JP2561325B2 - Three-dimensional shape forming method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for forming a three-dimensional shape, and an article having a three-dimensional shape using a photocurable resin that is cured by irradiation with light. The present invention relates to a method of forming and manufacturing.

[Conventional technology]

The method of forming a three-dimensional shape using a photo-curable resin,
As a method that can easily and accurately form a complicated three-dimensional shape without using a molding die or a special processing tool, it is considered to be used for manufacturing various product models and three-dimensional models. These are disclosed, for example, in JP-A-62-35966 and JP-A-61-114817.

FIG. 6 shows an example of a conventional general method for forming a three-dimensional shape using a photo-curable resin. For a liquid photo-curable resin 2 stored in a resin liquid tank 1, By irradiating the light beam 3 such as a laser beam condensed by the condenser lens 30 from above the liquid surface, the photo-curable resin 2 near the focal position of the light beam 3 to a certain depth from the liquid surface is cured. Then, the irradiation position of the light beam 3 is sequentially moved to form the photo-curable layer 40 having a predetermined pattern.
When a new photo-curable resin liquid 2 is supplied onto the photo-curable layer 40 and the photo-curable resin liquid 2 is cured again by the light beam 3 in a predetermined pattern, Then, a photo-cured layer 40 having another pattern is formed. In this way, by sequentially stacking a plurality of photo-curing layers 40, the molded product 4 having a desired three-dimensional shape can be formed. By condensing the light beam 3 by the lens 30 and focusing it near the liquid surface, strong light energy is given near the focal position, so that the photo-curable resin 2 with a constant thickness just below the liquid surface is provided. Only one can be cured efficiently.

FIG. 7 schematically shows a state in the vicinity of the liquid surface irradiated with the light beam 3, in which the focal point F of the light beam 3 is at the liquid surface position, and the light beam 3 is vertically converged at the converging angle α. Irradiating. When such a light beam 3 is irradiated, the light beam 3
Since the resin liquid 2 is hardened by penetrating from the focal point position F of the liquid surface to a certain depth, the elongated conical hardening region 42 is formed below the liquid surface. By moving the light beam 3 in the horizontal direction, the curing region 42 is sequentially moved to form the photocuring layer 40 having a constant pattern. Therefore, at the outer end of the photo-curing layer 40, a constant inclination angle θ is formed corresponding to the outer shape of the curing region 42 of the light beam 3. In the case of FIG. 7, the inclination angle θ of the end surface of the photo-curable layer 40 is represented by θ = 90 ° −α / 2, and α is a relatively small angle.
Is close to 90 °.

[Problems to be Solved by the Invention]

In the conventional method for forming a three-dimensional shape as described above, in order to obtain a three-dimensional shaped molded product by stacking photo-cured layers having a certain thickness, a step for each photo-cured layer is formed on the outer surface of the molded product. There was a problem that.

FIG. 8 shows a cross-sectional structure of a molded product 4 formed by a conventional three-dimensional shape forming method. For example, a three-dimensional shape 4'having a smooth curved outer surface indicated by a chain double-dashed line is shown. Even if it is attempted to form, each photo-curing layer 40 is a plate having a constant thickness, and the end face of each photo-curing layer 40 is an inclined surface having the above-mentioned constant angle θ. Since a step-like step is formed for each 40, the outer surface of the actually molded product 4 is not smooth.

Therefore, as described above, an object of the present invention is to provide a method for forming a three-dimensional shape capable of smoothly forming an outer surface of molding in a method for forming a three-dimensional shape by stacking a plurality of photo-curing layers. To provide.

[Means for Solving the Problems] In the present invention for solving the above problems, the method for forming a three-dimensional shape according to claim 1 is to form a photocurable layer by irradiating a photocurable resin with light. In the method of stacking a plurality of photocurable layers to form a desired three-dimensional shape, by changing the focal position of the irradiation light beam in the vertical direction with respect to the surface of the photocurable resin, The inclination angle of the outer edge is changed.

The method according to claim 2 is the same as the method according to claim 1, wherein the angle of inclination of the outer end of each photocurable layer is changed by changing the converging angle of the irradiation light beam. I am trying.

According to a third aspect of the present invention, in the method for forming a three-dimensional shape similar to the method of the first aspect, the inclination angle of the outer end of each photocurable layer is changed by changing the irradiation angle of the light beam to be irradiated. I have to.

[Action]

By changing the shape of the cured area of the photocurable resin that is cured by irradiation of the light beam and changing the inclination angle of the outer end of the photocurable layer to be laminated, the shape of the outer surface of the three-dimensional shape to be formed can be adjusted. The inclination angle of the outer end of each photo-curable layer can be arbitrarily set, and a three-dimensional molded article having a smooth outer surface can be obtained.

