阅读说明：本技术 粉末床形貌测量装置及方法 (Powder bed shape measuring device and method ) 是由 王天骄 赵学峰 融亦鸣 于 2021-06-30 设计创作，主要内容包括：本公开实施例中提供了一种粉末床形貌测量装置及方法,属于金属增材制造技术领域,粉末床形貌测量装置,包括：线激光扫描仪；驱动装置,包括位于粉末床作业一侧的固定轨道、以及在所述固定轨道上运动的动力块；安装板,用于将所述线激光扫描仪固定于所述动力块上,使所述线激光扫描仪在所述粉末床表面一侧运动且朝向所述粉末床设置,以检测粉末床作业表面多个位置的高度。通过本公开的处理方案,能够防止凸点在铺粉装置移动过程中损伤铺粉装置,进而提高粉末床表面质量和形貌。(The embodiment of the disclosure provides a powder bed appearance measuring device and a method, which belong to the technical field of metal additive manufacturing, and the powder bed appearance measuring device comprises: a line laser scanner; the driving device comprises a fixed rail positioned on one side of the powder bed in operation and a power block moving on the fixed rail; the mounting panel, be used for with line laser scanner is fixed in on the power piece, make line laser scanner is in powder bed surface one side motion just moves towards the powder bed sets up to detect the height of powder bed operation surface a plurality of positions. Through this disclosed processing scheme, can prevent that the bump from spreading the powder device at the damage of spreading the powder device removal in-process, and then improve powder bed surface quality and appearance.)

1. A powder bed morphology measuring device, comprising:

a line laser scanner;

the driving device comprises a fixed rail positioned on one side of the powder bed in operation and a power block moving on the fixed rail;

the mounting panel, be used for with line laser scanner is fixed in on the power piece, make line laser scanner is in powder bed surface one side motion just moves towards the powder bed sets up to detect the height of powder bed operation surface a plurality of positions.

2. The powder bed morphology measurement device of claim 1, wherein the fixed track comprises a ball screw, the power block comprises a servo motor sleeved on the ball screw, and the ball screw rotates to drive the servo motor to move on the ball screw.

3. The powder bed topography measuring device of claim 1, wherein said mounting plate is provided with a plurality of screw holes, and said line laser scanner is secured to said mounting plate by means of bolts and said screw holes.

4. The powder bed topography measuring device of claim 3, further comprising a scraper powder spreading mechanism, said scraper powder spreading mechanism being fixed to said mounting plate by bolts and said screw holes.

5. The powder bed morphology measurement device of claim 3, further comprising a powder dropping and spreading mechanism, wherein the powder dropping and spreading mechanism is fixed on the mounting plate through a bolt and the screw hole;

the number of line laser scanners is two sets of, it is located two sets of to fall powder shop powder mechanism line laser scanners.

6. A powder bed topography measuring method applied to the powder bed topography measuring apparatus according to any one of claims 1 to 5, comprising:

in the process that the driving device drives the line laser scanner to move from the first end to the second end, the line laser scanner collects first heights of a plurality of positions on the surface of the powder bed;

when the height difference between the first height without position and the first average height at the peripheral position of the powder bed is larger than the first height difference, printing the surface of the powder bed according to a preset pattern;

after printing is finished, the line laser scanner is driven by the driving device to move from the second end to the first end, and the line laser scanner collects second heights of a plurality of positions on the printing surface of the powder bed;

and when the height difference between the second height of the target position and the second average height of the peripheral position of the target position is greater than the second height difference, stopping the movement of the mounting plate and outputting a reminding message.

7. The method of claim 6, wherein the step of moving the line laser scanner from the first end to the second end with the drive device, the line laser scanner acquiring a first height of a plurality of locations on the surface of the powder bed comprises:

the driving device drives the line laser scanner to move from a first end to a second end, wherein the line laser scanner is started after the mounting plate is located at the first position;

after the line laser scanner is started, the line laser scanner collects first heights of N positions on the surface of the powder bed at intervals of a preset distance period;

after the mounting plate is in the second position, the line laser scanner is turned off.

8. The method according to claim 6, applied to the powder bed topography measuring device of claim 4; drive arrangement drives line laser scanner moves the in-process of second end from first end, line laser scanner gathers the first height of powder bed surface multiple position, includes:

the driving device drives the line laser scanner to move from a first end to a second end, wherein the scraper powder spreading mechanism is started firstly, and the line laser scanner is started after the mounting plate is located at the first position;

after the scraper powder spreading mechanism is started, the scraper powder spreading mechanism drops powder; and after the line laser scanner is started, the line laser scanner collects the first heights of N positions on the surface of the powder bed at intervals of a preset distance period.

