JP2000218707A - Recoater for stereo-lithographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply a finish coating easily and quickly by forming a liquid reservior part at the lower part of a narrow gap. SOLUTION: The recoater 21 comprises members 32, 33 fixedly attached to a support member 31 and a groove 35 extending in a longitudinal direction on the member 32 and a supply tube 36 drilled communicating to a liquid supply device at the bottom of the groove 35. The surfaces of bank parts 37, 38 formed along the opening part 35a of the groove 35 are finished smoothly, and a gap 39 of about 0.3 mm is formed in a part between the bank part 38 and the member 32 side of the member 33. Further, the end part 40 of the lower part of the member 33 is folded at a folding part 41 to form a liquid reservior part 42. When the recoater 21 is retreated to the rearmost part of the optical shaping device to come into contact with the stopper of the rear part, the recoater 21 is rotated centered around a shaft provided in a shaft hole 34 of the support member 31 and leans obliquely to the rear side. In addition, liquid stored in the liquid reservior part 42 passing through the supply tube 36, groove 35 and gap 39 overflows from the end part 40 to be applied as a facing following the advance of the recoater 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recoater for an optical shaping apparatus, and more particularly to a recoater for an optical shaping apparatus which forms a cured product by irradiating a liquid surface of a photocurable liquid with light.

[0002]

2. Description of the Related Art In recent years, the surface of an optical molding resin, which is a liquid that is hardened by irradiation of light, particularly ultraviolet light, is selectively scanned and irradiated with a beam of ultraviolet light to form a three-dimensional cured product. The molding technology has been developed as a high-speed three-dimensional molding technology.
A laser is used as an ultraviolet light source.

A conventional stereolithography apparatus is as shown in FIG. The ultraviolet light flux L1 emitted from the light source 1 irradiates the liquid surface 7 of the liquid 6 via the scanner 5. The liquid 6 is accommodated in a liquid tank 8, and the hardened material 9 during molding is held on a holding table 10. The holding table 10 can be moved up and down by an elevator 11. The upper surface 9a of the cured product 9 is set at a position lower than the liquid level 7 by the elevator 11, and the upper surface 9a of the cured product 9 and the liquid surface 7
A thin layer 12 of liquid 6 is formed between the two. Luminous flux L on liquid surface 7
When 1 is irradiated, solidification occurs in the thin layer 12 below the irradiated portion, and a new hardened portion 13 is formed in a two-dimensional figure on the upper surface 9a of the hardened material 9. The three-dimensional cured product is completed by forming the cured portion in the thin layer formed by the descending of the elevator 11 sequentially.

[0004]

The elevator 11 is sequentially lowered and replenished by overcoating the liquid 6, a new thin layer is formed and the liquid level is maintained at the same level. 6
Is extremely viscous and has the following problems. A conventional recoater has a cross section as shown in FIG. A groove-shaped member provided with a supply pipe connected to the liquid supply device and a smooth and elongated rectangular flat plate member are fixed to each other, and a slit is formed at a lower portion. The opening of the slit is the liquid outlet 5
It becomes 6, and the liquid flows down. In such a conventional recoater, as shown in FIG. 11 at the time of flowing down due to the viscosity of the liquid. That is, the liquid film 5 flowing down from the outlet 56
7 is not performed in a uniform film form, and a break 58 occurs. For this reason, air bubbles generated by the entrapped air tend to remain on the liquid surface after flowing down, and many irregularities remain. After overcoating with a recoater, air bubbles were not easily removed even when the liquid level was smoothed with a squeegee. The movement speed of the squeegee is restricted in order to prevent the irregularities and bubbles from remaining, so that it takes a long time, and the remaining bubbles sometimes cause defective products. There is a problem that these are one of the factors that hinder the cost reduction of the optical molding.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide a recoater of an optical shaping apparatus capable of easily and quickly overcoating, thereby reducing the cost reduction of the optical shaping.

[0006]

According to the present invention, there is provided an optical molding apparatus for molding a cured product by irradiating a liquid surface of a photocurable liquid with light, and the liquid flows down from a slit to form the cured product. In the recoater of the optical shaping apparatus for coating the liquid surface of the liquid, a liquid reservoir is formed at a lower portion of the narrow space.

