JPH02103127A - Method and apparatus for forming three-dimensional configuration - Google Patents

Abstract

PURPOSE:To enhance the appearance quality of a molded product by vibrating the focal position of laser beam to be applied in the thickness direction of a photo-setting layer. CONSTITUTION:A molding stand 5 is sunk directly under the liquid level of a photo-setting resin solution 2 and laser beam 3 is applied the photo-setting resin solution 2 having a definite thickness between the molding stand 5 and the liquid level from above while the focal position of said beam is vibrated in an up-and-down direction to form a photo-set layer 40. Next, by allowing the molding stand to fall, the molded photo-set layer 40 is covered with the new resin solution 2 and again irradiated with laser beam 3 while the focal position of the beam 3 is vibrated up and down to form the second photo-set layer 40. The irradiation with the laser beam 3 and the falling of the molding stand 5 are set to one cycle each and, by successively repeating said cycle, the photo-set layer 40 is successively laminated and a molded product 4 having a desired three-dimensional configuration is obtained.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method and apparatus for forming a three-dimensional shape,
The present invention relates to a method of molding and manufacturing articles having a three-dimensional shape using a photocurable resin that is cured by irradiation with light, and an apparatus used to carry out this method.

(Prior art) A method of forming three-dimensional shapes using photocurable resins allows complex three-dimensional shapes to be formed easily and accurately without using molds or special processing tools. As a method, it is considered to be used for manufacturing various product models and three-dimensional models.
This method is disclosed in Japanese Patent Application Laid-Open No. 61-114817, etc.

FIG. 6 shows an example of a conventional general method for forming a three-dimensional shape using a photocurable resin, and shows how the liquid photocurable resin 2 stored in the resin liquid tank l is , on the molding table 5 submerged in the resin liquid, the condenser lens 3 is inserted from above the liquid surface.
By irradiating the light beam 3 such as a laser beam focused at 0, the photocurable resin 2 near the focal position of the light beam 3 from the liquid surface to the molding table 5 at a certain depth is cured, By sequentially moving the irradiation position of the light beam 3 in the horizontal direction, a photocured layer 40 having a predetermined pattern is formed. Next, the molding table 5 is lowered by operating the elevating arm 50 and the like, and a new photocurable resin liquid 2 is supplied onto the formed photocurable layer 40, and this resin liquid 2 is again applied to the light beam 3. When the photocured layer 40 is cured in a predetermined pattern, a photocured layer 40 having another pattern is formed on the photocured layer 40. In this way, the plurality of photocuring layers 4
0... can be sequentially stacked to form a molded product 4 having a desired three-dimensional shape. Light beam 3 through lens 30
By condensing the light and focusing it near the liquid surface, strong light energy is given to the vicinity of this focal point, which efficiently cures only the photocurable resin liquid 2 of a certain thickness just below the liquid surface. It is now possible to do so.

[Problem 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, each photo-cured layer is placed on the side part of the outer surface of the molded product. There was a problem in that there was a difference in level between each step.

As is clear from FIG. 6, each photocuring layer 40 is plate-shaped with a constant thickness, and the edge of each photocuring layer 40 has a clear outline corresponding to the irradiation range of the irradiated light beam. As a result, a step-like step was inevitably formed between the stacked photocured layers 40, making it impossible to smooth the outer surface side portions of the formed molded product 4.

Therefore, as described above, an object of the present invention is to provide a method in which a three-dimensional shape is formed by stacking a plurality of photocured layers, in which the side portions of the outer surface of a molded product can be formed smoothly; An object of the present invention is to provide a three-dimensional shape forming apparatus used in the method.

[Means to solve the problem]

A method for forming a three-dimensional shape according to claim 1 of the present invention that solves the above problems includes irradiating a photocurable resin with a light beam to form a photocured layer, and stacking a plurality of photocured layers. In the method of forming a desired three-dimensional shape, the focal position of the light beam is vibrated in the thickness direction of the photocured layer.

The three-dimensional shape forming apparatus according to claim 2 is a three-dimensional shape forming apparatus comprising: a resin liquid tank containing a photocurable resin liquid; and a light beam irradiation mechanism that irradiates a light beam near the liquid surface of the resin liquid tank. In the forming apparatus, the light beam irradiation mechanism is provided with an addition mechanism that vibrates the focal position of the light beam in the vertical direction.

[For production]

According to the method for forming a three-dimensional shape according to claim 1, by vibrating the focal position of the light beam for photocuring in the thickness direction of the photocurable layer, the area cured by the light beam of the photocurable resin liquid also changes in thickness. Due to the vibration in the direction, the outline of the edge of the photocured layer formed by the envelope line of the outer periphery of the vibrating cured area becomes blurred. When the edges of the photocured layers become blurred, the steps between the stacked photocured layers become less noticeable, so that the side portions of the outer surface of the molded product become smooth.

