JP2020142463A - Stereo molding equipment and method thereof - Google Patents

Abstract

To improve safety.SOLUTION: A stereo molding system has a temperature detection unit that detects a temperature of discharge means for discharging a modeling material, a mounting section that can attach a box section containing the modeling material, a setting unit that sets a reference temperature to determine whether the discharge means is overheated or not based on a predetermined number of parts provided in the box section, and a power supply shutoff unit that shuts off a power supply for a heat source to heat the modeling material based on the temperature of the discharge means and the reference temperature, and the number of predetermined members on the box section attached to the mounting section is greater than the number of predetermined members on said other box section when the melting point of the modeling material stored in the box section is higher than the melting point of the other modeling material stored in the other box section, and the setting section sets the reference temperature higher when the box section is attached to the mounting section than when the other box section is attached to the mounting section.SELECTED DRAWING: Figure 3

Description

The present invention relates to a three-dimensional modeling apparatus and a three-dimensional modeling method.

3D printers are becoming widespread as devices capable of producing high-mix low-volume products. In a 3D printer, it is necessary to change the temperature of the ejection means for each modeling material.

As a technique for determining the temperature of a modeling material, Patent Document 1 states that the shape and structure of a cartridge are changed for each type of modeling material, and the type of modeling material is determined by detecting the shape and structure of the cartridge. Is disclosed.

However, if there is a problem with the shape or structure of the cartridge, an error will occur in identifying the type of modeling material stored in the cartridge. In such a case, the temperature of the modeling material may be excessively increased because the temperature is adjusted not corresponding to the type of the modeling material.

The present invention has been made in view of the above, and an object of the present invention is to provide a three-dimensional modeling apparatus and a three-dimensional modeling method that prevent the modeling material from being overheated and improve safety.

In order to solve the above-mentioned problems and achieve the object, the three-dimensional modeling apparatus according to one embodiment of the present invention houses a temperature detection unit for detecting the temperature of the discharge means for discharging the modeling material and the modeling material. A mounting part to which the box part can be attached, a setting part that sets a reference temperature for determining whether or not the discharge means is overheated based on the number of predetermined members provided in the box part, and a temperature of the discharge means. And, based on the reference temperature, a power cutoff unit that shuts off the power supply of the heat source that heats the modeling material is provided, and the melting point of the modeling material stored in the box portion is stored in another box portion. When the temperature is higher than the melting point of the molding material, the number of predetermined members attached to the mounting portion and provided in the box portion is larger than the number of predetermined members provided in the other box portion. When the box portion is attached to the mounting portion, the setting unit sets a higher reference temperature than when another box portion is attached to the mounting portion.

According to the present invention, it is possible to prevent the modeling material from being overheated, which has the effect of improving safety.

FIG. 1 is a schematic view showing a configuration of a three-dimensional modeling apparatus according to an embodiment. FIG. 2 is a schematic view showing a cross section of a discharge module in the three-dimensional modeling apparatus according to the embodiment. FIG. 3 is a hardware configuration diagram of the three-dimensional modeling apparatus according to the embodiment. FIG. 4 is a three-view view showing a cartridge in which the filament according to the embodiment is stored. FIG. 5 is a diagram illustrating the relationship between the number of protrusions provided on the cartridge according to the embodiment and the melting point of the filament stored in the cartridge. FIG. 6 is a diagram illustrating a specific configuration up to controlling the relay circuit according to the embodiment.

Hereinafter, embodiments of the three-dimensional modeling apparatus and the three-dimensional modeling method will be described with reference to the attached drawings. The present invention is not limited to the following embodiments.

(Embodiment)
As one embodiment, an example of application to a three-dimensional modeling apparatus for modeling a three-dimensional model by the Fused Filament Fabrication (FFF) method is shown. The embodiment shown below does not limit the modeling method to the Fused Deposition Modeling Method (FFF). In addition, it may be applied to a three-dimensional modeling apparatus that models a three-dimensional model by any modeling method.

FIG. 1 is a schematic view showing a configuration of a three-dimensional modeling apparatus according to an embodiment. FIG. 2 is a schematic view showing a cross section of a discharge module in the three-dimensional modeling apparatus of FIG. The three-dimensional modeling device 1 can form a three-dimensional modeled object whose mold becomes complicated or cannot be molded by injection molding.

