid level inside the weir portion (portion surrounded by the weir portion) tends to rise due to surface tension, and poor molding Occurs. Conversely, if the speed is slow or the number of times is increased, it takes a long time to move the squeegee, and there is a disadvantage that the modeling time is prolonged.

In order to solve the above-mentioned drawbacks, a weir structure of a model is detected by EWS, and an appropriate moving speed or number of movements of the squeegee in the weir structure is determined. An object of the present invention is to provide a high-quality model quickly by accurately modeling the model and improving the modeling efficiency.

SUMMARY OF THE INVENTION An optical shaping apparatus according to the present invention comprises:
The liquid level of the photocurable resin stored in the molding tank of
Exposure and curing of the laser beam according to the shape data generated in advance by EWS, filling the uncured resin on the already-cured resin layer with one layer, and then moving the squeegee so that the uncured resin is A liquid is applied, an uncured resin film having a predetermined uniform thickness is formed, a laser beam is exposed to the uncured resin film, and the cured film is formed by sequentially forming a thin cured resin layer. In the optical shaping apparatus, based on a laminated model having a weir structure, an EWS that detects the weir structure in advance, and generates squeegee moving speed data or moving frequency data, and an EWS squeegee moving speed data or moving frequency data, Squeegee control means for controlling movement of the squeegee, and squeegee driving means for moving the squeegee in accordance with instructions from the squeegee control means And wherein the door. The optical shaping method of the present invention is to expose and harden a liquid surface of a photocurable resin housed in a shaping tank of an optical shaping apparatus by exposing and curing a laser beam according to shape data generated in advance by EWS. Fill the uncured resin liquid, and then move the squeegee to apply the uncured resin liquid to the unfilled portions to form an uncured resin film with a predetermined uniform thickness. In a method of manufacturing a photolithography product, which forms a laminated model by exposing and curing a film with laser light and sequentially forming a thin cured resin layer, a weir structure of the laminated model is detected in advance by the EWS, and the The minimum value / normal value of the moving speed of the squeegee or the maximum value / normal value of the number of times of movement of the squeegee is set. Then, it moves on the weir structure at the minimum moving speed, and moves at a portion other than the weir structure at the normal value. Alternatively, it is characterized in that it moves on the weir structure with the maximum number of times of movement, and moves other than the weir structure with the normal number of times of movement.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an optical shaping apparatus using a squeegee apparatus according to the present invention will be described with reference to FIGS. FIG. 1 schematically shows the configuration of an optical shaping apparatus (100) of the present invention. FIG. 2 is a perspective view illustrating the configuration of a squeegee device (200) of the optical shaping device (100) of the present invention. FIG. 3 shows an optical shaping apparatus (100) of the present invention.
It is sectional drawing of the blade part (201) of a squeegee apparatus (200), and a model. In FIGS. 1 and 2,
(1) is an engineering work station (hereinafter, referred to as EWS) including a three-dimensional CAD system. In a three-dimensional CAD system, as is well known,
The design information input and stored in the computer is taken out by the graphic display device (2), and the product is designed while looking at the screen. The product shape data is created, and the cross-sectional shape data of a horizontal section at minute intervals is created. Is performed. In the EWS, control information data of each part of the optical shaping apparatus is also created based on the cross-sectional shape data. (3) is a shaping tank containing the photocurable resin (4), (5) is a table provided in the shaping tank (3) so as to be able to move up and down, and the shaping tank is controlled by the table controller (6). The liquid level (12) of the photocurable resin (4) in (3)
Move up and down in parallel to. The squeegee device (200) includes a squeegee body (19), a blade (201) fixed to a side wall of the squeegee body (19), and a squeegee body (1).
A squeegee drive unit (20) for moving the squeegee drive unit (9) in the horizontal direction with respect to the liquid surface and a pair of squeegee drive units (20) are mounted on a shaft. (12) and a ball screw (22) that moves in parallel. The squeegee body (19) includes two pairs of ball screws (22) screwed to the squeegee body (19).
However, when the motor (not shown) built in the squeegee drive unit (20) rotates, the squeegee drive unit (20) moves horizontally on the photocurable resin liquid surface (12). As shown in FIG. 3, the blade part (201) includes a doctor blade (21) formed of urethane resin, which scrapes the uncured resin (4) on the cured resin layer (C) to a certain thickness, and And a stretching plate (18) on which the blade (21) is stretched. The laser light (9) is emitted from a laser light excitation device (8),
The laser light is irradiated onto the modeling liquid surface (12) via the laser beam scanning control device (7). The portion of the photocurable resin (4) irradiated with the laser beam (9) is immediately cured. When the curing for one layer is completed, the EWS (1) reads the data of the next layer, and also moves the table (5) further deeper by the stacking pitch (about 3 mm) by the elevator driving device (6). 12) Submerge and fill the hardened resin layer with fresh uncured resin. (7) is a laser beam scanning device, which scans the laser beam (9) excited by the laser beam excitation device (8) according to the scanning data, and collects the laser beam (9) guided to the modeling tank (3). The optical lens (11) constantly collects (10) on the modeling liquid surface (12). (13) is engineering
The product shape data (13) sent from the work station (hereinafter referred to as EWS) (1) includes laser beam scanning data (14),
Table drive data (15), squeegee drive data (1
6) is input to the laser beam scanning controller (7), the table controller (6), and the squeegee controller (17). In addition, the EWS detects the weir structure (A) from the external shape data of the product in advance, and sets the minimum value and the normal value of the moving speed of the squeegee during molding. In addition, EWS preliminarily obtains from the external shape data of the product.
