3D printing method, force sensor manufacturing method, 3D printing apparatus and force sensor

Abstract

To provide a three-dimensional printing method capable of modeling at once regardless of types of materials even when a plurality of materials are used, a method of manufacturing a force sensor, and a three-dimensional printer.SOLUTION: A three-dimensional printing method has: a first step of modeling a support body using a first material; and a second step of printing a second material different from the first material on the support body. In the second step, the second material is printed on the support body while melting the first material that constitutes a portion on which the second material is printed.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a three-dimensional printing method, a method for manufacturing a force sensor, and a three-dimensional printing device. [Background technology]

[0002] A three-dimensional printing device (3D printer) is a machine that creates a three-dimensional model by stacking sliced ​​two-dimensional layers based on design data. 3D printing devices are attracting attention due to their high degree of freedom in processing and high productivity.

[0003] For example, Patent Document 1 discloses a fused deposition modeling three-dimensional printing apparatus, and discloses a method for controlling the gap between an extrusion nozzle and a print surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-54057 Summary of the Invention [Problem to be solved by the invention]

[0005] Attempts to fabricate force sensors in one go using a 3D printing device have been considered. However, there are cases where it is not possible to ensure sufficient adhesion between the support material and the sensor. For example, a Fiber Bragg Grating (FBG) sensor is one of the sensors suitable for detecting the strain that occurs in an object when force is applied to the object, but since the fiber that contains the sensor itself does not have the ability to adhere to other objects, it is difficult to ensure sufficient adhesion between the support and the sensor. When trying to ensure sufficient adhesion between the support and the sensor, there are limitations on the material of the fiber that contains the sensor.

[0006] The present invention has been made in consideration of the above problems, and aims to provide a 3D printing method, a force sensor manufacturing method, and a 3D printing device that are capable of forming objects in one go, regardless of the material types, even when multiple materials are used. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides the following means.

[0008] (1) A three-dimensional printing method according to a first aspect includes a first step of forming a support body using a first material, and a second step of printing a second material different from the first material onto the support body, in which the second material is printed onto the support body while melting the first material that constitutes the portion onto which the second material is printed.

[0009] (2) The three-dimensional printing method according to the above aspect may further include a third step of covering the second material printed on the support with a third material.

[0010] (3) In the three-dimensional printing method according to the above aspect, in the second step, a nozzle that ejects the second material may be heated and the nozzle may be pressed against the support.

[0011] (4) In the three-dimensional printing method according to the above aspect, the tip of the nozzle may be heated to a temperature equal to or higher than the melting point of the first material.

[0012] (5) In the three-dimensional printing method according to the above aspect, the second material may be a fiber including a sensor.

[0013] (6) In the 3D printing method of the above aspect, in the second step, the position of the sensor in the fiber may be measured, and at least one of the feed speed of the second material, the movement speed of the nozzle that ejects the second material, and the movement path of the nozzle that ejects the second material may be adjusted.

[0014] (7) A method for manufacturing a force sensor according to a second aspect uses the three-dimensional printing method according to the above aspect.

[0015] (8) A three-dimensional printing device according to a third aspect includes a first nozzle and a second nozzle. The first nozzle ejects a first material. The second nozzle ejects a second material different from the first material and is configured to be pressed against a support shaped using the first material.

[0016] (9) In the three-dimensional printing device according to the above aspect, the second nozzle may have a roller that feeds the second material. The roller of the second nozzle is a circular roller in which the feeding direction of the second material is a circumferential direction, and the static friction of the feeding surface of the roller of the second nozzle with respect to the second material is 0.1 or more.

[0017] (10) In the three-dimensional printing device according to the above aspect, the first nozzle may have a roller that feeds the first material. The roller of the first nozzle is a circular roller that feeds the first material in a circumferential direction, and the feed surface of the roller of the first nozzle has projections and recesses.

[0018] In the three-dimensional printing apparatus according to the above aspect, the second nozzle may further include an imaging element that can measure the second material being fed to the second nozzle.

