WO2016173064A1

WO2016173064A1 - 3d printing supporting method and system

Info

Publication number: WO2016173064A1
Application number: PCT/CN2015/080188
Authority: WO
Inventors: 金宇林
Original assignee: 北京敏速自动控制设备有限公司
Priority date: 2015-04-30
Filing date: 2015-05-29
Publication date: 2016-11-03
Also published as: CN104827666A; CN104827666B

Abstract

The present invention relates to the technical field of printing. Disclosed is a 3D printing supporting method. The method comprises: detecting an included angle between each triangular surface of the surface of a to-be-printed 3D model and a horizontal plane; for a triangular surface having an included angle smaller than a predetermined included angle α, copying a supporting surface having a same shape with the triangular surface and paralleling to the triangular surface in a position having a predetermined distance d to the triangular surface and located below the triangular surface, wherein d is 0 to 2 times the layer height of a slice; and downward generating a supporting body model not intersecting with the 3D model by using the supporting surface as a top surface; and controlling a 3D printer to print the 3D model and the supporting body model. Also disclosed is a 3D printing supporting system. In 3D printing supporting method and system of the present invention, the supporting body has a certain distance to the 3D model, so that a supporting effect and smooth separation of the supporting body from the 3D model after the printing are achieved without affecting the surface smoothness of the supported 3D model, and a good 3D printing effect is achieved.

Description

3D printing support method and system

Technical field

The invention relates to the technical field of 3D printing, and in particular to a 3D printing support method and system.

Background technique

For Fused Deposition Modeling (FDM) three-dimensional printing technology, when printing a 3D model, it is printed layer by layer from the bottom surface to the top surface. Therefore, when the upper part of the 3D model is larger than the lower part, as shown in (a) and (b) of the two 3D models, the corresponding lower position of the upper part is required to have a corresponding supporting structure, that is, in Fig. 1 (a) And (b) forming a support structure below the shadow plane of the two 3D models, otherwise the protruding portion cannot be printed. At present, most of the support structures in the 3D printing method are printed integrally with the upper part of the 3D model. Therefore, when the support structure is separated from the 3D model after the 3D printing is completed, the contact surface may be damaged, so that it is difficult to separate the support structure from the 3D model after the printing is completed.

Summary of the invention

It is an object of the present invention to provide a 3D printing support method and system for printing a support structure and facilitating separation of the support structure from the 3D model.

According to an aspect of the present invention, a 3D printing support method is provided, comprising:

Detecting an angle between each triangular surface of the surface of the 3D model to be printed and the horizontal plane;

For a triangular surface having an angle smaller than a predetermined angle α, a support surface having the same and parallel shape as the triangular surface is replicated at a predetermined distance d below, and the d is 0 to 2 times the slice height;

Generating a support body model that does not intersect the 3D model with the support surface as a top surface;

The 3D printer is controlled to print the 3D model and the support model.

Wherein, for the hollow and closed 3D model to be printed, the angle between the respective triangular faces of the surface of the 3D model to be printed and the horizontal plane is detected, and the angle between the triangular face of the inner surface and the triangular face of the outer surface is detected.

Wherein, before detecting the angle between the triangular surface of the inner surface and the triangular surface of the outer surface, the method further comprises: indenting the inner surface of the hollow and closed 3D model to be printed inward by a predetermined distance t, so that the hollow to be printed The step of thickening the 3D model shell.

Wherein, for a triangular face whose inner angle is smaller than the predetermined angle α, the predetermined distance d=0.

Wherein, the specific steps of generating a support model that does not intersect the 3D model with the support surface as the top face down include:

Forming a cylinder model with the support surface as a top surface and a cross-sectional shape downward;

Performing a Boolean subtraction operation on the cylinder model and the 3D model to be printed, and for the portion where the cylinder model and the 3D model to be printed intersect, the cylinder model is shrunk away from the 3D model. The adjacent faces of the two are separated by a distance w to finally generate the support model.

Wherein, the w is 0 to 3 times the nozzle diameter.

Wherein, the predetermined angle α is 30° to 60°.

Wherein the predetermined angle α is 45°

Wherein the predetermined distance d is a layer height of the print slice.

Wherein, the control 3D printer prints the support body with a soluble material for printing.

Wherein, the support body model only includes the support surface and the inner filling structure of the support body.