Preferably, a lower end portion of the recoater contacts the liquid surface when the recoater advances, and retreats from the liquid surface when the recoater retreats. did.

[0008]

According to the first aspect of the present invention, the liquid is stored in the liquid pool below the slit of the recoater, and the liquid overflows therefrom, so that the liquid is uniformly coated.

According to the second aspect of the present invention, the liquid stored in the reservoir flows down to the liquid surface without forming a film, and does not disturb the liquid surface when the liquid retreats.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. The light source 1 is a pulse laser, and the emitted light flux L1 is guided by an optical system 2 composed of a mirror or the like, and irradiates a liquid surface 7 of a liquid 6 via a modulator 3, a light flux adjuster 4, and a scanner 5. The light beam control means 17 controls the light beam adjuster 4, and the scanning control means 18 controls the scanner 5.

Liquid 6 is a urethane acrylate resin having a viscosity of 1700 cps. The liquid 6 is accommodated in a liquid tank 8, and the hardened material 9 during molding is held on a holding table 10. The holding table 10 can be moved up and down by an elevator 11. The upper surface 9a of the cured product 9 is set at a position lower than the liquid level 7 by the elevator 11, and a thin layer 12 of the liquid 6 is formed between the upper surface 9a of the cured product 9 and the liquid surface 7. When the liquid surface 7 is irradiated with the light beam L <b> 1, solidification occurs in the thin layer 12 below the irradiated portion, and a new cured portion 13 is formed on the upper surface 9 a of the cured product 9. When the hardened portions 13 are gathered and a two-dimensional hardened portion is formed on the upper surface 9a of the hardened material 9, the elevator 11 is lowered by the thickness of one thin film so that the height of the liquid level 7 becomes the original. Is added to the recoater 21 by overcoating. The overcoated liquid level 7 is then smoothed by a squeegee 22. The overcoating control means 20 includes the recoater 21 and the squeegee 2
2 is controlled. The three-dimensional cured product is completed by successively laminating the two-dimensional thin cured portions in this manner.

Next, the relationship between the liquid tank, the recoater and the squeegee will be described. FIG. 2 and FIG. 3 are views of the liquid tank provided in the optical shaping apparatus as viewed from the front and side, respectively. A frame (not shown) that accommodates the rectangular liquid tank 8 includes a pair of girders 25 that are parallel to the left and right outer sides when viewed from the front of the liquid tank 8.
Is provided. The pair of girders 25 on both left and right sides are provided with a bridge 19 spanning the liquid tank 8. The beam 19 can be moved on the girder 25 via the car 26, and the beam 1
In 9, a recoater 21 and a squeegee 22 are provided so as to be above the liquid level 7. Further, a support member (not shown) is provided on the front side of the liquid tank 8, that is, front and back, that is, on the rear side, respectively, and a support member (not shown) is provided on a rear support member (not shown). A stopper 28 is provided on each of the support members (not shown).

Next, the structures of the recoater and the squeegee will be described. FIG. 4 is a sectional view of the recoater and the squeegee viewed in the direction of the beam.

The recoater 21 comprises a member 32 fixed to a support member 31 and a member 33. Member 3
Reference numeral 2 denotes a substantially rectangular member long in the longitudinal direction of the beam 19 fixed to the member 31, and member 33 is a plate-like member long in the longitudinal direction of the beam 19. The member 32 and the member 33 are screwed to each other and further screwed to the support member 31. Support member 31
Is formed with a shaft hole 34, and is rotatable around a shaft (not shown) provided in the beam 19. The member 32 is provided with a groove 35 extending in the longitudinal direction.
A supply pipe 36 that leads to a liquid supply device (not shown) is cut at the bottom of the. The opening 35 a of the groove 35 opens in the direction of the member 33. Embankments 37, 38 along opening 35a
The surface is finished smoothly. Compared with the height from the groove bottom of the upper bank portion 37 on the support member 31 side, the support member 31
The height of the lower embankment 38 that is not on the side from the groove bottom is about 0.3 m
m lower. Therefore, a gap 39 of about 0.3 mm is formed between the bank 38 and the member 32 side of the member 33. Gap 3
The size of 9 is usually selected from 0.2 to 0.5 mm according to the viscosity of the liquid 6, the size of the thin layer 12, the precision of molding and other factors. A lower end portion 40 of the member 33 which is not on the support member 31 side is folded at the folded portion 41 toward the member 32 at an angle of about 120 °. Folding part 41 and lower end part 3 of bank part 38
8a is about 20 mm, and the length between the end portions 40 of the folded portion 41 is about 10 mm. Therefore, the member 33
A liquid storage part 42 for storing the liquid upward is formed at the lower part.

