JP7762609B2 - modeling equipment - Google Patents

Description

The present invention relates to a molding device that molds a hardenable wire while maintaining a predetermined gap as it moves in the direction of the substrate's rotation axis.

Patent Document 1 describes a winding device for winding wire in layers and in an aligned manner around a bobbin, with the aim of achieving a wire winding device that easily and reliably prevents gaps between wire rods and wire climbing. The device includes a traverser that determines the winding position of the wire rod on the bobbin, a guide that guides the wire rod to the winding position, a camera that captures images of the winding state of the wire rod on the bobbin, and a control unit that performs calculations to control the movement speed of the traverser based on the winding state and controls the movement speed of the traverser based on the results of the calculations.

For reference, Patent Document 2 describes an automated process control of an additive manufacturing device that minimizes the number of tools an operator must use to control the device, in which at least one camera is provided to view the manufacturing volume of the device to generate network-accessible images of the object, and a computer stops the manufacturing process when the object is defective based on the image of the object.

Japanese Patent Application Laid-Open No. 2021-151900 JP 2019-10890 A

When a wire made of a fluid material that dries and solidifies is extruded from a nozzle onto a rotating, long, cylindrical substrate layer, and the wire is three-dimensionally spiraled along the substrate layer, if the substrate layer is distorted in the longitudinal or rotational direction, the wire will peel off or excessive extrusion will occur, preventing the desired structure from being layered. It is difficult to control the dimensions (gaps) when winding in an aligned manner.

In Patent Document 1, when winding wire in an aligned diagonal direction, it is difficult to determine the winding state through image processing when capturing images using a camera that is installed directly opposite the bobbin and does not move integrally with the traverser.

In Patent Document 2, the camera's line of sight and the direction of the gap do not match, so gap information cannot be obtained, or the difference in pixel information between the gap background and the wire is unclear, so the gap amount cannot be obtained through image processing, or the accuracy is low.

The objective of the present invention is to provide a shaping device that can shape a wire rod with a structure within an appropriate range even if the shaping base of the wire rod, including the surface of the substrate layer, is distorted in the longitudinal and rotational directions when shaping the wire rod along the substrate layer.

The modeling device of the present invention is a modeling device that moves a nozzle positioned opposite a substrate rotating along a rotation axis in the direction of the substrate's rotation axis while discharging a hardenable wire material onto at least the surface of the substrate while maintaining a predetermined gap. It has an imaging unit that images the gap area during modeling, an acquisition unit that acquires the amount of distortion of the substrate and the amount of wire material on the surface of the substrate based on image information captured by the imaging unit, a determination unit that determines whether the modeled shape of the wire material is appropriate based on the amount of distortion and the amount of wire material acquired by the acquisition unit, and a control unit that controls the unit amount of wire material discharged from the nozzle based on the determination result of the determination unit.

According to the present invention, the imaging unit captures images of the gap area during modeling.

The acquisition unit acquires the amount of distortion of the board and the amount of wire on the surface of the board based on the image information captured by the imaging unit.

The judgment section determines whether the wire shape is appropriate.

The control unit controls the unit amount of wire discharged from the nozzle based on the judgment result of the judgment unit.

As a result, when the wire is shaped along the substrate layer, even if the shaping base of the wire, including the surface of the substrate layer, is distorted in the longitudinal and rotational directions, the wire can be shaped with a structure within the appropriate range.

In this invention, the imaging unit is attached so as to follow the movement of the nozzle, and is capable of capturing images with its optical axis always maintained parallel to the winding direction of the wire and within the gap area, and the acquisition unit acquires the distortion of the substrate and the amount of wire on the surface of the substrate under the same conditions, regardless of the movement of the nozzle.

This invention is characterized in that by forming a wire rod on top of the wire rod formed on the surface of the substrate, a mesh-like wire rod forming portion with a group of interconnected air layers is formed on the surface of the substrate.

The present invention has the advantage that when a wire is shaped along a substrate layer, even if the shaping base of the wire, including the surface of the substrate layer, is distorted in the longitudinal direction and rotational direction, the wire can be shaped with a structure within an appropriate range.