The weir structure (A) is detected, and the maximum value and the normal value of the number of times the squeegee moves during modeling are set. (17) is E
From the presence / absence data of the weir structure (A) sent from WS,
This is a squeegee control device that sets the squeegee moving speed or the number of times of movement and generates squeegee movement data. For example, an example of setting data of the squeegee moving speed or the number of times of moving will be described with reference to FIG. 3. The cured resin layer (cross-sectional shape of the product) (C) has a hollow inside as shown in FIGS. 2 and 3. Assume that it has a weir structure (A) having a portion (B). In the photocurable resin liquid inside (B) surrounded by the weir structure (A), the photocurable resin liquid is raised along the inner contour of the weir structure (A) due to surface tension (d). The bulge due to the surface tension is at least as high as the height of the molding with the photocurable resin, and the liquid surface on the weir structure (A) and the liquid surface inside the weir structure are not connected on one surface. Therefore, weir structure (A)
If the surface tension portion in the upper portion and the inside of the weir structure (A) is squeegeeed quickly at the same speed, or if the number of squeegees is reduced, the liquid level inside the weir portion tends to rise, resulting in poor molding. Conversely, if the squeegee is moved at a low speed or a large number of times, no shaping defect occurs, but extra time is required for the squeegee moving time, and the entire shaping time is prolonged. Therefore, the present invention checks the presence or absence of the weir structure (A) in the outer shape of the product by EWS in advance,
If the weir structure (A) is present, the squeegee speed is reduced on the weir structure (A) (minimum value), and the squeegee speed is increased on parts other than the weir structure such as the inside of the weir structure (B) (normal value). )
Alternatively, if the number of squeegees is increased (maximum value) on the weir structure, and the number of squeegees is reduced (normal value) in portions other than the weir structure such as the inside of the weir structure (A), At the end of the weir structure (A), the photocurable resin is applied in a constant thickness to form a uniform cured resin layer, and a laminated model with stable quality can be obtained. The squeegee speed or the number of squeegees is instructed to the squeegee drive mechanism (20) by the squeegee control device (17). A series of operations of the embodiment of the present invention in the above configuration will be described with reference to FIGS. 1 to 3. When manufacturing a molded product, first, EWS
In (1), product shape data is created, and a cross-sectional shape of a horizontal section at minute intervals is created from the shape data. Next, the table (5) sinks from the liquid surface by the amount of the resin film, and the table (5) is filled with the uncured resin. Next, EWS
From (1), the weir structure (A) presence / absence data in the product outer shape data (13) is received. If the weir structure (A) is present in the product outer shape data (13), the weir structure (A)
Weir structure (A) according to the moving speed of the squeegee during molding set in advance by EWS in order to avoid molding defects
The squeegee is moved at the minimum speed, and the squeegee moving speed is set so that the squeegee moves at the normal speed in portions other than the inside of the weir structure (A). Alternatively, if the weir structure (A) exists in the outer shape data (13) of the product, the number of squeegees at the time of molding is set to a maximum value on the weir structure (A) in order to avoid molding failure of the weir structure (A). The number of squeegees is set so that the squeegee is performed with the number of times and the squeegee is performed with the number of times of the normal value in a portion other than the inside of the weir structure (A). The squeegee driving mechanism (20) is instructed according to the setting data of the squeegee moving speed or the number of times of movement from the squeegee control device (17), and the blade section (201) is driven according to the setting data. Hereinafter, the movement of the squeegee will be described. When controlling the squeegee by speed, the doctor blade (21) is positioned at one end of the weir structure (A),
Weir structure (A) from one end of weir structure (A) at minimum speed
The uncured resin is moved while scraping the uncured resin to the other end of the weir structure, the uncured resin portion inside the weir structure (A) is moved at a normal speed, and the minimum value is again returned from the end of the weir structure (A). At the speed, the uncured resin moves to the other end of the weir structure (A) while scraping it off. Next, when controlling by the number of squeegees, the doctor blade (21) is positioned at one end of the weir structure (A), and from one end of the weir structure (A), the number of squeegees of the weir structure (A) is increased to the maximum value. Move to the other end while scraping the uncured resin. The uncured resin portion inside the weir structure (A) is moved with a normal value of the number of squeegees, and the other end of the weir structure (A) is again moved from the end of the weir structure (A) with the maximum number of squeegees. Move while scraping the uncured resin to the part. That is, the moving speed of the squeegee is set to the minimum value on the weir structure (A), and the moving speed of the squeegee is set to the normal value inside the weir structure (A). The number of squeegee movements is set to the maximum value on the weir structure (A), and the number of squeegee movements is set to the minimum value inside the weir structure (A). Next, the laser beam scanning device (7) scans the laser beam (9) according to the scanning data. When the resin curing for one cross-sectional shape is completed, the table (5) is lowered by a very small amount by the table driving device (6), whereby the uncured resin is set on the weir structure (A) cured in the previous process. And the squeegee (201) moves again by the operation described above to form a uniform uncured resin film.
Scanning data relating to the next cross-sectional shape data is output from the WS (1), a laser beam (9) is scanned over the uncured resin film (12), and cured according to the next cross-sectional shape. Laminated on a layer. Thus, the laser beam (9) adapted to the cross-sectional shape at each minute interval
By repeating the resin curing by scanning, the lowering of the elevator (5), and the formation of the uncured resin film by the squeegee device (200), the optical molding is performed as a laminate (C) of the cured resin cured according to the sectional shape of each layer. The model is completed.