According to another aspect of the present invention, a 3D printing support system is provided, comprising:

An angle detecting unit for detecting an angle between each triangular surface of the surface of the 3D model to be printed and the horizontal plane;

a support surface generating unit, configured to: for a triangular surface having an angle smaller than a predetermined angle α, copy a support surface having the same and parallel shape as the triangular surface at a predetermined distance d below, where d is 0 to 2 times the slice layer height;

a support body generating unit, configured to generate a support body model that does not intersect the 3D model with the support surface as a top surface;

A print control unit for controlling the 3D printer to print the 3D model and the support body model.

Wherein, for the hollow and closed 3D model to be printed, the angle detecting unit includes an angle detecting a triangular surface of the inner surface and a triangular surface of the outer surface.

The method further includes: a retracting unit, configured to indent the inner surface of the hollow 3D model to be printed inward by a predetermined distance t to thicken the hollow and closed 3D model casing to be printed.

The support generating unit specifically includes:

a cylinder generating unit, configured to generate a cylinder model with the supporting surface as a top surface and a cross-sectional shape downward;

a Boolean operation unit, configured to perform a Boolean subtraction operation on the cylinder model and the 3D model to be printed, and to apply the cylinder model to a portion where the cylinder model and the 3D model to be printed intersect The direction away from the 3D model is indented such that the adjacent faces of the two are spaced apart by a distance w to ultimately generate the support model.

Wherein, the w is 0 to 3 times the nozzle diameter.

Wherein, the predetermined angle α is 30° to 60°.

Wherein the predetermined angle α is 45°

Wherein the predetermined distance d is a layer height of the print slice.

In the 3D printing support method and system of the present invention, the distance between the support body and the outer surface of the 3D model is 0-2 times higher than that of the slice layer, and the support effect is achieved, and the support body top surface and the 3D model support surface are not The pressure is too tight, and the support body and the 3D model can be smoothly separated after the printing is completed, without affecting the smoothness of the surface of the supported 3D model, and a better 3D printing effect is achieved.

DRAWINGS

(a) and (b) of Fig. 1 are schematic structural views of two 3D models, respectively;

2 is a flow chart of a 3D printing support method according to an embodiment of the present invention;

3 is a schematic view of a 3D model of a hollow structure indented and an internal support body;

Figure 4 (a) is a side view of the 3D model triangle face that needs to generate external support, and (b) is a side view of the 3D model triangle face that needs to generate internal support;

Figure 5 is a schematic view showing the generation of a support model for the 3D model in Figure 1 (a);

Figure 6 is a specific flow chart of step S300 of Figure 2;

Figure 7 is a schematic view showing the generation of a support model for the 3D model in Figure 1 (b);

FIG. 8 is a schematic structural diagram of a 3D printing support system according to an embodiment of the present invention; FIG.

9 is a schematic structural diagram of another 3D printing support system according to an embodiment of the present invention;

Fig. 10 is a schematic view showing the concrete structure of the support generating unit of Figs. 8 and 9.

detailed description

The present invention will be further described in detail below with reference to the specific embodiments thereof and the accompanying drawings. It is to be understood that the description is not intended to limit the scope of the invention. In addition, descriptions of well-known structures and techniques are omitted in the following description in order to avoid unnecessarily obscuring the inventive concept.

A 3D printing support method according to an embodiment of the present invention is shown in FIG. 2, and includes:

In step S100, it is detected that each triangular face of the surface of the 3D model to be printed (usually the three-dimensional model adopts a triangular face to approximate the surface of the simulated object) and the horizontal plane. In this step, the three-dimensional parameters of the respective triangular faces can be obtained by the parameters in the computer modeling, thereby obtaining the angle between the triangular faces and the horizontal plane.

In step S200, for a triangular surface having an angle smaller than a predetermined angle α, a support surface having the same and parallel shape as the triangular surface is replicated at a predetermined distance d below it. Wherein, the predetermined angle α can be specifically set according to actual conditions. The predetermined distance d is 0 to 2 times the slice height.

Step S300, generating a support that does not intersect the 3D model with the support surface facing downward. Body model.

Step S400, controlling the 3D printer to print the 3D model and the support model.

By supporting the distance between the support and the 3D model by 0 to 2 times the height of the slice layer, the support effect is achieved, and the support body top surface and the 3D model support surface are not pressed too tightly, and the support body can be made after printing is completed. Smooth separation from the 3D model without affecting the smoothness of the surface of the supported 3D model, achieving a better 3D printing effect.

The above method of printing the support is mainly directed to the case of external support, but the method is equally applicable to a 3D model requiring internal support.

