WO2019148653A1

WO2019148653A1 - Projection laser heating system and 3d printer

Info

Publication number: WO2019148653A1
Application number: PCT/CN2018/082749
Authority: WO
Inventors: 吴敏; 刘业; 蒋荣归; 顾晓川
Original assignee: 深圳升华三维科技有限公司
Priority date: 2018-01-30
Filing date: 2018-04-12
Publication date: 2019-08-08
Also published as: CN108248026B; CN108248026A

Abstract

Disclosed are a projection laser heating system and a 3D printer, wherein the projection laser heating system comprises an infrared laser (100), a laser power adjustment device, a beam splitter set, projection assemblies (300), and a workbench (400) provided with a pre-heating device and used for laying powder material, wherein the laser power adjustment device comprises a first rotary clamping assembly (201), a power meter (203), and a first half-wave plate (200), a polarization light splitter (202) and a beam expander set (204) arranged sequentially in the same direction. The first half-wave plate (200) is mounted on the first rotary clamping assembly (201); and the projection assemblies (300) are two or more in number and are respectively arranged in an emergence direction of the beam splitter set, and each projection assembly (300) comprises a DMD chip (301). The projection laser heating system further comprises a control system which controls the first rotary clamping assembly (201) and the DMD chip (301), and separately controls the shape and direction of projection of each DMD chip (301), such that the shape of projection of each DMD chip (301) onto the workbench is identical and coincides.

Description

投影式激光加热***和3D打印机 Projection laser heating system and 3D printer

技术领域Technical field

本申请涉及3D打印领域，特别涉及一种投影式激光加热***和3D打印机。The present application relates to the field of 3D printing, and in particular to a projection laser heating system and a 3D printer.

背景技术Background technique

自1960年美国加州Hughes实验室的Theodore Maiman实现了第一束激光之后，因激光自身的特性，使其在多个领域得到快速发展，至1990年激光应用于制造业，仅用了三十年时间。激光的引入为制造业带来了新生，传统制造业中难以处理的高精细加工问题都可以利用激光完美的解决。Theodore from Hughes Laboratories, California, USA, 1960 After Maiman realized the first laser, it was rapidly developed in many fields due to the characteristics of the laser itself. It took only 30 years for the laser to be used in the manufacturing industry in 1990. The introduction of lasers has brought new life to the manufacturing industry, and high-precision machining problems that are difficult to handle in traditional manufacturing can be solved perfectly with lasers.

3D打印技术自1986美国科学家Charles Hull开发了第一台商业3D印刷机之后的发展给制造业带来了一个新的方向，随着近些年的发展，可采用3D打印的产品越来越多，3D打印涉足的制作领域也越来越广泛。其中，DLP（Digital Light Processing）数字光处理技术应用到3D打印之后可以对液态光敏树脂进行3D成型的加工，DLP平面投影辐射可以使光敏树脂快速成型，打印速度快，但目前3D打印中使用的DLP投影技术只能针对光敏树脂进行冷加工处理，不能对材料进行加热，适用范围过窄，材料成本高昂；还有SLS（Selected Laser Sintering）激光选区烧结技术，3D打印的原料为粉末材料，对粉末材料进行点加热烧结，使其固化，需要将粉末材料加热至熔融状态，凝固冷却后取出。SLS技术在3D打印中可以适用多种原料，但是SLS技术是点式加热，路径扫描加热周期较长，制约3D打印的效率的提升。3D printing technology since 1986 American scientist Charles The development of Hull after the development of the first commercial 3D printing machine has brought a new direction to the manufacturing industry. With the development in recent years, more and more products can be used for 3D printing, and the production field of 3D printing is also involved. More and more extensive. Among them, DLP (Digital Light Processing) Digital light processing technology can be applied to 3D printing after 3D printing. DLP plane projection radiation can make photosensitive resin rapid prototyping and print speed is fast, but the current DLP projection technology used in 3D printing can only target The photosensitive resin is cold worked, the material cannot be heated, the application range is too narrow, and the material cost is high; and SLS (Selected) Laser Sintering) laser selective sintering technology, the raw material of 3D printing is powder material, the powder material is spot-heated and sintered to solidify, and the powder material needs to be heated to a molten state, and solidified and cooled to be taken out. SLS technology can be applied to a variety of raw materials in 3D printing, but the SLS technology is point heating, and the path scanning heating cycle is long, which restricts the efficiency of 3D printing.

发明内容Summary of the invention

本申请提出一种投影式激光加热***，解决现有DLP技术应用在3D打印***中只能采用低功率输出，无法实现对材料进行加热处理的问题，同时解决目前激光束在3D打印***中只能进行点线扫描加热、而无法实现对材料二维平面同时加热处理的问题。The present application proposes a projection type laser heating system, which solves the problem that the existing DLP technology can only adopt low power output in the 3D printing system, and can not realize the heat treatment of the material, and solves the current laser beam only in the 3D printing system. The problem of the point line scanning heating can be performed, and the simultaneous heating treatment of the two-dimensional plane of the material cannot be achieved.

为实现上述目的，本申请提出的投影式激光加热***，包括提供线形偏振光光源的红外激光器、用于调节红外激光器投影输出功率的激光功率调节装置、用于将经所述激光功率调节装置调节后的激光光束分成多束的分束镜组、用于将经分束镜分束后的激光光束进行投影的投影组件和设有预热装置且用于铺设粉体材料的工作台；其中，所述激光功率调节装置包括第一旋转夹持组件、功率计和在同一方向上依次排布的第一半波片、偏振分光镜和扩束镜组；所述第一半波片安装在所述第一旋转夹持组件上；所述功率计设在所述偏振分光镜的一侧；所述投影组件不少于两组；所述投影组件分别设于所述分束镜组的出射方向，且每组投影组件均包括一DMD芯片，每个所述DMD芯片均具有第一投影方向和第二投影方向；所述投影式激光加热***还包括控制***，所述控制***控制所述第一旋转夹持组件和所述DMD芯片，且单独控制每个所述DMD芯片的投影形状和方向，以使每个所述DMD芯片投影到工作台上的形状相同且重合。In order to achieve the above object, a projection type laser heating system proposed by the present application includes an infrared laser that provides a linear polarized light source, a laser power adjusting device for adjusting an infrared laser projection output power, and is used to adjust the laser power adjusting device. The rear laser beam is divided into a plurality of beam splitting mirror groups, a projection assembly for projecting the laser beam split by the beam splitting mirror, and a work table provided with a preheating device for laying the powder material; wherein The laser power adjusting device includes a first rotating clamping assembly, a power meter, and a first half wave plate, a polarization beam splitter, and a beam expanding mirror group arranged in sequence in the same direction; the first half wave plate is mounted at the On the first rotating clamping assembly; the power meter is disposed on one side of the polarization beam splitter; the projection assembly is not less than two groups; the projection assembly is respectively disposed in an exit direction of the beam splitting mirror group And each set of projection components includes a DMD chip, each of the DMD chips having a first projection direction and a second projection direction; the projection laser heating system further includes a control system, a control system controls the first rotating clamp assembly and the DMD chip, and individually controls a projection shape and direction of each of the DMD chips such that each of the DMD chips is projected onto a table with the same shape and coincidence .