The squeegee 22 is formed of a blade 47 fixed to the support member 31 and screwed to a tip 46 of a support rod 45. The blade portion 47 is formed so as to be inclined by about 30 ° to the front side of the liquid tank 8 with respect to the direction of the support rod 45, to form a blade edge 48.

Next, the overcoating operation of the liquid level 7 by the recoater 21 will be described. When the recoater 21 retreats to the rearmost position, the member 32 of the recoater 21 comes into contact with a stopper 27 provided on the rear side, and a shaft hole 34 formed in the support member 31 and a shaft provided in the beam 19 (not shown). , And the recoater 21 is inclined backward by about 30 °. This state is as shown in FIG. The liquid 6 passes through a supply pipe 36, a groove 35, and a gap 39 from a liquid supply device (not shown), is stored in a liquid reservoir 42, and overflows from an end 40. The liquid 6 is reduced as the elevator 11 descends.
b, and is overcoated with the advance of the recoater 21, and the liquid level 7c is formed after the recoater 21 advances. The difference between the liquid level 7c and the liquid level 7b is made substantially equal to the drop of the liquid level 7 by the elevator 11, and the liquid level 7 is kept constant.
This state is as shown in FIG.

Next, the operation of the squeegee 22 for smoothing the liquid surface 7 will be described. When the recoater 21 advances to the forefront, the squeegee 2 is moved to a stopper 28 provided on the near side.
The second member 45 contacts the squeegee 22, and the squeegee 22 is tilted down by about 30 ° toward the front. This state is as shown in FIG. The cutting edge 48 comes into contact with the liquid surface 7c formed after the recoater 21 advances, and the liquid surface 7c is smoothed as the squeegee 22 recedes, so that the liquid surface 7 to be irradiated is formed. The difference in height between the liquid level 7c and the liquid level 7 is extremely small. During this time, the recoater 21 is not in contact with the liquid level 7c or the liquid level 7. This state is as shown in FIG.

It is needless to say that the shape of the liquid reservoir of the recoater 21 may be different from that of the embodiment in terms of the folded length, angle, curvature, etc., depending on the liquid, the shape and precision of the cured product, and the like.

[0019]

According to the present invention, it is possible to reduce the cost of the optical molding by providing a recoater of the optical molding apparatus capable of easily overcoating at a high speed.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an optical shaping apparatus according to one embodiment of the present invention.

FIG. 2 is a front view of a liquid tank according to one embodiment of the present invention.

FIG. 3 is a side view of a liquid tank according to one embodiment of the present invention.

FIG. 4 is a sectional view of a recoater and a squeegee according to an embodiment of the present invention.

FIG. 5 is a sectional view of a recoater and a squeegee according to one embodiment of the present invention.

FIG. 6 is a sectional view of a recoater and a squeegee according to an embodiment of the present invention.

FIG. 7 is a sectional view of a recoater and a squeegee according to an embodiment of the present invention.

FIG. 8 is a sectional view of a recoater and a squeegee according to an embodiment of the present invention.

FIG. 9 is a conceptual diagram of a conventional optical shaping apparatus.

FIG. 10 is a sectional view of a conventional recoater.

FIG. 11 is a view showing a state of a liquid film by a conventional recoater.

[Explanation of symbols]

1 ... light source, L1 ... light flux, 5 ... scanner, 7 ...
..Liquid level, 21 ... Recoater, 22 ... Squeegee

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Claims (2)

[Claims] 1. A light for irradiating a liquid surface of a photo-curable liquid with light to form a cured product, and the light is formed to flow down the liquid from a slit to coat the liquid surface of the liquid. A recoater for an optical shaping apparatus, wherein a liquid reservoir is formed below the narrow space. 2. A recoater for an optical shaping apparatus, wherein a lower end of the recoater abuts on the liquid surface when the recoater advances, and retreats from the liquid surface when the recoater retreats.