Light beam attenuation unit and device, and 3D printer optical path element detection device

Abstract

A light beam attenuation unit, comprising a collecting cylinder (110), a cooling sleeve (120), a beam splitting cone (130), and a cooling cylinder (140), wherein a first taper angle part (132) is arranged at the front end of the beam splitting cone (130), a first threaded part (111) is arranged on an inner wall of the collecting cylinder (110), the collecting cylinder (110) is connected to the beam splitting cone (130), the first taper angle part (132) is located inside the collecting cylinder (110), the cooling sleeve (120) is fitted outside the collecting cylinder (110), a blind hole is formed in the beam splitting cone (130), the cooling cylinder (140) is placed in the blind hole and is connected to the beam splitting cone (130), a first liquid inlet channel (141) is provided inside the cooling cylinder (140), and the beam splitting cone (130) is provided with a first liquid outlet (134) communicated with the first liquid inlet channel (141). During a laser attenuation process, the heat dissipation is good, and the overall structure is simple. The present invention further relates to a light beam attenuation device and a 3D printer optical path element detection device.

Description

Beam attenuation unit, device and 3D printer optical path element detection device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on November 27, 2023, with application number 202311598854.X. The entire contents of this application are incorporated by reference into this application. Technical Field

[0002] The present application relates to a beam attenuation technology, for example, to a beam attenuation unit, device and 3D printer optical path element detection device. Background Art

[0003] Selective laser melting (SLM) is an important branch of metal three-dimensional (3D) printing technology. SLM technology uses a focused light spot to selectively and quickly melt metal powder in a specified area on the powder bed, thereby solidifying it into parts of any shape. The entire process uses laser as the energy source. After passing through optical elements such as the focusing field lens, the laser scans layer by layer on the powder bed to melt and solidify the powder into the designed parts. Generally, before production, it is necessary to inspect the focusing field lens and other components in the optical path to eliminate unqualified components. Due to the high energy of the light spot after high-power laser focusing, the quality requirements for the components of the detection platform are high and the cost is relatively high. It is usually necessary to attenuate the laser energy in advance to protect the detection components and reduce the manufacturing cost of the detection platform.

[0004] Existing patent CN213482580 U discloses a high-power laser attenuator with a fiber optic output device (Quartz Block Head, QBH) on the right side. Laser light is output through the QBH. When the incident laser passes through the first optical wedge, its refracted light is incident on the first optical wedge fixing plate and enters the high-power light-collecting pool. This refracted light is incident on the reflective copper plate, which reflects it onto the first light-absorbing cone below. The first light-absorbing cone absorbs the light energy, converting it into heat energy. Heat is then dissipated through a water-cooling plate, completing the absorption of the reflected light. However, this high-power light-collecting pool only uses the water-cooling plate to dissipate heat, which can lead to poor heat dissipation during the attenuation process. Existing patent CN201450219 U discloses a carbon dioxide laser full-absorption optical gate. When high-energy light enters the absorber of the mirror cover, it is reflected by the reflective cone mirror to the coarse threads inside the cylindrical absorber and absorbed. The reflective cone is located inside the mirror cover absorber and is fixed to the small diameter countersunk hole of the cooling body. The hollow part of the reflective cone forms a first cooling cavity. The cooling body is provided with first, second, and third pipelines, a second cooling cavity, a water outlet pipeline and a water inlet pipeline. Dual water cooling is performed, but the processing of multiple internal pipelines is difficult and costly.

[0005] Summary of the Invention

[0006] The present application provides a beam attenuation unit, device, and 3D printer optical path element detection device to solve the problems of poor heat dissipation and high cost of traditional laser attenuation devices.

[0007] A beam attenuation unit includes a collecting tube, a cooling sleeve, a beam splitting cone and a cooling tube, the front end of the beam splitting cone is provided with a first cone angle portion for absorbing at least one of a light beam and a reflected light beam, the inner wall of the collecting tube is provided with a first threaded portion for absorbing at least one of a light beam and a reflected light beam, the collecting tube is connected to the beam splitting cone, the first cone angle portion is located inside the collecting tube, the cooling sleeve is arranged outside the collecting tube, a blind hole is provided in the beam splitting cone, the cooling tube is placed in the blind hole and connected to the beam splitting cone, a first liquid inlet is provided in the cooling tube, and the beam splitting cone is provided with a first liquid outlet connected to the first liquid inlet.

