JP2021104581A - Manufacturing device of three-dimensional shaped product, and detection device of excess resin particles - Google Patents

Abstract

To provide a manufacturing device of a three-dimensional shaped product that can accurately detect excess resin particles.SOLUTION: A manufacturing device of a three-dimensional shaped product includes layer formation means 110 and energy applying means. The layer formation means includes: a resin particle transfer part 111; a first temperature sensor 112 disposed in the vicinity of the resin particle transfer part and at a position where it is contactable with a resin particle when the amount of resin particles P to be transferred to a shaping area exceeds a predetermined amount, so as to measure a temperature of the resin particle when contacting with the resin particle; a second temperature sensor 113 disposed in the vicinity of the first temperature sensor and at a position where it is not contactable with the resin particle, so as to measure an atmospheric temperature in the shaping area; means for storing an individual difference between a temperature measured by the first temperature sensor and a temperature measured by the second temperature sensor; and a circuit for accurately detecting the generation of excess resin particles, by means of a circuit for detecting the generation of a predetermined temperature difference as a result of adding the individual difference to the temperature measured by the first temperature sensor and the temperature measured by the second temperature sensor.SELECTED DRAWING: Figure 2A

Description

The present invention relates to an apparatus for manufacturing a three-dimensional object and an apparatus for detecting surplus resin particles.

A method of producing a three-dimensional model such as a prototype or a final product by selectively fusing resin particles to each other is known.

For example, in the powder bed fusion (PBF) method, a thin layer of resin particles is irradiated with a laser to selectively fuse the resin particles to each other, and the resulting molding layers are laminated to form a three-dimensional shape. Manufacture things. The PBF method includes an SLS (Selective Laser Sintering) method in which resin particles are selectively irradiated with a laser to form a model, and an SMS (Selective Mask Sintering) method in which the resin particles are partially masked and the laser is irradiated in a plane. The method etc. are included. Further, as an application of the PBF method, an MJF (Multi Jet Fusion) method in which a liquid containing a heat absorbing material is dropped on resin particles and the resin particles are selectively fused to each other by heating with infrared light is also known. ing.

When modeling with resin particles, in order to keep the internal stress between the modeling layers low and relax (relax), resin particles adjusted to a temperature near the softening point may be used for modeling. When the laser is applied to the resin particles adjusted to a temperature near the softening point, the resin particles are heated to a temperature higher than the softening point and melted.

In such a method, in the method of selectively melting and modeling the resin particles, excess resin particles that have not been fused in the modeling process may be recycled. For example, a three-dimensional modeling method has been proposed in which the looseness density of excess resin particles is set in the range of more than 20% with respect to the true density, and the excess resin particles are reused (see, for example, Patent Document 1).
However, the surplus resin particles that have not been fused in the molding process are exposed to a temperature near the softening point, so that the properties of the resin particles such as oxidation and polymerization deteriorate. As a result, the mechanical properties and surface roughness of the modeled object are adversely affected. Therefore, the deteriorated resin particles must be discarded without being recycled. As a result, the material to be discarded directly affects the cost of the modeled object, so it is important not to generate excess resin particles as much as possible. Therefore, an apparatus and a method for not generating excess resin particles have been proposed (see, for example, Patent Document 2).

An object of the present invention is to provide a three-dimensional model manufacturing apparatus capable of accurately detecting excess resin particles and optimizing the amount of resin particles transferred by the resin particle transfer unit.

The apparatus for manufacturing a three-dimensional model of the present invention as a means for solving the above problems includes a layer forming means for transferring resin particles to a modeling region to form a resin particle layer, and the resin particle layer in the modeling region. It has an energy applying means for selectively applying energy to the resin particles to fuse the resin particles in the resin particle layer, and the layer forming means transfers the resin particles to the resin particle transfer unit and the resin particles. When the amount of the resin particles transferred to the modeling region exceeds a predetermined amount and is in the vicinity of the resin particle transfer portion, the resin particles are arranged at a position where they can come into contact with the resin particles, and when the particles come into contact with the resin particles. A first temperature sensor that measures the temperature of the resin particles, and a molding region that is located near the first temperature sensor and at a position where it cannot contact the resin particles, and the resin particle layer is exposed. A means for storing in advance individual differences between the temperature measured by the second temperature sensor for measuring the ambient temperature, the temperature measured by the first temperature sensor, and the temperature measured by the second temperature sensor, and the measurement by the first temperature sensor. A circuit that accurately detects the generation of excess resin particles by a circuit that detects that a predetermined temperature difference has occurred as a result of adding the individual difference to the temperature and the temperature measured by the second temperature sensor. Have.

According to the present invention, it is possible to provide a three-dimensional model manufacturing apparatus capable of accurately detecting excess resin particles and optimizing powder consumption.