The three-dimensional modeling device 1 includes a housing 2 and a cartridge mounting portion 5 (an example of mounting portion).

The inside of the housing 2 has a processing space for modeling the three-dimensional model M. A modeling table 3 as a mounting table is provided inside the housing 2, and a three-dimensional model M is modeled on the modeling table 3.

For modeling, a long filament F made of a resin composition using a thermoplastic resin as a matrix is used as a modeling material. The filament F is a solid molding material having an elongated wire shape. Although the present embodiment describes an example in which the filament F is used as the modeling material, the present embodiment does not limit the modeling material to the filament F, and may be applicable to the modeling of a three-dimensional modeled object.

The cartridge mounting portion 5 can mount the cartridge 50 in which the filament F is stored. Further, the cartridge mounting portion 5 is provided with a recess at a position corresponding to the protrusion 51 provided on the cartridge 50. A switch pressed by the protrusion 51 is stored in the recess. The protrusion 51 provided on the cartridge 50 will be described later.

In FIG. 1, an example in which one cartridge mounting portion 5 is provided will be described for ease of explanation, but the example is not limited to the example in which one cartridge mounting portion 5 is provided, and a plurality of cartridge mounting portions 5 may be provided. Further, it is assumed that the cartridge 50 shows an example of a box portion in which the filament F (modeling material) is stored.

A reel 4 is provided inside the cartridge 50. The reel 4 rotates by being pulled by the rotation of the extruder 11, which is the driving means of the filament F, without exerting a large resistance force.

A discharge module 10 (modeling head) as a modeling material discharge member is provided above the modeling table 3 inside the housing 2. The discharge module 10 is modularized by an extruder 11, a cooling block 12, a filament guide 14, a heating block 15, a discharge nozzle 18, and other components. The filament F is supplied to the discharge module 10 of the three-dimensional modeling apparatus 1 by being pulled in by the extruder 11.

The heating block 15 has a heat source 16 such as a heater and a thermistor 17 for controlling the temperature of the heater, and the filament F supplied to the discharge module 10 is heated and melted via a transfer path and discharged. It is supplied to the nozzle 18.

The thermistor 17 detects the temperature of the discharge nozzle 18 that discharges the molten filament F. In this embodiment, the thermistor 17 is used as the temperature detection unit, but any configuration may be used as long as the temperature of the discharge nozzle 18 can be detected, and for example, a thermocouple may be used.

The cooling block 12 is provided above the heating block 15. The cooling block 12 has a cooling source 13 and cools the filament. As a result, the cooling block 12 prevents the molten filament FM from flowing back to the upper part in the discharge module 10, increasing the resistance to push out the filament, or preventing clogging in the transfer path due to the solidification of the filament. A filament guide 14 is provided between the heating block 15 and the cooling block 12.

As shown in FIGS. 1 and 2, a discharge nozzle 18 for discharging the filament F, which is a modeling material, is provided at the lower end of the discharge module 10. The discharge nozzle 18 discharges the molten or semi-melted filament FM supplied from the heating block 15 so as to be linearly extruded onto the modeling table 3. The discharged filament FM is cooled and solidified to form a layer having a predetermined shape. Further, the discharge nozzle 18 stacks and stacks new layers by repeating the operation of ejecting the molten or semi-melted filament FM into the formed layer in a linear manner. As a result, a three-dimensional model can be obtained.

In this embodiment, the discharge module 10 is provided with two discharge nozzles. The first discharge nozzle melts and discharges the filament of the model material constituting the three-dimensional model, and the second discharge nozzle melts and discharges the filament of the support material. In FIG. 1, the second discharge nozzle is arranged behind the first discharge nozzle. The number of discharge nozzles is not limited to two and is arbitrary.

The support material discharged from the second discharge nozzle is usually a material different from the model material constituting the three-dimensional model. The support portion formed by the support material is finally removed from the model portion formed by the model material. The filament of the support material and the filament of the model material are each melted in the heating block 15, discharged so as to be extruded from the respective discharge nozzles 18, and sequentially laminated in layers.

