Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As used in this specification and the appended claims, the term "if" may be interpreted contextually as "when", "upon" or "in response to a determination" or "in response to a detection". Similarly, the phrase "if it is determined" or "if a [ described condition or event ] is detected" may be interpreted contextually to mean "upon determining" or "in response to determining" or "upon detecting [ described condition or event ]" or "in response to detecting [ described condition or event ]".
In order to explain the technical means of the present invention, the following description will be given by way of specific examples.
Fig. 1 is a schematic flow chart of a dynamic light emitting control method for a powder laying type 3D printing apparatus according to an embodiment of the present invention. As shown in fig. 1, the light emitting dynamic control method of the powder spreading type 3D printing apparatus may include the following steps:
step S01: determining the powder laying length of each powder laying layer according to the printing task;
wherein, for a 3D printing task, any two layers of 3D printing can be completely the same, not completely the same or even completely different. The design of the invention is that the touch threshold of each layer of 3D printing is judged and regulated, the touch threshold is increased as much as possible under the condition that the powder laying shaft does not interfere with the laser light emitting and printing actions, and the waiting time is reduced, thereby improving the production efficiency of the equipment. Each touch threshold value is the light-emitting safety point provided by the invention, namely when the powder spreading shaft carries out powder spreading operation, the moment when the powder spreading shaft moves to the light-emitting safety point and the moment later, the powder spreading shaft does not interfere with laser light-emitting and printing actions, and the equipment is safe in production.
Here, it should be noted that, the light-emitting safety point is the light-emitting safety zone to the end position of the powder laying shaft, that is, the light-emitting safety zone, in principle, when the powder laying shaft moves at any position of the light-emitting safety zone, the light-emitting operation can be performed, and it can be ensured that the powder laying shaft does not interfere with the laser light-emitting and printing actions, and the production safety is ensured, but in order to save time, the larger the light-emitting safety zone is, the better the light-emitting safety zone is, that is, the closer the light-emitting safety point is to the initial position of the powder laying shaft is, the better the light-emitting safety point is.
It should be further noted that since the 3D printing can be performed after the powder spreading operation is completed, the light-emitting safety point and the light-emitting safety interval are both relative to or adjacent to the end point of the powder spreading axis for both the single-pass powder spreading operation and the reciprocating powder spreading operation.
Step S02: determining the light-emitting safety points of each powder laying layer according to the powder laying length of each powder laying layer; the length of the light-emitting safety point from the initial position of the powder laying shaft is the powder laying length;
for any 3D printing task, determining the powder laying length of each powder laying layer, wherein the powder laying length is the length of powder laying required by the powder laying layer, namely the length of a powder laying shaft moving from an initial position to a light-emitting safety point position, namely the minimum value of the printing task which can be met when the powder laying layer finally emits light for printing.
Step S03: and when the powder spreading shaft moves to the light emergent safety point, carrying out light emergent operation.
In order to reduce waiting time as much as possible, the powder laying shaft controls the light emitting operation when moving to the light emitting safety point. Here, it should be noted that when the powder spreading shaft moves to the light-emitting safety point, specifically, the powder spreading operation of the powder spreading shaft is not completed, but the powder spreading operation of the portion to be 3D printed of the current layer is completed, and the powder spreading shaft now performs the powder spreading movement to the end position.
Further, as a preferred embodiment of the present invention, the step of moving the powder spreading shaft to the light-emitting safety point is as follows:
determining the time for the powder spreading shaft to move to the light-emitting safety point according to the powder spreading length and the movement speed of the powder spreading shaft;
when the powder spreading shaft starts to spread powder from the initial position, timing is started;
and when the timing exceeds the reaching time, carrying out the light emitting operation.
The method comprises the steps that a timing method is adopted to determine the time when a powder spreading shaft moves to a light-emitting safety point, and the time when the powder spreading shaft moves to the light-emitting safety point can be determined through calculation after the powder spreading length of each powder spreading layer is determined due to the fact that the movement speed of the powder spreading shaft is preset by powder spreading type 3D printing equipment.
Fig. 2(a) is a specific powder-laying shaft speed-time chart according to an embodiment of the present invention.