可选地，所述投影式激光加热***还包括第二旋转夹持组件，所述偏振分光镜固定于所述第二旋转夹持组件，所述控制***控制所述第二旋转夹持组件与所述第一旋转夹持组件配合，以控制所述DMD芯片的入射光的偏振方向平行于所述DMD芯片的微镜反射面。Optionally, the projection laser heating system further includes a second rotating clamping assembly, the polarization beam splitter is fixed to the second rotating clamping assembly, and the control system controls the second rotating clamping assembly The first rotating clamping assembly cooperates to control a polarization direction of incident light of the DMD chip parallel to a micromirror reflecting surface of the DMD chip.

可选地，所述第一旋转夹持组件包括一级旋转夹持器和二级旋转夹持器；所述第一半波片固定在所述一级旋转夹持器上，所述一级旋转夹持器可转动的连接于所述二级旋转夹持器，并且，所述一级旋转夹持器的角分辨率大于所述二级旋转夹持器的角分辨率。Optionally, the first rotating clamping assembly comprises a first-stage rotating holder and a second-stage rotating holder; the first half-wave plate is fixed on the first-stage rotating holder, the first stage A rotary gripper is rotatably coupled to the secondary rotary gripper, and an angular resolution of the primary rotary gripper is greater than an angular resolution of the secondary rotary gripper.

可选地，每个所述DMD芯片在所述工作台上形成第一投影区域，每个所述第一投影区域重合。Optionally, each of the DMD chips forms a first projection area on the table, and each of the first projection areas coincides.

可选地，每组所述投影组件还均包括消光组件，且每组所述消光组件均对应设于每个所述DMD芯片的第二投影方向上。Optionally, each set of the projection components further includes a matte component, and each set of the extinction components is correspondingly disposed in a second projection direction of each of the DMD chips.

可选地，所述工作台具有围合的侧壁；所述消光组件包括贴设于所述侧壁的光吸收组件，和用于将所述第二投影方向的光束反射至所述光吸收组件的反光组件。Optionally, the workbench has an enclosed sidewall; the matte assembly includes a light absorbing assembly attached to the sidewall, and a light beam for reflecting the second projection direction to the light absorbing Reflective component of the component.

可选地，每个所述DMD芯片上均设有散热装置，每个所述散热装置均包括液氮循环冷却管路和贴设于所述DMD芯片的导热块，每个所述导热块均开设有通孔，所述通孔连接所述液氮循环冷却管路。Optionally, each of the DMD chips is provided with a heat dissipating device, and each of the heat dissipating devices includes a liquid nitrogen circulating cooling pipe and a heat conducting block attached to the DMD chip, and each of the heat conducting blocks is A through hole is opened, and the through hole is connected to the liquid nitrogen circulation cooling line.

可选地，所述红外激光器为CO2脉冲激光器。Optionally, the infrared laser is a CO2 pulsed laser.

本申请还提出一种3D打印机，包括投影式激光加热***，所述投影式激光加热***包括提供线形偏振光光源的红外激光器、用于调节红外激光器投影输出功率的激光功率调节装置、用于将经所述激光功率调节装置调节后的激光光束分成多束的分束镜组、用于将经分束镜分束后的激光光束进行投影的投影组件和设有预热装置且用于铺设粉体材料的的工作台；其中，所述激光功率调节装置包括第一旋转夹持组件、功率计和在第一方向上依次排布的第一半波片、偏振分光镜和扩束镜组；所述第一半波片安装在所述第一旋转夹持组件上；所述功率计设在所述偏振分光镜的一侧；所述投影组件不少于两组；所述投影组件分别设于所述分束镜组的出射方向，且每组投影组件均包括一DMD芯片，每个所述DMD芯片均具有第一投影方向和第二投影方向；所述投影式激光加热***还包括控制***，所述控制***控制所述第一旋转夹持组件和所述DMD芯片，且单独控制每个所述DMD芯片的投影形状和方向，以使每个所述DMD芯片投影到工作台上的形状相同且重合。The present application also proposes a 3D printer comprising a projection laser heating system, the projection laser heating system comprising an infrared laser providing a linear polarized light source, a laser power adjusting device for adjusting the projection output power of the infrared laser, The laser beam adjusted by the laser power adjusting device is divided into a plurality of beam splitting mirror groups, a projection assembly for projecting the laser beam split by the beam splitting mirror, and a preheating device for laying the powder a working table of the bulk material; wherein the laser power adjusting device comprises a first rotating clamping assembly, a power meter, and a first half wave plate, a polarization beam splitter and a beam expanding mirror group arranged in sequence in the first direction; The first half wave plate is mounted on the first rotating clamping component; the power meter is disposed on one side of the polarization beam splitter; the projection component is not less than two groups; the projection components are respectively set In the exit direction of the beam splitter lens, and each set of projection components includes a DMD chip, each of the DMD chips having a first projection direction and a second projection direction; the projection laser The thermal system also includes a control system that controls the first rotational clamping assembly and the DMD chip and individually controls the projected shape and orientation of each of the DMD chips to project each of the DMD chips The shapes on the workbench are the same and coincide.

本申请技术方案通过采用红外波段的激光器，降低DMD芯片的吸收率，和通过扩束镜组和分束镜组降低射到DMD芯片上的光功率密度，以降低DMD芯片的产热速率；同时通过多组投影组件在工作台上投影出相同且完全重合的形状和通过在工作台上设置预热装置，降低对激光光源功率的需求，使DMD芯片在投影用于加热待加工材料的激光时维持在可以正常工作的温度范围之内；从而在3D打印中实现投影式激光加热。The technical solution of the present application reduces the absorption rate of the DMD chip by using a laser in the infrared band, and reduces the optical power density incident on the DMD chip by the beam expander lens group and the beam splitter lens group, thereby reducing the heat generation rate of the DMD chip; Reducing the power of the laser source by projecting the same and completely coincident shape on the table by multiple sets of projection assemblies, so that the DMD chip is projecting the laser for heating the material to be processed It is maintained within a temperature range in which it can operate normally; thus, projection laser heating is achieved in 3D printing.

附图说明DRAWINGS

为了更清楚地说明本申请实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图示出的结构获得其他的附图。In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings to be used in the embodiments or the prior art description will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present application, and other drawings can be obtained according to the structures shown in the drawings without any creative work for those skilled in the art.

图1为本申请投影式激光加热***的结构示意图。1 is a schematic structural view of a projection type laser heating system of the present application.

附图标号说明：Description of the reference numerals:

标号 Label	名称 Name	标号 Label	名称 Name
100100	红外激光器Infrared laser	300300	投影组件Projection component
200200	第一半波片First half wave plate	301301	DMD芯片DMD chip
201201	第一旋转夹持组件First rotating clamping assembly	302302	导热块Thermal block
202202	偏振分光镜Polarizing beam splitter	400400	工作台Workbench
203203	功率计 dynamometer	401401	预热装置Preheating device
204204	扩束镜组Beam expander	500500	控制设备controlling device

本申请目的的实现、功能特点及优点将结合实施例，参照附图做进一步说明。The implementation, functional features and advantages of the present application will be further described with reference to the accompanying drawings.

具体实施方式Detailed ways

下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本申请的一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。The technical solutions in the embodiments of the present application are clearly and completely described in the following with reference to the drawings in the embodiments of the present application. It is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present application without departing from the inventive scope are the scope of the present application.

需要说明，若本申请实施例中有涉及方向性指示（诸如上、下、左、右、前、后……），则该方向性指示仅用于解释在某一特定姿态（如附图所示）下各部件之间的相对位置关系、运动情况等，如果该特定姿态发生改变时，则该方向性指示也相应地随之改变。It should be noted that, if there is a directional indication (such as up, down, left, right, front, back, ...) in the embodiment of the present application, the directional indication is only used to explain in a certain posture (as shown in the drawing) The relative positional relationship between the components, the motion situation, and the like, if the specific posture changes, the directional indication also changes accordingly.