Further, the three-dimensional modeling apparatus 1 is provided with a heating module 20 that heats the lower layer of the layer being formed by the discharge module 10. The heating module is provided with a laser light source 21 that irradiates a laser. The laser light source 21 irradiates the laser at a position in the lower layer immediately before the filament FM is discharged. The laser light source is not particularly limited, but a semiconductor laser is exemplified, and the irradiation wavelength of the laser is 445 nm.

The discharge module 10 and the heating module 20 are held so as to be slidable with respect to the X-axis drive shaft 31 (X-axis direction) extending in the left-right direction of the device (left-right direction = X-axis direction in FIG. 1) via a connecting member. Has been done. The discharge module 10 can be moved in the left-right direction (X-axis direction) of the device by the driving force of the X-axis drive motor 32.

The X-axis drive motor 32 is held so as to be slidable along the Y-axis drive axis (Y-axis direction) extending in the front-rear direction of the device (depth direction = Y-axis direction in FIG. 1). When the X-axis drive shaft 31 moves along the Y-axis direction by the driving force of the Y-axis drive motor 33 together with the X-axis drive motor 32, the discharge module 10 and the heating module 20 move in the Y-axis direction.

On the other hand, the modeling table 3 is passed through the Z-axis drive shaft 34 and the guide shaft 35, and can be moved along the Z-axis drive shaft 34 extending in the vertical direction of the device (vertical direction in FIG. 1 = Z-axis direction). It is held. The modeling table 3 moves in the vertical direction (Z-axis direction) of the device by the driving force of the Z-axis drive motor 36. The modeling table 3 may be provided with a heating unit for heating the loaded modeled object.

The discharge module 10 is provided with a heating mechanism such as the heat source 16. In this embodiment, the heat source 16 is controlled based on the temperature information from the nozzle temperature detection mechanism (thermistor 17) provided in the discharge module 10. Conventionally, it is common to prepare an overheating prevention function so as not to overheat even if a problem occurs in the control of the heat source 16. Power shutoff by a thermostat or a thermal fuse is generally used as an overheat prevention function, but it is not realistic to replace the thermal fuse or the thermostat every time the resin material used is replaced. Therefore, in the present embodiment, the following power cutoff means is proposed.

FIG. 3 is a hardware configuration diagram of the three-dimensional modeling apparatus according to the embodiment. The three-dimensional modeling device 1 has a control unit 100. The control unit 100 is constructed by a CPU (Central Processing Unit), a circuit, or the like, and is electrically connected to each unit as shown in FIG.

The three-dimensional modeling apparatus 1 is provided with an X-axis coordinate detection mechanism that detects the position of the discharge module 10 in the X-axis direction. The detection result of the X-axis coordinate detection mechanism is sent to the control unit 100. The control unit 100 controls the drive of the X-axis drive motor 32 based on the detection result, and moves the discharge module 10 to the target X-axis direction position.

The three-dimensional modeling apparatus 1 is provided with a Y-axis coordinate detection mechanism that detects the position of the discharge module 10 in the Y-axis direction. The detection result of the Y-axis coordinate detection mechanism is sent to the control unit 100. The control unit 100 controls the drive of the Y-axis drive motor 33 based on the detection result, and moves the discharge module 10 to the target Y-axis direction position.

The three-dimensional modeling apparatus 1 is provided with a Z-axis coordinate detection mechanism that detects the position of the modeling table 3 in the Z-axis direction. The detection result of the Z-axis coordinate detection mechanism is sent to the control unit 100. The control unit 100 controls the drive of the Z-axis drive motor 36 based on the detection result, and moves the modeling table 3 to the target Z-axis direction position.

In this way, the control unit 100 moves the relative three-dimensional positions of the discharge module 10 and the modeling table 3 to the target three-dimensional position by controlling the movement of the discharge module 10 and the modeling table 3.

If the melt discharge of the filament is continued over time, the peripheral portion of the discharge nozzle 18 may be contaminated with the molten resin. On the other hand, the cleaning brush 37 provided in the three-dimensional modeling apparatus 1 periodically performs a cleaning operation on the peripheral portion of the discharge nozzle 18 to prevent the resin from sticking to the tip of the discharge nozzle 18. it can. Preferably, from the viewpoint of preventing sticking, the cleaning operation is preferably performed before the temperature of the resin is completely lowered. In this case, the cleaning brush 37 is preferably made of a heat-resistant member. The polishing powder generated during the cleaning operation may be accumulated in the dust box 38 provided in the three-dimensional modeling apparatus 1 and discarded periodically, or may be provided with a suction path and discharged to the outside.