FIG. 1 is a schematic view showing a three-dimensional model manufacturing apparatus according to an embodiment of the present invention. FIG. 2A is a schematic view showing a supply unit according to an embodiment of the present invention. FIG. 2B is a schematic view showing a supply unit according to an embodiment of the present invention. FIG. 3A is an explanatory diagram showing an example of an operation in which a conventional three-dimensional object manufacturing apparatus accommodates excess resin particles in a purge area. FIG. 3B is an explanatory diagram showing an example of an operation in which a conventional three-dimensional object manufacturing apparatus accommodates excess resin particles in a purge area. FIG. 3C is an explanatory diagram showing an example of an operation in which a conventional three-dimensional object manufacturing apparatus accommodates excess resin particles in a purge area. FIG. 3D is an explanatory diagram showing an example of an operation in which a conventional three-dimensional object manufacturing apparatus accommodates excess resin particles in a purge area. FIG. 3E is an explanatory view showing an example of an operation in which a conventional three-dimensional object manufacturing apparatus accommodates excess resin particles in a purge area. FIG. 3F is an explanatory diagram showing an example of an operation in which a conventional three-dimensional object manufacturing apparatus accommodates excess resin particles in a purge area. FIG. 3G is an explanatory diagram showing an example of an operation in which a conventional three-dimensional object manufacturing apparatus accommodates excess resin particles in a purge area. FIG. 3H is an explanatory diagram showing an example of an operation in which a conventional three-dimensional object manufacturing apparatus accommodates excess resin particles in a purge area. FIG. 3I is an explanatory diagram showing an example of an operation in which a conventional three-dimensional object manufacturing apparatus accommodates excess resin particles in a purge area. FIG. 3J is an explanatory diagram showing an example of an operation in which a conventional three-dimensional object manufacturing apparatus accommodates excess resin particles in a purge area.

(Manufacturing equipment for three-dimensional objects and excess resin particle detection equipment)
The apparatus for producing a three-dimensional model of the present invention is a layer forming means for transferring resin particles to a modeling region to form a resin particle layer, and selectively applying energy to the resin particle layer in the modeling region to obtain the above-mentioned It has an energy applying means for fusing the resin particles in the resin particle layer, and the layer forming means is in the vicinity of the resin particle transfer portion for transferring the resin particles and the resin particle transfer portion, and A first temperature at which the resin particles are arranged at a position where they can come into contact with the resin particles when the amount of the resin particles transferred to the modeling region exceeds a predetermined amount, and the temperature of the resin particles when they come into contact with the resin particles is measured. A sensor, a second temperature sensor that measures the ambient temperature of the molding region that is located near the first temperature sensor and is in contact with the resin particles and in which the resin particle layer is exposed. A means for storing individual differences between the temperature measured by the first temperature sensor and the temperature measured by the second temperature sensor in advance, and the temperature measured by the first temperature sensor and the temperature measured by the second temperature sensor. It also has a circuit that accurately detects the generation of excess resin particles by a circuit that detects that a predetermined temperature difference has occurred as a result of adding the individual differences to the above, and further, if necessary, other Have means.

In the conventional three-dimensional modeling method in which the surplus resin particles are reused, the three-dimensional model manufacturing apparatus of the present invention uses the recycled resin powder to form the three-dimensional model, and the three-dimensional model has rough surfaces, holes, and distortions. Alternatively, it is based on the finding that surface defects called orange peel may occur or the tensile strength of the three-dimensional model may decrease.

In the three-dimensional model manufacturing apparatus of the present invention, when the first temperature sensor is in the vicinity of the resin particle transfer section for transferring resin particles and the amount of resin particles transferred to the modeling area exceeds a predetermined amount. It is arranged at a position where it can come into contact with the resin particles, and the temperature of the resin particles when they come into contact with the resin particles is measured. Further, the second temperature sensor is arranged in the vicinity of the first temperature sensor and at a position where it cannot come into contact with the resin particles, and measures the ambient temperature of the modeling region where the resin particle layer is exposed. As a result, for example, the difference between the measured value of the ambient temperature and the measured value of the temperature of the resin particles is obtained, and the influence of disturbances such as the temperature distribution inside the device and the air flow is canceled, so that the excess resin particles are detected accurately. I made it possible.
It should be noted that the three-dimensional model manufacturing apparatus controls the amount of the resin particles to be supplied to the modeling area next depending on whether or not the excess resin particles are detected, thereby producing the excess resin particles. It can be prevented from occurring.

A specific control method is shown below.
If the supply amount of the resin particle transfer part is appropriate and excess resin particles are not detected,
The amount calculated by the supply amount of the resin particle transfer unit = basic supply amount + maximum additional supply amount x (filled area / maximum filled area) + recovery amount is supplied.

If the supply amount of the resin particle transfer unit is excessive and excess resin particles are detected,
The amount calculated by the supply amount of the resin particle transfer unit = basic supply amount + maximum additional supply amount x (filled area / maximum filled area) + recovery amount-reduction amount is supplied.

Here, the definition of each element of the above equation is shown below.
The basic supply amount is the basic supply amount of resin particles in the resin particle transfer portion during the laminating operation, and is an amount corresponding to the required amount of resin particles for one layer of the modeling region.
The maximum additional supply amount is the maximum additional supply amount when the filled area is maximized, and by inputting this value, resin particles corresponding to the filled area of the layer are additionally supplied.
The recovered amount is the recovered amount of the resin particles on the side opposite to the tank on the side where the resin particles are supplied to the resin particle transfer portion during the laminating operation.
The supply reduction amount is the reduction amount of the resin particles when excess resin particles are detected.

Further, the surplus resin particle detection device of the present invention is used in a three-dimensional model manufacturing device, and detects that the amount of resin particles transferred to the modeling area in the three-dimensional model manufacturing device exceeds a predetermined amount. It is a resin particle detection device, and has a resin particle transfer unit, a first temperature sensor, and a second temperature sensor, similarly to the device for manufacturing a three-dimensional model of the present invention.
Therefore, since the surplus resin particle detection device of the present invention is sufficient for the description of the three-dimensional model manufacturing device of the present invention, the details of the surplus resin particle detection device of the present invention will be described through the description of the three-dimensional model manufacturing device of the present invention. Also reveal.

The apparatus for producing a three-dimensional object of the present invention includes a layer forming means, an energy applying means, and further, if necessary, other means.