9. The method of claim 8, wherein the driving device moves the line laser scanner from the second end to the first end, the line laser scanner acquiring a second height of the plurality of locations of the printing surface on the powder bed, comprising:

the driving device drives the line laser scanner to move from the second end to the first end, wherein after the mounting plate is located at the second position, the line laser scanner is started to periodically acquire second heights of N positions on the printing surface of the powder bed at intervals of a preset distance; the second position is located on a side of the first position near the second end.

10. The method according to claim 6, applied to the powder bed topography measuring device of claim 5; drive arrangement drives line laser scanner moves the in-process of second end from first end, line laser scanner gathers the first height of powder bed surface multiple position, includes:

the driving device drives the line laser scanner to move from the first end to the second end, wherein the first line laser scanner is started after the mounting plate is located at the first position; after the mounting plate is located at the second position, the powder falling and spreading mechanism is started; after the mounting plate is located at a third position, starting a second line laser scanner, wherein the first position, the second position and the third position are respectively and sequentially distributed from the second end to the first end, the first line laser scanner is a line laser scanner of which the powder falling and spreading mechanism is close to the second end, and the second line laser scanner is a line laser scanner of which the powder falling and spreading mechanism is close to the first end;

after the first line laser scanner is started, the first line laser scanner collects third heights of N positions on the substrate every other preset distance period; after the powder falling and spreading mechanism is started, the powder falling and spreading mechanism carries out first powder falling; after the second line laser scanner is started, the second line laser scanner collects first heights of N positions on the surface of the powder bed after powder falling for the first time at intervals of a preset distance period;

and under the condition that the height difference between the first height of one position and the first average height of the peripheral position of the position is greater than the first height difference, stopping the movement of the mounting plate and outputting a reminding message.

11. The method of claim 10, wherein the driving device moves the line laser scanner from the second end to the first end, the line laser scanner acquiring a second height of the plurality of locations of the printing surface on the powder bed, comprising:

the driving device drives the line laser scanner to move from the second end to the first end, wherein the second line laser scanner is started after the mounting plate is located at the fourth position; after the mounting plate is located at the fifth position, the powder falling and spreading mechanism is started; after the mounting plate is located at a sixth position, starting a first line laser scanner, wherein the fourth position, the fifth position and the sixth position are respectively distributed in sequence from the first end to the second end;

after the second line laser scanner is started, the second line laser scanner collects second heights of N positions on the printing surface of the powder bed at intervals of a preset distance period; after the powder falling and spreading mechanism is started, the powder falling and spreading mechanism carries out secondary powder falling; after the first line laser scanner is started, the first line laser scanner collects the fourth height of the N positions on the surface of the powder bed every other preset distance period after the powder falls for the second time.

12. The method according to claim 10 or 11, characterized in that the method further comprises:

under the condition that the height difference between the third height of one position and the third average height of the peripheral position of the position is smaller than the first height difference and larger than the third height difference, controlling the mounting plate to return to the first end so that the powder falling and spreading mechanism falls the powder again on the powder bed;

or under the condition that the height difference between the fourth height of one position and the fourth average height of the peripheral position of the position is smaller than the first height difference and larger than the third height difference, the mounting plate is controlled to return to the second end, so that the powder falling and spreading mechanism falls the powder again in the powder bed.

Technical Field

The disclosure relates to the technical field of metal additive manufacturing, in particular to a powder bed shape measuring device and method.

Background

With the continuous development of science and technology and the continuous improvement of economic level, metal additive manufacturing technology is also developed. Additive Manufacturing (AM) is commonly called 3D printing, combines computer aided design, material processing and molding technology, and is a Manufacturing technology for Manufacturing solid articles by stacking special metal materials, non-metal materials and medical biomaterials layer by layer through software and a numerical control system on the basis of a digital model file in modes of extrusion, sintering, melting, photocuring, spraying and the like.

In the existing mainstream metal additive manufacturing method, the formed part subjected to selective laser melting has high density, good mechanical property and good surface quality, and meanwhile, because the whole working chamber is sealed in an inert gas protection environment in the printing process, the oxidation reaction of the material and oxygen at high temperature is avoided, so that active metals such as titanium alloy and the like can be processed. In addition, various molded parts with complex structures can be printed by adding a supporting structure, so that the selective laser melting technology is more and more widely applied.

This technique also produces some defects during printing that degrade the powder bed surface quality and morphology.

Disclosure of Invention

In view of the above, embodiments of the present disclosure provide a powder bed topography measurement apparatus and method, which at least partially solve the problems in the prior art.