[0008] In one embodiment, the cooling cylinder includes an outer edge section, a connecting section, and a liquid outlet section, which are connected in sequence and whose outer diameters decrease in sequence. The first liquid inlet channel extends from the outer edge section to the liquid outlet section. The connecting section and the liquid outlet section extend into the beam splitting cone. The connecting section is sealedly connected to the inner wall of the beam splitting cone. The outer wall of the liquid outlet section and the inner wall of the beam splitting cone are spaced apart to form a first liquid outlet channel. The first liquid outlet is connected to the first liquid inlet channel through the first liquid outlet channel.

[0009] In one embodiment, there are two first liquid outlets, which are respectively disposed on two opposite sides of the liquid outlet section.

[0010] In one embodiment, the cone angle of the first cone angle portion ranges from 90° to 100°.

[0011] In one embodiment, the inner wall of the cooling jacket is provided with an annular groove, the cooling jacket is provided with a second liquid inlet and a second liquid outlet extending through the groove, and the inner walls of the cooling jacket on both sides of the groove are sealedly connected to the collecting tube.

[0012] In one embodiment, the first liquid outlet, the second liquid inlet, and the second liquid outlet are all tapered threaded holes, respectively used for connecting to water joints.

[0013] A beam attenuation device includes a prism unit, a secondary attenuation component, an attenuation mirror, and the beam attenuation unit. The prism unit has a first exit port, a second exit port, a third exit port, and an entrance port for injecting laser light. The collecting tube of the beam attenuation unit is connected to the first exit port, the secondary attenuation component is connected to the second exit port, and the attenuation mirror is arranged at the third exit port.

[0014] In one embodiment, the prism unit includes a first prism assembly, a connecting block and a second prism assembly connected in sequence, the first exit port is arranged in the first prism assembly, the second exit port is arranged in the second prism assembly, and the entrance port and the third exit port are arranged in the connecting block.

[0015] In one embodiment, the secondary attenuation component includes an attenuation sleeve and an attenuation cone, the inner wall of the attenuation sleeve is provided with a second threaded portion for absorbing at least one of the light beam and the reflected light beam, the front end of the attenuation cone is provided with a second cone angle portion for absorbing at least one of the light beam and the reflected light beam, one end of the attenuation sleeve is connected to the second prism assembly, and the other end of the attenuation sleeve is connected to the attenuation cone, and the second cone angle portion is located inside the attenuation sleeve.

[0016] In one embodiment, the beam attenuation device further includes a mounting plate and a plurality of connecting rods, wherein the plurality of connecting rods are arranged around the outer circumference of the third emission port, one end of the connecting rod is connected to the prism unit, and the other end of the connecting rod is connected to the mounting plate, and the attenuation mirror is mounted on the connecting rod and is located between the prism unit and the mounting plate.

[0017] A 3D printer optical path component detection device includes an optical fiber assembly, a beam attenuation device, a beam expander, a scanning galvanometer, a focusing field lens, and a beam quality analyzer arranged in sequence along the incident direction of the laser beam, wherein the optical fiber assembly is connected to the incident port of the beam attenuation device, and the beam expander is arranged on the side of the attenuation mirror of the beam attenuation device away from the third exit port. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1 is a schematic structural diagram of a light beam attenuation device according to an embodiment of the present application;

[0019] FIG2 is a schematic diagram of a disassembled light beam attenuation device shown in FIG1 ;

[0020] FIG3 is a schematic diagram of a beam path of the beam attenuation device shown in FIG1 ;

[0021] FIG4 is a cross-sectional schematic diagram of a beam attenuation unit according to an embodiment of the present application;

[0022] FIG5 is a cross-sectional schematic diagram of a secondary attenuation component according to an embodiment of the present application;

[0023] FIG6 is a schematic structural diagram of a 3D printer optical path element detection device according to an embodiment of the present application.

