JP2715636B2 - Liquid level control mechanism of resin storage tank in three-dimensional shape forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of the Invention The present invention relates to a three-dimensional shape forming apparatus that forms a three-dimensional shape based on an arbitrarily designed three-dimensional image by irradiating a liquid curable resin agent with an exposure beam. More particularly, the present invention relates to a liquid level control mechanism of a resin storage tank in which the liquid photocurable resin agent is stored.

B. Summary of the Invention The present invention provides a cured resin having a pattern corresponding to the shape of an exploded plane decomposed in one direction of an arbitrarily designed stereoscopic image by irradiating a liquid surface of a liquid photocurable resin agent with a light beam. Form a layer, then position the liquid photocurable resin agent on the cured resin layer, again irradiating the liquid surface of the liquid photocurable resin beam with the cured resin layer so as to laminate the cured resin layer In a three-dimensional shape forming apparatus that sequentially forms layers to form an arbitrary three-dimensional shape, a replenishing resin supply unit that supplies a resin agent stored in the replenishing resin tank to the resin storage tank is provided, and a resin overflowing from the resin storage tank is provided. The agent is collected in the replenishing resin tank via a suction port or an overflow portion provided on one side of the resin storage tank.

C. Prior Art Conventionally, a method of forming an article of a desired shape by irradiating a liquid curable resin agent with a predetermined exposure beam has been proposed. For example, a forming method as disclosed in Japanese Patent Application No. 63-267945 has been proposed. Proposed.

FIG. 5 is a sectional view showing a main part of a three-dimensional shape forming apparatus using the above forming method. That is, this device 51
Has a stage 53 on a horizontal plate in a resin storage tank 52 in which a liquid curable resin agent A cured by irradiation with ultraviolet light is stored, and this stage 53 is an elevator that is moved in the vertical direction. A mechanism 54 is provided. Also, the above storage tank
Above 52, a beam scanner 55 for condensing and irradiating the exposure beam B onto the liquid surface of the liquid photocurable resin agent A is provided. Exposure by the beam scanner 55, scanning of the liquid surface, and movement of the stage 53 by the elevator mechanism 54 are controlled by a modeling controller 56.

With the three-dimensional shape forming apparatus configured as described above,
To form a predetermined three-dimensional shape, first, the elevator mechanism
54 is driven as shown by the solid line in FIG.
The upper liquid photocurable resin agent A moves to an initial position where it is located at a predetermined thickness. Next, the liquid surface is scanned by the exposure beam B. In this scanning, a raster scan is performed in a pattern corresponding to each of a plurality of planes (hereinafter, referred to as “decomposed planes”) that are multiply decomposed in one direction of an arbitrarily designed stereoscopic image.

When the scanning of the light beam B is performed, a portion of the liquid photocurable resin agent A irradiated with the light beam B is cured, and a sheet shape having the same shape as the disassembled plane in the liquid surface is used. Thus, one cured resin layer is formed. And
Each time the formation of one such cured resin layer is completed, the stage 53 is lowered downward by the elevator mechanism 54 at a predetermined pitch, that is, according to the decomposition pitch when the stereoscopic image is decomposed into many decomposition planes in one direction. Move down at the pitch you chose.
Then, the liquid photocurable resin agent A is supplied so as to flow at a thickness of one pitch onto the cured resin layer, and the light beam B is scanned on the next decomposition plane to form another cured resin layer. It is formed. At this time, the cured resin layer is bonded to the previous cured resin layer.

By sequentially laminating a new cured resin layer on the cured resin layer thus formed, a large number of the laminated cured resin layers form a desired three-dimensional shape.

Therefore, according to such a three-dimensional shape forming method,
A three-dimensional shape can be formed based on an arbitrarily designed three-dimensional image.

D. Problems to be Solved by the Invention Incidentally, in the three-dimensional shape forming apparatus, the portion irradiated with the exposure beam is cured on the liquid surface of the storage tank in which the liquid photocurable resin agent is stored. The spot diameter of the light beam applied to the liquid surface is determined by the distance between the objective lens and the liquid surface. Therefore, when the liquid level position of the storage tank is easily changed, the spot diameter of the light beam is changed, the reproducibility of the cured position of the liquid photocurable resin is deteriorated, and the three-dimensional shape to be formed is accurately formed. You will not be able to do it.