The powder spreading shaft is provided with N layers with the same printing layer number for ensuring the powder spreading quality, and each layer needs to be spread at a set powder spreading speed VpAnd (4) finishing. The area enclosed by the speed curve of the powder laying shaft and the time shaft is the moving distance of the powder laying shaft, and the moving distance is the distance from the powder laying shaft to the initial position under the general condition. Based on this, when the light-emitting safety point is determined, the distance from the light-emitting safety point to the initial position of the powder laying layer is also determined, and further, the time T from the movement of the powder laying layer in the powder laying layer to the light-emitting safety point can be determinedy。
Further, when the powder spreading shaft starts to spread powder from the initial position, timing is started;
when the timing exceeds the reaching time, the powder spreading shaft can be judged to move to a light-emitting safety point, the powder spreading shaft is determined to be not interfered with the laser light-emitting and printing actions, and the light-emitting operation is carried out at the moment, so that the printing waiting time can be reduced.
Further, as a preferred embodiment of the present invention, the moving speed of the powder spreading shaft is divided into a constant acceleration stage and a constant speed stage.
In this case, as shown in fig. 2(a), it can be seen that the movement of the powder spreading shaft is a constant acceleration phase-constant velocity phase-constant acceleration phase. Therefore, the accurate calculation of the time for the powder spreading shaft to reach the light-emitting safety point can be more conveniently carried out by the system, and the powder spreading quality is also facilitated.
This mode determines the light triggering mode in a speed-time manner.
Further, as a preferred embodiment of the present invention, the real-time position of the powder spreading shaft is monitored, and when the powder spreading shaft moves to the light-emitting safety point, the light-emitting operation is performed.
The powder spreading shaft can be monitored in real time in position through the motor encoder, the position is subjected to auxiliary judgment (dangerous accidents caused by disconnection of the motor and the linkage mechanism are avoided) by the aid of the high-definition camera, whether the powder spreading shaft reaches the light-emitting safety point position or not is determined, and the light-emitting triggering mode is directly determined by the mode of the powder spreading shaft.
Compared with the traditional mode and the unified threshold mode, the invention calculates the light-emitting safety points for each powder-laying layer (for a 3D printing task, under the condition that the system is set to be N layers of powder-laying layers, the dynamic calculation of the light-emitting safety points is realized on the whole, namely, the light-emitting control mode is realized dynamically), allows the laser to perform light-emitting operation before the powder-laying shaft moves to the end position, namely, through the mode that the powder-laying time of the light-emitting safety points is coincided with the printing time (at least partially coincided), reduces the waiting time under the condition that the powder-laying shaft is ensured not interfered with the laser light-emitting and printing actions, ensures the production safety, and improves the printing efficiency of the equipment; meanwhile, the triggering condition of the light emitting is accurately determined by adopting a time mode and a position mode.
The following compares the method proposed by the present invention, the conventional method, and the uniform threshold method with reference to fig. 2.
As shown in fig. 2, a schematic diagram of a comparison between the dynamic light output control method of the powder-spreading 3D printing apparatus provided by the present invention and a method in the prior art is shown. In the actual printing process, the powder spreading shaft is provided with N layers with the same printing layer number for ensuring the powder spreading quality, and each layer needs to be spread at a powder spreading speed V according to a set valuepThe powder spreading stroke is always kept unchanged to SpAnd the powder laying time T of each layerpAnd are all the same.
As shown in FIG. 2(a), in a conventional manner, each layer of powder laying shaft needs S to movepPrinting apparatusAll the devices need to wait for TpTime, i.e. the time required to wait after printing a task, is N x Tp。
Adopting a uniform threshold mode, and setting the light-emitting safety point to be Sy(this is understood to mean the distance from the initial position of the powder laying shaft to the position of the light-emitting safety point), the time required for the light-emitting safety point to reach the final position is TyAnd each layer adjusts the light emitting time to T through the in-place threshold valuep-TyThat is, the time required to wait for printing a job is N × (T)p-Ty) The distance saved is N × (S)p-Sy). However, the adjustment is also required to be the same value for each layer, and this value needs to be compatible with all layers of the whole part, and even more needs different parts to change different in-place thresholds, so that it is very inflexible and convenient.
