A three-dimensional (3D) printing system can be used to form 3D objects. A 3D printing system performs a 3D printing process, which is also referred to as an additive manufacturing (AM) process, in which successive layers of material(s) of a 3D object are formed under control of a computer based on a 3D model or other electronic representation of the object. The layers of the object are successively formed until the entire 3D object is formed.
Some implementations of the present disclosure are described with respect to the following figures.
In a 3D printing system, a build material (or multiple different build materials) can be used to form a 3D object, by depositing the build material(s) as successive layers until the final 3D object is formed. In some examples, a build material can include a powdered build material that is composed of particles in the form of fine powder or granules. The powdered build material can include metal particles, plastic particles, polymer particles, or particles of other materials.
In a 3D printing system, a heating lamp (or multiple heating lamps) can be provided to cause heating of a layer of a build material. A “heating lamp” can refer to a heating source that is activatable to generate energy that can be used to cause heating of a target, which in a 3D printing system can be a layer of build material. An example of a heating lamp is a halogen lamp that can generate visible light or near infrared light energy. In other examples, the heating lamp can include light emitting diodes (LEDs), laser diodes, a lamp to generate medium or far infrared light energy, a xenon lamp, and so forth. The heating of the layer build material can be performed to aid in the fusing of a portion of a layer of powdered build material, where powders in such portions are joined together to form a solid. An agent (e.g. a liquid agent or other substance) can also be applied to such portions of the layer of powdered build material for controlling fusing of the heated portions of the layer of powdered build material. In other examples, the heating of a layer of build material can be performed for other purposes.
During operation of a 3D printing system, the temperature of a heating lamp can rise to an elevated level. If the lamp is not cooled, damage to the lamp can occur. Forced air can be employed to generate a cooling airflow to cool the heating lamp. However, an issue associated with generating an airflow in a 3D printing system is that the airflow can disturb powders of a layer of powdered build material, which can cause some of the powder to disperse in a print chamber. Such powder can be ingested through nozzles of a printhead of the printing system, which can cause clogging of the printhead. Additionally, the disturbed powders can form a powder residue on a lamp, which can adversely affect the operation of the lamp. Moreover, in some cases, contact of build material powder with a lamp at high temperature should generally be avoided.
The bottom of the lamp assembly 100 is provided with a plate 103 formed of a substrate that is transmissive to energy produced by the heating lamps 104 to cause heating of a target on a build platform of the 3D printing system. For example, heat generated by the heating lamps 104 can be transmitted through the plate 103 towards a build platform of the 3D printing system. In some examples, the plate 103 can be a glass plate that allows for heat produced by the heating lamps 104 to pass through the glass plate towards the build platform below the lamp assembly 100. In some examples, the glass plate can be formed of quartz glass, borosilicate glass, aluminosilicate glass, or other type glass. In further examples, the plate 103 can be formed of a different material that is transmissive to energy produced by the heating lamps to cause heating of a target on the build platform, or a non-transparent plate such as a silicium plate, germanium plate, and so forth.
The housing has an airflow inlet 106, which can be in the form of an orifice in the housing 102. In other examples, the airflow inlet 106 can include multiple orifices formed in the housing 102.
In examples according to
The housing 102 is also provided with a pattern of exhaust holes 112 through which heated exhaust airflow is to exit from the inner chamber of the housing 102. The cooling airflow flows through the airflow inlet 106 into the inner chamber of the housing 102. The cooling airflow flows inside the housing 102 to cool the different elements of the lamp assembly 100 that have to be cooled. This cooling airflow is heated in the process, and the heated exhaust airflow exits through the pattern of exhaust holes 112 generally along a direction 120. In some examples, the elements that are cooled by the cooling airflow can include the plate 103, the end portions of the heating lamps 104, and a reflector (discussed further below).
The pattern of exhaust holes 112 can be formed on a side wall 114 provided on a lateral side of the housing 102. In further examples, the pattern of exhaust holes 112 can additionally or alternatively be formed on a different wall, such as an end wall 118 of the housing 102, or formed in both the side wall 114 and the end wall 118 of the housing 102.
