3D printer, powder spreading device of 3D printer and powder spreading material level detection control method and system

Abstract

The invention discloses a 3D printer, a powder spreading device of the 3D printer and a powder spreading material level detection control method and system, and relates to the field of 3D printing. At least three distance measuring sensors of the material level detection assembly are arranged at intervals in the second direction and conduct downward detection, and the set measuring distances of the distance measuring sensors decrease progressively along one side of the second direction. The powder spreading device moves to a powder adding station below the powder adding device in the first direction so as to add powder, or moves to a detection station below the material level detection assembly so as to detect the material level; the working states of the powder spreading device of the 3D printer comprise a powder adding state with the severity gradually increased, a powder shortage alarm state and a shutdown fault state, during material level detection, if the vertical distance between the actual material level of the powder spreading device and the distance measuring sensor is equal to or larger than the set measuring distance, the distance measuring sensor outputs abnormal state data, and the abnormal state data is sent to the powder spreading device. And the working state is switched to a state with higher severity along with more abnormal state data. The working state is adjusted according to the material level detection data, and uneven powder spreading caused by local powder shortage or too low material level of the powder spreading device is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of 3D printing, in particular to a 3D printer and a powder laying device thereof, a powder laying position detection control method and system. BACKGROUND

[0002] In the field of 3D printing, sand mold 3D printing technology is an additive manufacturing process based on binder jetting technology, mainly used for rapid production of complex sand mold products in the casting industry. Among them, the sand mold 3D printer selectively sprays ink onto the laid sand layer through an inkjet print head, layer by layer bonding and accumulating to form a three-dimensional precision sand mold product, and finally removing the un-solidified loose sand particles.

[0003] The structure of the sand mold 3D printer includes a rack, a printing platform, a printing mechanism, an ink supply mechanism, a powder laying mechanism, and a control system, etc. The powder laying mechanism includes a powder feeder and a powder laying device. The powder laying device is located below the powder feeder. When the powder laying device moves to the position directly below the powder feeder, the powder laying device can receive the powder (or sand) from the discharge port of the powder feeder and move in the horizontal direction to lay powder (or sand) layer by layer on the printing platform.

[0004] However, in the prior art, during the powder laying printing process, the powder laying may be uneven, the powder feeder may fail, and other situations may occur, resulting in local powder shortage of the powder laying device and poor powder laying effect, which further affects the printing efficiency and printing quality. Therefore, it is necessary to propose a new technical solution for the uneven powder laying caused by the local powder shortage of the powder laying device. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a 3D printer and a powder laying device thereof, a powder laying position detection control method and system, which can detect the powder laying position of the powder laying device and adjust the working state according to the powder laying position detection, thereby effectively solving the problem of poor powder laying uniformity caused by the local powder shortage or low powder laying position of the powder laying device.

[0006] The first aspect of the present application provides a powder laying device of a 3D printer, comprising: a powder feeder, below which is provided with a powder feeding station; a powder laying position detection assembly, which is spaced apart from the powder feeder along a first direction and below which is provided with a detection station, the powder laying position detection assembly comprising at least three ranging sensors arranged in a second direction and downward detection, each of the ranging sensors having a set measurement distance, and the set measurement distances of all the ranging sensors decreasing along one side of the second direction; A powder spreader is arranged below the powder feeder and the level detection assembly, and is movable to the powder feeding station in the first direction to feed powder, and is movable to the detection station in the first direction to detect the level, the first direction, the second direction and the up-down direction being perpendicular to each other; The working state of the powder spreading device of the 3D printer includes powder feeding states with increasing severity, an alarm powder shortage state and a shutdown failure state. When the level detection is performed, if the vertical distance between the actual level of the powder spreader and the ranging sensor is equal to or greater than the set measurement distance, the ranging sensor outputs abnormal state data, and the working state is switched to a state with greater severity as the number of abnormal state data increases.

[0007] The powder spreading device of the 3D printer according to the first aspect of the present application has at least the following beneficial effects: The powder feeder and the level detection assembly are arranged on both sides of the powder spreader in the first direction. When the powder spreader needs to be fed, the powder spreader moves to the powder feeding station in the first direction, and the powder feeder adds a certain amount of powder to the powder spreader, so that the powder spreader can spread powder before each printing operation. Since the powder feeder has poor uniformity in powder feeding, the powder feeder fails, and the like, the powder spreader may have a wave-shaped surface or insufficient powder in the second direction, which may cause local powder shortage or low level of the powder spreader, and thus reduce the powder spreading effect and deteriorate the printing quality. Therefore, after the powder spreader moves in the direction from the powder feeding station to the detection station and spreads powder, the level detection assembly detects the level of the powder spreader at the detection station. Moreover, the level detection assembly and the powder feeder are arranged in the first direction, which can ensure that the powder feeding and level detection are independent and do not interfere with each other.