As shown in figure 2(b), the powder laying time of each layer is still kept unchanged T by adopting the method provided by the invention
pBecause the safety intervals of each layer are different, the light-emitting safety point is arranged
Therefore, the light-emitting time is a dynamic light-emitting time
And the value is automatically calculated according to the position of the light-emitting safety point and the end point of the part needing 3D printing of the current layer, so that the control is more convenient and flexible. This T
sIs determined according to the position of the powder laying shaft reaching the light-emitting safety point, and finally the time saved by each layer is T
p-T
s(T
sIs a dynamic value), that is, the time required to wait for a job to be printed is
And compared to T in a uniform threshold manner
yIn the method of the present invention, the printing light-emitting time of the ith layer
Is provided with
Can obtain the product
The printing efficiency of the device is remarkably improved. Therefore, except for some special situations, compared with the prior art, the method provided by the invention can save the light emergent waiting time of the equipment to the maximum extent, so that the printing efficiency of the equipment tends to be optimal.
Fig. 3 is a schematic structural diagram of a light emitting dynamic control device of a powder laying type 3D printing apparatus according to a second embodiment of the present invention. As shown in fig. 3, the dynamic light-emitting control device may include:
the calculation unit is used for determining the powder laying length of each powder laying layer according to the printing task; determining the light-emitting safety point of each powder laying layer according to the powder laying length of each powder laying layer; wherein the length of the light-emitting safety point from the initial position of the powder laying shaft is the powder laying length
The monitoring unit is used for monitoring the movement of the powder spreading shaft to the light-emitting safety point and sending a light-emitting signal to the light-emitting control unit;
and the light emitting control unit is used for controlling light emitting when receiving the light emitting signal.
Wherein, for a 3D printing task, any two layers of 3D printing can be completely the same, not completely the same or even completely different. The design of the invention is that the calculation unit is adopted to judge and regulate the touch threshold value of each layer of 3D printing, the touch threshold value is increased as much as possible under the condition that the powder spreading shaft does not interfere with the laser light emitting and printing actions, and the waiting time is reduced, thereby improving the production efficiency of the equipment. Each touch threshold value is the light-emitting safety point provided by the invention, namely when the powder spreading shaft carries out powder spreading operation, the moment when the powder spreading shaft moves to the light-emitting safety point and the moment later, the powder spreading shaft does not interfere with laser light-emitting and printing actions, and the equipment is safe in production.
Here, it should be noted that the calculation unit calculates the end position from the light exit safety point to the powder spreading shaft, that is, the light exit safety zone, and in principle, when the powder spreading shaft moves at any position in the light exit safety zone, the light exit operation can be performed, so that the powder spreading shaft and the laser light exit and printing actions can be guaranteed to be not interfered with each other, and the production safety is guaranteed, but in order to save time, the larger the light exit safety zone is, that is, the closer the light exit safety point is to the initial position of the powder spreading shaft is, the better the 3D printing task is satisfied.
It should be further noted that since the 3D printing can be performed after the powder spreading operation is completed, the light-emitting safety point and the light-emitting safety interval are both relative to or adjacent to the end point of the powder spreading axis for both the single-pass powder spreading operation and the reciprocating powder spreading operation.
For any 3D printing task, determining the powder laying length of each powder laying layer, wherein the powder laying length is the length of powder laying required by the powder laying layer, namely the length of a powder laying shaft moving from an initial position to a light-emitting safety point position, namely the minimum value of the printing task which can be met when the powder laying layer finally emits light for printing.
In order to reduce waiting time as much as possible, the powder laying shaft controls the light emitting operation when moving to the light emitting safety point. Here, it should be noted that when the powder spreading shaft moves to the light-emitting safety point, specifically, the powder spreading operation of the powder spreading shaft is not completed, but the powder spreading operation of the portion to be 3D printed of the current layer is completed, and the powder spreading shaft now performs the powder spreading movement to the end position.
Further, as a preferred embodiment of the present invention, the calculating unit is further configured to determine the time for the powder spreading shaft to move to the light exit safety point according to the powder spreading length and the movement speed of the powder spreading shaft.
Further, as a preferred embodiment of the present invention, the monitoring unit is configured to count time, and when the powder spreading shaft starts spreading powder from the initial position, the monitoring unit starts counting time;
and when the timing of the monitoring unit exceeds the reaching time, sending the light emitting signal to the light emitting control unit.
The method comprises the steps that a timing method is adopted to determine the time when a powder spreading shaft moves to a light-emitting safety point, and the time when the powder spreading shaft moves to the light-emitting safety point can be determined through calculation after the powder spreading length of each powder spreading layer is determined due to the fact that the movement speed of the powder spreading shaft is preset by powder spreading type 3D printing equipment.
Fig. 2(a) is a specific powder-laying shaft speed-time chart according to an embodiment of the present invention.