<Layer forming means>
The layer forming means transfers the resin particles to the modeling region to form the resin particle layer.
The modeling region means an region in which energy is applied by the energy applying means and the resin particles are fused to each other to form a three-dimensional modeled object. Further, the resin particle layer means a layer of resin particles formed in the modeling region.
The layer forming means is not particularly limited as long as it has a resin particle transfer unit, a first temperature sensor, and a second temperature sensor, and can be appropriately selected depending on the intended purpose.

<< Resin particle transfer section >>
The shape, structure, size, and material of the resin particle transfer portion are not particularly limited as long as the resin particles can be transferred, and can be appropriately selected according to the purpose. For example, a roller, a flat plate-shaped squeegee, or the like. Can be mentioned. Among these, it is preferable to use a roller because the density of powder in the modeling tank can be increased.

<< First temperature sensor >>
The first temperature sensor is arranged in the vicinity of the resin particle transfer portion and at a position where it can come into contact with the resin particles when the amount of the resin particles transferred to the modeling region exceeds a predetermined amount, and comes into contact with the resin particles. The temperature of the resin particles is measured.
The predetermined amount is not particularly limited and may be appropriately selected depending on the amount of resin particles transferred by the resin particle transfer unit and the like.
When determining the optimum position of the first temperature sensor, when only the required amount of resin particles is transferred to the modeling region in the layer forming means with energy selectively applied to the modeling region, the first temperature sensor is made of resin. Temporarily install the first temperature sensor at a position where it does not come into contact with particles. After that, by setting a large maximum additional supply amount, a surplus exceeding the required amount of the resin particles is transferred to the modeling region, and it is derived by confirming that the first temperature sensor comes into contact with the resin particles. The optimum position of the first temperature sensor depends on the amount of resin particles required for one layer of the modeling area, but as a guide, it is 5 mm to 6 mm horizontally away from the resin particle transfer portion and 5 mm from the upper surface of the resin particle layer in the modeling area. It is preferably about 6 mm.

The type of temperature sensor used for the first temperature sensor is not particularly limited and can be appropriately selected according to the purpose, but the measurement accuracy and measurement stability are good, the response to temperature changes is high, and the detection can be performed quickly. It is preferable that the sheath of the detection unit of the temperature sensor has a small heat capacity. Examples thereof include a platinum resistance temperature detector (PT sensor) and a thermocouple, and a temperature sensor in which resin particles do not easily adhere to the surface is particularly preferable. This is because if the resin particles are hard to adhere, it is possible to prevent the occurrence of erroneous detection due to measuring the temperature of the adhered resin particles.
If resin particles easily adhere to the surface of the first temperature sensor, it is erroneous that some of the resin particles remain attached to the surface of the first temperature sensor after the excess resin particles are detected by the first temperature sensor. It becomes easy to detect, and from this point, it can be said that it is easy to make a false detection when there is only one temperature sensor.

<< Second temperature sensor >>
The second temperature sensor is arranged in the vicinity of the first temperature sensor and at a position where it cannot come into contact with the resin particles, and measures the ambient temperature of the modeling region where the resin particle layer is exposed.
As the vicinity of the first temperature sensor, it is preferable that the ambient temperature measured by the first temperature sensor and the ambient temperature measured by the second temperature sensor are substantially the same.

The second temperature sensor is not particularly limited and may be appropriately selected according to the purpose. For example, a sensor similar to the first temperature sensor may be used, but the speed of measuring the temperature with the first temperature sensor may be used. Sensors with the same sampling frequency are preferred. In this respect, as the second temperature sensor, a sensor having the same part number as the first temperature sensor is more preferable. When the second temperature sensor is a preferable embodiment, it becomes easier to match the timing of measurement by each temperature sensor, and the measurement is performed when the difference between the temperature measured by the first temperature sensor and the ambient temperature measured by the second temperature sensor is obtained. It is advantageous in that an error due to a shift in the timing of is unlikely to occur.

It is preferable that the layer forming means can detect whether or not the temperature measured by the first temperature sensor is higher than the temperature measured by the second temperature sensor and higher than a predetermined temperature set in advance. In this way, when the resin particles are preheated in order to facilitate the fusion of the resin particles when energy is applied, the temperature of the resin particles is higher than the ambient temperature, so that the first temperature sensor If the temperature measured by is higher than a predetermined temperature set in advance, it can be determined that excess resin particles are generated.

In order to be able to detect whether or not the temperature is higher than the preset predetermined temperature, the layer forming means may have a detection unit that detects that the temperature measured by the first temperature sensor is higher than the preset predetermined temperature. Often, it may be held inside or outside the device.

As the preset predetermined temperature, the ambient temperature measured by the second temperature sensor was set to X (° C.), and the temperature of the resin particles measured when the first temperature sensor came into contact with the resin particles was set to Y (° C.). Then, it is preferably expressed by the following equation, [X + (Y−X) / 2] (° C.). As a result, the excess resin particles are detected at a temperature between the ambient temperature X measured by the second temperature sensor and the resin particle temperature Y measured when the first temperature sensor comes into contact with the resin particles. It can be set as the threshold value of, and it is possible to easily suppress the occurrence of false positives.

At this time, it is preferable to satisfy the following equation, | XY | ≤20 ° C., more preferably to satisfy the following equation, | XY | ≤15 ° C., and the following equation, | XY | ≤10. It is more preferable to satisfy ℃. When the following equation, | XY | ≤20 ° C. is satisfied, that is, when the difference between the ambient temperature and the temperature of the resin particles is small, only the temperature sensor that measures the temperature of the resin particles is used in the apparatus. Since the measured value of the atmospheric temperature changes due to the disturbance such as the air flow of the airflow and easily exceeds the threshold value, it is easy to make a false detection. In this respect, since the influence of the disturbance can be canceled in the three-dimensional model manufacturing apparatus, excess resin particles can be detected accurately even when the following equation, | XY | ≤ 20 ° C. is satisfied. However, it is essential to make a calculation that takes into account the individual differences between the first temperature sensor and the second temperature sensor.