As shown in FIG. 3, for the hollow and closed 3D model to be printed, the angle between the triangular face of the inner surface and the triangular face of the outer surface is detected in step S100.

Further, before detecting the angle between the triangular surface of the inner surface and the triangular surface of the outer surface, the method further comprises: indenting the inner surface of the hollow and closed 3D model to be printed inward by a predetermined distance t, so that the hollow waiting Print the steps to thicken the 3D model shell. The indentation distance t can be determined according to the actual situation. The larger the distance t, the thicker and thicker the model shell is, and the more consumables are; the smaller the distance t, the thinner the model shell and the less consumables. After the indentation, the support is printed in steps S100 to S400, as shown by the broken line in Fig. 3, which is a hollow and closed internal support of the 3D model to be printed. Since the closed hollow 3D model is printed and the support body does not need to be removed, the internal support solves the problem of unprintability and makes the 3D model more robust while saving some internal filling material.

In step S100, the angle between the triangular surface and the horizontal plane can be obtained by calculating the angle between the normal vector of the triangular surface and the vertical direction (ie, the z-axis). As shown in (a) of FIG. 4, for the case of external support, the angle between the normal vector and the negative direction of the z-axis is obtained. As shown in (b) of FIG. 4, for the case of internal support, the normal vector is found to be at an angle with the positive direction of the z-axis.

In step S200, the predetermined angle α can be set according to the actual situation. Since the triangular face is more difficult to print when the angle with the horizontal plane is at any value less than 30° to 60° and there is no support, α is preferably 30° to 60°, for example 45°. As shown in FIG. 3, the triangular surface on the left side of the outer surface of (a) in FIG. 4 has an angle β of less than 45° with the horizontal plane, and the support body needs to be printed below, and the triangular surface of the right side is at an angle θ greater than 45° with the horizontal plane. No support is required below; the top of the inner surface of (b) in Figure 4 The angle between the face and the right triangle face and the horizontal plane is less than 45°, and the support body needs to be printed below. The left side is at an angle θ greater than 45° from the horizontal plane, and no support is required below.

The predetermined distance d is preferably the layer height of the printed slice, and d is the control of the single slice height to facilitate the movement of the nozzle up and down. As shown in Fig. 5, for the 3D printed model in Fig. 1(a), a support surface S parallel to the bottom surface of the protruding portion is formed from the distance d below the protruding portion.

Further, since the support in the closed hollow 3D model cannot be taken out, the predetermined distance d can be set to 0 for the triangular face whose angle is smaller than the inner surface of the predetermined angle α, so that the top of the inner support body The surface is in full contact with the inner surface of the 3D model, and the support ability is stronger. The inner support is also preferably printed using the same material as the 3D model.

The specific process of step S300 is as shown in FIG. 6, and includes:

Step S301, generating a cylinder model with the support surface as a top surface and a cross-sectional shape downward. As shown in FIG. 5, a cylinder model having a cross-sectional shape (if S is not horizontal, that is, a cross-sectional shape parallel to S) S is generated from the support surface S at a distance d below the protrusion from the support surface S, Forming support for the protrusions.

Step S302, performing a Boolean subtraction operation on the cylinder model and the 3D model to be printed, and moving the cylinder model away from the 3D model for a portion where the cylinder model and the 3D model to be printed intersect. The direction of the indentation is such that the adjacent faces of the two are separated by a distance w to ultimately generate the support model. In the 3D model shown in (b) of Fig. 1, there is one protrusion on the upper and lower sides, so it is necessary to avoid the lower protrusion when printing the support. Fig. 6 shows the support structure of the 3D model shown in (b) of Fig. 1, that is, the cylinder model is subjected to a Boolean subtraction operation with the 3D model to be printed, and the portion overlapping with the lower projection is removed. Specifically, the three-dimensional coordinate system at the time of modeling (xyz coordinate system, xy is the bottom surface, and z is the vertical axis) can be utilized, and the cylinder model of the overlapping portion is indented in the xy plane away from the 3D model, so that the cylinder The model is spaced from the adjacent face of the 3D model to be printed w.

Wherein, w can be set according to actual conditions, preferably 0 times to 3 times the diameter of the nozzle, which can support the support body and the 3D model, as shown in the dotted oval frame in Fig. 6, the 3D model The lower projection serves as a support for the support.

