WO2020219037A1

WO2020219037A1 - Detection of accessory in additive manufacturing system

Info

Publication number: WO2020219037A1
Application number: PCT/US2019/028942
Authority: WO
Inventors: Wojciech Jerzy KRASOWSKI; Ernesto Alejandro Jones Poppescou; Arturo GARCIA GOMEZ; Josep Maria FERNANDEZ SANJUAN
Original assignee: Hewlett-Packard Development Company, L. P.
Priority date: 2019-04-24
Filing date: 2019-04-24
Publication date: 2020-10-29

Abstract

A system is provided, comprising a controller to cause movement of a feeding vane of a feed tray of an additive manufacturing system. The controller can determine whether contact between the feeding vane and an accessory has occurred, and can generate information relating to the positioning of the accessory relative to the feeding vane.

Description

DETECTION OF ACCESSORY IN ADDITIVE MANUFACTURING SYSTEM

BACKGROUND

Additive manufacturing systems are used to manufacture three- dimensional (3D) objects by, for example, utilizing a mechanism for successively delivering a build material to a print bed to build up a 3D object. Build material may be stored in a build unit, which may include a build material feed tray and feed vane located in the feed vane that assists in the supply of build material to the print bed.

BRIEF DESCRIPTION OF THE DRAWINGS

Some non-limiting examples of the present disclosure will be described in the following with reference to the appended drawings in which:

Figure 1 is a diagram of a first example of a build material delivery system; Figure 1 A is a simplified isometric illustration of movements that may be made by a feeding vane of figure 1 ;

Figure 2 is a diagram of one example of a portion of a build unit and a build material delivery system for detecting an accessory;

Figure 3 is a simplified side view of a portion of the build material delivery system for detecting an accessory according to one example;

Figure 4 is a simplified side view of another portion of the build material delivery system for detecting an accessory according to one example.

Figure 5 is a simplified side view of a feeding vane of figure 3 in a first orientation in the build unit of figure 2;

Figure 6 is a simplified side view of a feeding vane of figure 3 in a second orientation in the build unit of figure 2;

Figure 7 is a simplified side view of a feeding vane of figure 3 in a third orientation in the build unit of figure 2;

Figure 8 is a simplified side view of a feeding vane of figure 4 in a first orientation in the build unit of figure 2;

Figure 9 is a simplified side view of a feeding vane of figure 4 in a second orientation in the build unit of figure 2; Figure 10 is a flow diagram outlining an example method for detecting an accessory, according to one example.

Figure 1 1 is a flow diagram outlining an example method for detecting an accessory, according to another example.

DETAILED DESCRIPTION

Some additive manufacturing systems may include a build unit defining a volume in which a build platform is moved vertically while printing nozzles on a 3D printing section of the additive manufacturing system can be moved horizontally to additively build a 3D object in the build unit. After a 3D object has been built, the build unit may be moved to a post-processing section of the additive manufacturing system where further processing can be carried out on the 3D object.

In an example, the build unit may comprise the build platform and, in an additive manufacturing process, an initial layer of build material is spread on the surface of the build platform. Subsequent layers of build material are formed on a previously formed layer of build material. Each layer may be formed on a build area on the platform which is the uppermost surface of the build platform. Each layer of build material on the build platform may be selectively solidified by any suitable build material solidification system before forming the next layer. Examples of such build material solidification systems are fusing agent deposition and heating systems, binder agent deposition systems, laser sintering systems, and the like.

The build material may be, for example, in the form of a powder or granulate, and may be formed from plastic, ceramic, metal, or any powder-like material. In some examples, the powder may be formed from, or may include, short fibres that may, for example, have been cut into short lengths from long strands or threads of material. During the additive manufacturing process, the build material can be added to the build platform by a build material delivery system that may form part of the build platform.

Figure 1 shows an example of a portion of a build material delivery system 100 that may be positioned in a build unit. A feed tray 105 may be provided in the build material delivery system and the tray 105 can receive and contain build material (not shown) that is supplied from a build material store (not shown) in the build unit during an additive manufacturing process. The feed tray 105 is located proximal a build platform 1 10 and, during an additive manufacturing process, at least some of the build material is supplied from the feed tray 105 to the build platform 1 10 such that the additive manufacturing process can be carried out on the build material by a 3D printing section of the additive manufacturing system. The build platform 1 10 may move vertically as shown by the arrow B.

The feed tray 105 further comprises a feeding vane 1 15 or plate for removing build material from the feed tray 105 to proximal a build area 120 that is formed by an uppermost layer of the build platform 1 10. A spreader (not shown) can spread a layer of build material on the build area 120 as an initial layer or a layer on a previously formed layer in the build area 120.

