A 3D printing method and 3D printing device based on variable parameters

Abstract

The present invention relates to a 3D printing method and a 3D printing device based on variable parameters. First, a variable parameter F is obtained. s The standard printing model of the adapted print part, the standard lattice rod diameter of the standard printing model is, and the standard light intensity parameters and standard single-layer exposure time corresponding to each part of the standard printing model are calculated; then the target weight parameters are collected, and the target lattice rod diameter of the corresponding target print part is calculated, so that the target bending stress is consistent with the standard bending stress; finally, based on the target lattice rod diameter, the target printing parameters corresponding to each part of the target print part are generated, including the target light intensity parameters and the target single-layer exposure time, and the print adapted to the target weight F is printed. t The printed parts can be adapted to different weights and pressures by only changing the light intensity parameters and single-layer exposure time without regenerating the printed parts' 3D model. This ensures that the printed parts have consistent deformation after being subjected to force, and have unified support force and comfort, making them suitable for large-scale mass production.

Description

Technical Field

[0001] The present invention relates to the field of 3D printing, and in particular to a 3D printing method and a 3D printing device based on variable parameters. Background Art

[0002] In recent years, the photocuring 3D printing technology has developed rapidly, and 3D printing technology has been widely used in the field of shoemaking. 3D printed products have the advantages of rich shapes, good resilience, breathability, and lightness. However, there are still some problems that cannot be overcome. After some printed parts are printed, their resilience and support performance are fixed. For example, for shoes, when users of different weights wear the same model of shoes, the user's foot feel is different. People with light weight feel that the foot feel is hard, while people with heavy weight feel that the foot feel is soft and easy to deform.

[0003] 3D-printed sports shoes, cushioning parts and other products are all composed of several continuous lattice structures. The factors such as the photosensitive resin material used in printing and the coarse and fine structure of the lattice affect the physical parameters such as hardness, rebound, and weight of the printed products. When it is necessary to print products with different performance parameters, it is often solved through a customized solution, that is, remodeling according to different performance parameters, and then printing according to the new model. However, due to the high requirements for computer computing power during modeling, it often takes several hours, which makes the production efficiency of commercial customized printing very low. How to provide prints with different support performances for different pressure conditions without regenerating the 3D model is an urgent problem to be solved. To this end, the present invention provides a 3D printing method based on variable parameters to meet the requirements for the same support, comfort or hardness of printed parts under pressure. Summary of the invention

[0004] In view of the above problems, a 3D printing method based on variable parameters includes the following steps:

[0005] S1: Obtain a standard printing model of a printed part. The standard printing model is consistent with the standard weight F s The standard printing model is composed of several standard lattice rods interconnected with each other, and the diameter of the standard lattice rod is d s , according to the standard printing model, calculate the standard light intensity parameter P corresponding to each location of the standard printing model s and standard single layer exposure time t s ;

[0006] S2: Input target weight F t Parameters, based on the target weight F t Calculate the target lattice rod diameter d of the corresponding target print t , so that the target print piece is within the target weight F tThe corresponding target bending stress σ t With this standard print model in this standard weight F s The corresponding standard bending stress σ s Stay consistent;

[0007] S3: Based on the target lattice rod diameter d t , generate the target printing parameters corresponding to each part of the target print, and print the target weight F based on the target printing parameters. t .

[0008] Furthermore, the target lattice rod diameter d t The following relations are satisfied: Where n is the adjustment coefficient, n=0.7-1.3.

[0009] Furthermore, in step S3, the target printing parameter is the target light intensity parameter P t .

[0010] Furthermore, the target light intensity parameter Pt satisfies the formula: Wherein, τ is the light transmittance per unit thickness of the photosensitive printing resin, and Δd is the unit thickness of the photosensitive printing.

[0011] Furthermore, in step S3, the target printing parameter is the target single layer exposure time t t .