[0019] (12) In the three-dimensional printing apparatus according to the above aspect, the second nozzle may further include a roller that feeds the second material, and a control unit that controls the roller. The control unit controls the movement of the roller or the second nozzle based on the measurement result of the imaging element. Effect of the Invention

[0020] According to the three-dimensional printing method, the force sensor manufacturing method, and the three-dimensional printing apparatus of the present embodiment, a three-dimensional structure can be formed at once using different materials, regardless of the material type. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic diagram of a three-dimensional printing device according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of a first nozzle of the three-dimensional printing device according to the first embodiment. [Diagram 3] FIG. 2 is a cross-sectional view of a second nozzle of the three-dimensional printing device according to the first embodiment. [Figure 4] 5A to 5C are schematic views for explaining a first step of the method for manufacturing the force sensor according to the first embodiment. [Diagram 5] 5A to 5C are schematic views for illustrating a second step of the method for manufacturing the force sensor according to the first embodiment. [Figure 6] 5A to 5C are schematic views for illustrating a second step of the method for manufacturing the force sensor according to the first embodiment. [Figure 7] 5A to 5C are schematic views for illustrating a third step of the method for manufacturing the force sensor according to the first embodiment. [Figure 8] 1A to 1C are schematic diagrams of a force sensor manufactured by a method for manufacturing a force sensor according to a first embodiment. [Figure 9] FIG. 1 is a diagram showing a second material printed on a support in Example 1. [Figure 10] 4 shows test results of the force sensor according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The present embodiment will be described in detail below. The following description is an example of the present invention, and the present invention is not limited thereto, and can be appropriately modified and implemented without departing from the gist of the present invention.

[0023] "First embodiment" 1 is a schematic diagram of a three-dimensional printing apparatus 100 according to a first embodiment. The three-dimensional printing apparatus 100 includes a first nozzle 10 and a second nozzle 20. The first nozzle 10 ejects a first material 1. The second nozzle 20 ejects a second material 2. The second material 2 is different from the first material 1.

[0024] 2 is a cross-sectional view of a first nozzle 10 of the three-dimensional printing apparatus 100 according to the first embodiment. The first nozzle 10 has, for example, a roller 11 and a heating unit 12. The first nozzle 10 ejects a first material 1 from a tip 13 of the nozzle.

[0025] Roller 11 feeds out first material 1. Roller 11 is a circular roller with a circular cross section. Roller 11 may be spherical or cylindrical. The circumferential direction of roller 11 coincides with the feeding direction of first material 1. Roller 11 has, for example, unevenness on feeding surface 11S. The unevenness on feeding surface 11S of roller 11 bites into first material 1, allowing first material 1 to be fed under desired conditions. There may be one or more rollers 11.

[0026] The heating section 12 heats the first nozzle 10, and heats the first material 1. The first material 1 is heated by the heating section 12 and melts. The melted first material 1 is injected from the tip portion 13.

[0027] The first material 1 is, for example, a resin material. The first material 1 is, for example, an acrylonitrile-butadiene-styrene copolymer synthetic resin (ABS resin), polycarbonate, polylactic acid resin (PLA resin), etc. The first material 1 solidifies by cooling after being injected from the tip portion 13.

[0028] 3 is a cross-sectional view of the second nozzle 20 of the three-dimensional printing apparatus 100 according to the first embodiment. The second nozzle 20 has, for example, a roller 21, a heating unit 22, an image sensor 24, a control unit 25, and a driving unit 26. The second nozzle 20 ejects the second material 2 from a tip 23 of the nozzle.

[0029] The roller 21 feeds out the second material 2. The roller 21 is a circular roller with a circular cross section. The roller 21 may be spherical or cylindrical. The circumferential direction of the roller 21 coincides with the feeding direction of the second material 2.

[0030] For example, the roller 21 has a flat sending-out surface 21S. The flat sending-out surface 21S of the roller 21 can prevent the roller 21 from damaging the second material 2. When the second material 2 is an optical fiber, if the roller 21 has unevenness, the surface of the optical fiber may be damaged, resulting in a deterioration of the optical characteristics.