[0024] Description of reference numerals: 10, beam attenuation unit; 110, collecting tube; 111, first threaded portion; 120, cooling jacket; 122, Groove; 124, second liquid inlet; 125, second liquid outlet; 130, beam splitter; 132, first cone angle portion; 134, first liquid outlet; 140, cooling cylinder; 141, first liquid inlet; 142, outer edge section; 144, connecting section; 146, liquid outlet section; 147, first liquid outlet; 150, water connector; 20, prism unit; 210, first prism assembly; 220, second prism assembly; 230, connecting block; 30, secondary attenuation assembly; 310, attenuation sleeve; 311, second threaded portion; 320, attenuation cone; 322, second cone angle portion; 40, attenuation mirror; 50, connecting rod; 60, mounting plate; 70, optical fiber assembly; 710, clamp seat; 720, optical fiber clamp; 730, optical fiber head; 740, optical fiber sleeve; 80, beam expander. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present disclosure to explain the technical solutions in the embodiments of the present disclosure, rather than all embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present disclosure.

[0026] The specific embodiments of the present disclosure are described below with reference to the accompanying drawings.

[0027] 1 and 2 , an embodiment of the present application provides a beam attenuation device, comprising a prism unit 20, a secondary attenuation assembly 30, an attenuation mirror 40, and a beam attenuation unit 10. The prism unit 20 has a first exit port, a second exit port, a third exit port, and an entrance port for injecting laser light. The collection tube 110 of the beam attenuation unit 10 is connected to the first exit port, the secondary attenuation assembly 30 is connected to the second exit port, and the attenuation mirror 40 is disposed at the third exit port.

[0028] 3 , the laser beam to be attenuated is incident through the incident port of the prism unit 20, part of it enters the beam attenuation unit 10 and is absorbed, part of it is reflected and enters the secondary attenuation component 30 and is absorbed again, and part of it is reflected again and exits the prism unit 20 through the third exit port, and then enters the attenuation mirror 40 and is attenuated again, so as to achieve the purpose of protecting the detection element and reduce the manufacturing cost of the detection platform.

[0029] 4 , in one embodiment, the beam attenuation unit 10 includes a collecting tube 110, a cooling sleeve 120, a beam splitting cone 130, and a cooling tube 140. The front end of the beam splitting cone 130 is provided with a first cone angle portion 132 for absorbing and / or reflecting the light beam. The inner wall of the collecting tube 110 is provided with a first threaded portion 111 for absorbing and / or reflecting the light beam. The collecting tube 110 is connected to the beam splitting cone 130, and the first cone angle portion 132 is located inside the collecting tube 110. The cooling sleeve 120 is sleeved on the outside of the collecting tube 110. A blind hole is provided in the beam splitting cone 130, and the cooling tube 140 is placed in the blind hole and connected to the beam splitting cone 130. A first liquid inlet 141 is provided in the cooling tube 140, and the beam splitting cone 130 is provided with a first liquid outlet 134 connected to the first liquid inlet 141. Optionally, the beam attenuation unit 10 is made of aluminum alloy throughout. The beam attenuation unit 10 is subjected to a matte black oxidation treatment.

[0030] During use, the laser beam to be attenuated enters the collecting tube 110 and strikes the first cone-shaped portion 132. The cone surface of the first cone-shaped portion 132 absorbs some of the energy, and the remaining laser beam is then reflected back to the first threaded portion 111 within the collecting tube 110. The beam splitting cone 130 is then reflected and absorbed multiple times by the inclined surface of the first threaded portion 111. Because a cooling tube 140 is provided within the beam splitting cone 130, coolant is injected into the cooling tube 140 through the first liquid inlet 141 and then flows into the blind hole of the beam splitting cone 130, absorbing the heat generated by the energy absorption process of the beam splitting cone 130. Finally, the coolant flows out through the first liquid outlet 134. The heat generated by the energy absorption process of the collecting tube 110 is removed by the cooling jacket 120 disposed outside of the collecting tube 110. Compared to the traditional method of dissipating heat solely through a cooling plate, the beam splitting cone 130 and the collecting tube 110 are cooled by the cooling jacket 120 and cooling jacket 140, respectively. This provides excellent heat dissipation during the laser attenuation process, and the overall structure is simple, eliminating the need for multiple internal pipes and the need for axicon assembly. The multiple parts are easily processed and assembled, thus reducing costs.