另外，若本申请实施例中有涉及“第一”、“第二”等的描述，则该“第一”、“第二”等的描述仅用于描述目的，而不能理解为指示或暗示其相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括至少一个该特征。另外，各个实施例之间的技术方案可以相互结合，但是必须是以本领域普通技术人员能够实现为基础，当技术方案的结合出现相互矛盾或无法实现时应当认为这种技术方案的结合不存在，也不在本申请要求的保护范围之内。In addition, if there is a description relating to "first", "second", etc. in the embodiments of the present application, the description of "first", "second", etc. is used for descriptive purposes only, and is not to be construed as an Its relative importance or implicit indication of the number of technical features indicated. Thus, features defining "first" or "second" may include at least one of the features, either explicitly or implicitly. In addition, the technical solutions between the various embodiments may be combined with each other, but must be based on the realization of those skilled in the art, and when the combination of the technical solutions is contradictory or impossible to implement, it should be considered that the combination of the technical solutions does not exist. Nor is it within the scope of protection required by this application.

3D打印技术日益成熟，其应用也逐渐开始普遍，在3D打印领域，现在应用比较广泛的是利用DLP投影紫外光照射液态光敏树脂，使被照射区域内的光敏树脂固化，多层固化后形成3D打印产品。DLP投影的核心是DMD芯片，DMD芯片具有很多的微镜反射面（微镜反射面的数量和分辨率有关，例如，如需投影出4K分辨率的影像，则理论上至少需要4096×2160=8847360个微镜反射面）， DMD的控制器可以单独控制每个微镜反射面的方向，精确投影出需要的图形。DLP投影技术主要应用于家用或商用投影，例如常见的投影仪和近些年出现的投影电视等。DLP投影技术在3D打印领域可以实现快速而精确的3D打印，但因为DLP投影的核心部件DMD芯片对光的吸收较多，投影光的功率较大时，DMD芯片会因高温而失效，所以，目前DLP投影技术在3D打印中的应用仅限于使用液态光敏树脂作为打印原材料的情况，不适用于使用粉末材料进行熔融或烧结固化从而实现3D打印的情形。为此，本申请提出一种投影式激光加热***，以扩展DLP投影技术在3D打印中的应用范围。3D printing technology is becoming more and more mature, and its application is gradually becoming more and more popular. In the field of 3D printing, it is now widely used to irradiate liquid photosensitive resin with DLP projection ultraviolet light to cure the photosensitive resin in the irradiated area, and form a 3D after curing. Print the product. The core of DLP projection is the DMD chip. The DMD chip has many micromirror reflection surfaces (the number of micromirror reflection surfaces is related to the resolution. For example, if you want to project 4K resolution images, theoretically at least 4096×2160= 8847360 micromirror reflecting surfaces), The DMD controller can individually control the direction of each micromirror's reflective surface to accurately project the desired pattern. DLP projection technology is mainly used for home or commercial projection, such as common projectors and projection televisions that have appeared in recent years. DLP projection technology can achieve fast and accurate 3D printing in the field of 3D printing, but because the DMD chip's core component DMD chip absorbs more light, when the power of the projection light is large, the DMD chip will fail due to high temperature, so At present, the application of DLP projection technology in 3D printing is limited to the case of using liquid photosensitive resin as a printing raw material, and is not suitable for the case where 3D printing is realized by melting or sintering solidification using a powder material. To this end, the present application proposes a projection type laser heating system to expand the application range of DLP projection technology in 3D printing.

本申请提出一种投影式激光加热***和采用该投影式激光加热***的3D打印机，其中的投影式激光加热***，请参照图1，包括提供线形偏振光光源的红外激光器100、用于调节红外激光器100投影输出功率的激光功率调节装置、用于将经所述激光功率调节装置调节后的激光光束分成多束的分束镜组、用于将经分束镜分束后的激光光束进行投影的投影组件300和设有预热装置401的工作台400，所述工作台用于铺设粉体原材料；其中，所述激光功率调节装置包括第一旋转夹持组件201、功率计203和在同一方向上依次排布的第一半波片200、偏振分光镜202和扩束镜组204；所述第一半波片200安装在所述第一旋转夹持组件201上；所述功率计203设在所述偏振分光镜202的一侧；所述投影组件300不少于两组；所述投影组件300分别设于所述分束镜组的出射方向，且每组投影组件300均包括一具有第一投影方向和第二投影方向的DMD芯片301；所述投影式激光加热***还包括控制***，所述控制***控制所述第一旋转夹持组件201和所述DMD芯片301，且单独控制每个所述DMD芯片301的投影形状和方向，以使每个所述DMD芯片301投影到工作台400上的形状相同且重合。The present application proposes a projection type laser heating system and a 3D printer using the projection type laser heating system, wherein the projection type laser heating system, referring to FIG. 1, includes an infrared laser 100 for providing a linear polarized light source for adjusting infrared a laser power adjusting device for projecting output power of the laser 100, a beam splitting mirror for dividing the laser beam adjusted by the laser power adjusting device into a plurality of beams, and for projecting a laser beam split by the beam splitting mirror a projection assembly 300 and a table 400 provided with a preheating device 401 for laying a powder raw material; wherein the laser power adjusting device comprises a first rotating clamping assembly 201, a power meter 203 and the same a first half wave plate 200, a polarization beam splitter 202, and a beam expanding mirror group 204 arranged in sequence in the direction; the first half wave plate 200 is mounted on the first rotating clamp assembly 201; the power meter 203 The projection assembly 300 is disposed at one side of the polarization beam splitter 202; the projection assembly 300 is disposed in an exit direction of the beam splitting mirror group, and each set of projection components 300 is disposed. A DMD chip 301 having a first projection direction and a second projection direction is included; the projection laser heating system further includes a control system, the control system controls the first rotation clamping assembly 201 and the DMD chip 301, And the projection shape and direction of each of the DMD chips 301 are individually controlled so that the shape of each of the DMD chips 301 projected onto the table 400 is the same and coincides.