2A and 2B are schematic diagrams showing main parts of a three-dimensional modeling apparatus according to the present embodiment, in which (A) is a top view and (B) is a cross-sectional view taken along line IB-IB in FIG. 3 is a control block diagram of a molding control device according to the present embodiment. 1 is a functional block diagram of a forming state determination unit according to an embodiment of the present invention; 10 is a flowchart showing a main routine of object-forming control according to the present embodiment. 10 is a flowchart showing a molding shape determination process control routine according to the present embodiment. FIG. 10 is a front view of an image captured and binarized in the present embodiment. FIG. 10 is a diagram illustrating transitions between wire rods, showing the results of measurement by the shaping state determination unit according to the present embodiment. 10 is a diagram showing the appropriate and inappropriate relationship between the gap between the wires and the height of the substrate surface layer. FIG. 1A and 1B are top views showing the positional relationship between the camera and the nozzle, where (A) is a configuration in which the camera and the nozzle move synchronously according to the present embodiment, and (B) is a configuration in which the camera and the nozzle move asynchronously according to a comparative example. 1A and 1B are side views showing the positional relationship between the camera and the nozzle, in which (A) shows a configuration in which the camera and the nozzle move synchronously according to the present embodiment, and (B) shows a configuration in which the camera and the nozzle move asynchronously according to a comparative example.

Figure 1 is a schematic diagram showing the main components of a three-dimensional modeling device 10 according to this embodiment.

As shown in FIG. 1(A), the three-dimensional modeling device 10 includes a modeling control device 12, which controls a nozzle movement mechanism 14, a discharge rate adjustment mechanism 16, and a substrate rotation mechanism 18.

The nozzle movement mechanism 14 is composed of a drive system (e.g., a rack and pinion mechanism) that moves an arm 24 attached to a nozzle 22 that ejects the hardenable wire 20 in a gel state. The nozzle movement mechanism 14 moves the arm 24 at a constant speed in the x direction in Figure 1.

The discharge rate adjustment mechanism 16 is composed of a drive system (such as a motor-driven on-off valve) that adjusts the opening of the pipe 26 that supplies the wire rod 20 to the nozzle 22. The discharge rate adjustment mechanism 16 adjusts the unit discharge rate of the wire rod 20 discharged from the nozzle 22. The discharge rate of the wire rod 20 discharged from the nozzle 22 can be adjusted by changing the rotation speed of the motor-driven screw (not shown) that feeds the wire rod 20, or by changing the pressure (air pressure) applied to the pipe 26, etc.

The substrate rotation mechanism 18 is composed of a drive system (e.g., a motor) that rotates the cylindrical substrate 28, which is the base material for forming the wire 20. The substrate rotation mechanism 18 rotates the substrate 28 at a constant speed around its axis in the θ direction in Figure 1.

Movement in the x direction of FIG. 1 by the nozzle movement mechanism 14 and rotation in the θ direction of FIG. 1 by the substrate rotation mechanism 18 causes the nozzle 22 to move in a spiral shape on the substrate 28. Note that in this embodiment, the shape does not need to be a geometric spiral (it does not need to be wound at equal intervals like a screw), but rather it can be a so-called "spiral shape" formed by movement along the rotation axis while rotating.

When the wire 20, whose discharge rate has been adjusted by the discharge rate adjustment mechanism 16, is discharged from the nozzle 22 while the nozzle 22 is moving, the wire 20 is formed into a spiral shape with a predetermined interval, as shown in Figure 1. Hereinafter, the direction in which this spiral shape is formed will be referred to as the winding direction of the wire 20.

For reference, the object produced in this embodiment is applied to an air conditioner that utilizes the waste heat from an adsorption refrigerator. The substrate 28 is a pipe through which a refrigerant passes, and the material of the wires 20 contains silica gel, which absorbs water. By stacking the wires 20 in a spiral shape, a network of interconnected spaces is formed, allowing heat exchange to occur.

Here, the three-dimensional printing device 10 of this embodiment is equipped with a camera 30 as an imaging unit for monitoring the printing status of the wire 20.

The camera 30 is attached so that it moves in synchronization with the nozzle 22. For example, using the arm 24 shown in Figure 1 as an example, the nozzle 22 is attached to one end of the L-shaped arm 24, and the camera 30 is attached to the other end.

Here, when the nozzle movement mechanism 14 drives the arm 24 to move in the x direction in Figure 1, the camera 30 moves in synchronization with the movement of the nozzle 22, while maintaining their relative positions.

As shown in Figure 1(A), the optical axis L of the camera 30 is parallel to the winding direction of the wire 20 and is positioned in the gap between the wire 20(n-1) formed one turn before the wire 20 and the wire (n) being formed this time.

Also, as shown in Figure 1(B), the optical axis L of the camera 30 is positioned midway between the discharge outlet of the nozzle 22 and the discharge base of the wire 20. The discharge base is the surface of the substrate 28 in the first layer, and the top surface of the previously formed spiral wire 20 in the second and subsequent layers.