[0008] During the level detection, at least three ranging sensors are arranged in the second direction and downwardly detect the actual level of the powder spreader to realize that the level detection assembly can detect multiple level positions of the powder spreader in the second direction, so as to know whether the powder spreader has local powder shortage or low level. If the vertical distance between the actual level of the powder spreader and the ranging sensor is less than the set measurement distance of the ranging sensor, the ranging sensor outputs normal state data, otherwise, the ranging sensor outputs abnormal state data. If the number of abnormal state data is greater, the level of the powder spreader is more serious, and the working state of the powder spreading device of the 3D printer needs to be adjusted according to the severity of the level. Specifically, the working state of the powder spreading device of the 3D printer is switched to a state with greater severity as the number of abnormal state data increases.

[0009] If the working state is adjusted to the powder adding state, the powder adding device is allowed to add powder to the powder spreading device; if the working state is adjusted to the alarm low material state, the worker is informed to check and maintain the powder adding device; if the working state is adjusted to the stop fault state, the worker is informed to comprehensively check the powder spreading device of the 3D printer. The working state of the powder spreading device of the 3D printer is adjusted according to different material level detection conditions, so as to avoid the problems of uneven powder spreading, reduced printing efficiency and quality caused by local powder shortage or too low material level of the powder spreading device.

[0010] In some embodiments of the present application, all the distance measuring sensors are arranged on the same horizontal plane and uniformly spaced along the second direction, and the set measurement distances of all the distance measuring sensors are in equal difference.

[0011] In some embodiments of the present application, all the distance measuring sensors are symmetrically arranged about the central axis of the powder spreading device extending in the first direction.

[0012] In some embodiments of the present application, the powder spreading device of the 3D printer further comprises a rack and a motion driving device, the powder adding device and all the distance measuring sensors are fixed on the rack, and the output end of the motion driving device is connected with the powder spreading device to drive the powder spreading device to move back and forth along the first direction.

[0013] In some embodiments of the present application, the powder spreading device of the 3D printer further comprises a control device and an alarm device, the control device is electrically connected with the material level detection assembly, the alarm device, the powder adding device and the motion driving device respectively, the control device is configured to control the motion driving device to drive the powder spreading device to move to the powder adding station along the first direction and control the powder adding device to add powder to the powder spreading device when the working state is switched to the powder adding state, control the alarm device to send the alarm low material information when the working state is switched to the alarm low material state, and control the alarm device to send the stop fault information when the working state is switched to the stop fault state.

[0014] In some embodiments of the present application, the distance measuring sensor is provided with five, when the number of abnormal state data is one or two, the working state of the powder spreading device of the 3D printer is switched to the powder adding state to make the powder spreading device move to the powder adding station; when the number of abnormal state data is three or four, the working state of the powder spreading device of the 3D printer is switched to the alarm low material state; when the number of abnormal state data is five, the working state of the powder spreading device of the 3D printer is switched to the stop fault state; and / or, The distance measuring sensor is a laser distance measuring sensor or an infrared distance measuring sensor.

[0015] The second aspect of the present application provides a powder level detection control method applied to the powder laying device of the 3D printer as described in any of the first aspect embodiments, which comprises the following steps: controlling the powder laying device to move to the detection station, and controlling all the distance measuring sensors to perform powder level detection on the powder laying device; acquiring the data output by all the distance measuring sensors; calculating the number of abnormal state data; adjusting the working state of the powder laying device of the 3D printer according to the number of abnormal state data, wherein the adjustment rule is to switch to a state with a greater severity as the number of abnormal state data increases.

[0016] The powder level detection control method according to the second aspect of the present application has at least the following beneficial effects: when the powder laying device moves in the direction from the powder adding station to the detection station and completes the powder laying work, the powder laying device is controlled to move to the detection station in the first direction, and the powder level detection assembly is enabled to perform powder level detection on the powder laying device; at this time, if the vertical distance between the actual powder level of the powder laying device and the distance measuring sensor is equal to or greater than the set measurement distance of the distance measuring sensor, it indicates that the powder level is abnormal, and the distance measuring sensor outputs abnormal state data. After acquiring the data output by all the distance measuring sensors, the number of abnormal state data is counted, and then the working state of the powder laying device of the 3D printer is switched according to the number of abnormal state data according to the adjustment rule, which is to switch to a state with a greater severity as the number of abnormal state data increases. Specifically, in the case of abnormal state data, the number of abnormal state data is divided into three levels, which correspond to the powder adding state, the alarm low powder state and the shutdown fault state respectively, and the powder laying device of the 3D printer is controlled to select and switch between the powder adding state, the alarm low powder state and the shutdown fault state according to the current level, which can prevent the problem of local powder shortage or low powder level of the powder laying device from causing uneven powder laying, reduced printing efficiency and quality.

[0017] In some embodiments of the present application, the distance measuring sensor is provided with five, and the adjustment of the working state of the powder laying device of the 3D printer comprises the following steps: When the number of abnormal state data is one or two, the working state of the powder laying device of the 3D printer is switched to the powder adding state to move the powder laying device to the powder adding station; When the number of abnormal state data is three or four, the working state of the powder laying device of the 3D printer is switched to the alarm low powder state; When the number of the abnormal state data is five, the working state of the powder spreading device of the 3D printer is switched to the shutdown fault state.