具体的，本实施例中的激光器采用红外波段的激光器，且输出激光为线性偏振光。线形偏振光在通过半波片后，其偏振方向会发生旋转，且旋转角度为入射光偏振方向与半波片光轴夹角的两倍。因此可以利用半波片的旋转改变线形偏振光的偏振方向。偏振分光镜202可以将线形偏振光分成两束，一束是沿原方向传播的第一激光分量，另一束是偏离原方向的第二激光分量，其中，第一激光分量的功率为有效的加热输出功率，在不考虑损耗的情况下，第一激光分量和第二激光分量的功率之和等于入射到偏振分光镜202的光束的功率。功率计203检测第二激光分量的功率，并根据总功率得出第一激光分量的有效输出功率，而第一激光分量与第二激光分量的比值取决于入射到偏振分光镜202的光束的偏振方向与偏振分光镜202界面的夹角，因此可以通过改变半波片的光轴与入射光偏振方向的夹角来改变第一激光分量的输出功率。本实施例采用第一半波片200和第一旋转夹持组件201，在控制***的控制下，第一旋转夹持组件201带动第一半波片200旋转，以改变第一半波片200光轴的方向，从而改变激光光束的偏振方向，进而利用偏振分光镜202改变第一激光分量的输出功率。功率调节后的第一激光分量通过扩束镜组204扩大光束的直径，以降低第一激光分量的功率密度。Specifically, the laser in this embodiment uses a laser in an infrared band, and the output laser is linearly polarized light. After the linearly polarized light passes through the half-wave plate, its polarization direction rotates, and the rotation angle is twice the angle between the polarization direction of the incident light and the optical axis of the half-wave plate. Therefore, the polarization of the linearly polarized light can be changed by the rotation of the half-wave plate. The polarization beam splitter 202 can split the linearly polarized light into two beams, one beam is a first laser component propagating in the original direction, and the other beam is a second laser component deviating from the original direction, wherein the power of the first laser component is effective. The output power is heated, and the sum of the powers of the first laser component and the second laser component is equal to the power of the light beam incident to the polarization beam splitter 202, regardless of the loss. The power meter 203 detects the power of the second laser component and derives the effective output power of the first laser component based on the total power, and the ratio of the first laser component to the second laser component depends on the polarization of the beam incident on the polarization beam splitter 202. The angle between the direction and the polarization beam splitter 202 interface can thus change the output power of the first laser component by changing the angle between the optical axis of the half wave plate and the polarization direction of the incident light. In this embodiment, the first half-wave plate 200 and the first rotating clamping assembly 201 are used. Under the control of the control system, the first rotating clamping assembly 201 drives the first half-wave plate 200 to rotate to change the first half-wave plate 200. The direction of the optical axis, thereby changing the polarization direction of the laser beam, and thereby changing the output power of the first laser component by the polarization beam splitter 202. The power-adjusted first laser component expands the diameter of the beam through the beam expanding mirror set 204 to reduce the power density of the first laser component.

第一激光分量经扩束镜组204扩束后，再经分束镜组进行分束，将第一激光分量分成多束，进一步降低每束激光分量的功率密度，但同时保持第一激光分量的总功率不变。投影组件300与分束后的第一激光分量对应设置多组，每组投影组件300均包括一个DMD芯片301，以将第一激光分量的每束激光分量都投射到工作台400上。工作台400上设置预热装置401，以将铺设于工作台上的待加工粉体材料进行预热。The first laser component is expanded by the beam expanding mirror group 204, and then split by the beam splitting mirror group to split the first laser component into multiple beams, further reducing the power density of each laser component while maintaining the first laser component. The total power is unchanged. The projection assembly 300 is provided in plurality corresponding to the split first laser component, and each set of projection assemblies 300 includes a DMD chip 301 for projecting each laser component of the first laser component onto the table 400. A preheating device 401 is disposed on the table 400 to preheat the powder material to be processed laid on the workbench.

本实施例投影式加热***具有一控制设备500，该控制设备500统一控制投影式加热***。The projection type heating system of this embodiment has a control device 500 that collectively controls the projection type heating system.

控制***集成了激光功率调节的控制和DMD芯片301的控制。控制***根据预设的激光输出功率控制第一旋转夹持组件201的旋转，根据功率计203检测到的第二激光分量的功率确认第一激光分量的功率是否达到预设值。激光器本身产生的激光的偏振方向和功率固定，第一旋转夹持组件201处于初始位置时，第一激光分量的功率最小，也即是控制***控制激光功率调节装置从有效输出功率最小时开始逐渐增大；控制***单独控制每个DMD芯片301的微镜反射面。DMD芯片301投影的形状由微镜反射面的倾斜方向决定，DMD芯片301的微镜反射面的数量越多，其投影图形的分辨率越高。本实施例每个DMD芯片301在工作台400上的投影区域相同，控制***控制每个DMD芯片301的微镜反射面使每个DMD芯片301在工作台400上的投影图形完全重合。The control system integrates control of the laser power adjustment and control of the DMD chip 301. The control system controls the rotation of the first rotary clamping assembly 201 according to the preset laser output power, and determines whether the power of the first laser component reaches a preset value according to the power of the second laser component detected by the power meter 203. The polarization direction and power of the laser generated by the laser itself are fixed. When the first rotating clamping component 201 is in the initial position, the power of the first laser component is the smallest, that is, the control system controls the laser power regulating device to gradually start from the minimum effective output power. The control system individually controls the micromirror reflecting surface of each DMD chip 301. The shape projected by the DMD chip 301 is determined by the tilt direction of the micromirror reflecting surface, and the more the number of micromirror reflecting surfaces of the DMD chip 301, the higher the resolution of the projected pattern. In this embodiment, the projection area of each DMD chip 301 on the workbench 400 is the same, and the control system controls the micromirror reflection surface of each DMD chip 301 so that the projection patterns of each DMD chip 301 on the workbench 400 are completely coincident.

在其他实施例中，投影式激光加热***也可以采用红外激光器100、激光功率调节装置、投影组件300作为一组激光输出源，整个***设置多组激光输出源，且每组激光输出源在工作台400上的投影图形完全重合。In other embodiments, the projection laser heating system may also use an infrared laser 100, a laser power adjustment device, and a projection assembly 300 as a set of laser output sources. The entire system is provided with multiple sets of laser output sources, and each set of laser output sources is working. The projected graphics on stage 400 are completely coincident.

本申请技术方案通过采用红外激光器100产生的位于红外波段的激光光源作为能量输出源，可以有效减少DMD芯片301的微镜反射面对激光的吸收从而降低大功率光源射向MD芯片时，DMD芯片301的发热。DMD芯片301的微镜反射面采用的是金属铝，金属铝对电磁波的反射率随着电磁波波长的增大而增大，在红外波段，高纯度金属铝理论上的反射率可以达到100%，也即是吸收率为零。但工业应用中，难以达到理想条件，DMD芯片301即使投射红外波段的激光，仍然会存在一定的吸收问题，但其对红外波段电磁波的吸收率远远低于可见光可紫外波段的吸收率，因此，采用红外激光作为投影的输入光源，DMD芯片301因吸收而造成的功率损耗远远低于采用紫外波段作为输入光源时的功率损耗。投影式加热是对一个区域的加热，需要的功率很高，远远高于常规DLP投影的最大输入功率，而制约DLP投影的亮度的一个很重要的因素就是DMD芯片301的发热问题，作为最精密的光学元件，DMD芯片301一向以“娇贵”著称，其最高工作温度只有几十度，采用常规加热用的激光器照射DMD芯片301，可以将DMD芯片301的微镜反射面瞬间融化，根本无法通过DMD芯片301将激光进行投射。本实施例所采用激光光源为红外激光光源，并且经过扩束镜组204的扩束和分束镜组的分束之后，其光功率密度密度大为减小，与此同时，加上DMD芯片301对红外光的高反射率，本实施例中高功率红外波段的激光光束照射到DMD芯片301之后，DMD芯片301仅会吸收极少一部分能量，可以通过可实现的散热方式进行散热而保持DMD芯片301在持续工作时，其温度不高于最大耐受温度，可以保持正常工作。The technical solution of the present application can effectively reduce the absorption of the laser beam by the micromirror reflection of the DMD chip 301 by using the infrared light source generated by the infrared laser 100 as an energy output source, thereby reducing the DMD chip when the high power light source is directed to the MD chip. 301 fever. The micromirror reflecting surface of the DMD chip 301 is made of metal aluminum, and the reflectance of the metal aluminum to the electromagnetic wave increases as the wavelength of the electromagnetic wave increases. In the infrared band, the theoretical reflectance of the high-purity metal aluminum can reach 100%. That is, the absorption rate is zero. However, in industrial applications, it is difficult to achieve ideal conditions. DMD chip 301 still has certain absorption problems even if it projects infrared lasers, but its absorption rate in the infrared band is much lower than that in visible light. The infrared laser is used as the input source of the projection, and the power loss caused by the absorption of the DMD chip 301 is far lower than that when the ultraviolet band is used as the input source. Projection heating is the heating of a region, the power required is very high, much higher than the maximum input power of conventional DLP projection, and a very important factor that restricts the brightness of DLP projection is the heating problem of DMD chip 301, as the most The precision optical component, the DMD chip 301 has always been known as "quiet", its maximum operating temperature is only a few tens of degrees, and the DMD chip 301 is irradiated by a conventional heating laser, and the micromirror reflecting surface of the DMD chip 301 can be instantly melted. It is impossible to project the laser through the DMD chip 301 at all. The laser light source used in this embodiment is an infrared laser light source, and after the beam expansion of the beam expander lens group 204 and the splitting of the beam splitting mirror group, the optical power density density thereof is greatly reduced, and at the same time, the DMD chip is added. 301 pairs of high reflectivity of infrared light. After the high power infrared band laser beam is irradiated to the DMD chip 301 in this embodiment, the DMD chip 301 can only absorb a small amount of energy, and can dissipate heat through the achievable heat dissipation method to maintain the DMD chip. When the 301 is in continuous operation, its temperature is not higher than the maximum withstand temperature and can maintain normal operation.