Among the means for changing the inclination angle of the outer end of the photo-curing layer, according to the method of claim 1, the curing region by the light beam has a conical shape in the opposite direction above and below the focal position. By changing the focus position of the light beam to the vertical direction of the photocurable resin with respect to the surface, the inclination angle of the outer end of each photocurable layer can be changed in the opposite direction.

According to the method of the second aspect, it is possible to change the inclination angle of the outer end of each photo-curing layer by utilizing the fact that the hardening region by the light beam changes depending on the size of the converging angle.

According to the method of the third aspect, it is possible to change the inclination angle of the outer end of each photo-curing layer by utilizing the fact that the curing region by the light beam changes depending on the inclination of the irradiation angle.

〔Example〕

The present invention will be described below in detail with reference to the drawings showing the embodiments. In addition, the basic formation method,
Also, since the forming apparatus used therefor is the same as that of the above-described conventional technique, common portions are denoted by the same reference numerals, and overlapping description will be omitted.

FIG. 1 shows the overall structure of the molding apparatus. A liquid photocurable resin 2 is stored in the resin liquid tank 1. A molding table 5 on which the photocurable layer 40 is formed is provided in the resin liquid tank 1. The molding table 5 is provided so as to be vertically movable via an elevating arm 50 and the like. Resin liquid tank 1
A light beam irradiation mechanism including a condenser lens 30 and a laser generator (not shown) is provided above the light beam, and the light beam is focused so as to focus near the liquid surface of the photocurable resin liquid 2. 3 can be irradiated.

Since the light beam 3 is irradiated in a conical shape that is opened vertically at a constant angle around the focal point F, the conical opening angle is defined as the converging angle α. The angle formed by the central axis of the light beam 3 and the liquid surface is defined as the irradiation angle β. In the case of FIG. 1, the focal point F of the light beam 3 coincides with the liquid surface, and since the liquid beam of the light beam 3 is irradiated perpendicularly, the irradiation angle β is 90 °.

In this device, the focal position F of the light beam 3, the converging angle α, and the irradiation angle β are variable. Light beam 3
In order to change the focus position F in the vertical direction with respect to the liquid surface, the focus position F is moved in the vertical direction by moving all or part of the optical system of the light beam irradiation mechanism including the condenser lens 3 in the vertical direction. Can be made. To change the converging angle α, the light beam 3 may be adjusted by changing the focal length by moving the lens of the optical system. In order to change the irradiation angle β, a part or the whole of the light beam irradiation mechanism or the optical system may be tilted. These focus positions F,
Since a mechanism or structure adopted in various ordinary optical devices such as a known laser irradiation system is applied to the variable mechanism of the converging angle α and the irradiation angle β, detailed description thereof will be omitted. The apparatus used in the method of the present invention may be such that only one of the focal position F, the converging angle α and the irradiation angle β is variable, but a plurality of conditions or all the conditions are variable. However, the irradiation time may be variable.

Next, a method for forming a three-dimensional shape using the above-described apparatus will be described.

In this method, the molding table 5 is submerged just below the liquid surface of the photocurable resin liquid 2, and the photocurable resin liquid 2 having a constant thickness between the molding table 5 and the liquid surface is irradiated with the light beam 3 from above. By forming the photocurable layer 40 and then lowering the molding table 5,
The formed photocurable layer 40 is covered with a new resin liquid 2, and the second photocurable layer 40 is formed by irradiating a light beam again. By sequentially repeating the irradiation of the light beam 3 and the lowering of the molding table 5 in one cycle, the photo-curing layers 40 are laminated one after another to obtain a molded product 4 having a desired three-dimensional shape.

Next, a method of changing the inclination angle of the outer end of the photo-curable layer 40 will be described.

First, FIG. 2 shows the case where the focal position F is changed. In FIG. 2 (a), the focal position F coincides with the liquid surface, and in FIG. 2 (b), the focal position F is farther than the liquid surface. FIG. 2 (c) shows the case where the focus position F is above the liquid surface by the distance f when the depth is f deep. Looking at the hardening region 42 in each state, in FIG. 2 (a), it has a conical shape which spreads downward with the liquid surface as the apex, and the outer circumference of the hardening region 42 which is the outer end of the photohardening layer 40. The inclination angle θ is θ = 90 ° −α / 2, as in the above-mentioned conventional technique. However, the second
In FIG. 6B, the hardening region 42 has a conical shape with the liquid surface as the bottom surface, so the inclination angle θ is θ = 90 ° + α / 2, and the photocuring layer 40 is different depending on the focal position F. The inclination angle θ of the outer edge of the changes. In particular, in this case, the inclination is completely opposite to the vertical direction, so that a more complicated three-dimensional shape can be dealt with by combining it with a change of the converging angle α described later.