Further, the support body model only serves as a support, so the generated support body only includes the support surface And the inner filling structure of the support body, that is, the outer surface is not included (the outer surface is not printed as the 3D model), which saves the material and does not print the outer surface, which is equivalent to the cylinder having a certain indentation in the xy plane itself, which is equivalent Where w is the thickness of the outer surface (i.e., the thickness of the nozzle diameter), the support is easily separated after printing is completed. Therefore, for the 3D model of (a) of Figure 1, the cylinder does not intersect or overlap with the 3D model to be printed.

Further, in order to more conveniently and more completely separate the support, in step S400, the 3D printer is controlled to print the support with a soluble material such as polyvinyl alcohol (PVA) or impact resistant polystyrene (HIPS). Wait. Especially when d is 0 and/or w is 0, if the support is printed with the same material as the 3D model, there will always be traces of material remaining on the 3D model after separation. The soluble material is dissolved by soaking after the printing is completed, so that the supported surface of the 3D model is smoother. Soluble materials can be used to print the support, whether external or internal.

The present invention also provides a 3D printing support system, as shown in FIG. 8, comprising:

The angle detecting unit 100 is configured to detect an angle between each triangular surface of the surface of the 3D model to be printed and the horizontal plane.

The support surface generating unit 200 is configured to: for a triangular surface having an angle smaller than a predetermined angle α, copy a support surface having the same and parallel shape as the triangular surface at a predetermined distance d below, wherein the d is 0 to 2 times the slice Layer height.

The support body generating unit 300 is configured to generate a support body model that does not intersect the 3D model with the support surface facing downward.

The print control unit 400 is configured to control the 3D printer to print the 3D model and the support model.

In this embodiment, for a hollow and closed 3D model to be printed, the included angle detecting unit includes an angle that detects a triangular surface of the inner surface and a triangular surface of the outer surface.

For a hollow and closed 3D model to be printed, as shown in FIG. 9, the 3D printing support system further includes: a retracting unit 50 for indenting the hollow and closed inner surface of the 3D model to be printed inward by a predetermined distance t a step of thickening the hollow 3D model casing to be printed. Since the closed hollow 3D model is printed and the support body does not need to be removed, the internal support is solved. The problem of printing, while saving some internal filling material, makes this 3D model more robust. Since the closed hollow 3D model is printed and the support body does not need to be removed, the internal support solves the problem of unprintability and makes the 3D model more robust while saving some internal filling material.

In this embodiment, the specific structure of the support generating unit 300 is as shown in FIG. 10, and includes:

The cylinder generating unit 310 is configured to generate a cylinder model with the supporting surface as a top surface and a cross-sectional shape downward.

a Boolean operation unit 320, configured to perform a Boolean subtraction operation on the cylinder model and the 3D model to be printed, and select the cylinder model for a portion where the cylinder model and the 3D model to be printed intersect Retracting away from the 3D model, the adjacent faces of the two are spaced apart by a distance w to ultimately generate the support model. Wherein, the w is 0 to 3 times the nozzle diameter.

Since the triangular face is more difficult to print in the case where the angle with the horizontal plane is in the range of less than 30 to 60 and without support, the predetermined angle α is preferably 30 to 60, such as 45.

In this embodiment, the predetermined distance d is the layer height of the print slice, and d is the control of the single slice height to facilitate the movement of the nozzle up and down.

Further, for the hollow and closed 3D model, since the inner support cannot be taken out, the triangular surface of the inner surface whose angle is smaller than the predetermined angle α is a predetermined distance d=0 from the lower support surface. Thus, the top surface of the support body is in full contact with the inner surface of the 3D model, and the support capability is stronger. The support is also preferably printed using the same material as the 3D model.

In this embodiment, the print control unit 400 prints with a soluble material when printing the support, especially when d is 0 and/or w is 0. This makes it easier and more complete to separate the support after printing is completed. Soluble materials such as polyvinyl alcohol (PVA) or impact polystyrene (HIPS).

Since the support body model only serves as a support, the support body model only includes the support surface and the inner filling structure of the support body, that is, does not include the outer surface (the outer surface is not printed as the 3D model), thus saving material, Moreover, the outer surface is not printed, which is equivalent to a certain indentation of the cylinder in the xy plane itself, and the support body is easily separated after printing is completed.