此外，为进一步降低DMD芯片301的发热，本实施例在工作台400上设置预热装置401对待加热的原料进行预热处理，将原料的温度进行加热，使原材料的温度处于熔融或烧结温度以下的一个范围之内，例如可以将原材料的温度加热到比熔融或烧结温度低10℃到50℃，这样，激光投影加热使原料温度提高至熔融或烧结温度只需要较低的功率就可以快速实现，从而降低对激光光源功率的要求，可以采用功率较低的激光光源作为输出源，减少DMD芯片301的发热量，以进一步降低DMD芯片301的工作温度。In addition, in order to further reduce the heat generation of the DMD chip 301, in the embodiment, the preheating device 401 is provided on the table 400 to preheat the raw material to be heated, and the temperature of the raw material is heated to make the temperature of the raw material below the melting or sintering temperature. Within a range, for example, the temperature of the raw material can be heated to a temperature 10 ° C to 50 ° C lower than the melting or sintering temperature, so that laser projection heating increases the temperature of the raw material to a melting or sintering temperature, requiring only a lower power to be quickly realized. In order to reduce the power requirement of the laser light source, a lower power laser light source can be used as an output source to reduce the heat generation of the DMD chip 301 to further reduce the operating temperature of the DMD chip 301.

经偏振分光镜202射出的第一激光分量为线形偏振光，反射介质对线形偏振光的反射率与入射角和偏振方向与反射面的夹角有关，在偏振方向平行于反射面时，吸收率最低，反射率最高。The first laser component emitted by the polarization beam splitter 202 is linearly polarized light, and the reflectance of the reflective medium to the linearly polarized light is related to the angle between the incident angle and the polarization direction and the reflective surface, and the absorption ratio is when the polarization direction is parallel to the reflective surface. The lowest, the highest reflectivity.

在经过扩束镜组204和分束镜组之后，每束第一激光分量的偏振方向会有所变化，且根据DMD芯片301的设置位置，每束第一激光分量照射到DMD芯片301上时与DMD芯片301的微镜反射面的夹角会有所差异，在针对扩束镜组204和分束镜组对第一激光分量的偏振方向的影响而针对性的设置每个DMD芯片301的位置和角度时，可以通过调整偏振分光镜202的角度，使其以第一激光分量的光路为转轴旋转的方式同步调整每束第一激光分量，使经分束镜组分束后的每一束第一激光分量照射到DMD芯片301上时其偏振方向与对应的DMD芯片301的微镜反射面之间的夹角为零，进而进一步提高微镜反射面的反射率。为此，本申请提出另一实施例，在偏振分光镜202上设置第二旋转夹持组件，以带动偏振分光镜202绕第一激光分量光路的方向旋转，同步调整每束第一激光分量的偏振方向使其对对应的DMD芯片301的微镜反射面平行。本方案可以在上一实施例的基础上通过增加第一激光分量在DMD芯片301的微镜反射面的反射以降低DMD芯片301对第一激光分量的吸收率，从而进一步减少DMD芯片301因吸收光源辐射而产生的热量。在其他实施例中，当投影式激光加热***的具体设置不适合采用本实施例中针对性的调整DMD芯片301的位置和角度的方式使每束第一激光分量的偏振方向与对应DMD芯片301的微镜反射面的夹角同步时，可以通过在每束第一激光分量的光路上设置第二半波片和带动所述第二半波片以对应的每束第一激光分量的光路为轴旋转的第三旋转夹持组件的方式，单独调整每束第一激光分量的偏振方向与对应DMD芯片301的微镜反射面之间的夹角，使每一束第一激光分量射入到DMD芯片301时，其偏振方向与DMD芯片301的微镜反射面平行。After passing through the beam expanding mirror group 204 and the beam splitting mirror group, the polarization direction of each of the first laser components may vary, and according to the position of the DMD chip 301, each of the first laser components is irradiated onto the DMD chip 301. The angle with the micromirror reflecting surface of the DMD chip 301 may be different, and each DMD chip 301 is disposed in a targeted manner for the influence of the beam expanding mirror group 204 and the beam splitting mirror on the polarization direction of the first laser component. At the position and angle, each of the first laser components can be synchronously adjusted by adjusting the angle of the polarization beam splitter 202 such that the optical path of the first laser component is rotated, such that each of the beamsplitter components are bundled. When the first laser component is irradiated onto the DMD chip 301, the angle between the polarization direction and the micromirror reflecting surface of the corresponding DMD chip 301 is zero, thereby further improving the reflectivity of the micromirror reflecting surface. To this end, the present application proposes another embodiment, in which a second rotating clamping assembly is disposed on the polarization beam splitter 202 to drive the polarization beam splitter 202 to rotate around the optical path of the first laser component, and synchronously adjust the first laser component of each beam. The polarization direction is made parallel to the micromirror reflecting surface of the corresponding DMD chip 301. The solution can reduce the absorption rate of the first laser component by the DMD chip 301 by increasing the reflection of the first laser component on the micromirror reflecting surface of the DMD chip 301 on the basis of the previous embodiment, thereby further reducing the absorption of the DMD chip 301 by the DMD chip 301. The heat generated by the radiation of the light source. In other embodiments, when the specific arrangement of the projection laser heating system is not suitable for adjusting the position and angle of the DMD chip 301 in the embodiment, the polarization direction of each of the first laser components is matched with the corresponding DMD chip 301. When the angles of the micromirror reflecting surfaces are synchronized, the second half wave plate is disposed on the optical path of each of the first laser components, and the optical path of each of the first laser components corresponding to the second half wave plate is driven The third rotating clamping assembly of the shaft rotates the angle between the polarization direction of each of the first laser components and the micromirror reflecting surface of the corresponding DMD chip 301 separately, so that each of the first laser components is incident on the beam In the case of the DMD chip 301, its polarization direction is parallel to the micromirror reflection surface of the DMD chip 301.