In a first aspect, an embodiment of the present disclosure provides a powder bed topography measurement apparatus, including:

a line laser scanner;

the driving device comprises a fixed rail positioned on one side of the powder bed in operation and a power block moving on the fixed rail;

the mounting panel, be used for with line laser scanner is fixed in on the power piece, make line laser scanner is in powder bed surface one side motion just moves towards the powder bed sets up to detect the height of powder bed operation surface a plurality of positions.

Further, the fixed track includes ball, the power piece is located including the cover ball on the servo motor, ball rotates in order to drive servo motor is in the motion on the ball.

Furthermore, a plurality of screw holes are formed in the mounting plate, and the line laser scanner is fixed on the mounting plate through bolts and the screw holes.

Further, still include scraper and spread powder mechanism, scraper spread powder mechanism pass through the bolt with the screw is fixed in on the mounting panel.

The powder falling and spreading mechanism is fixed on the mounting plate through bolts and the screw holes;

the number of line laser scanners is two sets of, it is located two sets of to fall powder shop powder mechanism line laser scanners.

In a second aspect, embodiments of the present disclosure also provide a powder bed shape measuring method applied to the powder bed shape measuring apparatus described above, including:

in the process that the driving device drives the line laser scanner to move from the first end to the second end, the line laser scanner collects first heights of a plurality of positions on the surface of the powder bed;

when the height difference between the first height without position and the first average height at the peripheral position of the powder bed is larger than the first height difference, printing the surface of the powder bed according to a preset pattern;

after printing is finished, the line laser scanner is driven by the driving device to move from the second end to the first end, and the line laser scanner collects second heights of a plurality of positions on the printing surface of the powder bed;

and when the height difference between the second height of the target position and the second average height of the peripheral position of the target position is greater than the second height difference, stopping the movement of the mounting plate and outputting a reminding message.

Further, in the process that drive arrangement drove line laser scanner and move from first end to second end, line laser scanner gathers the first height of powder bed surface multiple position, includes:

the driving device drives the line laser scanner to move from a first end to a second end, wherein the line laser scanner is started after the mounting plate is located at the first position;

after the line laser scanner is started, the line laser scanner collects first heights of N positions on the surface of the powder bed at intervals of a preset distance period;

after the mounting plate is in the second position, the line laser scanner is turned off.

Further, in the process that drive arrangement drove line laser scanner and move from first end to second end, line laser scanner gathers the first height of powder bed surface multiple position, includes:

the driving device drives the line laser scanner to move from a first end to a second end, wherein the scraper powder spreading mechanism is started firstly, and the line laser scanner is started after the mounting plate is located at the first position;

after the scraper powder spreading mechanism is started, the scraper powder spreading mechanism drops powder; and after the line laser scanner is started, the line laser scanner collects the first heights of N positions on the surface of the powder bed at intervals of a preset distance period.

Further, in the process that drive arrangement drove line laser scanner and move from the second end to first end, line laser scanner gathers the second height of the multiple position of the surface of printing on the powder bed, includes:

the driving device drives the line laser scanner to move from the second end to the first end, wherein after the mounting plate is located at the second position, the line laser scanner is started to periodically acquire second heights of N positions on the printing surface of the powder bed at intervals of a preset distance; the second position is located on a side of the first position near the second end.

Further, in the process that drive arrangement drove line laser scanner and move from first end to second end, line laser scanner gathers the first height of powder bed surface multiple position, includes:

the driving device drives the line laser scanner to move from the first end to the second end, wherein the first line laser scanner is started after the mounting plate is located at the first position; after the mounting plate is located at the second position, the powder falling and spreading mechanism is started; after the mounting plate is located at a third position, starting a second line laser scanner, wherein the first position, the second position and the third position are respectively and sequentially distributed from the second end to the first end, the first line laser scanner is a line laser scanner of which the powder falling and spreading mechanism is close to the second end, and the second line laser scanner is a line laser scanner of which the powder falling and spreading mechanism is close to the first end;

after the first line laser scanner is started, the first line laser scanner collects third heights of N positions on the substrate every other preset distance period; after the powder falling and spreading mechanism is started, the powder falling and spreading mechanism carries out first powder falling; after the second line laser scanner is started, the second line laser scanner collects first heights of N positions on the surface of the powder bed after powder falling for the first time at intervals of a preset distance period;

and under the condition that the height difference between the first height of one position and the first average height of the peripheral position of the position is greater than the first height difference, stopping the movement of the mounting plate and outputting a reminding message.