[0031] Optionally, in one embodiment, the inner wall of the cooling sleeve 120 is provided with an annular groove 122, and the cooling sleeve 120 is provided with a second liquid inlet 124 and a second liquid outlet 125 that penetrate the groove 122. The inner walls of the cooling sleeve 120 located on both sides of the groove 122 are sealed and connected to the collecting tube 110. The coolant is injected into the groove 122 through the second liquid inlet 124, absorbs the heat generated by the energy absorption process of the collecting tube 110, and finally flows out from the second liquid outlet 125. The beam splitting cone 130 and the collecting tube 110 are cooled through different flow channels respectively, which not only has a better cooling effect, but also facilitates the processing of the internal flow channels of multiple parts, is simpler to assemble, and effectively reduces costs. The cooling sleeve 120 and the collecting tube 110 are sealed and threaded.

[0032] Optionally, in other embodiments, the cooling jacket 120 may be configured as a device having a heat-conducting function, and the heat of the collecting cylinder 110 is conducted to the cooling jacket 120 for dissipation.

[0033] 2 and 4 , in one embodiment, the cooling cylinder 140 includes an outer edge section 142, a connecting section 144, and a liquid outlet section 146, which are sequentially connected and have decreasing outer diameters. The first liquid inlet channel 141 extends from the outer edge section 142 to the liquid outlet section 146. The connecting section 144 and the liquid outlet section 146 extend into the beam splitting cone 130, and the connecting section 144 is sealed to the inner wall of the beam splitting cone 130. The outer wall of the liquid outlet section 146 is separated from the inner wall of the beam splitting cone 130 to form a first liquid outlet channel 147. The first liquid outlet 134 communicates with the first liquid inlet channel 141 through the first liquid outlet channel 147.

[0034] The cooling cylinder 140 is threadedly connected to the inner wall of the beam splitting cone 130 via a connection section 144, which is sealed with a sealant coating. Optionally, its outer edge section 142 abuts the end of the beam splitting cone 130, and its liquid outlet section 146 is spaced apart from the inner wall of the beam splitting cone 130. Cooling liquid, such as water, is injected into the first liquid inlet channel 141 of the cooling cylinder 140, then flows into the first liquid outlet channel 147, absorbs heat, and then flows out through the first liquid outlet 134. Optionally, in one embodiment, two first liquid outlets 134 are provided, one on each opposite side of the liquid outlet section 146.

[0035] Optionally, the cone angle of the first cone angle portion 132 ranges from 90° to 100°. In this embodiment, the cone angle of the first cone angle portion 132 is 100°.

[0036] In one embodiment, the first liquid outlet 134, the second liquid inlet 124, and the second liquid outlet 125 are all tapered threaded holes, respectively used to connect to the water connector 150, and serve as water inlet and outlet through the water connector 150. Optionally, the inlet of the first liquid inlet channel 141 is also configured as a tapered threaded hole for connecting to the water connector 150.

[0037] 3 , in one embodiment, the prism unit 20 includes a first prism assembly 210, a connecting block 230, and a second prism assembly 220 connected in sequence, the first exit port is arranged on the first prism assembly 210, the second exit port is arranged on the second prism assembly 220, and the incident port and the third exit port are arranged on the connecting block 230.

[0038] The laser beam enters through the incident port of the prism unit 20, part of the beam is refracted by the first prism component 210 and enters the beam attenuation unit 10 to be absorbed, part of the beam is reflected by the first prism component 210 and refracted again by the second prism component 220 to enter the secondary attenuation component 30 to be absorbed again, the remaining beam is reflected again by the second prism component 220, and finally passes through the attenuation mirror 40 from the third exit to attenuate the energy again, and the attenuated laser beam enters the beam expander 80 again to achieve the purpose of protecting the detection element and reduce the manufacturing cost of the detection platform.

[0039] 5 , in one embodiment, the secondary attenuation assembly 30 includes an attenuation sleeve 310 and an attenuation cone 320. The inner wall of the attenuation sleeve 310 is provided with a second threaded portion 311 for absorbing and / or reflecting light beams. The front end of the attenuation cone 320 is provided with a second cone-angle portion 322 for absorbing and / or reflecting light beams. One end of the attenuation sleeve 310 is connected to the second prism assembly 220, and the other end of the attenuation sleeve 310 is connected to the attenuation cone 320. The second cone-angle portion 322 is located within the attenuation sleeve 310. Optionally, the secondary attenuation assembly 30 is entirely made of aluminum alloy and is subjected to a matte black oxidation treatment.

[0040] The laser beam attenuated by the beam attenuation unit 10 enters the attenuation sleeve 310 and strikes the second cone-angle portion 322. Part of the energy is absorbed by the cone surface of the second cone-angle portion 322. The remaining laser beam is then reflected to the second threaded portion 311 in the attenuation sleeve 310 and is reflected and absorbed multiple times by the inclined surface of the second threaded portion 311.