在对粉末状原料进行加热处理时，温度过高会影响熔融或烧结边缘的精细度，造成过度熔融或过度烧结，在成品表面形成毛刺，而温度过低又会导致在预设时间内无法完成熔融或烧结，使成品表面产生缺口，因此投影式激光加热***需要对投影激光的功率进行精确控制，本申请提出另一实施例，本实施例中的第一旋转夹持组件201包括一级旋转夹持器和二级旋转夹持器；第一半波片200固定在一级旋转夹持器上，一级旋转夹持器可转动的连接于所述二级旋转夹持器，且一级旋转夹持器的角分辨率大于所述二级旋转夹持器的角分辨率。When the powdered raw material is heat treated, the excessive temperature may affect the fineness of the molten or sintered edge, causing excessive melting or excessive sintering, forming burrs on the surface of the finished product, and the temperature may be too low to be completed within a preset time. Melting or sintering, the surface of the finished product is notched. Therefore, the projection type laser heating system needs precise control of the power of the projection laser. Another embodiment is proposed in the present application. The first rotating clamping assembly 201 in this embodiment includes a first rotation. a holder and a secondary rotary holder; the first half wave plate 200 is fixed on the first rotation holder, and the first rotation holder is rotatably connected to the second rotation holder, and the first stage The angular resolution of the rotary gripper is greater than the angular resolution of the secondary rotary gripper.

在红外激光器100本身的功率一定时，第一半波片200的旋转决定了本申请发投影式激光加热***的有效输出功率，通过第一夹持组件的旋转带动第一半波片200的旋转实现输出功率的调节，其转动角度的控制精度决定了激光输出功率的准确度，为减小实现照射到工作台400上的激光功率与预设值的偏差，需要精确调节第一半波片200的旋转角度。本实施例通过设置两级不同角分辨率的旋转夹持器的方式，在满足快速调节功率的情况下，又可以实现精细化的功率调节，以减小实际输出功率与预设值的偏差，增加工作台400上烧结区域边缘的精细度，避免成品表面毛刺和缺口的产生。When the power of the infrared laser 100 itself is constant, the rotation of the first half-wave plate 200 determines the effective output power of the projection laser heating system of the present application, and the rotation of the first half-wave plate 200 is driven by the rotation of the first clamping assembly. To achieve the adjustment of the output power, the accuracy of the control of the rotation angle determines the accuracy of the laser output power. To reduce the deviation between the laser power that is irradiated onto the table 400 and the preset value, it is necessary to precisely adjust the first half-wave plate 200. The angle of rotation. In this embodiment, by setting two rotation clamps with different angular resolutions, in the case of satisfying the fast adjustment power, fine power adjustment can be realized to reduce the deviation between the actual output power and the preset value. The fineness of the edge of the sintering zone on the table 400 is increased to avoid the occurrence of burrs and nicks on the finished surface.

本申请的DMD芯片301仅用于将第一激光分量通过反射的方式投射到工作台400上，而DMD芯片301的微镜反射面只能在与DMD芯片301表面呈±12°的两个位置偏转，因此当一个DMD芯片301全部的微镜反射面均与DMD芯片301表面呈12°夹角状态时，投影方向为第一投影方向，对应的投影区域为第一投影区域，当全部微镜反射面均与DMD芯片301表面呈-12°夹角时，投影方向为第二投影方向，对应的投影区域为第二投影区域。本申请每个DMD芯片301的第一投影区域均在工作台400内，并且，通过设置DMD的具***置使每个DMD芯片301在工作台400上的每个第一投影区域完全重合。控制***可以单独控制每个DMD芯片301在工作台400上的投影图形，并使每个DMD芯片301在工作台400上的投影图形重叠。此时，对应每束第一激光分量来说，工作台400上的投影图形与第一投影区域面积之比为有效加热功率与第一激光分量功率之比，在第一激光分量功率不变的情况下，工作台400上投影图形的投影功率密度不变。若第一激光分量功率为P，工作台400上的投影区域面积为S，工作中投影到工作台400上的图形的面积为S0，则投影到工作台400上的光功率密度为：ρ=P/S，且加热速率正比于功率密度。此时，投影到第二投影区域内的功率为P1=P-ρS0，在实际工作中，通常情况下S0小于（S-S0），也即是通常情况下，投影第二投影区域的功率大于投影到第一投影区域的功率。The DMD chip 301 of the present application is only used to project the first laser component onto the table 400 by reflection, and the micromirror reflecting surface of the DMD chip 301 can only be at two positions of ±12° from the surface of the DMD chip 301. Deflection, so when all the micromirror reflection surfaces of one DMD chip 301 are at an angle of 12° with the surface of the DMD chip 301, the projection direction is the first projection direction, and the corresponding projection area is the first projection area, when all the micromirrors When the reflecting surfaces are at an angle of -12° to the surface of the DMD chip 301, the projection direction is the second projection direction, and the corresponding projection area is the second projection area. The first projection area of each DMD chip 301 of the present application is within the table 400, and each of the first projection areas of each DMD chip 301 on the stage 400 is completely coincident by setting a specific position of the DMD. The control system can individually control the projected graphics of each DMD chip 301 on the workbench 400 and overlay the projected graphics of each DMD chip 301 on the workbench 400. At this time, for each beam of the first laser component, the ratio of the projected pattern on the table 400 to the area of the first projection area is the ratio of the effective heating power to the power of the first laser component, and the power of the first laser component is constant. In this case, the projection power density of the projected pattern on the workbench 400 does not change. If the power of the first laser component is P, the area of the projection area on the table 400 is S, and the area of the pattern projected onto the table 400 during operation is S0, the optical power density projected onto the table 400 is: ρ= P/S, and the heating rate is proportional to the power density. At this time, the power projected into the second projection area is P1=P-ρS0. In actual operation, S0 is usually smaller than (S-S0), that is, the power of the projected second projection area is generally larger than that. The power projected to the first projection area.

这部分投影到第二投影区域的功率除了造成浪费之外，还会影响整个投影式激光加热***，因此需要对投影第二投影区域的光束进行处理。本实施例工作台具有围合的侧壁，且在每个DMD芯片301的第二投影方向上设置消光组件，以消除DMD芯片301投影到第二投影区域的光束。具体可以采用反光组件和光吸收组件组合的形式，光吸收组件贴设在工作台400的侧壁，反光组件可以设置多组的平面或曲面反射镜，将DMD芯片301投影到第二投影区域的光束反射到光吸收组件上，光吸收组件吸收这部分光束能量后温度升高，用于加热工作台400的底部，可以作为辅助加热，将这部分能力加以利用，使工作台400上粉末原料的熔融烧结更加快速。This part of the power projected onto the second projection area, in addition to causing waste, also affects the entire projection laser heating system, so that the beam projecting the second projection area needs to be processed. The workbench of the embodiment has a side wall enclosed, and a matting component is disposed in a second projection direction of each DMD chip 301 to eliminate the light beam projected by the DMD chip 301 to the second projection area. Specifically, a combination of a reflective component and a light absorbing component may be adopted. The light absorbing component is attached to the sidewall of the worktable 400. The reflective component may be provided with a plurality of sets of planar or curved mirrors, and the light beam of the DMD chip 301 is projected to the second projection area. Reflected onto the light absorbing assembly, the light absorbing member absorbs the energy of the portion of the beam and the temperature rises, and is used to heat the bottom of the table 400. This can be used as auxiliary heating to utilize this capacity to melt the powder material on the table 400. Sintering is faster.