[0012] Furthermore, the target single layer exposure time t t Satisfy the formula: Wherein, τ is the light transmittance per unit thickness of the photosensitive printing resin, and Δd is the unit thickness of the photosensitive printing.

[0013] The present invention further provides a 3D printing device, which is configured to generate target printing parameters based on a standard printing model and target weight input information, and print a 3D printed part based on the target printing parameters.

[0014] Furthermore, the target printing parameter is light intensity or single layer exposure time.

[0015] The present invention further provides a 3D printing device, including a storage device and a processing device, wherein the storage device is used to store at least one program, and the processing device is connected to the storage device and is used to execute at least one program to coordinate the storage device to execute and implement the above method.

[0016] The present invention further provides a computer-readable storage medium storing at least one program, which implements the above method when called.

[0017] A 3D printing method and a 3D printing device based on variable parameters provided by the present invention first obtain a standard printing model of a print adapted to a standard weight Fs, the standard printing model has a standard lattice rod diameter, and the standard light intensity parameters and standard single-layer exposure time corresponding to various parts of the standard printing model are calculated; then the target weight parameters are collected, and the target lattice rod diameter of the corresponding target print is calculated, so that the target bending stress is consistent with the standard bending stress; finally, based on the target lattice rod diameter, the target printing parameters corresponding to various parts of the target print are generated, including the target light intensity parameters and the target single-layer exposure time, and the print adapted to the target weight Ft is printed. Without regenerating the 3D model of the print, the print is adapted to be used under different pressures by only changing the light intensity parameters and the single-layer exposure time, so that the deformation of the print is consistent after being subjected to force, and the performance after being subjected to force is uniform, which is suitable for large-scale mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a flow chart of a 3D printing method based on variable parameters of the present invention;

[0019] Figure 2 This is a schematic diagram of the decay relationship of light intensity in resin in a 3D printing method based on variable parameters of the present invention.

[0020] Description of Reference Numerals

[0021] 1. DLP light source; 2. Molding surface. DETAILED DESCRIPTION

[0022] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the following detailed description is given in conjunction with the embodiments.

[0023] The present application can be used for industrial manufacturing of 3D printed shoe soles, load-bearing corrective devices, pillows, spring shock absorbers, cushions and other items with elasticity and buffering properties, but the present invention is not limited thereto.

[0024] This application aims to provide a printing method suitable for mass customization. Under different pressure conditions, the target weight parameter is input, and by changing the light intensity parameter or the single-layer exposure time of 3D printing, the printed part can be deformed uniformly after being subjected to force without regenerating the 3D model, so as to achieve uniform support force for the printed part under different weight conditions. In view of this, the present invention provides a 3D printing method based on variable parameters, see Figure 1 , Figure 1 The present invention is a flow chart of a 3D printing method based on variable parameters, comprising the following steps:

[0025] S1: Obtain a standard printing model of a printed part. The standard printing model is consistent with the standard weight F sThe standard printing model is composed of several standard lattice rods interconnected with each other, and the diameter of the standard lattice rod is d s , according to the standard printing model, calculate the standard light intensity parameter P corresponding to each location of the standard printing model s and standard single layer exposure time t s ;

[0026] S2: Input target weight F t Parameters, based on the target weight F t Calculate the target lattice rod diameter d of the corresponding target print t , so that the target print piece is within the target weight F t The corresponding target bending stress σ t With this standard print model in this standard weight F s The corresponding standard bending stress σ s Keep consistent, where the "input target weight F t The ways of "parameters" include: input through human-computer interaction interface, input collected by sensors and input by reading computer-readable storage media;

[0027] S3: Based on the target lattice rod diameter d t , generate the target printing parameters corresponding to each part of the target print, and print the target weight F based on the target printing parameters. t .