The height position of the liquid level in the storage tank easily changes when the liquid itself decreases due to repeated changes in the liquid temperature or processing.

Further, when the size of the storage tank itself is increased or when the depth of the end point is reduced by narrowing the spot, strict liquid level control is required.

However, a mechanism for controlling the height position of the liquid level in the storage tank has not been developed so far.

Therefore, the present invention provides a liquid level control mechanism for a resin storage tank in a three-dimensional shape forming apparatus that controls the liquid level position of the storage tank by a simple method and improves the accuracy of the three-dimensional shape to be formed. With the goal.

E. Means for Solving the Problems In order to achieve the above object, the present invention was decomposed in one direction of an arbitrarily designed stereoscopic image by irradiating a light beam on a liquid surface of a liquid photocurable resin agent. A cured resin layer having a pattern corresponding to the shape of the decomposition plane is formed, and then the liquid photocurable resin is positioned on the cured resin layer, and the liquid surface of the liquid photocurable resin is again irradiated with a beam and cured. In a three-dimensional shape forming apparatus for forming an arbitrary three-dimensional shape by sequentially laminating cured resin layers so as to laminate resin layers, a replenishing resin supply means for supplying the resin agent stored in the replenishing resin tank to the resin storage tank And the resin agent overflowing from the resin storage tank is collected in the replenishment resin tank via a suction port or an overflow portion provided on one side of the resin storage tank.

F. Action In the present invention, the resin agent in the replenishment resin tank is always supplied to the resin storage tank by the replenishment resin supply means, and the resin agent overflowing from the resin storage tank is provided on one side of the storage tank. By being collected in the replenishing resin tank by the suction port or the overflow portion, the resin level in the resin storage tank can be always kept constant, and the height position of the liquid level can be kept constant.

G. Embodiment Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of a main part showing a configuration on the resin storage tank 2 side for explaining a liquid level control mechanism of the resin storage tank 2 in the three-dimensional shape forming apparatus 1 according to the present invention. That is, the liquid photocurable resin agent A which is cured by irradiating ultraviolet light
Is placed on a base 3 having a liquid level adjustment mechanism 3a, and a heater 4 for setting the resin temperature is wound around the outer periphery thereof.

The heater 4 is controlled by a temperature controller 6 based on temperature information of the liquid resin agent A detected by the temperature sensor 5, and maintains the temperature of the resin in the storage tank 2 at a predetermined temperature.

The resin storage tank 2 is provided with an elevator mechanism (not shown) for vertically moving a horizontal plate-like stage, and an exposure beam is provided above the storage tank 2 in a liquid state. A beam scanner for converging and irradiating the liquid surface of the photocurable resin agent A is provided. The exposure by the beam scanner and the scanning of the liquid surface and the movement of the elevator are controlled by the modeling controller in the same manner as in the conventional apparatus, and a predetermined disassembly plane can be formed by irradiating a light beam. I have.

Here, in the first embodiment of the present invention, an overflow section 7 is provided on at least one side of the storage tank 2. The overflow section 7 is for collecting excess resin agent A overflowing into a replenishing resin tank 8 described later in order to adjust the height position of the liquid surface.

That is, the overflow section 7 includes an edge 9 formed on one side of the storage tank 2 at a position slightly lower than the upper end 2a of the storage tank, and a resin pool 10 provided on the outside thereof. The edge tip position is a position corresponding to a predetermined liquid level position.

Since the resin agent A is a material having a very high viscosity and a large surface tension coefficient, it is heated by the heater 4 to lower its viscosity. However, as shown in FIG. Before the resin agent A spills out of the storage tank 2,
The liquid level position is displaced to some extent due to surface tension. Therefore, in strictly controlling and adjusting the height position of the liquid level,
The displacement width of the liquid level position up to the overflow poses a major problem.

Therefore, in the present invention, the edge 9 of the overflow portion 7 is formed such that its tip 9a is formed at an acute angle as shown in FIG. 2 (A), and the liquid surface always overflows from this edge 9 portion. The displacement of the liquid surface due to the surface tension of the resin agent A is prevented.

Next, the resin agent A that has overflowed in the overflow section 7 and has been guided to the resin reservoir 10 is guided to the replenishing resin tank 8 via the recovery pipe 11. The replenishing resin tank 8 is used to store the storage tank 2
The excess resin agent A that has overflowed is collected.