[0018] The third aspect of the present application provides a powder level detection control system, which is applied to the powder spreading device of the 3D printer as described in any of the first aspect embodiments, and comprises: a control unit configured to control the powder spreader to move to the detection station and control all the distance measuring sensors to detect the powder level of the powder spreader; an acquisition unit configured to acquire the data output by all the distance measuring sensors; a calculation unit configured to calculate the number of abnormal state data; a state adjustment unit configured to adjust the working state of the powder spreading device of the 3D printer according to the number of abnormal state data, wherein the adjustment rule is to switch to a state with a greater severity as the number of abnormal state data increases.

[0019] The powder level detection control system according to the third aspect of the present application has at least the following beneficial effects: when the powder spreader moves from the powder adding station to the detection station and performs the powder spreading work, the control unit controls the powder spreader to move and stop at the detection station, and controls the powder level detection assembly to complete the powder level detection of the powder spreader; during the powder level detection, if the vertical distance between the actual powder level of the powder spreader and the distance measuring sensor is equal to or greater than the set measurement distance of the distance measuring sensor, the distance measuring sensor will output abnormal state data. After the acquisition unit acquires the data output by all the distance measuring sensors, the calculation unit calculates the number of the collected abnormal state data, and the state adjustment unit switches the working state of the powder spreading device of the 3D printer according to the number of abnormal state data and the adjustment rule, which is to switch to a state with a greater severity as the number of abnormal state data increases. In this way, the situation that the powder is not uniformly spread, the printing efficiency and quality are reduced due to the local powder shortage or low powder level of the powder spreader can be avoided.

[0020] The fourth aspect of the present application provides a 3D printer, which comprises the powder spreading device of the 3D printer as described in any of the first aspect embodiments, or is configured with the powder level detection control system as described in the third aspect of the present application.

[0021] According to the 3D printer provided by the fourth aspect of the present application, at least the following advantages are achieved: the 3D printer can effectively detect the multiple material position points of the powder distributor along the second direction, so as to obtain the specific material position information inside the powder distributor, and switch and adjust the working state of the powder distributor of the 3D printer according to the material position detection result, thereby effectively solving the problem of poor powder distribution uniformity caused by the local powder shortage or low material position of the powder distributor.

[0022] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent from the description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and attained by means of the instrumentalities particularly pointed out in the description and claims, and the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structural schematic diagram of a powder distributor of a 3D printer provided according to an embodiment of the present application; Figure 2 is a working principle schematic diagram of a material position detection assembly in a powder distributor of a 3D printer provided according to an embodiment of the present application; Figure 3 is an electrical connection schematic diagram of a control device, a powder distributor, an alarm device and a motion driving device in a powder distributor of a 3D printer provided according to an embodiment of the present application; Figure 4 is a specific flow schematic diagram of a powder material position detection control method provided according to an embodiment of the present application; Figure 5 is a specific flow schematic diagram of step S4 in a powder material position detection control method provided according to an embodiment of the present application; Figure 6 is a structural schematic diagram of a powder material position detection control system provided according to an embodiment of the present application.

[0024] Reference signs: 110, powder distributor; 111, material receiving hopper; 120, powder distributor; 130, linear guide rail; 140, printing plane; 150, support; 160, distance measuring sensor; 161, detection light beam; 162, intersection point; 170, inclined reference line; 180, sand surface. DETAILED DESCRIPTION

[0025] Embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0026] In the description of the present application, it should be understood that the features defined with "first", "second" can be explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0027] In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] The following refers to Figures 1 to 6 The 3D printer and its powder laying device, powder laying position detection control method and system according to the embodiments of the present application are described.

[0029] As Figures 1 to 3 shown, the powder laying device of the 3D printer according to the first embodiment of the present application can be applied to a sand mold 3D printer to complete the powder laying work before printing. The powder laying device of the 3D printer of the present embodiment can detect the powder laying position of the powder laying device 120 and adjust the working state according to the powder laying position detection, thereby effectively solving the problem of poor powder laying uniformity caused by the local lack of powder or the low powder laying position of the powder laying device 120.

[0030] The powder laying device of the 3D printer has a first direction, a second direction and an up-down direction, wherein the first direction, the second direction and the up-down direction are perpendicular to each other. In the present embodiment, it is assumed that the first direction is the front-back direction and the second direction is the left-right direction.

[0031] As Figure 1 and Figure 2 shown, the powder laying device of the 3D printer includes a powder adding device 110, a powder laying device 120 and a powder laying position detection assembly.

[0032] The powder adding device 110 is fixedly arranged, and a powder adding station is arranged below the powder adding device 110. It can be understood that the powder adding device 110 includes a cylinder extending along the second direction, and the upper part of the cylinder is provided with a receiving hopper 111, which can guide the prepared powder (or sand) into the inside of the cylinder. The lower part of the cylinder is provided with a powder outlet, and the powder in the cylinder is sent to the inside of the powder laying device 120 through the powder outlet, thereby completing the powder adding work of the powder laying device 120.

[0033] The material level detection assembly is fixedly arranged, and the material level detection assembly and the powder adding device 110 are arranged at intervals along the first direction. Moreover, a detection station is arranged below the material level detection assembly. It can be understood that the sand 3D printer is provided with a printing plane 140, and powder spreading printing is performed on the printing plane 140, so as to manufacture a three-dimensional precision sand mold product. The powder adding station is arranged on one side of the printing plane 140 along the first direction, and the detection station is arranged on the other side of the printing plane 140 along the first direction. The powder adding station and the detection station do not affect the product printing work performed on the printing plane 140.