[0028] Taking the production of 3D printed shoe midsoles as an example, the specific implementation process of this method is as follows:

[0029] First, obtain the standard printing model of the print part. The standard printing model is adapted to the standard weight F s The standard printing model refers to the standard comfort that users of standard weight feel when wearing 3D printed shoes. The standard weight only represents a benchmark to provide reference for other weights. Technical personnel in this field can select it based on previous design experience. Users of standard weight feel moderate when stepping on the shoes, neither too soft nor too hard. The 3D printed midsole is composed of a number of continuous lattice rods cross-linked. The standard lattice rod diameter of the standard printing model is d s , calculate the standard light intensity parameter P corresponding to each location of the standard printing model according to the standard printing model s and standard single layer exposure time t s .

[0030] Then collect the target weight F t , the standard weight and target weight are in kg, the target weight F t The target weight can be manually input, or directly connected to a weight scale to read the target weight in real time, which is not limited in the present invention.t Calculate the target lattice rod diameter d of the corresponding target print t , so that the target print piece is within the target weight F t The corresponding target bending stress σ t With this standard print model in this standard weight F s The corresponding standard bending stress σ s Keep it consistent. Under different weights, the bending stress of the midsole remains consistent, so the deformation is consistent, and the user feels the same when stepping on the shoe.

[0031] Finally, based on the target lattice rod diameter d t , generate the target printing parameters corresponding to each part of the target print, and print the target weight F according to the target printing parameters t midsole.

[0032] Since the relationship between the deformation of the printed part and the supporting force is described by Hooke's law, the basic form of Hooke's law is F=kx, where F is the applied force, x is the displacement of the object, and k is the elastic constant. In actual operation, it is necessary to consider the diameter of the lattice rod and the angle between the lattice rod and the ground. In this case, the calculation formula for the bending stress σ of the shoe is: σ=My / I, where M is the bending moment, y is the distance between the lattice rod and the midline axis, which is half of the diameter d, and I is the area moment.

[0033] Bending moment is a type of internal moment on the cross section of a stressed printed part, representing the moment required for the printed part to bend. The calculation formula for the bending moment M is: M=FLcosθ, where F is the applied force, L is the length of the lattice rod, and θ is the horizontal inclination angle between the lattice rod and the ground and the horizontal plane.

[0034] The calculation formula of the above area moment I is: Where π is the circumference of a circle, d is the diameter of the lattice rod, and the area moment refers to the distance between the centroid of a figure and the specified coordinate axis. The farther the centroid of a figure is from a certain coordinate, the greater the absolute value of the area moment with respect to the coordinate axis.

[0035] The above target weight F t The stress generated t =(32F t Lcosθ) / πd t 3 , where F t is the target weight, L is the length of the lattice rod, θ is the horizontal inclination angle between the lattice rod and the horizontal plane, π is the circumference, d t is the diameter of the lattice rod. Standard weight F s The stress generated s =(32F s Lcosθs ) / πd s 3 , where F s is the standard weight, L is the length of the lattice rod, θ s is the horizontal inclination angle between the lattice rod and the horizontal plane (or the bottom surface of the printed part), π is the circumference of a circle, and d s is the standard lattice diameter. If the rebound, hardness and other properties of the printed part need to be uniform under different pressures, the stress generated on the printed part under different weights must be the same, that is: t =σ s ,σt=(32F t Lcosθ t ) / πd t 3 When the length of the lattice rod and the horizontal inclination angle θ of the lattice rod remain unchanged, we can obtain: In some cases, personal body feeling may vary according to personal preference. To further improve comfort and facilitate fine-tuning, the target lattice rod diameter d t The following relations are satisfied: Where n is the adjustment coefficient, n=0.7-1.3.