The image captured by the camera 30 is converted into a binarized image (the target image is black and the background is white) as shown in Figure 6, and the appropriateness of the gaps between the wires 20 is determined (details will be described later).

Figure 2 shows the control blocks of the molding control device 12 according to this embodiment. Note that the control blocks for each control object shown in Figure 2 do not limit the hardware configuration, and some or all of the controls may be operated as software programs.

As shown in FIG. 2, the modeling control device 12 includes a modeling instruction unit 32. The modeling instruction unit 32 stores initial information such as the diameter and length of the substrate 28, and the physical properties and viscosity of the wire 20, and instructs the nozzle movement control unit 34 and the substrate rotation control unit 36 to set their initial positions according to the modeling instructions.

In addition, when it is time to start modeling, the modeling instruction unit 32 starts synchronous driving of the nozzle mounting base 38 and the substrate mounting base 40 for the nozzle movement mechanism unit 14 and the substrate rotation mechanism unit 18 via the nozzle movement control unit 34 and the substrate rotation control unit 36.

Furthermore, the modeling instruction unit 32 controls the discharge amount adjustment mechanism unit 16 via the discharge amount control unit 42 to discharge the wire 20 from the nozzle 22 at a predetermined discharge amount (a fixed unit discharge amount).

Here, the modeling instruction unit 32 instructs the camera 30 to take an image when modeling begins.

In response to an instruction from the modeling instruction unit 32, the camera 30 begins capturing images and sends the captured images to the modeling state determination unit 44.

The forming state determination unit 44 determines whether the forming state is appropriate. Specifically, it determines whether the state of the gap between the wire 20(n-1) formed one revolution before the wire 20 and the wire (n) formed this time is appropriate. Details of the forming state determination unit 44 will be explained using Figure 3.

The modeling state determination unit 44 is connected to the discharge amount control unit 42, and sends the determination result to the discharge amount control unit 42. In this embodiment, if the determination result is inappropriate, information regarding the determination result (error information, etc.) is sent to the discharge amount control unit 42.

The discharge volume control unit 42 calculates a correction value based on the error information and instructs the discharge volume adjustment mechanism unit 16 to make the correction (adjust the discharge volume).

(Detailed configuration of the modeling state determination unit 44)

Figure 3 is a functional block diagram of the modeling state determination unit 44. Note that the control blocks shown in Figure 3 are classified by function and do not limit the hardware configuration.

Image information captured by the camera 30 is acquired by the image acquisition unit 46 and sent to the binarization processing unit 48.

The binarization processing unit 48 performs binarization processing, turning the subject into black and the background into white.

Figure 6 shows an example of an image after binarization processing by the binarization processing unit 48.

The binarized image is classified into a black image 50, which combines the substrate layer image, wire image, and nozzle image, and a white background image 52.

However, as long as the subject and background can be clearly distinguished, the colors can be inverted, the image can be in color, or the image can be an outline image.

The binarization processing unit 48 is connected to the substrate layer strain measurement area extraction unit 54 and the wire quantity measurement area extraction unit 56.

The substrate layer distortion measurement area extraction unit 54 measures the amount of distortion for area A1 in Figure 6. The distortion is the height of the modeling base (the surface of the substrate 28 during modeling of the first layer) when imaged by the camera 30, and is called distortion because the height changes over time due to the rotation of the substrate and the movement of the nozzle. Specifically, the white ratio W1 relative to the total area of area A1 in Figure 6 is extracted.

The substrate layer distortion measurement area extraction unit 54 is connected to the substrate layer distortion measurement processing unit 58 and sends the extracted whiteness ratio W1 to the substrate layer distortion measurement processing unit 58.

The substrate layer distortion measurement processing unit 58 recognizes the reference position of the substrate 28 (the height position of the surface layer of the substrate 28) by setting the whiteness ratio W1 as the reference whiteness ratio W0.

The substrate layer distortion measurement processing unit 58 is connected to the appropriateness determination unit 60 and sends the reference white ratio to the appropriateness determination unit 60.

Meanwhile, the wire quantity measurement area extraction unit 56 measures the wire quantity for areas A2, A3, and A4 in Figure 6. Specifically, it extracts the whiteness ratios W2, W3, and W4 relative to the total area of each of areas A2, A3, and A4 in Figure 6.

The wire quantity measurement area extraction unit 56 is connected to the appropriateness determination unit 60 and sends the extracted whiteness rates W2, W3, and W4 to the appropriateness determination unit 60.

The appropriateness determination unit 60 determines whether the gaps between the wires 20 are appropriate based on the whiteness rates W1, W2, W3, and W4, and sends the determination result (error information) to the wire unit discharge amount calculation unit 62 of the discharge amount control unit 42.