[0034] The material level detection assembly comprises at least three distance measuring sensors 160, and all the distance measuring sensors 160 are arranged at intervals along the second direction. All the distance measuring sensors 160 are downward detection, so as to detect the material level in the powder spreading device 120. In the embodiment, the distance measuring sensor 160 is a laser distance measuring sensor or an infrared distance measuring sensor. Specifically, when detecting the material level of the powder spreading device 120, each distance measuring sensor 160 can vertically emit a detection light beam 161 downward, and the detection light beam 161 is reflected by the sand surface 180 in the powder spreading device 120 and is received by the distance measuring sensor 160, so as to complete the material level detection of the powder spreading device 120.

[0035] Each distance measuring sensor 160 has a set measurement distance, and the specific value of the set measurement distance is set by the worker or according to the actual requirement, which is not limited here. After manual setting, the value of the set measurement distance is constant and does not change due to the material level of the powder spreading device 120. Moreover, the set measurement distances of all the distance measuring sensors 160 decrease along one side of the second direction. For example, the set measurement distances of all the distance measuring sensors 160 decrease from left to right; or the set measurement distances of all the distance measuring sensors 160 decrease from right to left. The decreasing amplitude is not limited and can be set by the worker.

[0036] The powder spreading device 120 is arranged below the powder adding device 110 and the material level detection assembly, so that the powder spreading device 120 can reach the powder adding station or the detection station. Moreover, the powder spreading device 120 is configured to move back and forth along the first direction to perform powder spreading work on the printing plane 140. The powder spreading device 120 can move to the powder adding station along the first direction to add powder, so as to complete the powder supplement work. Moreover, the powder spreading device 120 can also move to the detection station along the first direction to detect the material level. As shown in FIG. 1, the solid line represents that the powder spreading device 120 is located at a position directly below the powder adding device 110, and can receive the powder flowing out of the powder adding device 110. The dashed line represents that the powder spreading device 120 is located at a position directly below the powder adding device 110, and can be detected by the material level detection assembly. Figure 1

[0037] ​In the embodiment, as shown in Figure 1 and Figure 2 , all the distance measuring sensors 160 are in the same horizontal plane, i.e. the installation height positions of all the distance measuring sensors 160 are consistent, and all the distance measuring sensors 160 are uniformly spaced along the second direction, i.e. all the distance measuring sensors 160 are equidistantly arranged along the second direction, and meanwhile, the set measurement distances of all the distance measuring sensors 160 are in an arithmetic progression. Further, all the distance measuring sensors 160 are symmetrically arranged about the central axis of the powder spreader 120 extending along the first direction.

[0038] It can be understood that, as shown in Figure 2 , when the powder spreader 120 stays at the detection station, the material level detection assembly is located directly above the powder spreader 120. The detection light beam 161 emitted by the emitting end of each distance measuring sensor 160 will intersect with the inclined reference line 170 and form an intersection point 162, at which time the distance between the emitting end of the distance measuring sensor 160 and the intersection point 162 is the set measurement distance. The inclined reference line 170 forms an acute angle θ with the horizontal line extending along the second direction, and the specific value of the acute angle θ is not limited and can be set according to actual conditions.

[0039] The working states of the powder spreading device of the 3D printer include a powder adding state, an alarm powder shortage state and a shutdown failure state, and the severity of the powder adding state, the alarm powder shortage state and the shutdown failure state is in an increasing manner. It can be understood that, in addition to the above three, the working states of the powder spreading device of the 3D printer also include a powder spreading state, a standby state, etc.

[0040] When performing the material level detection work, if the vertical distance between the actual material level of the powder spreader 120 and the distance measuring sensor 160 is less than the set measurement distance, the distance measuring sensor 160 will output normal state data, at which time the working state of the powder spreading device of the 3D printer does not need to be switched to the powder adding state, the alarm powder shortage state or the shutdown failure state; if the vertical distance between the actual material level of the powder spreader 120 and the distance measuring sensor 160 is equal to or greater than the set measurement distance, the distance measuring sensor 160 will output abnormal state data, and simultaneously, the working state of the powder spreading device of the 3D printer will be switched to the state with greater severity as the number of abnormal state data increases, i.e. the working state of the powder spreading device of the 3D printer will be switched to the powder adding state, the alarm powder shortage state or the shutdown failure state. Among them, the distance measuring sensor 160 can output high and low levels to respectively represent the output of normal state data and abnormal state data.

[0041] It can be understood that, in the actual powder spreading printing process, it is found that the sand surface 180 inside the powder spreader 120 is not horizontal, but presents a certain degree of wavy shape along the second direction, as shown in Figure 2As shown, this embodiment therefore includes at least three distance sensors 160 spaced apart along the second direction to detect multiple material level positions of the powder spreader 120 along the second direction. Furthermore, the set measurement distance of all distance sensors 160 is set to decrease progressively along one side of the second direction, thereby better determining whether the material level inside the powder spreader 120 meets the requirements (i.e., whether there is localized powder shortage or excessively low material level). By comparing the vertical distance between the transmitter of the distance sensor 160 and the sand surface 180 inside the powder spreader 120 with the set measurement distance, it is determined whether the material level in the powder spreader 120 meets the requirements.