The feeding vane 1 15 may be rotatable about an axis A of the feed tray 105 and may be rotated 360 degrees about the axis as shown in figure 1A.

The feed tray 105 is located at a top side of the build unit and one feed tray 105 is shown in Figure 1. Two feed trays may be provided and located at, for example, opposite sides of the build unit, such as the front and back of the build unit respectively as will be described later. Each feed tray and associated feeding vane may have similar functionality in that each feeding vane can remove some build material from its respective feed tray and move the build material to proximal each side of the build area 120.

The build material delivery system may comprise a controller 125 to control and cause rotational movement of the feeding vane 1 15 and can be in communication with a drive unit 130 which may be implemented by a motor to drive the feeding vane 125. The controller 125 may be configured in a build material supply mode to control movement of the feeding vane 1 15 to supply build material from the feed tray 105 to proximal the build area 120 of the build unit. In one example, the build material is moved from the feed tray 105 to the feeding vane 1 15 and the vane 1 15 is selectively moved under control of the controller such that a surface of the vane 1 15 that carries build material is aligned with the surface of the build area 120. A spreader (not shown) can spread a layer of build material on the build area 120. The build material supply mode may be activated when the build unit is positioned in a 3D printing section of the additive manufacturing system.

The build unit is removable from the 3D printing section of the manufacturing system such that after a 3D object has been built in the build unit, the build unit may be removed from the 3D printing section and moved to a post processing section from removal of the 3D object from the build unit.

An accessory such as a container for the 3D object may be received by the build unit for connection to the build unit. The container can be placed on the build unit at the post-processing section. The container may receive the 3D object from the build unit for subsequent cooling. In one example, the build material delivery system may detect the presence and orientation of the container before the 3D object is moved into the container for cooling.

Figure 2 shows one example of a portion of a build unit 140 and a build material delivery system that can be used to detect an accessory such as a container 150. The container 150 has a front 150a and a back 150b and may have similar dimensions to at least a portion of the build unit that contains a 3D printed object and may be of a volume to enable the 3D printed object of the build unit to be received in the container 150. The container 150 may be a cooling container which can receive the contents of a top chamber 142 of the build unit 140 which may include the 3D printed object. The container 150 may cool the 3D object. In use, the container 150 may be positioned on the build unit 140, for example, by an operator, in a position such that the front 150a and back 105b of the container are aligned with the corresponding sides of the top chamber 142 of the build unit 150. In addition or alternatively, in use, the container 150 may be positioned on the build unit 140 such that a central axis of the container is aligned with the central axis of the top chamber as closely as possible. The container 150 may non- powered and therefore may not have any electrical devices for sensing the build unit 140. The feeding vane 1 15 can be used to assist in checking whether the container is correctly positioned before the contents of the top chamber 142 of the build unit 140 are transferred to the container 150. If the build unit is non-powered, the transfer may occur in the post-processing section of an additive manufacturing system such that power from the post-processing section can be used to power devices in the build unit. In other examples, the build unit may have a power supply device.

The build material delivery system may comprise a first feed tray 105a and second feed tray 105b and an associated feeding vane 1 15a, 1 15b in each feed tray 105a, 105b that is the same configuration as the arrangement of figure 1. The build material delivery system further comprises the controller 125 as in figure 1 that can cause movement of each feeding vane of each feed tray but that is further configured to generate information indicative of the positioning, such as the presence and orientation, of a container relative to a feeding vane. The build material delivery system may further comprise the drive unit 130 as in figure 1 which is used to drive each feeding vane 1 15a, 1 15b. The controller 125 may send a control signal to the drive unit to cause movement of each feeding vane 1 15a, 1 15b. Each feeding vane 1 15a, 1 15b may then move by rotation. In one example, the drive unit 130 may comprise a first motor with an output that is connected to part of the first feeding vane 1 15a and a second motor with an output that is connected to part of the second feeding vane 1 15b. In another example, a mechanism may be provided where a single motor is used to drive both feeding vanes.