[0031] The delivery surface 21S of the roller 21 preferably has a static friction coefficient of 0.1 or more with respect to the second material 2. The delivery surface 21S of the roller 21 is preferably made of, for example, silicone or rubber. If the delivery surface 21S of the roller 21 has a sufficient frictional force with respect to the second material 2, the second material 2 is prevented from slipping against the roller 21 when the second material 2 is delivered, and the second material 2 can be delivered under desired conditions. The roller 21 may be one or more.

[0032] The heating unit 22 heats the second nozzle 20. For example, the heating unit 22 heats the tip 23 of the second nozzle 20 to a temperature equal to or higher than the melting point of the first material 1. By heating the tip 23, the first material 1 in contact with the portion from which the second material 2 is injected melts. When the second material 2 is a meltable material, the heating unit 22 may heat the tip 23 of the second nozzle 20 to a temperature equal to or higher than the melting point of the second material 2.

[0033] The second material 2 is different from the first material 1. The second material 2 is, for example, a fiber including a sensor. The sensor is, for example, a Fiber Bragg Grating (FBG) sensor. When the sensor is a Fiber Bragg Grating (FBG) sensor, the second material 2 is a fiber including a core including a diffraction grating and a cladding surrounding the core. The refractive index of the cladding is lower than that of the core.

[0034] The imaging element 24 can measure the second material 2 fed into the second nozzle 20. The imaging element 24 is, for example, a camera. The imaging element 24 captures, for example, an image of the vicinity of the entrance of the second material 2 into the second nozzle 20. For example, if the second material 2 is a fiber including a sensor 2A, the imaging element 24 detects the sensor 2A. If the sensor 2A is a Fiber Bragg Grating (FBG) sensor, the imaging element 24 detects the diffraction grating that has reached the entrance of the second nozzle 20.

[0035] The control unit 25 is connected to, for example, the imaging element 24, the roller 21, and the drive unit 26. Information captured by the imaging element 24 is sent to the control unit 25. Information transmission between the imaging element 24 and the control unit 25 may be wired or wireless. The control unit 25 grasps the position of the sensor 2A of the second material 2 fed into the second nozzle 20, for example, based on the measurement result of the imaging element 24. The control unit 25 controls the movement of the roller 21 or the drive unit 26, based on the measurement result of the imaging element 24. For example, when it is expected that the position where the sensor 2A is actually installed will deviate from the position where the sensor 2A is desired to be installed (hereinafter referred to as the desired installation position) based on the measurement result of the imaging element 24, the control unit 25 changes at least one of the rotation speed of the roller 21, the movement speed of the second nozzle 20, and the movement path of the second nozzle 20. By changing the rotation speed of the roller 21, the feed speed of the second material 2 can be changed, and the installation position of the sensor 2A can be adjusted to the desired installation position. Furthermore, by changing the moving speed or moving path of the second nozzle 20, the relative speed or path at which the second material 2 is ejected onto the support 30 can be changed, and the installation position of the sensor 2A can be adjusted to a desired installation position.

[0036] The drive unit 26 is connected to the second nozzle 20. The drive unit 26 controls the vertical lifting and lowering motion of the second nozzle 20 and the horizontal translation motion. The drive unit 26 can press the second nozzle 20 against the support by the lifting and lowering motion. In other words, the second nozzle 20 is configured to be able to be pressed against the support by the drive unit 26.

[0037] Although an example of the three-dimensional printing apparatus according to the first embodiment has been described here, the three-dimensional printing apparatus according to the present invention is not limited to this example. For example, the second nozzle 20 of the three-dimensional printing apparatus 100 may not have either the image sensor 24 or the control unit 25, or both.

[0038] Next, a description will be given of a manufacturing method of the force sensor according to the first embodiment. The force sensor according to the first embodiment can be manufactured using, for example, the above-mentioned three-dimensional printing apparatus 100.