在上述实施例中，为实现投影式激光加热***可以用于熔融或烧结常规的粉末材料，采用了红外波段波长的激光降低DMD芯片301的光吸收，增大激光束直径减小光功率密度，采用分束镜组进一步减小光功率密度，以实现DMD芯片301在正常工作温度范围内可以实现大功率的激光投影，但对于一些耐高温的待加工材料如金属陶瓷等，若实现金属和陶瓷等耐高温材料的烧结，需要更大功率的激光输出，此时，DMD芯片301的温度难易维持在正常工作温度范围内，本实施例采用液氮循环冷却***对DMD芯片301进行散热，液氮循环冷却***包括设于DMD芯片301背部的导热块302，导热块302中设有通孔，通孔连接液氮循环管路。在DMD芯片301温度升高到将要超出正常工作温度范围时，控制***控制液氮循环***启动液氮循环。液氮循环冷却装置设有储液罐，和循环泵，当启动循环时，液氮被泵入循环管路，通过导热块302将DMD芯片301上产生的热量快速传递出来，当终止液氮循环时，管路中的液氮回流入储液罐。本实施例中循环管路的管道为双层，内层供液态流动，外层与内层之间设有隔层，以防止外层管道在启动液氮循环时凝露或结霜。同时本实施例采用CO2脉冲激光器，CO2激光器的激光波长为10.6μm，DMD芯片301的铝制微镜反射面在理论上对10.6μm的电磁辐射反射率可以达到100%，可以使DMD芯片301聚集的热量更少；而采用脉冲的方式进行加热是因为工作台400上待烧结材料为粉末状，其本身的导热较差，脉冲式激光仍然可以使待熔融或待烧结材料温度上升至熔融或烧结温度，而DMD芯片301导热性良好，同样可以使待加工的粉末状材料熔融或烧结时，脉冲式激光更利于DMD芯片301保持较低的温度。In the above embodiment, in order to realize that the projection type laser heating system can be used for melting or sintering a conventional powder material, the laser of the infrared wavelength band is used to reduce the light absorption of the DMD chip 301, and the laser beam diameter is increased to reduce the optical power density. The optical power density is further reduced by using the beam splitting mirror group to realize high-power laser projection of the DMD chip 301 in a normal operating temperature range, but for some high-temperature resistant materials to be processed, such as cermet, if metal and ceramic are realized The sintering of the high temperature resistant material requires a higher power laser output. At this time, the temperature of the DMD chip 301 is difficult to maintain within the normal operating temperature range. In this embodiment, the liquid nitrogen circulating cooling system is used to dissipate heat from the DMD chip 301. The nitrogen circulation cooling system includes a heat conducting block 302 disposed on the back of the DMD chip 301. The heat conducting block 302 is provided with a through hole, and the through hole is connected to the liquid nitrogen circulation line. The control system controls the liquid nitrogen circulation system to initiate a liquid nitrogen cycle as the temperature of the DMD chip 301 rises above the normal operating temperature range. The liquid nitrogen circulation cooling device is provided with a liquid storage tank, and a circulation pump. When the circulation is started, liquid nitrogen is pumped into the circulation pipeline, and the heat generated on the DMD chip 301 is quickly transmitted through the heat conduction block 302, when the liquid nitrogen circulation is terminated. At the time, the liquid nitrogen in the pipeline flows back into the reservoir. In the embodiment, the pipeline of the circulation pipeline is double-layered, the inner layer is provided for liquid flow, and the outer layer and the inner layer are provided with a compartment to prevent the outer pipeline from being condensed or frosted when starting the liquid nitrogen circulation. At the same time, the CO2 pulse laser is used in this embodiment. The laser wavelength of the CO2 laser is 10.6 μm. The aluminum micromirror reflection surface of the DMD chip 301 can theoretically achieve 100% electromagnetic radiation reflectance of 10.6 μm, which can make the DMD chip 301 gather. The heat is less; the heating is performed in a pulsed manner because the material to be sintered on the table 400 is powdery, and its own heat conduction is poor, and the pulsed laser can still raise the temperature of the material to be melted or the material to be sintered to melt or sinter. The temperature, while the DMD chip 301 has good thermal conductivity, and the powdered material to be processed can also be melted or sintered, the pulsed laser is more favorable for the DMD chip 301 to maintain a lower temperature.

以上所述仅为本申请的优选实施例，并非因此限制本申请的专利范围，凡是在本申请的发明构思下，利用本申请说明书及附图内容所作的等效结构变换，或直接/间接运用在其他相关的技术领域均包括在本申请的专利保护范围内。The above description is only a preferred embodiment of the present application, and is not intended to limit the scope of the patents of the present application, and the equivalent structural transformation, or direct/indirect use, of the present application and the contents of the drawings is used in the present invention. All other related technical fields are included in the patent protection scope of the present application.

Claims

一种投影式激光加热***，其中，包括： A projection type laser heating system, comprising:

红外激光器，产生线形偏振光；An infrared laser that produces linearly polarized light;

激光功率调节装置，所述激光功率调节装置包括第一半波片、第一旋转夹持组件、偏振分光镜、功率计和扩束镜组；所述第一半波片安装于所述第一旋转夹持组件；所述第一半波片、偏振分光镜和扩束镜组在同一方向上依次排布；a laser power adjusting device comprising: a first half wave plate, a first rotating clamping assembly, a polarization beam splitter, a power meter and a beam expanding mirror; the first half wave plate being mounted on the first Rotating the clamping assembly; the first half wave plate, the polarization beam splitter and the beam expanding mirror group are sequentially arranged in the same direction;

分束镜组，将经所述扩束镜组扩束的激光光束分成不少于两束；a beam splitting mirror group, the laser beam expanded by the beam expanding mirror group is divided into not less than two beams;

投影组件，所述投影组件不少于两组，分别设于两所述分束镜组的出射方向；每组所述投影组件均包括一具有第一投影方向和第二投影方向的DMD芯片；a projection assembly, the projection assembly is not less than two sets, respectively disposed in an exit direction of the two splitting mirror groups; each set of the projection assembly includes a DMD chip having a first projection direction and a second projection direction;

工作台，位于所述DMD芯片的第一投影方向，用于铺设粉体材料，且所述工作台还设有预热装置；a worktable, located in a first projection direction of the DMD chip, for laying a powder material, and the workbench is further provided with a preheating device;