Further, in the process that drive arrangement drove line laser scanner and move from the second end to first end, line laser scanner gathers the second height of the multiple position of the surface of printing on the powder bed, includes:

the driving device drives the line laser scanner to move from the second end to the first end, wherein the second line laser scanner is started after the mounting plate is located at the fourth position; after the mounting plate is located at the fifth position, the powder falling and spreading mechanism is started; after the mounting plate is located at a sixth position, starting a first line laser scanner, wherein the fourth position, the fifth position and the sixth position are respectively distributed in sequence from the first end to the second end;

after the second line laser scanner is started, the second line laser scanner collects second heights of N positions on the printing surface of the powder bed at intervals of a preset distance period; after the powder falling and spreading mechanism is started, the powder falling and spreading mechanism carries out secondary powder falling; after the first line laser scanner is started, the first line laser scanner collects the fourth height of the N positions on the surface of the powder bed every other preset distance period after the powder falls for the second time.

Further, the method further comprises:

under the condition that the height difference between the third height of one position and the third average height of the peripheral position of the position is smaller than the first height difference and larger than the third height difference, controlling the mounting plate to return to the first end so that the powder falling and spreading mechanism falls the powder again on the powder bed;

or under the condition that the height difference between the fourth height of one position and the fourth average height of the peripheral position of the position is smaller than the first height difference and larger than the third height difference, the mounting plate is controlled to return to the first end, so that the powder falling and spreading mechanism falls the powder again in the powder bed.

In the embodiment of the disclosure, a line laser scanner is arranged on one working side of a powder bed, the height of each position is detected for multiple times when the line laser scanner passes through the powder bed, whether a bump higher than the peripheral position exists or not is distinguished, and when the bump is determined to exist, the movement of an installation plate is stopped and a worker is reminded; like this, can prevent that the bump from spreading the powder device at the damage of powder device removal in-process, and then improve powder bed surface quality and appearance.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings needed to be used in the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a powder bed topography measurement apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a powder bed topography measurement apparatus according to another embodiment of the present invention;

fig. 3 is a flowchart of a powder bed morphology measuring method according to an embodiment of the present invention.

Detailed Description

The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

The embodiments of the present disclosure are described below with specific examples, and other advantages and effects of the present disclosure will be readily apparent to those skilled in the art from the disclosure in the specification. It is to be understood that the described embodiments are merely illustrative of some, and not restrictive, of the embodiments of the disclosure. The disclosure may be embodied or carried out in various other specific embodiments, and various modifications and changes may be made in the details within the description without departing from the spirit of the disclosure. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

It is noted that various aspects of the embodiments are described below within the scope of the appended claims. It should be apparent that the aspects described herein may be embodied in a wide variety of forms and that any specific structure and/or function described herein is merely illustrative. Based on the disclosure, one skilled in the art should appreciate that one aspect described herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented and/or a method practiced using any number of the aspects set forth herein. Additionally, such an apparatus may be implemented and/or such a method may be practiced using other structure and/or functionality in addition to one or more of the aspects set forth herein.

It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present disclosure, and the drawings only show the components related to the present disclosure rather than the number, shape and size of the components in actual implementation, and the type, amount and ratio of the components in actual implementation may be changed arbitrarily, and the layout of the components may be more complicated.

In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects may be practiced without these specific details.

The embodiment of the present disclosure provides a powder bed shape measuring device 100, including:

a line laser scanner 110;

a driving device 120 including a fixed rail 121 located at a working side of the powder bed 200, and a power block moving on the fixed rail 121;

and a mounting plate 130 for fixing the line laser scanner 110 to the power block, so that the line laser scanner 110 moves toward the powder bed 200 on the side of the surface of the powder bed 200 and is disposed toward the powder bed 200 to detect the heights of the plurality of positions of the work surface of the powder bed 200.

In the embodiment of the disclosure, a line laser scanner is arranged on one working side of a powder bed, the height of each position is detected for multiple times when the line laser scanner passes through the powder bed, whether a bump higher than the peripheral position exists or not is distinguished, and when the bump is determined to exist, the movement of an installation plate is stopped and a worker is reminded; like this, can prevent that the bump from spreading the powder device at the damage of powder device removal in-process, and then improve powder bed surface quality and appearance.

The line laser scanner 110 is used to perform line scanning on the surface of the powder bed 200 at the position where the line is located, thereby determining height information of a plurality of positions of the line scanning. Specifically, the line laser scanner 110 scans N points at a time, and obtains height information of the N points.

Wherein the height information of each point is represented by H^d _mnWhere m denotes the X-axis position of the powder bed, n denotes the Y-axis position of the powder bed, and d denotes the number of layers on the powder bed during scanning. When d is an odd number, the data measured by the line laser scanner 110 is the surface information of the powder bed; when d is an even number, the data measured by the line laser scanner 110 is height information of the printing surface.