The above-described embodiments of the present invention are intended to be illustrative only and not to limit the invention. Therefore, any modifications, equivalent substitutions, improvements, etc., which are made without departing from the spirit and scope of the invention, are intended to be included within the scope of the invention. Rather, the scope of the appended claims is intended to cover all such modifications and modifications

Claims

A 3D printing support method, comprising:

Detecting an angle between each triangular surface of the surface of the 3D model to be printed and the horizontal plane;

For a triangular surface having an angle smaller than a predetermined angle α, a support surface having the same and parallel shape as the triangular surface is replicated at a predetermined distance d below, and the d is 0 to 2 times the slice height;

Generating a support body model that does not intersect the 3D model with the support surface as a top surface;

The 3D printer is controlled to print the 3D model and the support model.
The 3D printing support method according to claim 1, wherein for the hollow and closed 3D model to be printed, the angle between the respective triangular faces of the surface of the 3D model to be printed and the horizontal plane is detected, and the triangle for detecting the inner surface is detected. The angle between the face and the triangular surface of the outer surface.
The 3D printing support method according to claim 2, further comprising: before detecting the angle between the triangular surface of the inner surface and the triangular surface of the outer surface, the inner surface of the hollow and closed 3D model to be printed The step of retracting the predetermined distance t to thicken the hollow 3D model casing to be printed.
The 3D printing support method according to claim 2, wherein the predetermined distance d = 0 for a triangular face whose inner angle is smaller than the predetermined angle α.
The 3D printing support method according to any one of claims 1 to 3, wherein the specific step of generating a support body model that does not intersect the 3D model with the support surface as a top surface downward comprises:

Forming a cylinder model with the support surface as a top surface and a cross-sectional shape downward;

Performing a Boolean subtraction operation on the cylinder model and the 3D model to be printed, and for the portion where the cylinder model and the 3D model to be printed intersect, the cylinder model is shrunk away from the 3D model. The adjacent faces of the two are separated by a distance w to finally generate the support model.
The 3D printing support method according to claim 5, wherein the w is 0 to 3 times the head diameter.
The 3D printing support method according to any one of claims 1 to 3, wherein the predetermined angle α is 30° to 60°.
The 3D printing support method according to claim 7, wherein said predetermined angle α is 45°
The 3D printing support method according to any one of claims 1 to 3, wherein the predetermined distance d is a layer height of a print slice.
The 3D printing support method according to any one of claims 1 to 3, wherein the controlling the 3D printer prints the support with a soluble material.
The 3D printing support method according to any one of claims 1 to 3, wherein the support body model includes only the support surface and the support inner filling structure.
A 3D printing support system, comprising:

An angle detecting unit for detecting an angle between each triangular surface of the surface of the 3D model to be printed and the horizontal plane;

a support surface generating unit, configured to: for a triangular surface having an angle smaller than a predetermined angle α, copy a support surface having the same and parallel shape as the triangular surface at a predetermined distance d below, where d is 0 to 2 times the slice layer height;

a support body generating unit, configured to generate a support body model that does not intersect the 3D model with the support surface as a top surface;

A print control unit for controlling the 3D printer to print the 3D model and the support body model.
The 3D printing support system according to claim 12, wherein for the hollow and closed 3D model to be printed, the included angle detecting unit includes an angle that detects a triangular face of the inner surface and a triangular face of the outer surface.
The 3D printing support system according to claim 13, further comprising: a retracting unit configured to indent the inner surface of the hollow and closed 3D model to be printed inward by a predetermined distance t to make the hollow The step of thickening the 3D model shell to be printed.
The 3D printing support system according to claim 13, wherein said predetermined distance d = 0 for a triangular face having an inner surface having an angle smaller than said predetermined angle α.
The 3D printing support system according to any one of claims 12 to 14, wherein the support generating unit specifically comprises:

a cylinder generating unit, configured to generate a cylinder model with the supporting surface as a top surface and a cross-sectional shape downward;

a Boolean operation unit, configured to perform a Boolean subtraction operation on the cylinder model and the 3D model to be printed, and to apply the cylinder model to a portion where the cylinder model and the 3D model to be printed intersect The direction away from the 3D model is indented such that the adjacent faces of the two are spaced apart by a distance w to ultimately generate the support model.
The 3D printing support system according to any one of claims 12 to 14, wherein the w is 0 to 3 times the head diameter.
The 3D printing support system according to any one of claims 12 to 14, wherein the predetermined angle α is 30° to 60°.
The 3D printing support system according to claim 18, wherein said predetermined angle α is 45°
The 3D printing support system according to any one of claims 12 to 14, wherein the predetermined distance d is a layer height of a print slice.
The 3D printing support system according to any one of claims 12 to 14, wherein the control 3D printer prints the support with a soluble material.
The 3D printing support system according to any one of claims 12 to 14, wherein the support body model includes only the support surface and the support inner filling structure.