According to the three-dimensional shape forming apparatus according to claim 2, in contrast to a normal three-dimensional shape forming apparatus, the light beam irradiation mechanism includes:
The method according to claim 1 described above can be easily carried out simply by providing a vibration mechanism that vibrates the light beam in the vertical direction.

〔Example〕

The invention will now be described in detail below with reference to the drawings showing embodiments. Note that the basic forming method and forming apparatus are the same as those of the prior art described above,
Duplicate explanations will be omitted by assigning the same reference numerals to common parts.

FIG. 1 shows the overall structure of the molding device.

A liquid photocurable resin 2 is stored in a resin liquid tank 1. A molding table 5 on which a photocuring layer 40 is formed is provided in the resin liquid tank 1 . The molding table 5 is a lifting arm 5
0 etc., it can be raised and lowered in the vertical direction. A light beam irradiation mechanism consisting of a condensing lens 30, a laser generator (not shown), etc. is provided above the resin liquid tank l, and a focal point F is set near the liquid surface of the photocurable resin liquid 2. It is now possible to irradiate a light beam 3 that connects the two.

In this device, the focal position F of the light beam 3 described above can be vibrated in the vertical direction in the figure, that is, in the thickness direction of the photocured layer 40 to be formed. In order to vibrate the light beam 3, a vibrating mechanism 6 is provided that vibrates the entire or part of the optical system of the light beam irradiation mechanism in the vertical direction.

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

Basically, it is carried out in the same way as the conventional method. That is,
The molding table 5 is submerged just below the liquid surface of the photocurable resin liquid 2, and the light beam 3 is irradiated from above onto the photocurable resin liquid 2 with a certain thickness between the molding table 5 and the liquid surface to form a photocurable layer 40. Next, by lowering the molding table 5, the formed photocured layer 140 is covered with new resin liquid 2, and the second photocured layer 40 is formed by irradiation with 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 photocured layers 40 are laminated one after another, and a molded product 4 having a desired three-dimensional shape is obtained.

This method differs from conventional methods in the following points. That is, in the conventional method, the focal position of the light beam was fixed at a constant height near the liquid surface, but in the method according to the present invention, the light beam 3 is irradiated while the focal position is vibrated in the vertical direction. . FIG. 2 schematically shows the photocuring effect when the light beam 3 is irradiated with the focal position F oscillating. First, in step (a), the focal position F of the tapered light beam 3 having a constant condensing angle is aligned with the surface of the photocured layer 40 that has been cured previously. In this state, since the resin liquid 2 irradiated with the light beam 3 is photocured between the liquid level of the resin liquid 2 and the focal position F, a tapered hardening area 42 that opens upward above the focal position F is formed. is formed. Next, in step (b), since the focal position F of the light beam 3 is aligned with the liquid level of the resin liquid 2, a tapered cured region 42 that opens downward is formed below the focal position F. . For example, if the light beam 3 is irradiated with the focal position F fixed in the state of (a), a photocured layer having a clear outline according to the outer shape of the cured area yA42 will be formed, which will be different from the conventional method. Needless to say, it will be the same.

In this way, by periodically changing the focal position of the light beam 3 in the vertical direction (vibrating the focal position in the vertical direction),
The hardening area 42 also changes periodically in the vertical direction between the stage (a) and the stage (bl).
A photocured layer is formed whose outer shape is the envelope 45 of the outer periphery of 2, and this photocured layer is irradiated with a light beam over the entire area surrounded by the envelope 45. While the beam 3 is vibrating in the vertical direction, the center part or the part almost along the central axis of the light beam 3 is always irradiated by the light beam 3, whereas the outer part near the envelope 45 is It is only irradiated intermittently. Therefore, there is a difference in the photocuring effect between the center and the outer periphery, and the closer to the periphery the weaker the amount of light irradiation, that is, the photocuring effect, the closer to the periphery the outline becomes blurred and ambiguous. . When the cured area 42 moves up and down, the light beam 3 is newly irradiated onto the upper part of the cured area 42 formed in the previous step, so the light is reflected on the surface of the cured area 42 below. It also happens that the contour of the hardening area 42 of the light beam 3 becomes blurred due to scattering. Note that the above explanation of the principle and the drawings are intended to show the photocuring effect of the method of this invention in an ideal and schematic state, and in reality, light scattering within the resin liquid 2 and Due to deviations of the light beam 3, variations in the degree of curing of the photocurable resin, etc., the photocured layer is not necessarily formed in the shape exactly as shown.

FIG. 3 shows the outer shape of the photocured layer 40 and molded article 4 thus formed, and the edge 46 of each photocured layer 40 has a blurred outline. This kind of blurred edge 4
On the outer surface of the molded product 4 in which the photocured layers 40 are stacked, the contours of the steps between the photocured layers 40 are faded and unnoticeable, resulting in a smoothly connected state.

Note that the material of the photocurable resin, the type of light beam, the structure of the molding device, etc. used in the photocurable molding method of the present invention can be carried out under the same conditions as in known photocurable molding methods. for example,
As the light beam, a light beam having an arbitrary wavelength component such as visible light or ultraviolet light is used depending on the material of the photocurable resin.