[0042] like Figure 2 As shown, taking one of the ranging sensors 160 as an example, the vertically downward detection beam 161 emitted by the ranging sensor 160 intersects with the inclined reference line 170, forming an intersection point 162, which is point A. The vertical distance between point A and the emitting end of the ranging sensor 160 is set as the preset measurement distance. Simultaneously, the detection beam 161 intersects with the sand surface 180, forming point B. The vertical distance between point B and the emitting end of the ranging sensor 160 is set as the vertical distance. Since point B is located above point A, meaning the vertical distance is less than the preset measurement distance, the material level at this location is determined to be within acceptable limits, and the ranging sensor 160 will output normal status data.

[0043] Taking another ranging sensor 160 as an example, the detection beam 161 emitted by the ranging sensor 160 intersects with the inclined reference line 170, forming an intersection point 162, which is point C. The vertical distance between point C and the emitting end of the ranging sensor 160 is set as the preset measurement distance. At the same time, the detection beam 161 intersects with the sand surface 180, forming a point D. The vertical distance between point D and the emitting end of the ranging sensor 160 is set as the vertical distance. Since point D is located below point C, that is, the vertical distance is greater than the preset measurement distance, the material level at this position is judged as either compliant or non-compliant, and the ranging sensor 160 will output abnormal status data.

[0044] When abnormal status data is output, the number of abnormal status data is divided into three levels, which correspond to the powder filling status, alarm material shortage status, and shutdown fault status, respectively. Based on the current level, the powder spreading device of the 3D printer is controlled to select and switch between the powder filling status, alarm material shortage status, and shutdown fault status.

[0045] In this embodiment, as Figure 1 and Figure 2As shown, the distance measuring sensor 160 is provided with five. Moreover, when the number of abnormal state data is one or two, the powder distributor 120 appears to be a local lack of powder, so as to switch the working state of the powder distribution device of the 3D printer to the powder adding state, so as to make the powder distributor 120 move to the powder adding station along the first direction, so as to make the powder adding device 110 be able to add powder to the powder distributor 120.

[0046] When the number of abnormal state data is three or four, the powder distributor 120 appears to be a general low material level, which may be due to the total amount of powder added by the powder adding device 110 to the powder distributor 120 in the previous time being insufficient, so as to switch the working state of the powder distribution device of the 3D printer to the alarm material shortage state, at this time, the powder adding device 110 and the powder distributor 120 are both stopped running, the powder distributor 120 cannot carry out the powder distribution work, and the powder adding device 110 cannot add powder to the powder distributor 120, so as to facilitate the staff to check the powder adding device 110 and its material level, and pour the powder into the powder adding device 110.

[0047] When the number of abnormal state data is five, the powder distributor 120 appears to be a serious low material level, which may be due to the powder distributor 120 appearing to be a powder leakage fault or the powder adding device 110 appearing to be a powder adding fault, so as to switch the working state of the powder distribution device of the 3D printer to the shutdown fault state, at this time, the powder distribution device of the 3D printer or even the sand mold 3D printer is in a shutdown state, so as to facilitate the staff to carry out fault maintenance work.

[0048] In the embodiment, as shown in Figure 1 The powder distribution device of the 3D printer further comprises a rack and a motion driving device. The powder adding device 110 and all the distance measuring sensors 160 are fixedly arranged on the rack. Specifically, a U-shaped support 150 is arranged on the rack, and all the distance measuring sensors 160 are installed on the support 150. The motion driving device can be installed on the rack, and the output end of the motion driving device is fixedly connected with the powder distributor 120, so as to drive the powder distributor 120 to move back and forth along the first direction. Specifically, at least two straight linear guides 130 are arranged on the rack, and the bottom of the powder distributor 120 is slidably connected to the straight linear guides 130, so that the powder distributor 120 can move linearly along the first direction stably. The motion driving device can be a linear driving device such as a pneumatic cylinder, an electric cylinder, a hydraulic cylinder or a linear module. The powder distributor 120 can adopt a one-way powder distribution mode or a two-way powder distribution mode.

[0049] Further, as shown in Figure 1 and Figure 3As shown, the powder laying device of the 3D printer further comprises a control device and an alarm device. The control device is electrically connected with the level detection assembly, the alarm device, the powder feeder 110 and the motion driving device through lines, so that they can transmit data. The level detection assembly can send the output data to the control device, and the control device can send control instructions to the level detection assembly, the alarm device, the powder feeder 110 and the motion driving device to control them to start or stop.

[0050] Moreover, the control device is configured to control the motion driving device to work when the working state is switched to the powder feeding state, so that the motion driving device drives the powder laying device 120 to move to the powder feeding station along the first direction, and controls the powder feeder 110 to work, so that the powder feeder 110 performs powder feeding treatment on the powder laying device 120; and the control device is configured to control the alarm device to work when the working state is switched to the alarm low material state, so that the alarm device sends the alarm low material information; and the control device is configured to control the alarm device to work when the working state is switched to the shutdown fault state, so that the alarm device sends the shutdown fault information.