[0036] During 3D printing, the 3D model is sliced ​​into multiple layers, and the image of each layer is projected onto the liquid photosensitive resin through the DLP light source to solidify it. The DLP light source usually uses an ultraviolet LED lamp, because the photosensitive resin is sensitive to ultraviolet rays. The depth and speed of light curing can be controlled by controlling the light intensity parameters of the ultraviolet LED light source and the exposure time of a single layer. Figure 2 , Figure 2 The figure is a schematic diagram of the decay relationship of light intensity in resin in a 3D printing method based on variable parameters of the present invention. The decay of light intensity in resin follows a fixed relationship, namely: Where d is the shortest straight line distance from the point to the projected image, and τ is the light transmittance per unit thickness of the resin, that is, the ratio of the transmitted light flux to the incident light flux per unit thickness of Δd is τ. The more light dispersant is added, the smaller τ is. The decay light intensity P received by the resin at point d is d It is related to the light transmittance τ of the material and the distance d, and the overall exponential relationship weakens. It can be seen from the figure that when the DLP light source 1 irradiates the molding surface 2, the light intensity received by the molding surface 2 is P = Pτ 0 When the DLP light source 1 irradiates the molding surface 2 and passes through a unit thickness of Δd, the light intensity is P1 = Pτ 1 When the DLP light source 1 irradiates the molding surface 2 and passes through 2 Δd units of thickness, the light intensity is P2 = Pτ 2 When the DLP light source 1 irradiates the molding surface 2 and passes through 3 Δd units of thickness, the light intensity is P3 = Pτ 3, and so on, we get P4=Pτ 4 ,

[0037] For photosensitive resin, as long as the energy E t Exceeding critical exposure E c For discrete layer-by-layer photocuring printing, the light intensity multiplied by the time needs to be greater than the critical exposure E. c ,Right now: That is, the resin that is d away from the actual exposure edge will solidify. If the printed object needs to be thicker or thinner, the difference in distance d can be substituted into the formula to recalculate the light intensity parameter P or the single-layer exposure time t.

[0038] When the standard lattice diameter d s , becomes the target lattice diameter d t , which is equivalent to a change of 0.5(d t -d s ), since τ is the light transmittance per unit thickness of the photosensitive printing resin, the value range of τ is greater than or equal to 0 and less than or equal to 1, so to achieve the target lattice diameter d t The comfort effect produced can be enhanced by increasing the light intensity parameter P to enhance the light diffusion.

[0039] Preferably, the target printing parameter in step S3 is the target light intensity parameter P t In the standard lattice diameter d s By adjusting the target light intensity parameter P t Reach the target lattice diameter d t The comfort effect produced is known to Therefore, the target light intensity parameter P can be obtained t Satisfy the formula: Among them, τ is the light transmittance per unit thickness of photosensitive printing resin, Δd is the unit thickness of photosensitive printing, when the target weight is greater than the standard weight, d s -d t is a negative number, so τ The power is greater than 1, P t Greater than P s ; When the target weight is less than the standard weight, d s -d t is a positive number, P t Less than P s Based on the above target light intensity P s The 3D printed parts printed at the right size can meet the usage requirements under the target weight and obtain the same supporting force as the 3D printed parts under the standard weight.

[0040] The printed parts involved in the present invention include 3D printed shoes, corrective appliances, pillows, shock absorbers, bicycle seats, grippers, etc. In the field that is not directly described by weight, the weight parameters can be converted into corresponding pressure parameters for calculation, which should be regarded as equivalent replacements and are also changes and modifications made within the spirit and scope of the present invention. When the printed part is a shoe sole, for example: assuming that the standard lattice diameter of the sole of a size 42 shoe is 1.1mm, it is suitable for people with a standard weight of 65kg. People with a target weight of 80kg will feel soft when wearing this shoe. At this time, the target lattice diameter of the target print corresponding to the target weight is obtained as:

[0041] It is also known that a certain elastic 3D printing material has a light transmittance of 90% for every 0.1mm thickness of its photosensitive printing resin, which means that every 0.1mm of photosensitive printing resin loses 10% of the light intensity. When printing, the light intensity used is 6mw / cm 2 , so the parameters are τ=0.9,Δd=0.1,P s =6, according to the target light intensity parameter P t The formula that satisfies available That is to say, without regenerating the target print model and changing the standard lattice rod diameter, the light intensity parameter P is directly t From the standard light intensity parameter 6mw / cm 2 Increase to target light intensity parameter 6.25mw / cm 2 , which allows the printed soles produced with standard lattice rod diameter to meet the needs of people with a target weight of 80kg.