The lower limit of the average thickness of the resin particle layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 μm or more, more preferably 50 μm or more, still more preferably 100 μm or more. The upper limit of the average thickness of the resin particle layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably less than 200 μm, more preferably less than 150 μm, and even more preferably less than 120 μm.

<Energy applying means>
The energy applying means selectively applies energy to the resin particle layer in the modeling region to fuse the resin particles in the resin particle layer.
The energy applying means is not particularly limited as long as energy can be selectively applied to the resin particle layer in the modeling region, and can be appropriately selected according to the purpose. For example, a laser irradiation means, an infrared irradiation source, and a microwave generation. Examples include a vessel, a radiant heater, an LED lamp, or a combination thereof. Among these, the laser irradiation means is advantageous in that it is easy to selectively apply energy to a narrow range and the modeling accuracy of the three-dimensional modeled object is improved.
Examples of the laser irradiation means include a CO ₂ laser and the like. The laser output is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 watts or more and 150 watts or less.

When the energy applying means is an infrared irradiation source, a microwave generator, a radiant heater, an LED lamp, or the like, for example, a part of the resin particles is masked with a shielding mask, and the unmasked part is covered with infrared rays or the like. It is formed by irradiating the electromagnetic rays of the above and selectively fusing the resin particles to each other. In this case, the resin particles preferably contain at least one kind of heat absorbing material or dark-colored substance that enhances the infrared absorption characteristics.
Examples of the heat absorbing material or the dark-colored substance include carbon fiber, carbon black, carbon nanotube, and cellulose nanofiber.

<Other means>
The other means are not particularly limited and may be appropriately selected depending on the purpose.

<Resin particles>
The resin particles mean particles containing a thermoplastic resin.
Examples of the material of the particles containing the thermoplastic resin include a resin composition containing a thermoplastic resin as a resin component and, if necessary, other components.

-Thermoplastic resin-
The thermoplastic resin means a resin that is plasticized and melted when heat is applied.
The thermoplastic resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include crystalline resin, amorphous resin and liquid crystal resin. Among these, as the thermoplastic resin, a crystalline resin and a liquid crystal resin are preferable. Further, as the thermoplastic resin, a resin having a large difference between the melting start temperature and the recrystallization temperature at the time of cooling is preferable.
The crystalline resin is a resin in which a melting point peak is detected in a measurement based on ISO3146 (plastic transition temperature measuring method, JIS K7121).

Examples of the thermoplastic resin include polyolefin, polyamide, polyester, polyether, polyphenylene sulfide, liquid crystal polymer (LCP: Liquid Crystal Polymer), polyacetal (POM: Polyoxymethylene), polyimide, fluororesin and the like. These may be used alone or in combination of two or more.

Examples of the polyolefin include polyethylene (PE) and polypropylene (PP).

Examples of the polyamide include polyamides such as polyamide 410 (PA410), polyamide 6 (PA6), polyamide 66 (PA66), polyamide 610 (PA610), polyamide 612 (PA612), polyamide 11 (PA11), and polyamide 12 (PA12). Examples include semi-aromatic polyamides such as polyamide 4T (PA4T), polyamide MXD6 (PAMXD6), polyamide 6T (PA6T), polyamide 9T (PA9T), and polyamide 10T (PA10T).

Examples of the polyester include polyethylene terephthalate (PET), polybutadiene terephthalate (PBT), polylactic acid (PLA) and the like. Among these, those having an aromatic component containing terephthalic acid or isophthalic acid as a part are preferable from the viewpoint of imparting heat resistance.

Examples of the polyether include polyarylketone and polyethersulphon.
Examples of the polyarylketone include polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketone ketone (PEKK), polyaryletherketone (PAEK), polyetheretherketone ketone (PEEKK), and polyether. Examples thereof include ketone ether ketone ketone (PEKEKK).

Polypropylene (PP) is preferable as the thermoplastic resin from the viewpoint of further improving the strength in the stacking direction of the three-dimensional modeled object and the modeling accuracy.
The polypropylene is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include random polypropylene, homopolypropylene and block polypropylene. Among these, block polypropylene is preferable.
As the polypropylene, a commercially available product can be used. As the commercially available product, for example, the block polypropylene is Sumitomo Noblen AW564 (manufactured by Sumitomo Chemical Co., Ltd.), the homopolypropylene is VS700R (manufactured by SunAllomer Ltd.), and random. Examples of polypropylene include J226T (manufactured by Prime Polymer Co., Ltd.).

-Other ingredients-
Examples of other components in the resin particles include additives such as fillers, deterioration inhibitors, fluidizing agents, flame retardants, plasticizers, and crystal nucleating agents, and amorphous resins. These may be used alone or in combination of two or more. In addition, other components may be mixed with each thermoplastic resin particle and used, or may be used by coating the surface of each thermoplastic resin particle.

The filler is not particularly limited as long as it contains silicon dioxide as a main component, and can be appropriately selected depending on the intended purpose. Examples thereof include talc, mica, clay, montmorillonite, bentonite, and zonolite. These may be used alone or in combination of two or more. Among these, talc is particularly preferable as the filler. When the filler is talc, the strength in the stacking direction of the three-dimensional modeled object and the modeling accuracy can be particularly improved.