控制***，用于控制所述第一旋转夹持组件和所述DMD芯片；所述控制***单独控制每个所述DMD芯片的投影形状和方向，以使每个所述DMD芯片投影到所述工作台上的形状相同并且重合。a control system for controlling the first rotational clamping assembly and the DMD chip; the control system individually controlling a projected shape and direction of each of the DMD chips to project each of the DMD chips to the The shapes on the workbench are the same and coincide.
如权利要求1所述的投影式激光加热***，其中，所述投影式激光加热***还包括第二旋转夹持组件，所述偏振分光镜固定于所述第二旋转夹持组件，所述控制***控制所述第二旋转夹持组件与所述第一旋转夹持组件配合，以控制所述DMD芯片的入射光的偏振方向平行于所述DMD芯片的微镜反射面。The projection type laser heating system of claim 1 wherein said projection type laser heating system further comprises a second rotary clamping assembly, said polarization beam splitter being fixed to said second rotary clamping assembly, said controlling The system controls the second rotating clamping assembly to cooperate with the first rotating clamping assembly to control the polarization direction of the incident light of the DMD chip to be parallel to the micromirror reflecting surface of the DMD chip.
如权利要求1所述的投影式激光加热***，其中，所述第一旋转夹持组件包括一级旋转夹持器和二级旋转夹持器；所述第一半波片固定在所述一级旋转夹持器上，所述一级旋转夹持器可转动的连接于所述二级旋转夹持器，并且，所述一级旋转夹持器的角分辨率大于所述二级旋转夹持器的角分辨率。A projection type laser heating system according to claim 1, wherein said first rotary gripping assembly comprises a primary rotary gripper and a secondary rotary gripper; said first half waveplate being fixed to said one On the stage rotary holder, the first-stage rotary holder is rotatably coupled to the secondary rotary holder, and the angular resolution of the primary rotary holder is greater than the secondary rotary clamp The angular resolution of the holder.
如权利要求1所述的投影式激光加热***，其中，每个所述DMD芯片在所述工作台上形成第一投影区域，每个所述第一投影区域重合。The projection type laser heating system of claim 1, wherein each of said DMD chips forms a first projection area on said table, each of said first projection areas being coincident.
如权利要求4所述的投影式激光加热***，其中，每组所述投影组件还均包括消光组件，且每组所述消光组件均对应设于每个所述DMD芯片的第二投影方向上。The projection type laser heating system of claim 4, wherein each of said set of projection assemblies further comprises a matte component, and each set of said extinction assemblies is correspondingly disposed in a second projection direction of each of said DMD chips .
如权利要求5所述的投影式激光加热***，其中，所述工作台具有围合的侧壁；所述消光组件包括贴设于所述侧壁的光吸收组件，和用于将所述第二投影方向的光束反射至所述光吸收组件的反光组件。The projection type laser heating system of claim 5 wherein said table has enclosed side walls; said matte assembly includes a light absorbing assembly attached to said side wall, and for said The light beam in the two projection directions is reflected to the light reflecting component of the light absorbing assembly.
如权利要求1所述的投影式激光加热***，其中，每个所述DMD芯片上均设有散热装置，每个所述散热装置均包括液氮循环冷却管路和贴设于所述DMD芯片的导热块，每个所述导热块均开设有通孔，所述通孔连接所述液氮循环冷却管路。The projection type laser heating system according to claim 1, wherein each of said DMD chips is provided with a heat dissipating device, and each of said heat dissipating devices comprises a liquid nitrogen circulating cooling line and is attached to said DMD chip. The heat conducting block, each of the heat conducting blocks is provided with a through hole, and the through hole is connected to the liquid nitrogen circulation cooling line.
如权利要求1所述的投影式激光加热***，其中，所述红外激光器为CO2脉冲激光器。The projection laser heating system of claim 1 wherein said infrared laser is a CO2 pulsed laser.
一种3D打印机，包括投影式激光加热***，其中，所述投影式激光加热***包括：A 3D printer comprising a projection laser heating system, wherein the projection laser heating system comprises:

红外激光器，产生线形偏振光；An infrared laser that produces linearly polarized light;

激光功率调节装置，所述激光功率调节装置包括第一半波片、第一旋转夹持组件、偏振分光镜、功率计和扩束镜组；所述第一半波片安装于所述第一旋转夹持组件；所述第一半波片、偏振分光镜和扩束镜组在同一方向上依次排布；a laser power adjusting device comprising: a first half wave plate, a first rotating clamping assembly, a polarization beam splitter, a power meter and a beam expanding mirror; the first half wave plate being mounted on the first Rotating the clamping assembly; the first half wave plate, the polarization beam splitter and the beam expanding mirror group are sequentially arranged in the same direction;

分束镜组，将经所述扩束镜组扩束的激光光束分成不少于两束；a beam splitting mirror group, the laser beam expanded by the beam expanding mirror group is divided into not less than two beams;

投影组件，所述投影组件不少于两组，分别设于两所述分束镜组的出射方向；每组所述投影组件均包括一具有第一投影方向和第二投影方向的DMD芯片；a projection assembly, the projection assembly is not less than two sets, respectively disposed in an exit direction of the two splitting mirror groups; each set of the projection assembly includes a DMD chip having a first projection direction and a second projection direction;

工作台，位于所述DMD芯片的第一投影方向，用于铺设粉体材料，且所述工作台还设有预热装置；a worktable, located in a first projection direction of the DMD chip, for laying a powder material, and the workbench is further provided with a preheating device;

控制***，用于控制所述第一旋转夹持组件和所述DMD芯片；所述控制***单独控制每个所述DMD芯片的投影形状和方向，以使每个所述DMD芯片投影到所述工作台上的形状相同并且重合。a control system for controlling the first rotational clamping assembly and the DMD chip; the control system individually controlling a projected shape and direction of each of the DMD chips to project each of the DMD chips to the The shapes on the workbench are the same and coincide.
如权利要求9所述的3D打印机，其中，所述投影式激光加热***还包括第二旋转夹持组件，所述偏振分光镜固定于所述第二旋转夹持组件，所述控制***控制所述第二旋转夹持组件与所述第一旋转夹持组件配合，以控制所述DMD芯片的入射光的偏振方向平行于所述DMD芯片的微镜反射面。The 3D printer of claim 9, wherein said projection laser heating system further comprises a second rotary clamping assembly, said polarization beam splitter being fixed to said second rotary clamp assembly, said control system control station The second rotating clamping assembly cooperates with the first rotating clamping assembly to control the polarization direction of the incident light of the DMD chip parallel to the micromirror reflecting surface of the DMD chip.
如权利要求9所述的3D打印机，其中，所述第一旋转夹持组件包括一级旋转夹持器和二级旋转夹持器；所述第一半波片固定在所述一级旋转夹持器上，所述一级旋转夹持器可转动的连接于所述二级旋转夹持器，并且，所述一级旋转夹持器的角分辨率大于所述二级旋转夹持器的角分辨率。A 3D printer according to claim 9, wherein said first rotary gripping assembly comprises a primary rotary gripper and a secondary rotary gripper; said first half-wave plate being fixed to said primary rotary clamp a first-stage rotary holder rotatably coupled to the secondary rotary holder, and an angular resolution of the primary rotary holder is greater than that of the secondary rotary holder Angular resolution.
如权利要求9所述的3D打印机，其中，每个所述DMD芯片在所述工作台上形成第一投影区域，每个所述第一投影区域重合。The 3D printer of claim 9, wherein each of said DMD chips forms a first projection area on said table, each of said first projection areas being coincident.
如权利要求12所述的3D打印机，其中，每组所述投影组件还均包括消光组件，且每组所述消光组件均对应设于每个所述DMD芯片的第二投影方向上。The 3D printer of claim 12, wherein each of said set of projection assemblies further comprises a matte component, and each set of said extinction components is correspondingly disposed in a second projection direction of each of said DMD chips.
如权利要求13所述的3D打印机，其中，所述工作台具有围合的侧壁；所述消光组件包括贴设于所述侧壁的光吸收组件，和用于将所述第二投影方向的光束反射至所述光吸收组件的反光组件。The 3D printer of claim 13 wherein said table has enclosed side walls; said matte assembly includes a light absorbing assembly attached to said side wall, and for said second projection direction The beam of light is reflected to the retroreflective component of the light absorbing assembly.
如权利要求9所述的3D打印机，其中，每个所述DMD芯片上均设有散热装置，每个所述散热装置均包括液氮循环冷却管路和贴设于所述DMD芯片的导热块，每个所述导热块均开设有通孔，所述通孔连接所述液氮循环冷却管路。The 3D printer of claim 9, wherein each of the DMD chips is provided with a heat sink, each of the heat sinks comprising a liquid nitrogen circulation cooling line and a heat conducting block attached to the DMD chip Each of the heat conducting blocks is provided with a through hole, and the through hole is connected to the liquid nitrogen circulation cooling line.
如权利要求9所述的3D打印机，其中，所述红外激光器为CO2脉冲激光器。 The 3D printer of claim 9 wherein said infrared laser is a CO2 pulsed laser.