[0042] Preferably, in step S3, the target printing parameter is the target single layer exposure time t t In the standard lattice diameter d s By adjusting the exposure time t of the target single layer t Reach the target lattice diameter d t The support force and hardness effect generated when the standard lattice diameter d s , becomes the target lattice diameter d t , which is equivalent to a change of 0.5(d t -d s ), since τ is the light transmittance per unit thickness of the photosensitive printing resin, the value range of τ is greater than or equal to 0 and less than or equal to 1, so to achieve the target lattice diameter d t The comfort effect can be achieved by increasing the single layer exposure time t t Enhance light diffusion. Specifically: Then the target single layer exposure time t is obtained t Satisfy the formula: Among them, τ is the light transmittance per unit thickness of photosensitive printing resin, Δd is the unit thickness of photosensitive printing, when the target weight is greater than the standard weight, d s -d t is a negative number, so τ The power is greater than 1, t t Greater than t s ; When the target weight is less than the standard weight, d s -d t is a positive number, t t Less than t s .

[0043] Let's continue with the example of shoe soles: Assuming that the standard lattice diameter of a size 42 shoe sole is 1.1mm, it is suitable for people with a standard weight of 65kg. People with a target weight of 80kg will find this shoe soft. If the target weight group requires the same foot feel as the standard weight group, the target lattice diameter d is required. t for: It is also known that a certain elastic 3D printing material has a light transmittance of 90% for every 0.1mm thickness of its photosensitive printing resin, which means that every 0.1mm of photosensitive printing resin loses 10% of the light intensity. The exposure time of each layer during printing is 2.2 seconds. Therefore, the parameters are τ=0.9,Δd=0.1,t s =2.2, according to the target single layer exposure time t t Satisfy the formula: The target single layer exposure time is: That is to say, without regenerating the target print model and changing the standard lattice rod diameter, the single-layer exposure time is directly increased from the standard single-layer exposure time of 2.2 seconds to the target single-layer exposure time of 2.4 seconds, so that the soles produced with the standard lattice rod diameter can meet the needs of people with a target weight of 80kg.

[0044] The present invention further provides a 3D printing device, which is configured to generate target printing parameters based on a standard printing model and target weight input information, and print 3D prints based on the target printing parameters. The standard printing model corresponds to a standard weight information, and the standard printing model includes lattice information corresponding to the printing model, such as lattice rod diameter d, horizontal inclination angle θ and other parameters. The 3D printing device can generate standard printing parameters according to the standard printing model, and the standard printing parameters include light intensity parameters, single-layer exposure time, printing speed, layer height, etc. It can be known from the aforementioned method that the lattice rod diameter under different target weights can be calculated through the relationship between the standard weight and the target weight of the standard printing model, and then the target printing parameters are generated based on the target lattice rod diameter for printing. Specifically, the standard printing model can be stored in the 3D printing device, and different target light intensity parameters or target single-layer exposure times are generated by inputting different weight information to print prints adapted to different weights.

[0045] The present invention further provides a 3D printing device, including a storage device and a processing device, wherein the storage device is used to store at least one program, and the processing device is connected to the storage device and is used to execute at least one program to coordinate the storage device to execute and implement the above-mentioned 3D printing method based on variable parameters.

[0046] The present invention further provides a computer-readable storage medium, storing at least one program, which implements the above-mentioned 3D printing method based on variable parameters when called. The computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. The computer-readable storage medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the above. Alternatively, the computer-readable storage medium can be a machine-readable signal medium. More specific examples of machine-readable storage media may include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above.