Note that in FIG. 2 (c), since the strong range of light energy is shallow, there is an effect that the thickness of the cured region 42 becomes thinner and the inclination angle θ becomes smaller than that in the case of FIG. 2 (a). . This is because the pattern of the hardening region 42 is schematically shown in the figure, and therefore the tilt angle θ is the same both at the position close to the focus F and at the position far from the focus F. Since the hardened region 42 is formed so that the conical shape of is connected to a smooth curved line, the inclination angle θ near the focal point F is larger than that shown in the figure, and is close to vertical, that is, 90 °. Therefore, compared to FIG. 2 (a),
A hardening region 42 is formed at a position far from the focal point F (FIG. 2 (c)).
In this state, the tilt angle θ becomes smaller than that in the case of FIG. 2 (a).

Next, FIG. 3 shows a case where the converging angle α is changed. The inclination angle θ is θ = 90 ° -as in the case of FIG. 2 (a).
Since it is α / 2, the inclination angle θ is smaller in the case of FIG. 3 (e) where the converging angle α is larger than in the case of FIG. 3 (d).

FIG. 4 shows a case where the irradiation angle β is changed. in this case,
The inclination angle θ becomes θ = β−α / 2, and the inclination angle θ can be freely changed by changing β, and the third angle
As can be seen by comparing FIG. 3 (f) with FIG. 3 (g), it is possible to make an inclination in the opposite direction to the vertical direction.

2 to 4 show the case where the three conditions of the condensing position F, the converging angle α, and the irradiation angle β are independently changed, but by combining the respective conditions arbitrarily, A complicated inclination angle θ can be set, and the outer surface of the three-dimensional shape can be smoothed.

FIG. 5 shows a molded product 4 formed by the apparatus and method for forming a three-dimensional shape according to the present invention as described above, and each photo-curable layer according to the intended three-dimensional shape 4 '. By changing the inclination angle θ of the outer end of 40, a molded product 4 having a three-dimensional shape in which the outer surface is much smoother than that of the conventional example shown in FIG. 8 and having excellent appearance quality is obtained. To be

〔The invention's effect〕

According to the method for forming a three-dimensional shape according to any one of claims 1 to 3 of the invention described above, the focus position of the light beam, the converging angle, and the irradiation angle are changed so that the curing region of the light beam is changed. By changing the shape, the inclination angle of the outer edge of the photo-curing layer can be changed, so that the inclination angle of the outer edge of each photo-curing layer can be adjusted according to the shape of the outer surface of the three-dimensional shape to be formed. Can be arbitrarily set, and a three-dimensional molded article having a smooth outer surface can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall structural view of a three-dimensional shape forming apparatus showing an embodiment of the present invention, and FIGS. 2 (a), (b) and (c) are cases where the focal position is changed. 3 (d) and 3 (e) are schematic views showing the irradiation state when the converging angle is changed, and FIGS. 4 (f) and 4 (g) are the irradiation angles changed. FIG. 5 is a cross-sectional view of the formed product, FIG. 6 is a schematic structural view of a conventional example, FIG. 7 is a schematic view showing the irradiation state, and FIG. 8 is formed. It is a sectional view of a molded product. 2 ... Photocurable resin liquid, 3 ... Light beam, 30 ... Condenser lens, 4 ... Molded product, 40 ... Photocured layer, 42 ... Cured area,
F: focus position, α: converging angle, β: irradiation angle, θ
...... Inclination angle

Claims (3)

(57) [Claims] 1. A method of irradiating a photocurable resin with light to form a photocurable layer, and stacking a plurality of the photocurable layers to form a desired three-dimensional shape. A method for forming a three-dimensional shape, which comprises changing the inclination angle of the outer end of each photocurable layer by changing the focal position in the vertical direction with respect to the surface of the photocurable resin. 2. A method for forming a photocurable layer by irradiating a photocurable resin with light to form a photocurable layer and stacking a plurality of the photocurable layers to form a desired three-dimensional shape. A method for forming a three-dimensional shape, characterized in that the inclination angle of the outer end of each photo-curing layer is changed by changing the angle. 3. A method of forming a photocurable layer by irradiating a photocurable resin with light to form a photocurable layer and stacking a plurality of the photocurable layers to form a desired three-dimensional shape. By changing the inclination angle of the outer end of each photo-curing layer.