A supply pipe 13 for supplying the resin agent A to the storage tank 2 via a supply pump 12 is attached to the refill resin tank 8. The other end of the supply pipe 13 is guided to the storage tank 2. The supply pipe 13 is for always supplying the resin agent A into the storage tank 2. That is, the resin agent A in the storage tank 2 is always supplied from the replenishing resin tank 8 to the storage tank 2 in a predetermined amount, so that the resin agent A in the storage tank 2 always overflows from the overflow section 7.
Is to always control the liquid level position to a predetermined height position.

If a filter 14 is provided in the middle of the supply pipe 13 as shown in FIG. 3, when the resin agent A is supplied to the storage tank 2, dust such as an unnecessary hardened material in the resin agent A is removed. be able to.

Further, a liquid level detector 15 using a laser may be provided to monitor and adjust the liquid level position. This detector 15
The laser is irradiated from the laser tube 16 onto the liquid surface, and the incident angle of the reflected light is detected by the line sensor 17 to detect the height position of the liquid surface. And, by the detection signal,
If the adjustment rod 18 submerged in the liquid is inserted / removed to change the volume in the storage tank 2 and the amount of overflow from the overflow section 7 is adjusted, the liquid level position can be more reliably adjusted. Can do it.

Next, in a second embodiment shown in FIG. 4, instead of the overflow section 7 in the first embodiment, the suction port 21 for directly sucking the resin agent A overflowing by the suction pump 20 is stored in the collecting pipe 11. It is provided at the tank side end. That is, the suction port 21 is provided at one or several places as a predetermined liquid level position, and the resin agent A directly sucked and collected from the suction port 21 is guided to the replenishing resin tank 8.

Further, also in this example, a liquid level detector 15 using a laser is provided to monitor and adjust the liquid level position, and the suction pump 20 and the replenishing pump 12 are operated by a detection signal from the detector 15. Control may be performed to adjust the liquid level position.

As described above, according to the present invention, the liquid level height position can be maintained constant by positively variably adjusting the liquid level level position.

H. Effects of the Invention According to the present invention, the resin agent in the replenishing resin tank is always supplied to the resin storage tank by the replenishing resin supply means, and the resin agent overflowing from the resin storage tank is supplied to the storage tank. By being collected in the replenishing resin tank by the suction port or the overflow portion provided on the side surface, the resin level in the resin storage tank can be always kept constant, and the height position of the liquid level can be kept constant.

Therefore, an appropriate liquid level position of the storage tank can be maintained by a simple method, and the accuracy of the three-dimensional shape formed with an accurate beam spot diameter of the light beam to be irradiated can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a first embodiment of a liquid level height control mechanism of a resin storage tank in a three-dimensional shape forming apparatus according to the present invention, and FIG. FIG. 2 (B) is an enlarged sectional view of a main part showing an edge portion.
Is an enlarged sectional view of a main part showing a comparative example. FIG. 3 is a sectional view schematically showing a modification in which a filter mechanism and a laser detection mechanism are added to the first embodiment. FIG. 4 is a sectional view schematically showing the second embodiment. FIG. 5 is a sectional view schematically showing a conventional three-dimensional shape forming apparatus. DESCRIPTION OF SYMBOLS 1 ... Three-dimensional-shape forming apparatus 2 ... Resin storage tank 7 ... Overflow part 8 ... Refill resin tank 9 ... Edge 11 ... Recovery pipe 12 ... Supply pump 13 ... Supply pipe 21 ... Suction port

Claims (1)

(57) [Claims] 1. A method of irradiating a liquid surface of a liquid photocurable resin agent with a light beam to form a cured resin layer having a pattern corresponding to the shape of an exploded plane decomposed in one direction of an arbitrarily designed stereoscopic image. Then, the liquid photocurable resin is positioned on the cured resin layer, and the cured resin layers are sequentially laminated so that the liquid surface of the liquid photocurable resin is irradiated with a beam again to laminate the cured resin layers. In a three-dimensional shape forming apparatus for forming an arbitrary three-dimensional shape, a replenishing resin supply means for supplying a resin material stored in a replenishing resin tank to the resin storage tank is provided, and a resin material overflowing from the resin storage tank is supplied to the resin A liquid level control mechanism for a resin storage tank in a three-dimensional shape forming apparatus configured to be collected in the refill resin tank via a suction port or an overflow portion provided on one side surface of the storage tank.