[0047] A 3D printing method and a 3D printing device based on variable parameters provided by the present invention first obtain a standard printing model of a print adapted to a standard weight Fs, wherein the standard printing model includes standard lattice rod diameter information, and the standard light intensity parameters and standard single-layer exposure time corresponding to each part of the standard printing model are calculated; then the target weight parameter is input, and the target lattice rod diameter of the corresponding target print is calculated, so that the target bending stress is consistent with the standard bending stress; finally, based on the target lattice rod diameter, the target printing parameters corresponding to each part of the target print are generated, including the target light intensity parameter and the target single-layer exposure time, and the print adapted to the target weight Ft is printed, and the printing parameters are quickly generated without regenerating the 3D model of the print, thereby achieving the adaptation of the print to use scenarios of different weights by only changing the light intensity parameter and the single-layer exposure time, so that the deformation of the prints under different weights is consistent after being subjected to force, and the supporting force, rebound performance, comfort, etc. are unified, which is particularly suitable for commercial applications of mass customization.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0049] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, which can be embodied in any computer-readable medium for use by an instruction execution system, apparatus or device (such as a computer-based system, a system including a processor or other system that can fetch instructions from an instruction execution system, apparatus or device and execute instructions), or used in combination with these instruction execution systems, apparatuses or devices.

[0050] The present invention has been described by the above-mentioned relevant embodiments, however, the above-mentioned embodiments are only examples for implementing the present invention. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, changes and modifications made without departing from the spirit and scope of the present invention are all within the scope of patent protection of the present invention.

Claims

1. A 3D printing method based on variable parameters, characterized in that: The steps include: S1: Obtain a standard printing model of a printed part. The standard printing model is consistent with the standard weight F s The standard printing model is composed of several standard lattice rods interconnected with each other, and the diameter of the standard lattice rod is d s , according to the standard printing model, calculate the standard light intensity parameter P corresponding to each location of the standard printing model s and standard single layer exposure time t s ; S2: Input target weight F t Parameters, based on the target weight F t Calculate the target lattice rod diameter d of the corresponding target print t , so that the target print piece is within the target weight F t The corresponding target bending stress σ t With this standard print model in this standard weight F s The corresponding standard bending stress σ s Stay consistent; S3: Based on the target lattice rod diameter d t , generate the target printing parameters corresponding to each part of the target print, and print the target weight F based on the target printing parameters. t .

2. A 3D printing method based on variable parameters according to claim 1, characterized in that: The target lattice rod diameter d t The following relations are satisfied: Where n is the adjustment coefficient, n=0.7-1.

3.

3. A 3D printing method based on variable parameters according to claim 1, characterized in that: In step S3, the target printing parameter is the target light intensity parameter P t .

4. A 3D printing method based on variable parameters according to claim 3, characterized in that: The target light intensity parameter P t Satisfy the formula: Wherein, τ is the light transmittance per unit thickness of the photosensitive printing resin, and Δd is the unit thickness of the photosensitive printing.

5. The 3D printing method based on variable parameters according to claim 1, characterized in that: In step S3, the target printing parameter is the target single layer exposure time t t .

6. A 3D printing method based on variable parameters according to claim 5, characterized in that: The target single layer exposure time t t Satisfy the formula: Wherein, τ is the light transmittance per unit thickness of the photosensitive printing resin, and Δd is the unit thickness of the photosensitive printing.

7. A 3D printing device for implementing the printing method according to any one of claims 1 to 6, characterized in that: The system is configured to generate target printing parameters based on a standard printing model and target weight input information, and print a 3D printed part based on the target printing parameters.

8. The 3D printing device according to claim 7, characterized in that: The target printing parameter is light intensity or single layer exposure time.

9. A 3D printing device, characterized in that: It comprises a storage device and a processing device, wherein the storage device is used to store at least one program, and the processing device is connected to the storage device and is used to execute at least one program to coordinate the storage device to execute and implement the method according to any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that: At least one program is stored, and when the at least one program is called, the method according to any one of claims 1 to 6 is implemented.

Images