Further, the control unit 100 controls the drive of the discharge nozzle 18, the heat source 16 of the heating block 15, the cooling source 13 of the cooling block 12, the extruder 11, and the laser light source 21 by transmitting control signals. To do.

The cartridge mounting portion 5 is provided with a temperature setting unit (an example of the setting unit) 102. Then, the temperature setting unit 102 sets the overheating determination temperature according to the number of protrusions 51 provided on the cartridge 50 mounted on the cartridge mounting unit 5. The overheating determination temperature is a reference temperature for determining whether or not the discharge nozzle 18 is overheating according to the filament F stored in the cartridge 50. Then, the temperature setting unit 102 outputs a voltage representing the overheating determination temperature to the comparator 101.

Further, the three-dimensional modeling apparatus 1 has a comparator 101. The comparator 101 receives a current in which the temperature of the discharge nozzle 18 is expressed as a voltage from the thermistor 17 provided in the heating block 15. Further, the comparator 101 receives a current in which the overheating determination temperature (reference temperature) is expressed as a voltage from the temperature setting unit 102 provided in the cartridge mounting unit 5. Then, the comparator 101 determines whether or not the voltage representing the temperature of the discharge nozzle 18 is higher than the voltage representing the overheating determination temperature (reference temperature) output from the temperature setting unit 102. Then, the comparator 101 controls the relay circuit 103 based on the determination result. In this embodiment, an example in which the comparator 101 is used as a mechanism for determining whether or not the voltage is higher than the voltage representing the overheating determination temperature (reference temperature) has been described, but it represents the overheating determination temperature (reference temperature). Other mechanisms may be used as a mechanism for determining whether or not the voltage is higher than the voltage.

The relay circuit 103 functions as a power cutoff unit that cuts off the power supply that supplies electric power to the heat source 16 that melts the filament F. That is, the relay circuit 103 can shut off the power supply of the heat source 16 that melts the filament F based on the temperature of the discharge nozzle 18 and the overheating determination temperature (reference temperature) by using the determination result of the comparator 101. .. In this embodiment, as an example of the power cutoff mechanism, the relay circuit 103 is applied, and any mechanism may be used as long as the mechanism can cut off the power supply.

FIG. 4 is a three-view view showing the cartridge 50 in which the filament is stored. As shown in FIG. 4, the cartridge 50 is provided with a protrusion 51 and a handle 52. As shown in FIG. 4, the filament F is set in the reel 4 in the cartridge 50 in a wound state. In this embodiment, the cartridge 50 is applied as an example of the box portion in which the modeling material is stored. Further, the cartridge 50 is provided with a hole 53 for outputting the filament F.

The filament F used in this embodiment is a solid material having an elongated wire shape. This embodiment shows an example in which a filament is used as an example of the modeling material, and the modeling material is not limited to the filament, and can be applied to various modeling materials used in the three-dimensional modeling apparatus 1. ..

In the present embodiment, the filament F can be supplied by attaching the cartridge 50 to the cartridge mounting portion 5 of the three-dimensional modeling apparatus 1.

The cartridge 50 is provided with a protrusion 51. The number of protrusions 51 varies depending on the type of filament F housed in the cartridge 50. In this embodiment, in order to determine the type of filament F, the number of protrusions is made different depending on the melting point of the filament F.

FIG. 5 is a diagram illustrating the relationship between the number of protrusions provided on the cartridge 50 and the melting point of the filament F stored in the cartridge 50. As shown in FIG. 5, as the melting point of the filament F stored in the cartridge 50 decreases, the number of protrusions provided on the cartridge 50 decreases. That is, in the present embodiment, when the number of protrusions provided on the cartridge 50 can be detected, the melting point of the filament stored in the cartridge 50 can be grasped.

In the present embodiment, an example in which the cartridge 50 is provided with the number of protrusions 51 according to the melting point of the filament has been described, but the cartridge 50 is not limited to the protrusions 51, and different numbers of members are provided according to the melting point of the filament. Just do it.