When the required measurement width exceeds the measurement width L of the line laser measuring instrument 110, the number of line laser measuring instruments 110 can be increased at the same height to increase the measurement width. The method for calculating the number i of the laser measuring instruments comprises the following steps: the number of effective line scanning points of a single laser measuring instrument is p, and i is n/p.

The driving device 120 is used for driving the laser measuring instrument 110 to move back and forth on the working side of the powder bed 200, and specifically, comprises a fixed rail 121 located on the working side of the powder bed 200, and a power block moving on the fixed rail 121. The extending direction of the fixed rail 121 is parallel to the X-axis direction of the powder bed 200, and the scanning line direction of the line laser scanner 110 is parallel to the Y-axis direction of the powder bed 200, so as to obtain height information of a plurality of positions on the entire plane of the powder bed 200.

The mounting plate 130 is fixedly coupled to the power block and the line laser scanner 110, respectively, to fix the line laser scanner 110 to the power block. And, the probe of the line laser scanner 110 is directed toward the powder bed.

Further, the fixed track 121 includes a ball screw, the power block includes a servo motor sleeved on the ball screw, and the ball screw rotates to drive the servo motor to move on the ball screw.

In this embodiment, the servo motor is sleeved on the ball screw, and the ball screw is controlled to rotate to control the servo motor to move on the ball screw. Because the ball screw has a thread, when the ball screw rotates in the forward direction or in the reverse direction, the thread drives the servo motor to move leftward or rightward, i.e., to move forward or backward on the X-axis of the powder bed 200.

Further, the mounting plate 130 is provided with a plurality of screw holes, and the line laser scanner 110 is fixed to the mounting plate 130 by bolts and the screw holes.

As shown in fig. 1, the mounting plate 130 is formed with a plurality of screw holes so that the line laser scanner 110 is fixed to the screw holes using bolts. The plurality of screw holes may be used to mount the plurality of sets of line laser scanners 110 on the mounting plate 130, and may also be used to mount other devices, which are not limited herein.

Further, as shown in fig. 1, the powder bed topography measuring apparatus 100 further includes a scraper powder spreading mechanism 140, and the scraper powder spreading mechanism 140 is fixed on the mounting plate 130 through a bolt and the screw hole.

The scraper powder spreading mechanism 140 utilizes the flowability of the powder, and the powder is spread on the substrate under the pushing of the scraper and moves by the blade edge of the scraper to form a powder layer. The method avoids the adhesion of the powder because the contact area between the scraper and the powder is small and the scraper almost has no pressure on the powder layer.

Further, as shown in fig. 2, the powder bed shape measuring device 100 further includes a powder falling and spreading mechanism 150, wherein the powder falling and spreading mechanism 150 is fixed on the mounting plate 130 through bolts and the screw holes;

the number of the line laser scanners 110 is two, and the powder falling and spreading mechanism 150 is located between the two line laser scanners 110.

The embodiment of the present disclosure also provides a powder bed shape measuring method, as shown in fig. 3, applied to the powder bed shape measuring apparatus described above, including:

step 310: in the process that the driving device drives the line laser scanner to move from the first end to the second end, the line laser scanner collects first heights of a plurality of positions on the surface of the powder bed;

step 320: when the height difference between the first height without position and the first average height at the peripheral position of the powder bed is larger than the first height difference, printing the surface of the powder bed according to a preset pattern;

step 330: after printing is finished, the line laser scanner is driven by the driving device to move from the second end to the first end, and the line laser scanner collects second heights of a plurality of positions on the printing surface of the powder bed;

step 340: and when the height difference between the second height of the target position and the second average height of the peripheral position of the target position is greater than the first height difference, stopping the movement of the mounting plate and outputting a reminding message.

In the embodiment of the disclosure, a line laser scanner is arranged on one working side of a powder bed, the height of each position is detected for multiple times when the line laser scanner passes through the powder bed, whether a bump higher than the peripheral position exists or not is distinguished, and when the bump is determined to exist, the movement of an installation plate is stopped and a worker is reminded; like this, can prevent that the bump from spreading the powder device at the damage of powder device removal in-process, and then improve powder bed surface quality and appearance.

As shown in fig. 1, the line laser scanner is located at the right side of the figure, which is the first end, and the line laser scanner is located at the left side of the figure, which is the second end.

The driving device is used for driving the laser measuring instrument to move back and forth on the working side of the powder bed, and specifically comprises a fixed rail positioned on the working side of the powder bed and a power block moving on the fixed rail. The extending direction of the fixed track is parallel to the X-axis direction of the powder bed, the scanning line direction of the line laser scanner is parallel to the Y-axis direction of the powder bed, and then height information of a plurality of positions of the whole plane of the powder bed is obtained.