The controller 125 may comprise, for example a programmable logic controller such as a microprocessor, forming part of processing circuitry of the build unit 140. The controller 125 may control the general operation of the build material delivery system. The controller 125 may be coupled to a memory 155 that stores machine executable instructions. The memory can be a non-transitory machine-readable storage medium and may, for example, be a read only memory and / or a random access memory. The programmable logic controller may carry out the instructions stored in the memory. The feeding vane 1 15 is shown as a rectangular plate in figures 1 and 2 for ease of reference. In other implementations, the feeding vane has other configurations. As shown in figure 3, in an example according to the present disclosure, the feeding vane 1 15a may be formed of a plate 155a and a support member 160a for the plate, and the support member 160a may be connected to a pivot 165a in the feed tray 105a to allow rotation of the feeding vane 1 15a about the feed tray pivot 165a. The pivot 165a may be connected to the drive unit 130 and a control signal from the controller 135 may cause movement of the pivot 165a of the feeding vane 1 15a. The example in Figure 3 is representative of a feed tray 105a and feeding vane 1 15a that is located proximal a front side of the build unit 140 and is referred to hereinafter as the front feed tray 105a and front feeding vane 1 15a. A similar feeding vane that is located proximal a back side of the build unit in shown in Figure 4. As shown in figure 4, in an example according to the present disclosure, the feeding vane 1 15b may formed of a plate 155b and a support member 160b for the plate, and the support member 160b may be connected to a pivot 165b in the feed tray 105b to allow rotation of the feeding vane 1 15b about the feed tray pivot 165b. The pivot 165b may be connected to the drive unit 130 and a control signal from the controller 135 may cause movement of the pivot 165b of the feeding vane 1 15b. The example in Figure 4 is representative of a feed tray 105b and feeding vane 1 15b that is located proximal a back side of the build unit 140 and is referred to hereinafter as the back feed tray 105b and back feeding vane 1 15b.

An operation of the front and back feeding vanes such as in Figure 3 and 4 will now be described with reference to figures 2, 5 to 9. The operation may be carried out after the controller 125 is set or switched to a container detection mode.

The front and back feeding vanes 1 15a, 1 15b can be used to determine if a container 150 is present on the build unit 140. This can be achieved through the control of the controller 125 which can cause selective movement of each of the feeding vanes 1 15a, 1 15b, determine whether contact between one or both of the feeding vanes 1 15a, 1 15b and the container 150 has occurred, and generate information relating to the positioning of the container 150 relative to the respective feeding vane 1 15a, 1 15b.

Referring to the front feeding vane 1 15a, the controller 125 causes the front feeding vane 1 15a to rotate in a clockwise direction about a pivot 165a about which the front feeding vane 1 15a is connected. Contact with a container 125 can cause the feeding vane 1 15a to stop rotating and a starting, first, position is set by the controller 125. The initial contact as shown in Figure 5 can cause the controller 125 to generate information indicating that the feeding element is obstructed and indicate that a container 150 is present. The controller 125 then causes the feeding vane 1 15a to rotate in an opposite, anti-clockwise direction. The movement of the feeding vane 1 15a and the angular displacement can be monitored by the controller 125. The feeding vane 1 15a will stop moving in the anti-clockwise direction at a second position when contact is made with an accessory. The controller 125 can generate information which includes the angular displacement of the feeding vane from the first rotational position to the second rotational position. The value of the angular displacement can be compared with a predetermined angular value or range of angular values that may be stored in the memory 155. The angular displacement of the feeding vane 1 15a can be indicative of whether a front side 150a of the container 150 is correctly positioned on the build unit and a determination of whether the container is correctly installed and / or oriented on the build unit 140 can be made by the controller 125. The controller 125 may output a notification on a display (not shown), for example, of the measured angular displacement and / or the determination of correct orientation or connection of the container.

In one example as shown in figure 6, a predetermined angular displacement at a value x in a range of 163 degrees to 167 degrees from the first position, or 165 degrees from the first position, is indicative of the front side of the container being correctly positioned on the build unit. The first range may be different depending on the angle tolerance that is chosen. Other angular displacements can be indicative of the correct orientation depending on the dimensions of the container or any other accessory that is to be detected. In another example as shown in figure 7, a predetermined angular displacement at a value y in a range of 78 degrees to 82 degrees from the first position, or 80 degrees from the first position, is indicative of another accessory such as a guillotine 170 that is used to cut and separate powder between the build unit 140 and the container 150 being present on the front side of the container and is indicative of a guillotine being positioned on the build unit. The second range may be different depending on the angle tolerance that is chosen.

The controller can therefore cause movement of the first feeding vane 1 15a of a first feed tray 105a of the additive manufacturing system, determine whether contact between the first feeding vane 1 15a and an accessory has occurred, and generate information relating to the positioning of the accessory relative to the first feeding vane 1 15a.