[0051] It can be understood that the alarm device can be a sound alarm, a light alarm or a sound and light alarm. The alarm device can send the alarm low material information and the shutdown fault information by controlling the strength of the sound or the color of the light, so that the staff can clearly know that the current working state of the powder laying device of the 3D printer is the alarm low material state or the shutdown fault state.

[0052] When the powder laying device of the 3D printer provided by the first aspect of the present application is used, because the powder feeder 110 and the level detection assembly are arranged on both sides of the powder laying device 120 moving along the first direction, when the powder laying device 120 needs to be fed, the powder laying device 120 moves to the powder feeding station along the first direction, so that the powder feeder 110 adds a certain amount of powder to the powder laying device 120, so that the powder laying device 120 can lay powder before each printing work.

[0053] Because there are problems such as poor uniformity of the powder falling from the powder feeder 110, failure of the powder feeder 110 and the like in the powder laying printing work, which will cause the powder laying device 120 to have a wavy surface or insufficient amount of powder inside along the second direction, and further cause the powder laying device 120 to have local powder shortage or low material level, resulting in reduced powder laying effect and poor printing quality, therefore, after the powder laying device 120 moves along the direction from the powder feeding station to the detection station and lays powder, the level detection assembly detects the material level of the powder laying device 120 at the detection station; and the level detection assembly and the powder feeder 110 are arranged in a spaced manner along the first direction, so as to ensure that the powder feeding work and the material level detection work are completed independently and do not interfere with each other.

[0054] During the material level detection process, at least three distance sensors 160 are arranged at intervals along the second direction and can detect the actual material level of the powder spreader 120 downwards. This allows the material level detection component to detect multiple material level positions of the powder spreader 120 along the second direction, thereby determining whether there is localized powder shortage or excessively low material level in the powder spreader 120. If the vertical distance between the actual material level of the powder spreader 120 and the distance sensor 160 is less than the set measurement distance of the distance sensor 160, it indicates that the material level is within the acceptable range, and the distance sensor 160 outputs normal status data. Otherwise, the distance sensor 160 outputs abnormal status data. The more abnormal status data there are, the more severe the material level problem in the powder spreader 120. In this case, the working state of the 3D printer's powder spreading device needs to be adjusted according to the severity of the material level problem. Specifically, the working state of the 3D printer's powder spreading device is switched towards the state with the greater severity as the number of abnormal status data increases.

[0055] If the operating status is adjusted to the powder adding state, the powder adder 110 will add powder to the powder spreader 120. If the operating status is adjusted to the low powder alarm state, the staff will be notified to check and maintain the powder adder 110. If the operating status is adjusted to the shutdown fault state, the staff will be notified to conduct a comprehensive inspection of the 3D printer's powder spreading device. The operating status of the 3D printer's powder spreading device is adjusted according to different powder level detection conditions to avoid uneven powder spreading, reduced printing efficiency, and reduced quality caused by localized powder shortages or low powder levels in the powder spreader 120.

[0056] like Figures 1 to 5 As shown, the powder level detection and control method according to a second aspect embodiment of the present invention is applied to the powder spreading device of a 3D printer as described in the first aspect embodiment. The powder level detection and control method includes the following steps: Step S1: Control the powder spreader 120 to move to the detection station, and control all the distance sensors 160 to detect the material level of the powder spreader 120.

[0057] Step S2: Acquire the data output by all ranging sensors 160.

[0058] Step S3: Calculate the number of abnormal state data.

[0059] Step S4: Adjust the working status of the powder spreading device of the 3D printer according to the number of abnormal status data. The adjustment rule is to switch to the state with greater severity as the number of abnormal status data increases.

[0060] It can be understood that in step S1, the powder distributor 120 can be moved in the first direction by controlling the driving device to run. In step S2, data acquisition is performed on all the distance sensors 160, regardless of whether the data output by the distance sensors 160 is normal state data or abnormal state data. In step S3, the data from the distance sensors 160 is analyzed to be abnormal state data or normal state data, and the number of abnormal state data is counted. In step S4, according to the number of abnormal state data, it is determined which situation the current powder level of the powder distributor 120 belongs to, and then the working state of the powder distribution device of the 3D printer is switched to the corresponding state.

[0061] If it belongs to the local powder shortage situation, the working state of the powder distribution device of the 3D printer is adjusted to the powder adding state; if it belongs to the general low powder level situation, the working state of the powder distribution device of the 3D printer is adjusted to the alarm low powder state; and if it belongs to the serious low powder level situation, the working state of the powder distribution device of the 3D printer is adjusted to the shutdown fault state.

[0062] In the execution process of the powder level detection control method provided in the second aspect of the present application, when the powder distributor 120 moves in the direction from the powder adding station to the detection station and completes the powder distribution work, the powder distributor 120 is controlled to move in the first direction to the detection station, and the powder level detection assembly is enabled to perform powder level detection processing on the powder distributor 120. At this time, if the vertical distance between the actual powder level of the powder distributor 120 and the distance sensor 160 is equal to or greater than the set measurement distance of the distance sensor 160, it indicates that the powder level is abnormal, and the distance sensor 160 outputs abnormal state data.