The wire unit discharge rate calculation unit 62 calculates the wire unit discharge rate in response to instructions from the modeling instruction unit 32, and sends the potential unit discharge rate adjusted (corrected) based on the judgment results (error information) obtained during modeling to the discharge rate adjustment mechanism unit 16 via the discharge rate calculation value output unit 64.

The operation of this embodiment will be explained below with reference to the flowcharts in Figures 4 and 5.

Figure 4 is a flowchart showing the main modeling control routine according to this embodiment.

In step 100, it is determined whether a modeling command has been issued, and if the determination is negative, the routine ends. If the determination is positive in step 100, the routine proceeds to step 102, where the substrate 28 is positioned, then to step 104, where the amount of wire 20 dispensed is adjusted, and then to step 106.

In step 106, rotation of the substrate 28 begins (θ direction), then proceeds to step 108, where movement of the nozzle 22 begins (x direction), and proceeds to step 110.

In step 110, the discharge of the wire 20 begins. As a result, the wire 20 is formed in a spiral shape on the surface layer of the substrate 28 (in the first case).

In the next step 112, a printing state determination process is executed. The printing state determination process will be described later.

In the next step 114, it is determined whether or not the formation of the wire 20 has been completed. If the determination is negative, the process returns to step 102 and executes the formation status determination process. If the determination is affirmative in step 114, the process proceeds to step 116, where all operations are stopped, and the process proceeds to step 118.

In step 118, it is determined that the next layer is to be built, and if the determination is affirmative, the routine proceeds to step 102 and the above process is repeated. If the determination is negative in step 116, the routine ends.

(Building status determination process)

Figure 5 is a control flowchart showing details of the modeling state determination process executed in step 112 of Figure 4.

In step 150, it is determined whether it is time to make a judgment, and if the judgment is negative, the process returns (returns to step 114 in Figure 4).

Also, if a positive judgment is made in step 150, the process proceeds to step 152, where an image captured by camera 30 is acquired, and then the process proceeds to step 154, where binarization processing of the acquired image is performed, and the process proceeds to step 156.

In step 156, an image of area A1 in Figure 6 is extracted, and then the process proceeds to step 158, where the whiteness ratio W1 of the extracted area A1 is measured.

In the next step 160, the measured W1 is set as the reference white ratio W0 (the position corresponding to this white ratio W0 is the surface of the substrate (in the case of the first layer)).

In the next step 162, images of areas A2, A3, and A4 in Figure 6 are extracted, and then the process proceeds to step 164, where the whiteness ratios W2, W3, and W4 of the extracted areas A2, A3, and A4 are measured.

In the next step 166, it is determined whether or not the judgment formula (1) holds. Formula (1) determines whether adjacent wires 28 exist (whether each of areas A2 and A3 is filled in black) using a threshold value (here, 0.9). The lower limit of the threshold value is whiteness ratio = 0.

0≦(W2+W3)/2<0.9...(1)

If the result of step 166 is affirmative, the process proceeds to step 168, where the value is determined to be outside the appropriate range and error information is sent.

In the next step 170, a correction value for the wire 20 discharge rate is calculated based on the error information, and then the process proceeds to step 172, where a correction instruction is output to the wire discharge rate control unit 42, and the process returns to step 150.

On the other hand, if the determination in step 166 is negative, the process proceeds to step 174, where it is determined whether or not the determination formula (2) holds. In formula (2), after it is confirmed that wire 28 is present in formula (1), the extent of the gap is determined taking distortion into account.

(0.95×W0<W4<1.05×W0...(2)

If the determination in step 174 is negative, the process proceeds to step 168. If the determination in step 174 is positive, the process proceeds to step 176, where it is determined to be within the appropriate range, and the process returns to step 150.

Figure 7 is a transition diagram between wire rods, showing the results measured by the modeling state determination unit 44.

At measurement time a, the measurement result (gap amount) is within the appropriate range, so no correction of the discharge amount of wire 20 is required, and the manufacturing status determination continues.

Next, at measurement time b, the measurement result (gap amount) exceeds the upper limit of the appropriate range, and if this state continues for a certain period of time, an adjustment instruction is issued at adjustment time c to reduce the discharge amount of wire 20.

Measurement time c is the result of adjustment made at adjustment time c, and it can be seen that the measurement result (gap amount) is within the appropriate range. However, this type of judgment cannot be made accurately if there is distortion, etc., in the board 28.