[Manufacturing method of resin particles]
The resin may be granulated by crushing or cutting. As a method for pulverizing the resin, for example, it is obtained by pulverizing a pellet-shaped resin composition containing the above-mentioned thermoplastic resin with a pulverizer and classifying or filtering particles having a particle size other than the specified particle size with a filter. .. When crushing by utilizing the fragility of the resin, the environment at the time of crushing is set to the fragile temperature or lower of the resin, preferably room temperature or lower, more preferably 0 ° C. or lower, and further preferably -25 ° C. or lower. , Especially preferably −100 ° C. or lower. In order to improve the fluidity of the resin particles, it is preferable to remove particles having a size of 80 μm or more and 25 μm or less by a classification operation, for example. The resin powder is preferably dried to such an extent that it does not affect the molding. Therefore, the resin powder dried by a vacuum dryer or silica gel may be used for modeling. As a method of cutting the resin, the fibrous resin may be cut.

<Three-dimensional model>
The three-dimensional model formed by the resin particles is not particularly limited and may be appropriately selected depending on the purpose. For example, a prototype of an electronic device part or an automobile part, a prototype for a strength test, an aero space, or Examples include small-quantity products used in dress-up tools for the automobile industry. The PBF method is expected to be superior in strength to other methods such as the FFF (Fused filament Fabrication) method and the inkjet method, and therefore can be used as a practical product.
Regarding the production speed, for example, the required production amount can be obtained by producing a large number of small parts in a plane shape. Further, since the method for forming a three-dimensional object in the PBF method used in the present invention does not require a mold unlike injection molding, overwhelming cost reduction and delivery time reduction are achieved in trial production and prototype production. be able to.

Hereinafter, modes for carrying out the invention will be described with reference to the drawings. In each drawing, the same components may be designated by the same reference numerals and duplicate description may be omitted.

(First Embodiment)
In the first embodiment, the embodiment in which the three-dimensional model manufacturing apparatus of the present invention forms a three-dimensional model using the thermoplastic resin contained in the resin particles as polyamide 12 (PA12, melting point: 185 ° C.) will be described. do.

[Structure of manufacturing equipment for 3D objects]
FIG. 1 is a schematic view showing a three-dimensional model manufacturing apparatus according to an embodiment of the present invention.
As shown in FIG. 1, the three-dimensional model manufacturing apparatus 100 includes a supply unit 110 as a layer forming means, supply tanks 130 and 150, a modeling tank 140, a laser irradiation means 170 as an energy applying means, and a purge. It has areas 120 and 160.
The surface of the modeling tank 140 in which the laser L is irradiated by the laser irradiation means 170 to form a three-dimensional object is referred to as a modeling area Z.
Further, the bottom surfaces of the supply tanks 130 and 150 and the modeling tank 140 can be raised and lowered, respectively.

2A and 2B are schematic views showing a supply unit according to an embodiment of the present invention.
As shown in FIG. 2A, the supply unit 110 includes a roller 111 as a resin particle transfer unit, first temperature sensors 112 and 114, and second temperature sensors 113 and 115.

The roller 111 moves while rotating around the axis so as to transfer the resin particles P of the supply tanks 130 and 150 while leveling them to the modeling region Z of the modeling tank 140, and has a resin particle layer having a thickness of one layer. To form.
The first temperature sensors 112 and 114 are arranged in the vicinity of the roller 111 and at positions where they can come into contact with the resin particles P when the amount of the resin particles P transferred to the modeling region Z exceeds a predetermined amount. The temperature of the resin particles P when they come into contact with the resin particles P is measured.
The second temperature sensors 113 and 115 are arranged in the vicinity of the first temperature sensors 112 and 114 and at positions where they cannot contact the resin particles P, respectively, and the ambient temperature of the modeling region Z where the resin particle layer is exposed can be measured. Measure.

Returning to FIG. 1, the supply tanks 130 and 150 store the resin particles P whose thermoplastic resin is PA12, respectively. The resin particles P stored in the supply tanks 130 and 150 are preheated at 150 ° C. by heaters installed above the supply tanks 130 and 150, respectively.

In the modeling tank 140, the resin particles P are transferred from the supply tank 130 or the supply tank 150 by the rollers 111 to form the resin particle layer. The resin particle layer formed in the modeling tank 140 is preheated at 170 ° C. by a heater installed above the modeling tank 140.

In the present embodiment, the thermoplastic resin is PA12, the preheating temperature of the supply tanks 130 and 150 is set to 150 ° C., and the preheating temperature of the modeling tank 140 is set to 170 ° C., but the present invention is not limited to this. The preheating temperature in the modeling tank 140 is preferably as high as possible in terms of suppressing the occurrence of warpage when the resin particles P are fused to each other, but the fusion of the resin particles P to each other in the modeling tank 140 is preferable. In terms of suppression, it is preferable that the temperature is 10 ° C. or higher lower than the melting point of the resin particles P.

The laser irradiation means 170 applies the laser L to the resin particle layer in the modeling region Z based on the two-dimensional data of the 3D (three-dimensional) model of the three-dimensional model, that is, the cross-sectional shape when the 3D model is sliced at predetermined intervals. By selectively irradiating and heating the resin particles P in the resin particle layer to a temperature equal to or higher than the melting point, the resin particles in the resin particle layer are fused to each other to form the modeling layer S.

As described above, the three-dimensional model manufacturing apparatus 100 supplies the resin particles P to the modeling tank 140 to form the resin particle layer, and heats the resin particles P in the resin particle layer to a temperature equal to or higher than the melting point to obtain a resin. The modeling layer S is laminated by repeating the steps of fusing the resin particles P in the particle layer to form the modeling layer S. When the modeling based on all of the plurality of two-dimensional data is completed, the three-dimensional model manufacturing apparatus 100 can obtain a three-dimensional model having the same shape as the 3D model.