[0041] Optionally, the cone angle of the second cone angle portion 322 ranges from 90° to 100°. In this embodiment, the cone angle of the second cone angle portion 322 is 100°.

[0042] In one embodiment, the beam attenuation device further includes a mounting plate 60 and a plurality of connecting rods 50. The plurality of connecting rods 50 are arranged around the periphery of the third emission port. One end of the connecting rod 50 is connected to the prism unit 20, and the other end of the connecting rod 50 is connected to the mounting plate 60. The attenuation mirror 40 is mounted on the connecting rod 50 and is located between the prism unit 20 and the mounting plate 60. In this embodiment, four through holes are provided on the periphery of the third emission port of the prism unit 20 for inserting the connecting rods 50, and the connecting rods 50 are fastened with set screws. The attenuation mirror 40 is a standard part and is tightly clamped to the connecting rod 50. A threaded blind hole is machined at one end of the connecting rod 50 for connection to the mounting plate 60. The mounting plate 60 is provided with a threaded inner hole for connection to the beam expander 80.

[0043] The beam attenuator's entrance has four threaded holes for connecting to the optical fiber assembly 70. The energy of the light beam is attenuated to 1% from the entrance to the third exit of the beam attenuator. Besides the reflected light, two main beams pass through the beam attenuator, one at the second exit and the other at the third exit. The second and third exits are threaded and connect to the beam attenuator unit 10 and the secondary attenuation assembly 30, respectively.

[0044] An embodiment of the present application provides a 3D printer optical path element detection device, comprising an optical fiber assembly 70, a beam attenuation device of any of the above embodiments, a beam expander 80, a scanning galvanometer, a focusing field lens and a beam quality analyzer arranged in sequence along the incident direction of the laser beam, wherein the optical fiber assembly 70 is connected to the incident port of the beam attenuation device, and the beam expander 80 is arranged on the side of the attenuation mirror 40 of the beam attenuation device away from the third exit port.

[0045] In the 3D printer optical path component detection device of this embodiment, the beam attenuation device is arranged after the optical fiber assembly 70 and before the beam expander 80 in the detection optical path. By attenuating the laser energy in advance, the purpose of protecting the detection component is achieved, while reducing the manufacturing cost of the detection platform.

[0046] In one embodiment, the optical fiber assembly 70 includes a clamp seat 710, an optical fiber clamp 720, an optical fiber head 730, and an optical fiber sleeve 740, which are arranged in sequence. The clamp seat 710 is connected to the prism unit 20, and the optical fiber clamp 720 is installed in the clamp seat 710. One end of the optical fiber head 730 is connected to the optical fiber clamp 720, and one end of the optical fiber head 730 is arranged in the optical fiber sleeve 740. The clamp seat 710 has four threaded holes evenly distributed on the radial circumference for installing set screws to install the optical fiber clamp 720. The optical fiber clamp 720 holds the optical fiber head 730 tightly. The optical fiber sleeve 740 is divided into two halves, which are screwed to hold the optical fiber line to standardize the collimation of the proximal optical fiber line.

[0047] In the above description of this specification, unless otherwise expressly specified or limited, terms such as "fixed," "mounted," "connected," or "connected" should be understood broadly. For example, the term "connected" can refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal connection between two elements or the interaction between two elements. Therefore, unless otherwise expressly defined in this specification, those skilled in the art can understand the meaning of the above terms in this application according to the circumstances.

[0048] According to the above description of this specification, those skilled in the art may also understand that the terms used below, such as "up", "down", "front", "back", "left", "right", "length", "width", "thickness", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", "center", "longitudinal", "lateral", "clockwise" or "counterclockwise", etc., which indicate orientation or positional relationships, are based on the orientation or positional relationships shown in the drawings of this specification, and are only for the purpose of facilitating the explanation of the scheme of this application and simplifying the description, rather than explicitly or implicitly indicating that the device or element involved must have the specific orientation, be constructed and operate in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms cannot be understood or interpreted as limitations on the scheme of this application.

[0049] In addition, the terms "first" or "second" used in this specification to refer to numbers or ordinal numbers are used for descriptive purposes only and should not be understood as explicitly or implicitly indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this specification, "plurality" means at least two, such as two, three or more, etc., unless otherwise expressly specified.