[0039] The method for manufacturing the force sensor according to the first embodiment can be produced by using the three-dimensional printing method according to the first embodiment. The three-dimensional printing method according to the first embodiment has, for example, a first step, a second step, and a third step.

[0040] FIG. 4 is a schematic diagram for explaining the first step. In the first step, the support 30 is formed using the first material 1. The first step is performed, for example, using the first nozzle 10 of the three-dimensional printing device 100. In the first step, sliced ​​two-dimensional layers are stacked based on design data to create the support 30. The first nozzle 10 ejects the first material 1 based on the design data. After being ejected from the first nozzle 10, the first material 1 cools and hardens. The first step is performed, for example, by fused deposition modeling (FDM). The support 30 is made of the first material.

[0041] FIG. 5 is a schematic diagram for explaining the second step. In the second step, the second material 2 is printed on the support 30. The second material 2 printed on the support 30 becomes, for example, a fiber 40. The fiber 40 has, for example, a sensor 40A inside. The fiber 40 is the second material 2 installed on the support 30. The sensor 40A is the sensor 2A installed on the support 30. The installation position of the sensor 40A can be adjusted, for example, by measuring the position of the sensor 2A in the second material 2 and adjusting at least one of the feed speed of the second material 2, the movement speed of the second nozzle 20 that ejects the second material 2, and the movement path of the second nozzle 20 that ejects the second material 2.

[0042] In the second step, the second material 2 is printed on the support 30 while melting the first material 1 that contacts the portion where the second material 2 is printed. The melted first material 1 is a part of the support 30. Fig. 6 is a schematic diagram for explaining an example of the second step. The second step includes, for example, a moving step, a melting step, and an ejecting step.

[0043] First, in the moving step, the second nozzle 20 is moved to a position where the fiber 40 is to be placed.

[0044] Next, in the melting step, the second nozzle 20 is heated, and the heated second nozzle 20 is pressed against the support 30. For example, the second nozzle 20 is heated by passing an electric current through the heating unit 22. For example, the tip 23 of the second nozzle 20 is heated to a temperature equal to or higher than the melting point of the first material 1. The tip 23 of the second nozzle 20 is pressed against the support 30 by lowering the entire second nozzle 20 toward the support 30 by the driving unit 26. When the heated tip 23 of the second nozzle 20 is pressed against the support 30, the first material 1 in the portion in contact with the tip 23 of the support 30 melts.

[0045] In the melting process, the tip 23 of the second nozzle 20 is located below the surface of the support 30. The depth of the tip 23 relative to the surface of the support 30 in the melting process is preferably, for example, half or more of the diameter of the fiber 40 after solidification, and more preferably equal to or less than the diameter of the fiber 40 after solidification. For example, the depth of the tip 23 relative to the surface of the support 30 in the melting process is preferably 0.1 mm or more and 5 mm or less. If the tip 23 is pressed too hard against the support 30, a load is applied to the second nozzle 20, which may cause the second nozzle 20 to break down. If the tip 23 is pressed too hard against the support 30, the support 30 may move when the second nozzle 20 is translated, and the modeling surface may be displaced. If the tip 23 is not pressed enough against the support 30, the adhesion between the fiber 40 and the support 30 may be reduced.

[0046] Here, an example is shown in which the first material 1 of a part of the support 30 is melted by pressing the heated tip 23 of the second nozzle 20 against the support 30. The method of melting the first material 1 is not limited to this example. For example, a laser may be irradiated onto the planned location from which the second material 2 is to be ejected, to melt the first material 1 located in the traveling direction of the second nozzle 20.

[0047] Next, in the injection process, the second nozzle 20 is translated while the second material 2 is injected from the second nozzle 20. By translating the second nozzle 20, the second material 2 becomes the fibers 40. After printing the fibers 40, the melted first material 1 re-solidifies. The re-solidification of the first material 1 brings the support 30 and the fibers 40 into close contact. The fibers 40 are, for example, embedded in the support 30.