In this embodiment, therefore, a camera 30 is installed to capture images of the forming state, with the optical axis L (see Figure 1) of the camera 30 parallel to the winding direction of the wire 20, positioned in the gap between the wire 20 (n-1) formed one turn before the wire 20 and the wire (n) being formed this time, and moved in synchronization with the movement of the nozzle 22.

This allows the wire to be shaped within an appropriate range of structure without being affected by distortion of the substrate 28.

Figure 8 is a diagram showing the appropriate and inappropriate relationship between the gap between the wires 20 and the height of the substrate 28.

Even if the substrate 28 is distorted and the surface of the substrate 28 is raised, the raised position is set as the reference position (whiteness ratio W0), so the gap can be adjusted appropriately by adjusting the discharge amount of the wire 20 to suit the reference position (see the top row of Figure 8).

If the substrate 28 is not distorted, the gap can be adjusted appropriately with a predetermined discharge amount (see the middle of Figure 8).

Even if the substrate 28 is distorted and the surface of the substrate 28 is lowered, the lowered position is set as the reference position (whiteness ratio W0), so the gap can be adjusted by adjusting the discharge amount of the wire 20 to suit the reference position (see the bottom of Figure 8).

(Actions and effects of synchronized movement of the camera 30 and nozzle 22)

Figures 9 and 10 show a comparison between when the camera and nozzle move synchronously and when they move asynchronously.

Figures 9(B) and 10(B) show a comparative example in which the camera and nozzle move asynchronously. When the nozzle 22 moves in the x direction, the optical axis L of the camera 30 always deviates from the gap between the wire 20(n-1) formed one revolution ago and the wire (n) formed this time, causing the field of view to deviate from the optical axis L and resulting in significant distortion.

In contrast, Figures 9(A) and 10(A) show a configuration in which the camera and nozzle in this embodiment move in sync. When the nozzle 22 moves in the x direction, the camera 30 is connected to the nozzle 22 via the arm 24. This means that the optical axis L is always maintained in the gap between the wire 20(n-1) formed one revolution ago and the wire (n) formed this time. This means that the field of view is centered on the optical axis L, and no distortion occurs in the captured image.

As explained above, in this embodiment, the camera 30 is physically fixed to the nozzle 22 (via the arm 24) so that its relative position with respect to the nozzle 22 is the same. The optical axis L of the camera 30 is always maintained parallel to the winding direction of the wire 20 and within the gap area as the nozzle 22 moves. Therefore, the field of view is centered on the optical axis L, resulting in less distortion.

10 Three-dimensional printing device (printing device)
12 Shape control device 14 Nozzle movement mechanism 16 Discharge amount adjustment mechanism 18 Substrate rotation mechanism 20 Wire rod 22 Nozzle 24 Arm 26 Pipe 28 Substrate 30 Camera (imaging unit)
32 Modeling instruction unit 34 Nozzle movement control unit 36 Substrate rotation control unit 38 Nozzle mounting base 40 Substrate mounting base 42 Discharge amount control unit (control unit)
44 Forming state determination unit 46 Image acquisition unit 48 Binarization processing unit (acquisition unit)
50 Black image 52 White image 54 Substrate layer strain measurement area extraction unit 56 Wire amount measurement area extraction unit 58 Substrate layer strain measurement processing unit 60 Adequacy determination unit (determination unit)
62 Wire rod unit discharge amount calculation unit 64 Discharge amount calculation value output unit

Claims (3)

A molding apparatus that moves a nozzle facing a substrate that rotates along a rotation axis in the direction of the rotation axis of the substrate while discharging a curable filament, thereby molding the filament on at least a surface layer of the substrate while maintaining a predetermined gap,
an imaging unit that images an image of an area within the gap during modeling;
an acquisition unit that acquires the amount of distortion of the substrate and the amount of wires on the surface of the substrate based on image information captured by the imaging unit;
a determination unit that determines whether or not a shaped shape of the wire is appropriate based on the amount of distortion and the amount of wire acquired by the acquisition unit;
a control unit that controls a unit discharge amount of the wire from the nozzle based on a determination result of the determination unit;
A molding device having the above structure. the imaging unit is attached so as to follow the movement of the nozzle, and can capture images while maintaining an optical axis always parallel to the winding direction of the wire and within the gap;
The molding apparatus according to claim 1 , wherein the acquisition unit acquires the distortion of the substrate and the state of the amount of wire material on the surface of the substrate under the same conditions regardless of movement of the nozzle. The manufacturing device described in claim 1 or 2, wherein a mesh-like wire manufacturing section having a group of interconnected air layers is formed on the surface of the substrate by manufacturing a wire on top of the wire already manufactured on the surface of the substrate.