Referring now to the back feeding vane 1 15b, the controller 125 causes the feeding vane 1 15b to rotate in an anti-clockwise direction about a pivot 165b about which the front feeding vane 1 15b is connected. Contact with the back of the container 125 can cause the feeding vane 1 15b to stop rotating and a starting, first, position for the feeding vane 1 15b is set by the controller 125. The initial contact as shown in Figure 8 can cause the controller 125 to generate information indicating that the feeding element is obstructed and indicate that a container 150 is present. This indication can be used as a confirmation of the information received in relation to the front feeding vane which may already have indicated that a container is present. Alternatively, the back feeding vane may provide the information before the front feeding vane or the angular information in relation to both feeding vanes 1 15a, 1 15b can be generated simultaneously. The controller 125 then causes the feeding vane 1 15b to rotate in an opposite, clockwise direction. The movement of the feeding vane 1 15b and the angular displacement can be monitored by the controller 125. The feeding vane 1 15b will stop moving in the clockwise direction at a second position when contact is made with an accessory. The controller 125 can generate information which includes the angular displacement of the back feeding vane 1 15b from the first position to the second position. The value of the angular displacement can be compared with a predetermined angular value or range of angular values that may be stored in the memory 155. The angular displacement of the feeding vane 1 15b can be indicative of whether a back side 150b of the container 150 is correctly positioned on the build unit 140 and a determination of whether the container 150 is correctly installed and / or oriented on the build unit 140 can be made by the controller 125. The controller 125 may output a notification on a display (not shown), for example, of the measured angular displacement and / or the determination of correct orientation or connection of the container.

In one example as shown in figure 9, a predetermined angular displacement at a value z in a range of 91 degrees to 95 degrees from the first position, or 93 degrees from the first position, is indicative of the back side of the container being correctly positioned on the build unit. The third range may be different depending on the angle tolerance that is chosen. Other angular displacements can be indicative of the correct orientation depending on the dimensions of the container or any other accessory that is to be detected.

A similar determination as made in relation to figure 7 for the presence of an accessory such as a guillotine may also be made in respect of the back feeding vane by the controller.

The controller can therefore cause movement of the second feeding vane 1 15b of a first feed tray 105b of the additive manufacturing system, determine whether contact between the first feeding vane 1 15b and an accessory has occurred, and generate information relating to the positioning of the accessory relative to the first feeding vane 1 15b.

The controller 125 may control each of the front and back feeding vanes 1 15a, 1 15b such that information relating to the positioning of the container relative to each of the vanes 1 15a, 1 15b can be generated. The movement of each vane may be controlled to occur simultaneously or consecutively. In other examples, separate controllers for each of the vanes may be provided and the angular displacement information relating to the positioning of the container can be generated separately and analyzed by a separate computing device (not shown) to generate information in relation to whether a container is positioned on each feed tray and / or whether an container is correctly oriented on the build unit by comparison of the angular displacement information with predetermined angular displacement information for each of the feeding vanes 1 15a, 1 15b.

Although the feeding vanes 1 15a, 1 15b in figures 3 to 9 have been described as a plate which will hold build material when in a build material supply mode and a support structure for the plate, the angular displacement as described above could also be determined using other configurations of feeding vane. If the feeding vane is a single plate, a top and bottom surface of the plate is arranged to contact different parts of the container. With the feeding vane as described in relation to figures 3 to 9, a first surface of the plate can contact a first part of the container and a surface of the support member is arranged to contact another part of the container when carrying out container detection. As the combination of the plate and support members increases the overall depth of the feeding vane, when the vane is rotated, it will need to be rotated at a relatively smaller angle compared to the implementation with the plate alone, before making contact with a container of other accessory.

Implementations of a method 200 for generating information indicative of an accessory in an accessory detection mode as disclosed herein may comprise, as illustrated in figure 10, at 210, moving a feeding vane of a feed tray of an additive manufacturing system. At 220, the position of the feeding vane is monitored. At 230, information is generated, the information indicative of whether the movement of the feeding vane is obstructed by an accessory based on the monitored position. The information may be the angular displacement of the feeding vane. Further, the generated information may relate to whether an accessory is positioned on the feed tray and / or whether an accessory is correctly oriented.