The line laser scanner is capable of detecting a first height of the plurality of locations by the laser light as the drive means drives the line laser scanner across the powder bed surface from the first end to the second end. Taking the line laser scanner to collect n positions at a time, for example, m times, a first height of m × n positions on the powder bed surface can be obtained.

By comparing the first height of each location with the first average height of several locations around it, the surrounding location of a location may be other locations within a 5 x 5 matrix centered at that location. If the height difference between the first height of a certain position and the first average height of the peripheral positions (namely the average value of the first heights of the peripheral positions) is larger than the first height difference, the existing powder bed surface (the surface before printing) is determined to have the convex points, so that the powder spreading device is easily damaged in the moving process, and the quality and the form of the powder bed surface are further deteriorated. Therefore, the movement of the line laser scanner is stopped, and the staff is reminded that the salient points exist on the surface of the powder bed.

If the height difference between the first height without the position and the first average height at the peripheral position is larger than the first height difference, the current powder bed surface (the surface before printing) is determined to be flat, and the surface of the powder bed can be printed according to a preset pattern;

after printing, when drive arrangement drive line laser scanner from second end to first end in-process when printing surface on the powder bed, line laser scanner can detect the second height in a plurality of positions through laser. Taking the line laser scanner to collect n positions at a time, for example, m times, a second height of m × n positions on the printing surface on the powder bed can be obtained.

By comparing the second height of each location with the second average height of several locations around it, the surrounding location of a location may be other locations within a 5 x 5 matrix centered at that location. If the height difference between the second height of a certain position and the second average height of the peripheral positions (namely the average value of the second heights of a plurality of peripheral positions) is larger than the first height difference, the printing surface is determined to have the convex points, so that the powder laying device is easily damaged in the moving process, and the surface quality and the form of the powder bed are further deteriorated. Therefore, the movement of the line laser scanner is stopped, and the staff is reminded that the salient points exist on the surface of the powder bed.

The first height difference may be 40 to 80 μm, and is not limited thereto.

Further, in the process that drive arrangement drove line laser scanner and move from first end to second end, line laser scanner gathers the first height of powder bed surface multiple position, includes:

the driving device drives the line laser scanner to move from a first end to a second end, wherein the line laser scanner is started after the mounting plate is located at the first position;

after the line laser scanner is started, the line laser scanner collects first heights of N positions on the surface of the powder bed at intervals of a preset distance period;

after the mounting plate is in the second position, the line laser scanner is turned off.

As shown in fig. 1, the mounting plate reaches the first position (point P) described above, i.e., the line laser scanner starts to overlap the powder bed, and when the mounting plate starts to reach the first position, the line laser scanner is turned on to start height detection of the position of the powder bed surface.

The mounting plate reaches the above-mentioned second position (point Q), i.e. the line laser scanner ends to coincide with the powder bed, and when the mounting plate starts to reach the second position, the line laser scanner is closed to end the height detection of the position of the powder bed surface.

The driving mechanism drives the mounting plate to move at a constant speed, and the preset distance period is any one distance value from 10 μm to 1mm, which is not limited herein.

In one embodiment, the method is applied to a powder bed topography measurement apparatus as shown in FIG. 1; 8. drive arrangement drives line laser scanner moves the in-process of second end from first end, line laser scanner gathers the first height of powder bed surface multiple position, includes:

the driving device drives the line laser scanner to move from a first end to a second end, wherein the scraper powder spreading mechanism is started firstly, and the line laser scanner is started after the mounting plate is located at the first position;

after the scraper powder spreading mechanism is started, the scraper powder spreading mechanism drops powder; and after the line laser scanner is started, the line laser scanner collects the first heights of N positions on the surface of the powder bed at intervals of a preset distance period.

In this embodiment, as shown in fig. 1, first, the scraper powder spreading mechanism, the line laser scanner and the mounting plate are located on the right side of fig. 1, and the ball screw rotates to drive the mounting plate, the scraper powder spreading mechanism and the line laser scanner to move left together.

Firstly, a scraper powder spreading mechanism is started to drop powder on a base plate to form a powder bed. After that, the mounting plate reaches the first position (point P), the line laser scanner starts to work, and then, as in the measurement principle, the line laser scanner collects once every time the mounting plate moves by the preset distance period a, and the first height of n points on the X-axis distance is obtained. And stopping the collection of the line laser scanner after the mounting plate reaches the point of the second position (Q). Let m equal L_PQAnd a, m represents how many times the layer is collected. The scanning of the layer will obtain an mxn matrix, where the mth row and nth column data is H^d _mn(in this case d is an odd number). When a certain collection is carried out, a first height of a certain position and a first height of a peripheral position of the certain position are foundAnd if the difference of the height difference of the average height is larger than the first height difference, stopping the movement of the mounting plate and prompting an operator.