In the example shown in FIG. 5, the filament stored in the cartridge 50A without protrusions has the lowest melting point, the cartridge 50B with one protrusion, the cartridge 50C with two protrusions, the cartridge 50D with three protrusions, and the protrusions. As the number of the four cartridges 50E and the number of protrusions increases, the melting point of the stored filament increases. In other words, when the melting point of the filament housed in the cartridge 50 is higher than the melting point of the other filament housed in the other cartridge, the protrusion (member) provided on the cartridge 50 attached to the cartridge mounting portion 5. ) Is larger than the number of protrusions provided on the other cartridge. Then, the temperature setting unit 102 sets the overheating determination temperature (reference temperature) higher when the cartridge 50 is attached to the cartridge attachment portion 5 than when another cartridge is attached to the cartridge attachment portion 5. To do.

Next, a specific configuration including the temperature setting unit 102 will be described. FIG. 6 is a diagram illustrating a specific configuration up to controlling the relay circuit 103. As shown in FIG. 6, the configuration up to controlling the relay circuit 103 is composed of a plurality of mechanisms. For example, the temperature setting unit 102 includes a type detection circuit 703 and a determination temperature setting circuit 704.

The type detection circuit 703 is composed of four switches SW1 to SW4. When the cartridge 50 is mounted on the cartridge mounting portion 5, the switches SW1 to SW4 are energized when pressed by the protrusion 51 provided on the cartridge 50.

In the present embodiment, the number of protrusions 51 is different depending on the type of material stored in the cartridge 50. Therefore, in other words, the type detection circuit 703 has the number of switches SW1 to SW4 pressed. Therefore, it can be said that the type of filament (filament according to melting point) stored in the cartridge 50 is detected.

The determination temperature setting circuit 704 is composed of a power supply 711, a resistor Ra, a resistor R1, a resistor R2, a resistor R3, a resistor R4, and a resistor Rb, and the number of protrusions 51 provided on the cartridge 50 is increased. This circuit is constructed so that the output voltage increases as the number increases.

The type detection circuit 703 and the determination temperature setting circuit 704 are voltage dividing circuits connected to the comparator 101, and are provided on the cartridge 50 when the cartridge 50 is attached to the resistors R1 to R4 and the cartridge mounting portion 5. A parallel circuit in which switches SW1 to SW4 that are energized when pressed by the protrusions are connected in parallel is provided as many as the number of protrusions 51 (4 in this embodiment) that can be provided in the cartridge 50. There is.

As shown in FIG. 6, when the protrusion 51 provided on the cartridge 50 presses the switches SW1 to SW4 of the cartridge mounting portion 5, the reference voltage output by the determination temperature setting circuit 704 to the comparator 101 changes.

For example, in the case of the cartridge 50A having no protrusions, SW1 to SW4 are open (non-energized state), so that the reference voltage Vr1 output to the comparator 101 is a value calculated by the following equation (1). The resistor Ra and the resistor Rb are resistors provided for adjusting the reference voltage. Further, the voltage V1 of the power supply 711 is set.

Vr1 = (Rb * V1) / ((Ra + R1 + R2 + R3 + R4) + Rb) ... (1)

As another example, in the case of the cartridge 50E having four protrusions, SW1 to SW4 are closed (energized state), so that the reference voltage Vr2 is a value calculated by the following formula (2).

Vr2 = (Rb * V1) / (Ra + Rb) ... (2)

As described above, in the present embodiment, as the number of protrusions 51 provided on the cartridge 50 increases, the reference voltage increases and the overheating determination temperature also increases. As a result, if the protrusions of the cartridge 50 are temporarily damaged, the number of protrusions is reduced, so that the reference voltage is lowered and the overheating determination temperature is set low. As a result, even if the protrusion 51 of the cartridge 50 is damaged, it is possible to prevent the filament from being overheated, so that safety can be improved. The number of protrusions and the number of switches shown in FIG. 6 are shown as an example, and may not be four.

As described above, in the present embodiment, the reference voltage can be adjusted according to the number of protrusions. As a result, for example, when the determination temperature setting circuit 704 uses a filament having a melting point of about 400 ° C., it outputs a reference voltage indicating 440 ° C. as the overtemperature detection temperature and uses a filament having a melting point of about 300 ° C. In this case, a reference voltage indicating 340 ° C. can be output as the overtemperature detection temperature.