[0063] After obtaining all the data output by the distance sensors 160, the number of abnormal state data is counted, and then according to the number of abnormal state data, the working state of the powder distribution device of the 3D printer is switched according to the adjustment rule. The adjustment rule is that the more the number of abnormal state data, the more the state switching to the more serious state. Specifically, in the case of abnormal state data, the number of abnormal state data is divided into three levels, which correspond to the powder adding state, the alarm low powder state and the shutdown fault state respectively. According to the current level, the powder distribution device of the 3D printer is selected and switched between the powder adding state, the alarm low powder state and the shutdown fault state. In this way, the problem of local powder shortage or low powder level of the powder distributor 120 can be prevented, and the problem of uneven powder distribution, low printing efficiency and low printing quality can be prevented.

[0064] In a specific embodiment, as shown in Figure 1 , Figure 2 and Figure 5As shown, the ranging sensor 160 has five sensors. Furthermore, step S4, which is the step of adjusting the operating state of the 3D printer's powder spreading device based on the number of abnormal status data, specifically includes the following steps: Step S41: When there is one or two abnormal status data, switch the working state of the 3D printer's powder spreading device to the powder adding state so that the powder spreading device 120 moves to the powder adding station.

[0065] Step S42: When the number of abnormal status data is three or four, switch the working status of the powder spreading device of the 3D printer to the alarm material shortage status.

[0066] Step S43: When the number of abnormal status data is five, switch the working status of the powder spreading device of the 3D printer to the shutdown fault state.

[0067] Based on the same inventive concept, and corresponding to the powder level detection and control method of the second aspect of the present invention, the third aspect of the present invention provides a powder level detection and control system.

[0068] like Figures 1 to 6 As shown, the powder level detection and control system according to a third aspect embodiment of the present invention is applied to the powder spreading device of a 3D printer as described in the first aspect embodiment. The powder level detection and control system includes a control unit, an acquisition unit, a calculation unit, and a state adjustment unit.

[0069] The control unit is capable of executing step S1 in the powder spreading level detection control method of the second aspect embodiment. Specifically, the control unit is used to control the powder spreader 120 to move to the detection station and control all the distance sensors 160 to detect the powder spreadinger 120 level.

[0070] The acquisition unit is capable of executing step S2 in the powder level detection and control method of the second aspect embodiment. Specifically, the acquisition unit is used to acquire the data output by all the ranging sensors 160.

[0071] The calculation unit is capable of executing step S3 in the powder level detection and control method of the second aspect embodiment. Specifically, the calculation unit is used to calculate the number of abnormal state data.

[0072] The state adjustment unit is capable of executing step S4 in the powder spreading level detection and control method of the second aspect embodiment. Specifically, the function of the state adjustment unit is to adjust the working state of the powder spreading device of the 3D printer according to the number of abnormal state data, wherein the adjustment rule is to switch to a state with greater severity as the number of abnormal state data increases.

[0073] Furthermore, the state adjustment unit can also execute steps S41, S42 and S43 in the powder level detection and control method of the second aspect embodiment.

[0074] During the operation of the powder spreading level detection and control system provided in the third aspect embodiment of the present invention, after the powder spreader 120 moves from the powder feeding station to the detection station and performs powder spreading work, the control unit controls the powder spreader 120 to move and stop at the detection station, and controls the level detection component to complete the level detection work of the powder spreader 120; during the level detection process, if the vertical distance between the actual level of the powder spreader 120 and the distance sensor 160 is equal to or greater than the set measurement distance of the distance sensor 160, the distance sensor 160 will output abnormal status data.

[0075] After the acquisition unit acquires the data output by all the ranging sensors 160, the calculation unit calculates the number of abnormal state data collected, and then the state adjustment unit switches the working state of the powder spreading device of the 3D printer according to the number of abnormal state data and the adjustment rules. The adjustment rules are that the more abnormal state data there are, the more severe the state will be. This can avoid uneven powder spreading, reduced printing efficiency and quality caused by local powder shortage or low material level of the powder spreader 120.

[0076] like Figures 1 to 6 As shown, according to a fourth aspect embodiment of the present invention, the 3D printer includes a powder spreading device as in the first aspect embodiment, or the 3D printer is configured with a powder spreading level detection and control system as in the third aspect embodiment.

[0077] The 3D printer in this embodiment is a sand mold 3D printer. The 3D printer, through its powder spreading device with the aforementioned structure, or equipped with the aforementioned powder spreading material level detection and control system, can effectively detect multiple material points along the second direction of the powder spreader 120. This allows for a clear understanding of the specific material level inside the powder spreader 120. Furthermore, based on the material level detection results, the working state of the 3D printer's powder spreading device is switched and adjusted. This prevents the powder spreading device from continuing to perform powder spreading work when it is in an abnormal state (such as powder adding state, alarm material shortage state, or machine shutdown fault state). This effectively solves the problem of poor powder spreading uniformity caused by localized powder shortages or excessively low material levels in the powder spreader 120, thus helping to ensure excellent printing results and reduce the defect rate of printed products.