Further, in the process that drive arrangement drove line laser scanner and move from the second end to first end, line laser scanner gathers the second height of the multiple position of the surface of printing on the powder bed, includes:

the driving device drives the line laser scanner to move from the second end to the first end, wherein after the mounting plate is located at the second position, the line laser scanner is started to periodically acquire second heights of N positions on the printing surface of the powder bed at intervals of a preset distance; the second position is located on a side of the first position near the second end.

In this embodiment, at first the scraper is spread powder mechanism, line laser scanner and mounting panel and is in the left side of the flourishing powder platform of printing in the cavity together, and ball screw rotates and drives mounting panel, scraper and spread powder mechanism and line laser scanner and move to the right together.

When the mounting plate reaches the point of the second position (Q), the line laser scanner starts to work, and then the line laser scanner collects once after moving the distance a according to the measurement principle, and height information of n points at the distance x is obtained. And stopping the collection of the line laser scanner after the mounting plate reaches the first position (P). When the mounting plate moves to the rightmost side, the servo motor is stopped. Let m equal L_PQAnd a, m represents how many times the layer is collected. The scanning of the layer will obtain an mxn matrix, where the mth row and nth column data is H^d _mn(where d is an even number). When the acquisition is carried out for a certain time, the difference of the height difference between the second height of a certain position and the second average height of the peripheral position is larger than the second height difference, the movement of the mounting plate is stopped, and an operator is prompted.

Wherein, the second height value can be 30-70 μm, which is not limited herein.

In another embodiment, to a powder bed topography measurement apparatus as shown in FIG. 2; drive arrangement drives line laser scanner moves the in-process of second end from first end, line laser scanner gathers the first height of powder bed surface multiple position, includes:

the driving device drives the line laser scanner to move from the first end to the second end, wherein the first line laser scanner is started after the mounting plate is located at the first position; after the mounting plate is located at the second position, the powder falling and spreading mechanism is started; after the mounting plate is located at a third position, starting a second line laser scanner, wherein the first position, the second position and the third position are respectively and sequentially distributed from the second end to the first end, the first line laser scanner is a line laser scanner of which the powder falling and spreading mechanism is close to the second end, and the second line laser scanner is a line laser scanner of which the powder falling and spreading mechanism is close to the first end;

after the first line laser scanner is started, the first line laser scanner collects third heights of N positions on the substrate every other preset distance period; after the powder falling and spreading mechanism is started, the powder falling and spreading mechanism carries out first powder falling; after the second line laser scanner is started, the second line laser scanner collects first heights of N positions on the surface of the powder bed after powder falling for the first time at intervals of a preset distance period;

and under the condition that the height difference between the first height of one position and the first average height of the peripheral position of the position is greater than the first height difference, stopping the movement of the mounting plate and outputting a reminding message.

In this embodiment, as shown in fig. 2, first, the powder mechanism, the line laser scanner and the mounting panel are located on the right side of fig. 2, and the ball screw rotates to drive the mounting panel, the powder mechanism, the first line laser scanner and the second line laser scanner to move left together. When the mounting plate reaches a first position (P), the first line laser scanner on the left side of the powder falling and spreading mechanism starts to work, and then the first line laser scanner collects once after every preset distance period a is moved according to the measuring principle, so that the third height of n points on the X-axis distance is obtained. And stopping the collection of the first line laser scanner after the mounting plate reaches the point of the sixth position (Q). Let m equal L_PQThe/a, m' indicates how many times the layer was collected. The layer is sweptAn mxn matrix is obtained by drawing, and the mth row and nth column data are H^d _mn(where d is an even number). When the acquisition is carried out for a certain time, if the difference between the height difference of the third height of a certain position and the third height of the peripheral position of the certain position is larger than the fourth height difference, the movement of the mounting plate is stopped, and an operator is prompted. And when the mounting plate reaches the point of the second position (E), the powder falling and spreading mechanism starts to perform the first powder falling. When the mounting plate reaches a third position (P'), the second line laser scanner on the right side of the powder falling and spreading mechanism starts to work, and then the line laser scanner collects once after each preset distance period a is moved according to the measurement principle, so that a first height of n points on the X-axis distance is obtained. And stopping the acquisition of the second line laser scanner after the mounting plate reaches the fourth position (Q'). Let m equal L_PQ’And a, m represents how many times the layer is collected. The scanning of the layer will obtain an mxn matrix, where the mth row and nth column data is H^d _mn(in this case d is an odd number). When the acquisition is carried out for a certain time, the difference between the height difference of the first height of a certain position and the first average height of the peripheral position of the certain position is found to be larger than the first height difference, the movement of the mounting plate is stopped, and an operator is prompted. And when the mounting plate reaches a fifth position (F), finishing the powder falling of the powder falling and spreading mechanism. When the mounting plate moves to the leftmost side, the servo motor is stopped.