The purge areas 120 and 160 accommodate the surplus resin particles P transferred by the roller 111 when the surplus resin particles P are generated.

Here, the operation of the conventional three-dimensional object manufacturing apparatus not provided with the first temperature sensors 112, 114 and the second temperature sensors 113, 115 will describe the operation of accommodating the surplus resin particles P in the purge areas 120 and 160. ..

3A to 3I are explanatory views showing an example of an operation in which a conventional three-dimensional object manufacturing apparatus accommodates excess resin particles in a purge area.
First, as shown in FIG. 3A, the three-dimensional model manufacturing apparatus 100 raises the bottom surface of the supply tank 130 to raise the resin particles P. Next, the three-dimensional model manufacturing apparatus 100 moves the roller 111 in the direction of arrow A while rotating it in the direction of arrow Ra in FIG. 3A, and as shown in FIGS. 3B and 3C, models the modeling tank 140. The resin particles P are transferred and supplied while being leveled in the region Z to form a resin particle layer C having a thickness equivalent to one layer. Then, as shown in FIG. 3D, excess resin particles P are deposited on a part of the upper surface of the supply tank 150. Further, the resin particles P transferred to the modeling region Z are heated by the heater.

Here, the three-dimensional model manufacturing apparatus 100 accepts input of a plurality of two-dimensional data generated from the 3D model. The three-dimensional model manufacturing apparatus 100 selectively irradiates the laser L with the laser irradiation means 170 based on the two-dimensional data, and fuses the resin particles P at the positions corresponding to the pixels indicated by the two-dimensional data. The modeling layer S is formed with.

Next, as shown in FIG. 3E, the three-dimensional model manufacturing apparatus 100 lowers the bottom surface of the modeling tank 140 so that a modeling space having a thickness of one resin particle layer is formed in the modeling region Z. Further, the three-dimensional model manufacturing apparatus 100 raises the bottom surface of the supply tank 150 so that the new resin particles P can be supplied to the modeling region Z. Subsequently, the three-dimensional model manufacturing apparatus 100 moves the roller 111 in the direction of arrow B while rotating the roller 111 in the direction of arrow Rb in FIG. 3E, and as shown in FIGS. 3F and 3G, the modeling tank 140 It is supplied while being leveled to the modeling region Z to form a resin particle layer having a thickness equivalent to one layer.

Next, the three-dimensional model manufacturing apparatus 100 raises the stage of the supply tank 150 to raise the resin particles P on which the surplus resin particles P are deposited. The three-dimensional model manufacturing apparatus 100 moves the roller 111 in the direction of arrow B while rotating the roller 111 in the direction of arrow Rb in FIG. 3F, and smoothes the roller 111 into the modeling area Z of the modeling tank 140 as shown in FIG. 3G. A resin particle layer C having a thickness equivalent to that of one layer is formed. Then, as shown in FIG. 3H, the purge area 120 contains the surplus resin particles P. Then, when the roller 111 is moved in the direction of the arrow A again, as shown in FIG. 3I, the excess resin particles P are also contained in the purge area 120, and when this is repeated, the purge area is repeated as shown in FIG. 3J. Both 120 and 160 are overflowed with excess resin particles P.

Therefore, as shown in FIG. 2A, the supply unit 110 in the three-dimensional model manufacturing apparatus 100 of the present embodiment measures the ambient temperature in addition to the first temperature sensor 112 that measures the temperature of the surplus resin particles P. A second temperature sensor 113 is provided. As a result, for example, by obtaining the difference between the measured value X of the atmospheric temperature and the measured value Y of the temperature of the resin particles P, the influence of disturbance such as the distribution of the atmospheric temperature inside the apparatus can be canceled, so that the excess resin particles P can be detected with high accuracy.
The detection of the excess resin particles P is whether or not the temperature measured by the first temperature sensor 112 is higher than the temperature measured by the second temperature sensor 113 and higher than a predetermined temperature (threshold) set in advance. To do. Specifically, when the following equation, [X + (YX) / 2] (° C.), is set as the threshold value, the atmospheric temperature X is 120 ° C., and the temperature Y of the resin particles is 150 ° C., [ 120+ (150-120) / 2] = 135 ° C. was set as the threshold value, and the threshold value was changed according to the atmospheric temperature.

Further, as shown in FIG. 2B, the supply unit 110 is preheated to 150 ° C. in the supply tank 150 so that excess resin particles P can be detected when the roller 111 is moved in the direction of the arrow B. It includes a first temperature sensor 114 that detects excess resin particles P at that temperature, and a second temperature sensor 115 that measures the ambient temperature.
As a result, the supply unit 110 can accurately detect the excess resin particles P regardless of which direction the arrow A or the arrow B moves the roller 111.

The three-dimensional model manufacturing apparatus 100 controls to reduce the amount of the resin particles P to be supplied to the modeling region Z next, depending on whether or not the surplus resin particles P are detected. It is possible to prevent the generation of various resin particles P.

(Second embodiment)
In the second embodiment, in the first embodiment, the thermoplastic resin is changed from polyamide 12 (PA12, melting point: 185 ° C.) to polypropylene (PP, melting point: 125 ° C.), and the preheating temperatures of the supply tanks 130 and 150 are set. It is the same as that of the first embodiment except that the temperature is set to 100 ° C. and the preheating temperature of the modeling tank 140 is set to 110 ° C.
In this case, the preheating temperatures of the supply tanks 130 and 150 and the modeling tank 140 are close to each other, and the preheating temperature itself is low and close to the atmospheric temperature. Therefore, when there is only one temperature sensor, the measured temperature does not easily change even if the resin particles P of the supply tanks 130 and 150 and the modeling tank 140 come into contact with the temperature sensor, and excess resin particles P are detected. May be difficult.