As the vibration mechanism 6 for vibrating the focal position F of the light beam 3, the optical system of the light beam irradiation mechanism may be vibrated by any mechanical or electrical means. 4 and 5 show a specific example of the vibration mechanism 6 that vibrates the light beam 3 by vibrating the condenser lens 30 of the optical system. In the embodiment shown in FIG. 4, the holding frame 60 of the condenser lens 30 and the main body portion 61 of the light beam irradiation mechanism are horizontally connected by a piezoelectric ring 62 in the shape of a hollow disc. By applying a voltage alternately to the lower surface of the piezoelectric ring 62, the center of the piezoelectric ring 62 vibrates to warp up and down, causing the condenser lens 30 connected to the piezoelectric ring 62 to vibrate up and down. In the embodiment shown in FIG. 5, a cylindrical piezoelectric ring 62 connects the main body portion 61 of the light beam irradiation mechanism and the holding frame 60 of the condensing lens 30 in the vertical direction. When a voltage is applied to the piezoelectric ring 62 to cause it to vibrate in the vertical direction, the condenser lens 30 also vibrates in the vertical direction.

As described above, the vibration mechanism that utilizes the vibration effect of a piezoelectric element can control vibration electrically, so it can provide accurate and minute vibrations and can be manufactured compactly.

For efficient photocuring, the focal position iF of the light beam 3 is oscillated so as to vary between the bottom surface of the photocurable layer 40 to be formed and the liquid level, as shown in FIG. However, it is preferable that the tapered cured regions 42 formed above and below the focal position F should be moved by the thickness of the photocuring layer 40. It may be set to move further downward.

It is the photocuring Ff that vibrates the focal position F of the light beam 3.
In order to blur the outline of the edge of 40, a photocuring layer 40 is applied.
When irradiating the light beam 3 only near the edges of the photocuring layer 40 and irradiating the central portion of the photocuring layer 40 with the light beam 3, the focal position may be kept fixed as in the conventional case.

Also, when irradiating the light beam 3 to a portion of the photocuring layer 140 where the slope of the outer surface side portion matches the taper angle of the curing area 42 of the light beam 3, the focal position F is adjusted. It may remain fixed.

The three-dimensional shape forming method and apparatus according to the present invention include:
In addition to the embodiments described above, it is also possible to combine appropriate methods and structures employed in various known three-dimensional shape forming methods and apparatuses. For example, in the embodiment described above, the photocured layer 40 is formed on the molding table 5, and the formed photocured layer 40 is lowered by lowering the molding table 5.
New resin liquid 2 is supplied onto the surface of the resin liquid 2, but the molding table 5 is fixed and the liquid level is raised by adding the supply amount of the resin liquid 2 stored in the resin liquid tank 1, and the light is increased. Curing tank 40
The resin liquid 2 may be supplied on top of the resin.

〔Effect of the invention〕

According to the method for forming a three-dimensional shape according to claim 1 of the present invention described above, the photocured layer is formed by vibrating the focal position of the irradiated light beam in the thickness direction of the photocured layer. It is possible to blur the outline of the edge of the layer to create an ambiguous state. Therefore, the difference in level between the stacked photocured layers becomes blurred and becomes less noticeable, so the outer surface of the molded product can be formed in a smooth state, and the appearance quality of the molded product can be improved.

According to the three-dimensional shape forming apparatus according to claim 2, in a normal three-dimensional shape forming apparatus, the light beam irradiation mechanism includes:
By simply providing an excitation mechanism that vibrates the focal position of the light beam in the vertical direction, the method according to the invention described in claim 1 described above can be easily and favorably implemented.

[Brief explanation of the drawing]

FIG. 1 is an overall structural diagram of a three-dimensional shape forming apparatus showing an embodiment of the present invention, and FIG. 2 is a schematic diagram illustrating the photocuring effect.
Figure 3 is a cross-sectional view of the formed molded product, Figures 4 and 5.
Each figure is a sectional view showing an example of the structure of the vibration mechanism, and FIG. 6 is an overall configuration diagram of a conventional example. 2... Photocurable resin liquid 3... Light beam 30...
・Condenser lens 4... Molded product 40... Photocured layer
6... Vibration mechanism

Claims (1)

[Scope of Claims] 1. A method of forming a photocured layer by irradiating a photocurable resin with a light beam, and stacking a plurality of photocured layers to form a desired three-dimensional shape. A method for forming a three-dimensional shape, characterized by vibrating the position in the thickness direction of a photocured layer. 2. In a three-dimensional shape forming apparatus equipped with a resin liquid tank containing a photocurable resin liquid and a light beam irradiation mechanism that irradiates a light beam near the liquid surface of the resin liquid tank, a light beam is emitted to the light beam irradiation mechanism. A three-dimensional shape forming device characterized by comprising an excitation mechanism that vertically vibrates the focal position of the image.