[0078] In the description of the specification, reference to "one embodiment", "some embodiments", "an exemplary embodiment", "an example", "a specific example", or "some examples" means that a particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the phrases "in one embodiment", "in some embodiments", "in an exemplary embodiment", "an example", "a specific example", or "some examples" in various places in the specification are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0079] Although embodiments of the application have been shown and described, it will be appreciated that those skilled in the art can make various changes, modifications, substitutions and alterations thereto without departing from the principles and scope of the application, which are defined by the claims and their equivalents.

Claims

1. A powder spreading device of a 3D printer, characterized by, The 3D printer comprises: a powder adding device arranged below the powder adding station; a material level detection assembly arranged below the powder adding device along the first direction, and provided with a detection station, the material level detection assembly comprising at least three ranging sensors arranged in the second direction and downwardly detecting, each ranging sensor having a set measurement distance, and the set measurement distances of all the ranging sensors decreasing on one side of the second direction; a powder laying device arranged below the powder adding device and the material level detection assembly, and movable along the first direction to the powder adding station for powder adding and to the detection station for material level detection, the first direction, the second direction and the up-down direction being perpendicular to each other; wherein the working state of the powder laying device of the 3D printer comprises powder adding states with increasing severity, an alarm powder shortage state and a shutdown failure state, when the material level detection is performed, if the actual material level of the powder laying device is equal to or greater than the vertical distance of the ranging sensor from the set measurement distance, the ranging sensor outputs abnormal state data, and the working state is switched to a state with greater severity as the number of abnormal state data increases.

2. The powder spreading device of a 3D printer according to claim 1, characterized in that, All the ranging sensors are arranged on the same horizontal plane and uniformly spaced in the second direction, and the set measurement distances of all the ranging sensors decrease in an arithmetic progression.

3. The powder spreading device of a 3D printer according to claim 2, characterized in that, All the ranging sensors are symmetrically arranged about the central axis of the powder laying device extending in the first direction.

4. The powder spreading device of a 3D printer according to claim 1, wherein, Further comprising a rack and a motion driving device, the powder adding device and all the ranging sensors are fixedly arranged on the rack, and the output end of the motion driving device is connected with the powder laying device to drive the powder laying device to move back and forth along the first direction.

5. The powder spreading device of a 3D printer according to claim 4, characterized in that, Further comprising a control device and an alarm device, the control device is electrically connected with the material level detection assembly, the alarm device, the powder adding device and the motion driving device, and is configured to control the motion driving device to drive the powder laying device to move to the powder adding station along the first direction when the working state is switched to the powder adding state, and control the powder adding device to perform powder adding process on the powder laying device, control the alarm device to issue an alarm powder shortage information when the working state is switched to the alarm powder shortage state, and control the alarm device to issue a shutdown failure information when the working state is switched to the shutdown failure state.

6. The powder spreading device of a 3D printer according to any one of claims 1 to 5, characterized in that, The ranging sensors are five, when the number of abnormal state data is one or two, the working state of the powder laying device of the 3D printer is switched to the powder adding state to make the powder laying device move to the powder adding station, when the number of abnormal state data is three or four, the working state of the powder laying device of the 3D printer is switched to the alarm powder shortage state, when the number of abnormal state data is five, the working state of the powder laying device of the 3D printer is switched to the shutdown failure state, and / or The ranging sensors are laser ranging sensors or infrared ranging sensors.

7. A powder bed level detection control method applied to a powder spreading device of a 3D printer as claimed in any one of claims 1 to 6, characterized in that, The method comprises the following steps: controlling the powder distributor to move to the detection station and controlling all the distance sensors to detect the powder level of the powder distributor; acquiring data output by all the distance sensors; calculating the number of abnormal state data; adjusting the working state of the powder distribution device of the 3D printer according to the number of abnormal state data, wherein the adjustment rule is to switch to a state with a greater severity as the number of abnormal state data is greater.

8. The powder bed level detection control method of claim 7, wherein, The distance sensor is provided with five, and the working state of the powder distribution device of the 3D printer is adjusted, including the following steps: When the number of abnormal state data is one or two, the working state of the powder distribution device of the 3D printer is switched to the powder adding state, so that the powder distributor moves to the powder adding station; When the number of abnormal state data is three or four, the working state of the powder distribution device of the 3D printer is switched to the alarm low material state; When the number of abnormal state data is five, the working state of the powder distribution device of the 3D printer is switched to the shutdown fault state.

9. A powder bed level detection control system applied to a powder spreading device of a 3D printer as claimed in any one of claims 1 to 6, characterized in that, It includes: a control unit for controlling the powder distributor to move to the detection station and controlling all the distance sensors to detect the powder level of the powder distributor; an acquisition unit for acquiring data output by all the distance sensors; a calculation unit for calculating the number of abnormal state data; a state adjustment unit for adjusting the working state of the powder distribution device of the 3D printer according to the number of abnormal state data, wherein the adjustment rule is to switch to a state with a greater severity as the number of abnormal state data is greater.

10. A 3D printer characterized by, The 3D printer includes a powder distribution device of the 3D printer as claimed in any one of claims 1 to 6, or is provided with a powder level detection control system as claimed in claim 9.

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