Therefore, in the second embodiment, the three-dimensional model manufacturing apparatus 100 measures the temperature with two temperature sensors, respectively, as in the first embodiment. As a result, the difference between the measured value of the ambient temperature and the temperature of the resin particles P is obtained, and the influence of disturbance such as the air flow inside the device is canceled to preheat the supply tanks 130 and 150 and the modeling tank 140. Even when the temperature is close and the preheating temperature itself is low, the surplus resin particles P can be detected with high accuracy.
In the second embodiment, as in the first embodiment, the detection of the excess resin particles P is such that the temperature measured by the first temperature sensor 112 is higher than the temperature measured by the second temperature sensor 113. This is performed depending on whether or not the temperature is higher than a preset predetermined temperature (threshold). Specifically, when the threshold value is the following equation, [X + (Y−X) / 2] (° C.), the atmospheric temperature X is 80 ° C., and the temperature Y of the resin particles is 100 ° C., [80+ (100-80) / 2] = 90 ° C. was set as the threshold value, and the threshold value was changed according to the atmospheric temperature.

As described above, when the following equation, | XY | ≤20 ° C. is satisfied, that is, when the difference between the ambient temperature and the temperature of the resin particles is small, only the temperature sensor that measures the temperature of the resin particles is used. Since the measured value of the ambient temperature changes due to disturbances such as airflow in the device and easily exceeds the threshold value, erroneous detection is likely to occur. In this respect, since the three-dimensional model manufacturing apparatus 100 can cancel the influence of disturbance, excess resin particles can be accurately detected even when the following equation, | XY | ≤ 20 ° C., is satisfied.

As described above, the three-dimensional model manufacturing apparatus of the present invention selectively applies energy to the layer forming means for transferring the resin particles to the modeling region to form the resin particle layer and the resin particle layer in the modeling region. Then, it has an energy imparting means for fusing the resin particles in the resin particle layer. The layer forming means includes a resin particle transfer unit for transferring resin particles, a first temperature sensor, and a second temperature sensor. This first temperature sensor is arranged in the vicinity of the resin particle transfer portion for transferring the resin particles and at a position where the resin particles can come into contact with the resin particles when the amount of the resin particles transferred to the modeling region exceeds a predetermined amount. , Measure the temperature of the resin particles when they come into contact with the resin particles. Further, the second temperature sensor is arranged in the vicinity of the first temperature sensor and at a position where it cannot come into contact with the resin particles, and measures the ambient temperature of the modeling region where the resin particle layer is exposed. As a result, for example, the difference between the measured value of the ambient temperature and the measured value of the temperature of the resin particles is obtained, and the influence of disturbances such as the temperature distribution inside the device and the air flow is canceled, so that the excess resin particles are detected accurately. I made it possible.
It should be noted that the three-dimensional model manufacturing apparatus controls the amount of the resin particles to be supplied to the modeling area next depending on whether or not the excess resin particles are detected, thereby producing the excess resin particles. It can be prevented from occurring.

Aspects of the present invention are, for example, as follows.
<1> A layer forming means for transferring resin particles to a modeling region to form a resin particle layer, and
It has an energy applying means for selectively applying energy to the resin particle layer in the modeling region to fuse the resin particles in the resin particle layer.
The layer forming means
A resin particle transfer unit for transferring the resin particles and
When the resin particles are arranged in the vicinity of the resin particle transfer portion and in a position where they can come into contact with the resin particles when the amount of the resin particles transferred to the modeling region exceeds a predetermined amount and come into contact with the resin particles. The first temperature sensor that measures the temperature of the resin particles in
A second temperature sensor that measures the ambient temperature of the modeling region that is located near the first temperature sensor and is in contact with the resin particles and exposes the resin particle layer.
A means for storing individual differences between the temperature measured by the first temperature sensor and the temperature measured by the second temperature sensor in advance, and
Excess resin particles were generated by the circuit that detects that a predetermined temperature difference was generated as a result of adding the individual difference to the temperature measured by the first temperature sensor and the temperature measured by the second temperature sensor. With a circuit that accurately detects
It is a three-dimensional model manufacturing apparatus characterized by having.
<2> The apparatus for manufacturing a three-dimensional model according to <1>, wherein the resin particle transfer portion in the layer forming means is a roller.
<3> The layer forming means can detect whether or not the temperature measured by the first temperature sensor is higher than the temperature measured by the second temperature sensor and higher than a predetermined temperature set in advance. A device for manufacturing a three-dimensional model according to any one of <1> to <2>.
<4> When the preset predetermined temperature is the temperature measured by the second temperature sensor as X (° C.) and the temperature of the resin particles is Y (° C.), the following equation, [X + (Y−) X) / 2] (° C.), which is the apparatus for manufacturing a three-dimensional model according to <3>.
<5> The apparatus for manufacturing a three-dimensional model according to <4>, which satisfies the following equation, | XY | ≤20 (° C.).
<6> A surplus resin particle detection device that is used in a three-dimensional model manufacturing device and detects that the amount of resin particles transferred to the modeling area in the three-dimensional model manufacturing device exceeds a predetermined amount.
A resin particle transfer unit that transfers the resin particles to the modeling region to form a resin particle layer,
When the resin particles are arranged in the vicinity of the resin particle transfer portion and in a position where they can come into contact with the resin particles when the amount of the resin particles transferred to the modeling region exceeds a predetermined amount and come into contact with the resin particles. The first temperature sensor that measures the temperature of the resin particles in
A second temperature sensor that measures the ambient temperature of the modeling region that is located near the first temperature sensor and is in contact with the resin particles and exposes the resin particle layer.
A means for storing individual differences between the temperature measured by the first temperature sensor and the temperature measured by the second temperature sensor in advance, and
Excess resin particles were generated by the circuit that detects that a predetermined temperature difference was generated as a result of adding the individual difference to the temperature measured by the first temperature sensor and the temperature measured by the second temperature sensor. With a circuit that accurately detects
It is a surplus resin particle detection device characterized by having.
<7> The surplus resin particle detection device according to <6>, wherein the resin particle transfer unit is a roller.
<8> It is possible to detect whether or not the temperature measured by the first temperature sensor is higher than the temperature measured by the second temperature sensor and higher than a predetermined temperature set in advance. <6> The surplus resin particle detection device according to any one of <7>.
<9> When the preset predetermined temperature is the temperature measured by the second temperature sensor as X (° C.) and the temperature of the resin particles is Y (° C.), the following equation, [X + (Y−) X) / 2] (° C.), which is the surplus resin particle detection device according to <8>.
<10> The surplus resin particle detection device according to <9>, which satisfies the following equation, | XY | ≤20 (° C.).