[0048] The moving speed of the second nozzle 20 is preferably, for example, less than 5 mm / sec, and more preferably 1 mm / sec or less. The moving speed of the second nozzle 20 is preferably, for example, 0.1 mm / sec or more. By setting the moving speed of the second nozzle 20 in an appropriate range, it is possible to ensure the time for melting and re-solidifying the first material 1 while ensuring production efficiency. The moving speed of the second nozzle 20 does not need to be constant at all times, and may be changed according to circumstances. By adjusting the moving speed of the second nozzle 20, the sensor 40A in the fiber 40 can be placed at a desired position.

[0049] The feed speed of the second material 2 from the second nozzle 20 is preferably, for example, less than 5 mm / sec, more preferably 1 mm / sec or less. The feed speed of the second material 2 from the second nozzle 20 is preferably, for example, 0.1 mm / sec or more. By setting the feed speed of the second material 2 from the second nozzle 20 within an appropriate range, it is possible to ensure the time for melting and resolidification of the first material 1 while ensuring production efficiency. The feed speed of the second material 2 from the second nozzle 20 does not need to be constant at all times, and may be changed depending on the situation. By adjusting the feed speed, the sensor 40A in the fiber 40 can be installed at a desired position.

[0050] FIG. 7 is a schematic diagram for explaining the third step. In the third step, the fiber 40 formed by the second material 2 printed on the support 30 is covered with the third material. The third material may cover the fiber 40 directly or indirectly through a space. In the third step, sliced ​​two-dimensional layers are stacked based on the design data to produce the cover 50. The third step is performed, for example, by fused deposition modeling (FDM). The cover 50 is made of the third material.

[0051] The third material may be the same as or different from the first material 1. When the third material is the same as the first material 1, the cover 50 is formed using the first nozzle 10. When the third material is different from the first material 1, the cover 50 is formed using a third nozzle different from the first nozzle 10 and the second nozzle 20.

[0052] Next, as shown in Fig. 8, one end of the fiber 40 is connected to a measuring device 60 to obtain a force sensor. When an external force F is applied to the force sensor, the sensor 40A of the fiber 40 is distorted. For example, if the fiber 40 is a fiber including an FBG sensor, the wavelength of the reflected light from the diffraction grating changes when the sensor 40A is distorted. In other words, by observing the change in the wavelength of the reflected light detected by the measuring device 60, the application of the external force F to the force sensor and the strength of the external force F can be calculated. The external force F is not limited to distortion and may be pressure or temperature.

[0053] As described above, the method for manufacturing a force sensor according to this embodiment includes a step of printing the second material 2 while melting the first material 1. Therefore, by utilizing the resolidification of the melted first material 1, it is possible to ensure sufficient adhesion between the support 30 and the fiber 40 without relying on the second material 2. Therefore, according to the method for manufacturing a force sensor according to this embodiment, a force sensor in which the sensor 40A is arranged at a predetermined position can be produced in a batch using a three-dimensional printing method. Furthermore, the three-dimensional printing device 100 according to this embodiment is suitable for this three-dimensional printing method.

[0054] Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. EXAMPLES

[0055] Example 1 In Example 1, a plate made of polylactic acid (PLA) resin was prepared. This plate corresponds to the support 30 in FIGS.

[0056] Next, the fiber including the FBG sensor was printed on the plate as the second material 2. In Example 1, the temperature of the nozzle tip during printing was set to 200°C. In Example 1, the fiber including the FBG sensor was ejected while pressing the nozzle tip against the plate made of PLA resin. In Example 1, the nozzle movement speed was 1 mm / sec, and the fiber feed speed was 1 mm / sec.

[0057] Fig. 9 is an image of the sample after processing in Example 1. As shown in Fig. 9, the fiber was fused to the plate material, and the fiber and the plate material were strongly adhered to each other. In addition, the fiber could be protruded from the end of the plate material, and a connection part with the measuring device 60 shown in Fig. 8 could be formed.

[0058] Next, an external force was applied to the fabricated sample of Example 1 to perform a force sensor test. In the force sensor test, a load (bending moment) was applied in a first direction, and then a load (bending moment) was applied in a second direction. The first direction and the second direction are opposite directions.