In another example, a method 300 for generating information indicative of an accessory using, for example, a build material delivery system described in relation to figures 2 to 4 may comprise, as illustrated in figure 1 1 , at 305, setting a start position of a feeding vane. This can be achieved by moving the feeding vane, for example, and contacting a surface of the accessory that is positioned on a build unit of an additive manufacturing system. At 310, a determination of whether there is contact between a feeding vane and an accessory is made. At 315, if there is no contact by either the front or back feeding vane, information is provided indicating that no accessory is present and the method ends. If there is contact, at 320, an indication is made that an accessory is present and the angle of the feeding vane is set to zero at the point at which contact is made. At 325, the orientation of the accessory may then be checked by rotating the feeding vane and monitoring the angular displacement of the feeding vane. At 330, it is determined that the angular displacement and therefore position of the feeding vane from the zero point is in a first range including a value of 80 degrees. At 335, information is provided indicating that a guillotine is present and the method ends. It will be appreciated that this determination can be made for both of the front and back feeding plates shown in figure 3 and 4. At 340, it is determined that the angular displacement and therefore position of the front feeding vane from the zero point is in a second range including a value of 93 degrees. It is also determined that the angular displacement and therefore position of the back feeding vane from the zero point is in a third range including a value of 165 degrees. At 345, information is provided indicating that the accessory is in the wrong orientation (back-to-front). At 350, it is determined that the angular displacement and therefore position of the front feeding vane from the zero point is in the third range including a value of 165 degrees. It is also determined that the angular displacement and therefore position of the back feeding vane from the zero point is in the second range including a value of 93 degrees. At 355, information is provided indicating that the accessory is positioned correctly. At 360, if a determination is made that the angular displacement of the front or back feeding vane is another value outside the first, second and third range, an indication is made to start the process again. The accessory can then be moved accordingly and the process 300 can be restarted.

In addition to the examples described in detail above, the skilled person will recognize that various features described herein can be modified and/or combined with additional features, and the resulting additional examples can be implemented without departing from the scope of the system of the present disclosure, as this specification merely sets forth some of the many possible example configurations and implementations for the claimed solution.

Claims

1. System comprising:

a controller to:

cause movement of a first feeding vane of a first feed tray of an additive manufacturing system;

determine whether contact between the first feeding vane and an accessory has occurred;

generate information relating to the positioning of the accessory relative to the first feeding vane.

2. The system in accordance with claim 1 , wherein the controller causes movement by selectively rotating the first feeding vane about an axis of the feed tray.

3. The system in accordance with claim 1 , wherein the controller causes movement by moving the first feeding vane in a first direction to a first position and if the determination of contact between the first feeding vane and the accessory is affirmative, causes movement of the first feeding vane in a second direction to a second position, the second direction being opposite to the first direction.

4. The system in accordance with claim 1 , wherein the controller is to generate information relating to angular displacement of the feeding vane between a first position and a second position.

5. The system in accordance with claim 1 , wherein if the controller determines that the angular displacement is a first value, the controller is to generate information that the accessory is correctly positioned, and wherein if the controller determines that the angular displacement is a second value, the controller is to generate information that the accessory is not correctly positioned.

6. The system in accordance with claim 1 , wherein the controller is to generate information in relation to whether an accessory is positioned on the first feed tray and / or whether an accessory is correctly oriented.

7. The system in accordance with claim 1 , wherein the controller is switchable to an accessory detection mode before causing movement of the first feeding vane.

8. The system in accordance with claim 1 , wherein the controller, in a build material supply mode, is to control the first feeding vane to supply build material from the first feeding tray.

9. The system in accordance with claim 1 , wherein the controller causes movement of the first feeding vane in a first direction, and the controller detects a contact of the first feeding vane at a first rotational position of the feeding vane, the controller then causes movement of the first feeding vane in a second opposite rotational direction, and the controller detects a contact of the first feeding vane at a second rotational position, wherein controller is to generate an angular displacement between the first rotational position and second rotational position which is indicative of whether an accessory is correctly connected relative to the first feeding vane.

10. The system in accordance with claim 1 , further comprising a build unit, and wherein the first feeding vane of a feeding tray is located at a top side of the build unit proximal a front of the build unit.

1 1. The system in accordance with claim 10, further comprising a second feeding vane of a second feeding tray located at a top side of the build unit proximal a back of the build unit.

12. The system in accordance with claim 1 1 , wherein the controller is to selectively rotate the second feeding vane about an axis of the second feed tray.

13. A non-transitory machine-readable storage medium encoded with instructions executable by a processor, the machine-readable storage medium comprising instructions to:

monitor a rotatable feeding vane used in an additive manufacturing process;

generate information indicative of whether the feeding element is obstructed by an accessory based on the monitoring.

14. The non-transitory machine-readable storage medium in accordance with claim 13, further comprising instructions to generate information indicative of whether the accessory is in a correct orientation relative to the feeding vane.

15. A method comprising:

moving a feeding vane of a feed tray of an additive manufacturing system; monitoring the position of the feeding vane;

generating information indicative of whether the movement of the feeding vane is obstructed by an accessory based on the monitored position.