According to the device for manufacturing a three-dimensional model according to any one of <1> to <5> and the surplus resin particle detection device according to any one of <6> to <10>, the above-mentioned problems in the prior art can be solved. It can be solved and the object of the present invention can be achieved.

Japanese Unexamined Patent Publication No. 2018-15792 Japanese Patent No. 4866145

100 Three-dimensional model manufacturing equipment (surplus resin particle detection equipment)
110 Supply unit (layer forming means)
111 Roller (resin particle transfer part)
112, 114 First temperature sensor 113, 115 Second temperature sensor 120, 160 Purge area 130, 150 Supply tank 140 Modeling tank 170 Laser irradiation means (energy applying means)
C Resin particle layer P Resin particles S Modeling layer Z Modeling area

Claims (10)

A layer forming means for transferring resin particles to a modeling region to form a resin particle layer,
It has an energy applying means for selectively applying energy to the resin particle layer in the modeling region and fusing the resin particles in the resin particle layer.
The layer forming means
A resin particle transfer unit for transferring the resin particles and
When the resin particles are arranged in the vicinity of the resin particle transfer portion and in a position where they can come into contact with the resin particles when the amount of the resin particles transferred to the modeling region exceeds a predetermined amount and come into contact with the resin particles. The first temperature sensor that measures the temperature of the resin particles in
A second temperature sensor that measures the ambient temperature of the modeling region that is located near the first temperature sensor and is in contact with the resin particles and exposes the resin particle layer.
A means for storing individual differences between the temperature measured by the first temperature sensor and the temperature measured by the second temperature sensor in advance, and
Excess resin particles were generated by the circuit that detects that a predetermined temperature difference was generated as a result of adding the individual difference to the temperature measured by the first temperature sensor and the temperature measured by the second temperature sensor. With a circuit that accurately detects
A device for manufacturing a three-dimensional object, which is characterized by having. The apparatus for manufacturing a three-dimensional model according to claim 1, wherein the resin particle transfer portion in the layer forming means is a roller. The layer forming means
Any of claims 1 and 2, which can detect whether or not the temperature measured by the first temperature sensor is higher than the temperature measured by the second temperature sensor and higher than a predetermined temperature set in advance. A device for manufacturing a three-dimensional model described in Crab. When the preset predetermined temperature is the temperature measured by the second temperature sensor as X (° C.) and the temperature of the resin particles is Y (° C.), the following equation, [X + (YX) / 2] The apparatus for manufacturing a three-dimensional model according to claim 3, which is represented by (° C.). The apparatus for manufacturing a three-dimensional model according to claim 4, wherein the following equation, | XY | ≤20 (° C.), is satisfied. A surplus resin particle detection device that is used in a three-dimensional model manufacturing device and detects that the amount of resin particles transferred to the modeling area in the three-dimensional model manufacturing device exceeds a predetermined amount.
A resin particle transfer unit that transfers the resin particles to the modeling region to form a resin particle layer,
When the resin particles are arranged in the vicinity of the resin particle transfer portion and in a position where they can come into contact with the resin particles when the amount of the resin particles transferred to the modeling region exceeds a predetermined amount and come into contact with the resin particles. The first temperature sensor that measures the temperature of the resin particles in
A second temperature sensor that measures the ambient temperature of the modeling region that is located near the first temperature sensor and is in contact with the resin particles and exposes the resin particle layer.
A means for storing individual differences between the temperature measured by the first temperature sensor and the temperature measured by the second temperature sensor in advance, and
Excess resin particles were generated by the circuit that detects that a predetermined temperature difference was generated as a result of adding the individual difference to the temperature measured by the first temperature sensor and the temperature measured by the second temperature sensor. With a circuit that accurately detects
A surplus resin particle detection device characterized by having. The surplus resin particle detection device according to claim 6, wherein the resin particle transfer unit is a roller. Any of claims 6 to 7, wherein it is possible to detect whether or not the temperature measured by the first temperature sensor is higher than the temperature measured by the second temperature sensor and higher than a predetermined temperature set in advance. Excess resin particle detection device described in Crab. When the preset predetermined temperature is the temperature measured by the second temperature sensor as X (° C.) and the temperature of the resin particles is Y (° C.), the following equation, [X + (YX) / 2] The surplus resin particle detection device according to claim 8, which is represented by (° C.). The surplus resin particle detection device according to claim 9, wherein the following equation, | XY | ≤20 (° C.), is satisfied.

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