[0059] As shown in Fig. 9, the force sensor of Example 1 properly measured the strain caused by the application of a load. The force sensor of Example 1 also detected the difference in the direction of the load application. Even when a load was applied to the force sensor of Example 1, the adhesion between the fiber and the plate material was ensured. [Industrial Applicability]

[0060] As described above, the three-dimensional printing method according to the present embodiment can be applied as a method for manufacturing a force sensor. The three-dimensional printing method according to the present embodiment can be applied not only to the manufacture of force sensors, but also to cases where there are limitations on the materials that can be used and it is difficult to ensure close contact between multiple different materials. Furthermore, a force sensor manufactured by this method can be used in a robot or the like. [Explanation of symbols]

[0061] Reference Signs List 1...first material, 2...second material, 2A...sensor, 10...first nozzle, 20...second nozzle, 11, 21...roller, 11S, 21S...feed surface, 13, 23...tip, 24...imaging element, 25...control unit, 26...driving unit, 30...support, 40...fiber, 40A...sensor, 50...cover, 60...measuring device, 100...3D printing device

Claims

1. The first step involves creating a support using the first material, The process includes a second step of printing a second material, which is different from the first material, onto the support, A three-dimensional printing method comprising the second step of printing the second material onto the support while melting the first material that constitutes the portion on which the second material is printed.

2. The three-dimensional printing method according to claim 1, further comprising a third step of covering the second material printed on the support with a third material.

3. The three-dimensional printing method according to claim 1, wherein in the second step, the nozzle for injecting the second material is heated and the nozzle is pressed against the support.

4. The three-dimensional printing method according to claim 3, wherein the tip of the nozzle is heated to a temperature above the melting point of the first material.

5. The three-dimensional printing method according to claim 1, wherein the second material is a fiber containing a sensor.

6. The three-dimensional printing method according to claim 5, wherein in the second step, the position of the sensor in the fiber is measured, and at least one of the feed rate of the second material, the movement speed of the nozzle for ejecting the second material, and the movement path of the nozzle for ejecting the second material is adjusted.

7. A method for manufacturing a force sensor using the three-dimensional printing method described in claim 1.

8. It comprises a first nozzle and a second nozzle, The first nozzle injects the first material, A three-dimensional printing apparatus in which the second nozzle is configured to inject a second material different from the first material and press it against a support formed using the first material.

9. The second nozzle has a roller for dispensing the second material, The roller of the second nozzle is a circular roller in which the direction of feeding the second material is the circumferential direction. The three-dimensional printing apparatus according to claim 8, wherein the feed surface of the roller of the second nozzle has a static friction of 0.1 or more with respect to the second material.

10. The first nozzle has a roller for dispensing the first material, The roller of the first nozzle is a circular roller in which the feeding direction of the first material is the circumferential direction. The three-dimensional printing apparatus according to claim 8, wherein the feed surface of the roller of the first nozzle has irregularities.

11. The second nozzle further comprises an image sensor, The three-dimensional printing apparatus according to claim 8, wherein the image sensor can measure the second material being fed into the second nozzle.

12. The second nozzle further comprises a roller for dispensing the second material and a control unit for controlling the roller, The three-dimensional printing apparatus according to claim 11, wherein the control unit controls the movement of the roller or the second nozzle based on the measurement results of the image sensor.

13. A support comprising a first material, The support comprises a fiber containing a second material embedded in the melted and solidified portion of the support, The aforementioned fiber includes a sensor inside. The sensor is a force sensor capable of detecting strain generated in the fiber when an external force is applied to the support.

14. Further comprising a cover, The force sensor according to claim 13, wherein the cover, together with the support, sandwiches the fiber.

15. The first end of the fiber protrudes from the support, The force sensor according to claim 13, wherein the first end is connectable to another device.

16. A support comprising a first material, The support comprises a fiber containing a second material embedded in the melted and solidified portion of the support, The fiber is manufactured by the three-dimensional printing method described in claim 1, and is used as a force sensor.