According to the present invention, by controlling the moving speed or the number of times of movement of the squeegee depending on the presence or absence of the weir structure on the surface to be formed, the weir structure portion can be surely formed by stereolithography, and a high-quality optically formed object can be obtained. Can be shaped. In addition, by controlling the moving speed or the number of times of movement, efficient stereolithography by the stereolithography apparatus can be performed, and the overall modeling time can be reduced.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, in which an optical shaping apparatus (10
FIG. 2 is a cross-sectional view illustrating the configuration of FIG.

FIG. 2 shows an optical shaping apparatus (1) according to an embodiment of the present invention.
FIG. 9 is a perspective view illustrating a configuration of a squeegee device (200) of FIG.

FIG. 3 shows an embodiment of the present invention, wherein an optical shaping apparatus (10
It is sectional drawing explaining operation | movement in the weir structure of 0) squeegee apparatus (200).

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 stereolithography apparatus 3 modeling tank 4 photocurable resin 12 liquid level 1 EWS 9 laser beam 4 uncured resin 201 squeegee 17 laminated model A weir structure 17 squeegee control device (squeegee control means) 20 squeegee drive device (squeegee drive mechanism)

Claims (2)

[Claims] A liquid surface of a photo-curable resin housed in a molding tank of an optical molding apparatus is exposed to laser light according to shape data generated in advance by EWS, and is hardened by exposure to a laser beam. Fill the cured resin, then by moving the squeegee, apply the uncured resin liquid to the unfilled part, to form an uncured resin film of a predetermined uniform thickness,
A laser beam is exposed and cured to the uncured resin film, and an optical modeling apparatus for forming a laminated model by sequentially forming a thin cured resin layer detects a laminated model having a weir structure and a weir structure in advance. An EWS for generating the squeegee moving speed data or the number of movements data, squeegee control means for controlling the movement of the squeegee based on the squeegee moving speed data or the number of movement data of the EWS, and an instruction from the squeegee control means And a squeegee driving means for moving the squeegee according to the following. 2. A liquid surface of a photocurable resin housed in a molding tank of an optical molding apparatus is exposed to laser light in accordance with shape data generated in advance by EWS, and is hardened by exposure to a laser beam. Fill the cured resin, then by moving the squeegee, apply the uncured resin liquid to the unfilled part, to form an uncured resin film of a predetermined uniform thickness,
In the method of manufacturing an optically molded article in which the uncured resin film is exposed and cured by a laser beam and a thin cured resin layer is sequentially formed to form a laminated model, the EWS is used in advance.
Detects the weir structure of the laminated model and sets the minimum value / normal value of the moving speed of the squeegee or the maximum value / normal value of the number of times of movement of the squeegee during modeling. And it moves on the said weir structure at the moving speed of the minimum value, and the part other than a weir structure moves by a normal value. Alternatively, a method for producing an optically shaped article, comprising: moving on a weir structure with a maximum number of movements, and moving a portion other than the weir structure with a normal number of movements.