Claims

1. A beam attenuation unit, comprising a collecting tube, a cooling sleeve, a beam splitting cone and a cooling tube, wherein the front end of the beam splitting cone is provided with a first cone angle portion for absorbing at least one of a light beam and a reflected light beam, the inner wall of the collecting tube is provided with a first threaded portion for absorbing at least one of a light beam and a reflected light beam, the collecting tube is connected to the beam splitting cone, the first cone angle portion is located inside the collecting tube, the cooling sleeve is sleeved outside the collecting tube, a blind hole is provided inside the beam splitting cone, the cooling tube is placed in the blind hole and connected to the beam splitting cone, a first liquid inlet is provided inside the cooling tube, and the beam splitting cone is provided with a first liquid outlet connected to the first liquid inlet.

2. The beam attenuation unit according to claim 1, wherein: The cooling cylinder includes an outer edge section, a connecting section and a liquid outlet section which are connected in sequence and whose outer diameters decrease in sequence, the first liquid inlet channel runs through the outer edge section to the liquid outlet section, the connecting section and the liquid outlet section extend into the beam splitting cone, the connecting section is sealed and connected to the inner wall of the beam splitting cone, the outer wall of the liquid outlet section and the inner wall of the beam splitting cone are spaced apart to form a first liquid outlet channel, and the first liquid outlet is connected to the first liquid inlet channel through the first liquid outlet channel.

3. The beam attenuation unit according to claim 2, wherein: The first liquid outlets are provided with two, which are respectively arranged on two opposite sides of the liquid outlet section.

4. The beam attenuation unit according to claim 1, wherein: The cone angle of the first cone angle portion ranges from 90° to 100°.

5. The beam attenuation unit according to any one of claims 1 to 4, wherein: The inner wall of the cooling jacket is provided with an annular groove, the cooling jacket is provided with a second liquid inlet and a second liquid outlet penetrating the groove, and the inner walls of the cooling jacket located on both sides of the groove are sealed and connected to the collecting tube.

6. The beam attenuation unit according to claim 5, wherein: The first liquid outlet, the second liquid inlet and the second liquid outlet are all tapered threaded holes, which are respectively used to connect water joints.

7. A beam attenuation device, comprising a prism unit, a secondary attenuation component, an attenuation mirror and the beam attenuation unit according to any one of claims 1 to 6, the prism unit having a first exit port, a second exit port, a third exit port and an entrance port for injecting laser light, the collecting tube of the beam attenuation unit is connected to the first exit port, the secondary attenuation component is connected to the second exit port, and the attenuation mirror is arranged at the third exit port.

8. The beam attenuation device according to claim 7, wherein: The prism unit includes a first prism assembly, a connecting block and a second prism assembly which are connected in sequence. The first exit port is arranged at the first prism assembly, the second exit port is arranged at the second prism assembly, and the incident port and the third exit port are arranged at the connecting block.

9. The beam attenuation device according to claim 8, wherein: The secondary attenuation component includes an attenuation sleeve and an attenuation cone. The inner wall of the attenuation sleeve is provided with a second threaded portion for absorbing at least one of the light beam and the reflected light beam. The front end of the attenuation cone is provided with a second cone angle portion for absorbing at least one of the light beam and the reflected light beam. One end of the attenuation sleeve is connected to the second prism assembly, and the other end of the attenuation sleeve is connected to the attenuation cone. The second cone angle portion is located inside the attenuation sleeve.

10. The beam attenuation device according to any one of claims 7 to 9 further comprises a mounting plate and a plurality of connecting rods, wherein the plurality of connecting rods are arranged around the outer circumference of the third emission port, one end of the connecting rod is connected to the prism unit, and the other end of the connecting rod is connected to the mounting plate, and the attenuation mirror is mounted on the connecting rod and is located between the prism unit and the mounting plate.

11. A three-dimensional 3D printer optical path element detection device, comprising an optical fiber assembly, a beam attenuation device according to any one of claims 7 to 10, a beam expander, a scanning galvanometer, a focusing field lens and a beam quality analyzer arranged in sequence along the emission direction of the laser beam, the optical fiber assembly is connected to the incident port of the beam attenuation device, and the beam expander is arranged on the side of the attenuation mirror of the beam attenuation device away from the third emission port.

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