During operation of the lamp assembly 100, heat generated by the heating lamps 104 is radiatively directed in a direction 116 towards a build platform of the 3D printing system on which layers of build material are formed. In the orientation of
By increasing the open area while using relatively small exhaust holes 112, instead of a single larger exhaust hole, the exhaust airflow velocity is reduced at a certain distance from the exhaust holes 112, while also reducing the risk of powder in the print chamber from going inside the lamp assembly housing 102 through the exhaust holes 112 due to movement of the carriage and air movement. Reducing the exhaust airflow velocity reduces the likelihood of disturbing the layer of powder on the build platform. The total area of the exhaust holes can be adjusted by adjusting the number of the exhaust holes.
The housing 102 is also provided with an attachment element 122 that is used to attach the housing 102 to a carriage of the 3D printing system. A “carriage” can refer to a structure that is used for carrying components, including a printhead for emitting an agent, as well as other components such as the lamp assembly 100, a sensor to sense a respective parameter, and so forth.
In some examples, the attachment element 122 includes posts that can fit into respective holes in a mounting structure of the carriage to attach the lamp assembly 100 to the carriage. In other examples, the attachment element 122 can include alternative or additional components to attach to the carriage (discussed further below).
In examples according to
In addition, a handle 210 can be attached to the top wall 108 of the housing 102, to allow a user to grip the handle 210 to manipulate the lamp assembly 100, such as to attach the lamp assembly 100 to the carriage or to remove the lamp assembly 100 from the carriage. In other examples, the lamp connector assembly 208 or the handle 210 can be omitted or placed elsewhere on the housing 102.
Each lamp assembly 100-1 and 100-2 can have the arrangement of the lamp assembly 100 shown in
As further shown in
The lamp assembly 100-1 includes an active cooling subsystem 202-1 that includes an airflow generator 204-1 and an air duct 206-1. Similarly, the lamp assembly 100-1 includes an active cooling subsystem 202-2 that includes an airflow generator 204-2 and an air duct 206-2. The active cooling subsystems 202-1 and 202-2 are similar in design to the active cooling subsystem 202 described in connection with
The carriage 302 further includes a support panel 306 to which the active cooling subsystems 202-1 and 202-2 are mounted. The support panel 306 can be attached to the mounting structure 304.
Although not shown, other components can be part of the carriage assembly 300, including cables, an active cooling subsystem for printheads in the carriage 302, and so forth.
This further attachment element is in the form of an L-shaped attachment plate 402 that is attached to a side wall of the housing 102 of the lamp assembly 100-1. The L-shaped attachment plate 402 has a mounting portion 403 that is bent from the main body of the attachment plate 402. The mounting portion 403 has an opening through which a screw 410 or other type of fastener can pass through.
An L-shaped fixing plate 404 is attached to side wall 408 of the carriage 302. The L-shaped fixing plate 404 has a mounting portion 406 that is bent from the main body of the fixing plate 404. The mounting portion 406 of the fixing plate 404 has an opening through which the screw 410 or other fastener can pass when the hole of the mounting portion 406 is aligned with the hole of the mounting portion 403. The screw 410 or other fastener passes through both the mounting portions 403 and 406 to fix the lamp assembly 100-1 to the carriage 302.
In other examples, a different type of attachment mechanism can be used to fix the lamp assembly 100-1 or 100-2 to the carriage 302.
The carriage 302 can carry a printhead to emit an agent(s) towards the layer 504 of build material. The emission of the agent(s) occurs in an active region 506 above the build platform 502 of the 3D printing system 500.
As discussed above, the lamp assembly 100 includes a heating lamp (or multiple heating lamps) to generate heat directed towards the build platform 502. The lamp assembly 100 also includes a housing that includes an inner chamber containing the heating lamp(s), an airflow inlet to receive a cooling airflow generated by an airflow generator, and a pattern of exhaust holes through which heated exhaust airflow is to exit from the inner chamber of the housing, where the exhaust holes are dimensioned and the pattern of exhaust holes is design to minimize the exhaust airflow velocity to prevent moving the powder from the build platform 502 while reducing or eliminating the powder ingestion through the exhaust holes 112.
In the foregoing description, numerous details are set forth to provide an understanding of the subject disclosed herein. However, implementations may be practiced without some of these details. Other implementations may include modifications and variations from the details discussed above. It is intended that the appended claims cover such modifications and variations.
Filing Document | Filing Date | Country | Kind |
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PCT/US2016/032038 | 5/12/2016 | WO | 00 |