The powder spreading shaft is provided with N layers with the same printing layer number for ensuring the powder spreading quality, and each layer needs to be spread at a set powder spreading speed VpAnd (4) finishing. The area enclosed by the speed curve of the powder laying shaft and the time shaft is the moving distance of the powder laying shaft, and the moving distance is the distance from the powder laying shaft to the initial position under the general condition. Based on this, when the light-emitting safety point is determined, the distance from the light-emitting safety point to the initial position of the powder laying layer is also determined, and further, the time T from the movement of the powder laying layer in the powder laying layer to the light-emitting safety point can be determinedy。
Further, as a preferred embodiment of the present invention, the moving speed of the powder spreading shaft is divided into a constant acceleration stage and a constant speed stage.
In this case, as shown in fig. 2(a), it can be seen that the movement of the powder spreading shaft is a constant acceleration phase-constant velocity phase-constant acceleration phase. Therefore, the accurate calculation of the time for the powder spreading shaft to reach the light-emitting safety point can be more conveniently carried out by the system, and the powder spreading quality is also facilitated.
This mode determines the light triggering mode in a speed-time manner.
Further, as a preferred embodiment of the present invention, the monitoring unit is configured to monitor a real-time position of the powder spreading shaft, and send the light-emitting signal to the light-emitting control unit when the real-time position of the powder spreading shaft is the light-emitting safety point.
The powder spreading shaft can be monitored in real time in position through the motor encoder, the position is subjected to auxiliary judgment (dangerous accidents caused by disconnection of the motor and the linkage mechanism are avoided) by the aid of the high-definition camera, whether the powder spreading shaft reaches the light-emitting safety point position or not is determined, and the light-emitting triggering mode is directly determined by the mode of the powder spreading shaft.
Compared with the traditional mode and the unified threshold mode, the invention calculates the light-emitting safety points for each powder-laying layer (for a 3D printing task, under the condition that the system is set to be N layers of powder-laying layers, the dynamic calculation of the light-emitting safety points is realized on the whole, namely, the light-emitting control mode is realized dynamically), allows the laser to perform light-emitting operation before the powder-laying shaft moves to the end position, namely, through the mode that the powder-laying time of the light-emitting safety points is coincided with the printing time (at least partially coincided), reduces the waiting time under the condition that the powder-laying shaft is ensured not interfered with the laser light-emitting and printing actions, ensures the production safety, and improves the printing efficiency of the equipment; meanwhile, the triggering condition of the light emitting is accurately determined by adopting a time mode and a position mode.
Fig. 4 is a schematic view of a dynamic structure of a light emitting dynamic control device of a powder laying type 3D printing apparatus according to an embodiment of the present invention. As shown in fig. 4:
the device comprises a laser 1, a galvanometer 2, an initial position 3, a focal plane 4, a powder feeding shaft 5, a forming shaft 6, a terminal position 7, a powder laying shaft 8, a safety interval 9 and a light emergent safety point 10.
Taking a 3D printing task as an example, in a powder spreading process of a certain powder spreading layer, since a calculating unit in the system has already calculated and determined the powder spreading length of the powder spreading layer, the light exit safety point position 10, and the time (i.e., the arrival time) required for the powder spreading axis to reach the light exit safety point position 10. When the powder spreading shaft 8 starts to spread powder from the powder spreading initial position 3, the detection unit starts to time; when the timing in the detection unit exceeds the arrival time, the powder paving shaft is judged to have arrived the light-emitting safety point 10, and the whole powder paving shaft has passed through the light-emitting safety point 10, so that the mutual noninterference between the powder paving shaft and the laser light-emitting can be ensured, and the production safety is ensured. The laser 1 emits light, and the laser light can effectively reach a designated position through the vibrating mirror 2. Thereafter, the layup shaft continues to move, but the layup operation may or may not be present, which does not affect subsequent printing of the 3D print job. It should be noted here that the light emission can only be carried out when the entire powder-laying shaft passes through the light emission safety point 10. Based on the angle, when the motor encoder and the high-definition camera of the system monitor that the powder paving shaft integrally passes through the light-emitting safety point 10, light can be emitted.
Wherein, the focal plane 4 determines the powder laying plane, thereby ensuring the powder laying quality. And repeating the operation on each powder layer to realize dynamic light emitting control, saving time on the whole by saving the time of each powder layer, and improving the work and production efficiency.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.