The temperature detection mechanism 701 is a circuit composed of a power supply 721, a thermistor 17, a resistor Rc, a resistor Rd, and a capacitor C1 so that the voltage increases according to the temperature of the discharge nozzle 18. ..

The overheating determination mechanism 702 includes a comparator 101. The comparator 101 receives the voltage V2 output from the thermistor 17, which changes depending on the temperature of the discharge nozzle 18 of the thermistor 17, at the + terminal. Further, the comparator 101 receives the reference voltage output from the determination temperature setting circuit 704 at the − terminal.

Then, the comparator 101 does not particularly control when the voltage of the − terminal is larger (= when the temperature of the discharge nozzle 18 is equal to or lower than the overtemperature determination temperature). On the other hand, when the voltage of the + terminal is larger (= when the temperature of the discharge nozzle 18 is larger than the overtemperature determination temperature), the comparator 101 shuts off the power supply to the heat source 16 by the relay circuit 103 and discharges the power. Prevents the filament supplied from the nozzle 18 from overheating.

In the present embodiment, as described above, an example of hardware configuration has been described as a configuration for preventing the filament from overheating. By configuring with hardware, it is possible to suppress malfunctions due to bugs, software runaway, defects at the time of version upgrade, etc., and improve safety. However, this embodiment is shown as an example, and may be realized by, for example, a part of software configuration, and an appropriate configuration may be used according to the implementation correspondence.

1 Three-dimensional modeling device 5 Cartridge mounting part 10 Discharge module 15 Heating block 16 Heat source 17 Thermistor 18 Discharge nozzle 50 Cartridge (box part)
51 Protrusion 101 Comparator 102 Temperature setting unit 103 Relay circuit F Filament R1, R2, R3, R4 Resistor SW1 to SW4 Switch

JP-A-2016-107629

Claims (5)

A temperature detector that detects the temperature of the discharge means that discharges the modeling material,
A mounting part to which the box part containing the modeling material can be mounted and
A setting unit that sets a reference temperature for determining whether or not the discharge means is overheated based on the number of predetermined members provided in the box unit.
A power cutoff unit that shuts off the power source of the heat source that heats the modeling material based on the temperature of the discharge means and the reference temperature is provided.
When the melting point of the modeling material stored in the box portion is higher than the melting point of the other modeling material stored in the other box portion, the predetermined value provided in the box portion attached to the mounting portion is provided. The number of members of the above is larger than the number of the predetermined members provided in the other box portion.
When the box portion is attached to the mounting portion, the setting portion sets the reference temperature higher than when the other box portion is attached to the mounting portion.
Three-dimensional modeling device. The temperature detection unit includes a circuit constructed so that the voltage increases according to the temperature of the discharge means.
The setting unit includes a circuit assembled so that the output voltage increases as the number of the predetermined members provided in the box unit increases.
A comparator for determining whether or not the voltage indicating the temperature of the discharging means output from the temperature detecting unit is higher than the voltage indicating the reference temperature output from the setting unit.
The three-dimensional modeling apparatus according to claim 1, further comprising. The predetermined member provided in the box portion is a protrusion.
The three-dimensional modeling apparatus according to claim 1 or 2. The setting unit is a circuit in which a resistor and a switch that is energized when pressed by the protrusion provided on the box portion when the box portion is attached to the mounting portion are connected in parallel. As many as the number of protrusions that can be provided on the box portion are provided.
The three-dimensional modeling apparatus according to claim 3. A temperature detection step that detects the temperature of the discharge means that discharges the modeling material,
Whether or not the discharge means is overheated based on the number of predetermined members provided in the box portion when the box portion is attached to the attachment portion to which the box portion in which the modeling material is stored can be attached. A setting step to set the reference temperature to determine whether
It has a power cutoff step for shutting off the power source of the heat source for heating the modeling material based on the temperature of the discharge means and the reference temperature.
When the melting point of the modeling material stored in the box portion is higher than the melting point of the other modeling material stored in the other box portion, the predetermined value provided in the box portion attached to the mounting portion is provided. The number of members of the above is larger than the number of the predetermined members provided in the other box portion.
In the setting step, when the box portion is attached to the mounting portion, the reference temperature is set higher than when the other box portion is attached to the mounting portion.
Three-dimensional modeling method.

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