Further, in the process that drive arrangement drove line laser scanner and move from the second end to first end, line laser scanner gathers the second height of the multiple position of the surface of printing on the powder bed, includes:

the driving device drives the line laser scanner to move from the second end to the first end, wherein the second line laser scanner is started after the mounting plate is located at the fourth position; after the mounting plate is located at the fifth position, the powder falling and spreading mechanism is started; after the mounting plate is located at a sixth position, starting a first line laser scanner, wherein the fourth position, the fifth position and the sixth position are respectively distributed in sequence from the first end to the second end;

after the second line laser scanner is started, the second line laser scanner collects second heights of N positions on the printing surface of the powder bed at intervals of a preset distance period; after the powder falling and spreading mechanism is started, the powder falling and spreading mechanism carries out secondary powder falling; after the first line laser scanner is started, the first line laser scanner collects the fourth height of the N positions on the surface of the powder bed every other preset distance period after the powder falls for the second time.

In this embodiment, at first powder mechanism, first line laser scanner, second line laser scanner and the mounting panel of falling are in the left side of the flourishing powder platform of printing in the cavity together, and ball screw is rotatory to be driven the mounting panel, the powder mechanism is spread in falling powder, first line laser scanner and second line laser scanning move to the right together. When the mounting plate reaches a fourth position (Q'), the second line laser scanning on the right side of the powder falling and spreading mechanism starts to work, and then according to the measuring principle, after the mounting plate moves for a preset distance period a, the second line laser scanner collects the second height of the n points on the X-axis distance once, so that the second height of the n points on the X-axis distance is obtained. And stopping the acquisition of the second line laser scanner after the mounting plate reaches the third position (P'). Let m equal L_P’Q’And a, m represents how many times the layer is collected. The scanning of the layer will obtain an mxn matrix, where the mth row and nth column data is H^d _mn(where d is an even number). When the acquisition is carried out for a certain time, the difference of the height difference between the second height of a certain position and the second average height of the peripheral position is larger than the second height difference, the movement of the mounting plate is stopped, and an operator is prompted. And when the mounting plate reaches a fifth position (F), the powder falling and spreading mechanism starts to perform secondary powder falling. When the mounting plate reaches a point (Q) at a sixth position, the first line laser scanner on the left side of the powder falling and spreading mechanism starts to work, and then the first line laser scanner collects once after moving a preset distance period a distance according to a measurement principle to obtain a fourth height of n points on the X-axis distance. And stopping the collection of the first line laser scanner after the mounting plate reaches the first position (P). Let m equal L_PQAnd a, m represents how many times the layer is collected. The scanning of the layer will obtain an mxn matrix, where the mth row and nth column data is H^d _mn(in this case d is an odd number). When a certain collection is carried out, the fourth height of a certain position and the peripheral position thereof are foundThe difference in height difference of the fourth average height is greater than the first height difference, the mounting plate is stopped from moving and an operator is prompted.

Further, the method further comprises:

under the condition that the height difference between the third height of one position and the third average height of the peripheral position of the position is smaller than the first height difference and larger than the third height difference, controlling the mounting plate to return to the first end so that the powder falling and spreading mechanism falls the powder again on the powder bed;

or under the condition that the height difference between the fourth height of one position and the fourth average height of the peripheral position of the position is smaller than the first height difference and larger than the third height difference, the mounting plate is controlled to return to the second end, so that the powder falling and spreading mechanism falls the powder again in the powder bed.

When the powder bed is collected for a certain time, if the difference between the height difference of the third height at a certain position and the third average height at the peripheral position is smaller than the first height difference and larger than the third height difference, the mounting plate is controlled to return to the first end, so that the powder falling and spreading mechanism falls the powder again.

When certain collection is carried out, when the difference of the height difference between the fourth height of a certain position and the fourth average height of the peripheral position of the certain position is found to be smaller than the first height difference and larger than the third height difference, the mounting plate is controlled to return to the second end, so that the powder falling and spreading mechanism carries out powder falling on the powder bed again.

That is, when the first height difference is not exceeded, there is currently no danger that the surface is not flat due to the exceeding of the third height difference, and the powder needs to be dropped again to form a flat surface for the flatness of the subsequent powder bed surface. Wherein the third height difference may be 15-25 μm, which is not limited herein.

The above description is only for the specific embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present disclosure should be covered within the scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.