Bidirectional powder spreading method, bidirectional powder spreading device and 3D printing equipment

Abstract

The present invention relates to the field of 3D printing technology, and in particular to a bidirectional powder spreading method, a bidirectional powder spreading device and a 3D printing device. The bidirectional powder spreading method includes dropping the powder of two powder spreadings to the rear of a scraper, the scraper moves backward, spreads the powder on a printing platform, and completes the first powder spreading; the scraper continues to move backward, the scraper abuts against a reversing mechanism, the scraper moves upward along the upper surface of the reversing mechanism, and a second layer of powder is left on the printing platform; the scraper descends to a second clamping position through the reversing mechanism, and moves forward at the height of the second clamping position, spreads the second layer of powder on the printing platform, and completes the second powder spreading. A single scraper bidirectional powder spreading is achieved, the powder spreading efficiency is improved, and then the printing efficiency is improved. The bidirectional powder spreading device using the bidirectional powder spreading method provided by the present invention can achieve bidirectional powder spreading, thereby improving the powder spreading efficiency. 3D printing equipment can improve printing efficiency by applying the above-mentioned bidirectional powder spreading device.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a two-way powder spreading method, a two-way powder spreading device and a 3D printing device. Background Art

[0002] With the continuous advancement of science and technology, industrial parts are gradually developing in the direction of precision and complexity. Traditional processing methods such as casting and forging can no longer meet the current manufacturing needs, so 3D printing technology has emerged. 3D printing technology is based on digital model files and uses powdered sand, metal, ceramics and other bondable materials to form parts through layer-by-layer printing and curing. It is one of the main means of additive manufacturing.

[0003] At present, the existing 3D printing equipment mostly adopts one-way powder spreading in the powder spreading process. The powder spreading mechanism first moves in one direction to spread the powder. After the powder spreading is completed, the powder spreading mechanism returns to the initial position, and then the printing mechanism performs laser scanning and printing. After the printing is completed, the printing mechanism returns to the initial position, and finally the next powder spreading process is carried out. There are idle strokes in the powder spreading movement and printing movement of this printing process, which makes the entire printing cycle longer and the efficiency lower.

[0004] Therefore, there is an urgent need for a two-way powder spreading method, a two-way powder spreading device and a 3D printing device to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a two-way powder spreading method, a two-way powder spreading device and a 3D printer, so as to improve the powder spreading efficiency and further improve the printing efficiency.

[0006] In order to achieve the above objectives, the following technical solutions are provided:

[0007] Two-way powder spreading method, including:

[0008] Let the powder from the two layers fall behind the scraper;

[0009] The scraper moves backward to spread the powder on the printing platform, completing the first powder spreading;

[0010] The scraper continues to move backward, the scraper abuts against the reversing mechanism, the reversing mechanism includes a pressing tongue, the scraper moves upward along the upper surface of the pressing tongue, and the second layer of powder is left on the printing platform;

[0011] The scraper continues to move backward and upward at the same time. When the scraper contacts the base, the scraper presses the tongue down. At this time, the tongue is lowered to the second clamping position.

[0012] The scraper moves forward at the height of the second clamping position to spread the second layer of powder on the printing platform, completing the second powder spreading.

[0013] As an optional solution, the distance from the bottom of the scraper to the bottom of the base is a first height, the height of the powder pile is a second height, and the first height is greater than the second height.

[0014] As an optional solution, when the scraper moves forward at the height of the second clamping position to spread the second layer of powder on the printing platform, the pressing tongue is switched to the first clamping position.

[0015] A two-way powder spreading device is used to perform the above-mentioned two-way powder spreading method, and the two-way powder spreading device comprises:

[0016] abutment;

[0017] A scraper, the scraper is slidably matched with the base, and the bottom of the scraper protrudes from the bottom surface of the base, and the scraper is used to spread the powder;

[0018] A reversing mechanism is arranged on the left and right sides of the scraper. The reversing mechanism includes a mounting seat and a pressing tongue. The front end of the pressing tongue is rotatably connected to the mounting seat through a rotating shaft. The height of the pressing tongue gradually increases from front to back. The scraper can abut against the pressing tongue to switch the pressing tongue between a first clamping position and a second clamping position.

[0019] As an optional solution, the reversing mechanism further includes:

[0020] A first elastic clamping member and a second elastic clamping member, a first clamping groove and a second clamping groove are provided on the pressing tongue, the first elastic clamping member can be clamped and matched with the first clamping groove, and the second elastic clamping member can be clamped and matched with the second clamping groove.

[0021] As an optional solution, the reversing mechanism further includes:

[0022] A first elastic member, one end of which abuts against the pressing tongue, and the other end of which abuts against the mounting seat.

[0023] As an optional solution, the bidirectional powder spreading device further includes:

[0024] A second elastic member, one end of the second elastic member abuts against the scraper, and the other end of the second elastic member abuts against the base.

[0025] As an optional solution, the bidirectional powder spreading device further includes:

[0026] The guide mechanism is disposed between the scraper and the base and is configured to move the scraper in an up-down direction.

[0027] As an optional solution, the guiding mechanism includes:

[0028] A mounting member and a plurality of ball bearings, wherein the mounting member is arranged on the base and is provided with a mounting groove extending in the up-down direction, a plurality of ball bearings are installed in the mounting groove in the up-down direction, a guide groove extending in the up-down direction is provided on the scraper, and the ball bearings are rollingly matched with the guide groove.

[0029] A 3D printing device includes a printing device and the above-mentioned two-way powder spreading device, wherein the printing device is used to sinter and shape the powder spread on the printing platform by the two-way powder spreading device.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The bidirectional powder spreading method provided by the present invention includes dropping the powder from two powder spreading operations to the rear of a scraper, the scraper moves backward, spreads the powder on a printing platform, and completes the first powder spreading operation; the scraper continues to move backward, abuts against a reversing mechanism, and moves upward along the upper surface of the reversing mechanism, leaving a second layer of powder on the printing platform; the scraper descends to a second clamping position through the reversing mechanism, and moves forward at the height of the second clamping position, spreads the second layer of powder on the printing platform, and completes the second powder spreading operation. Bidirectional powder spreading with a single scraper is achieved, and the powder spreading efficiency is improved, thereby improving the printing efficiency.

[0032] Based on the above, the bidirectional powder spreading device using the bidirectional powder spreading method provided by the present invention can realize bidirectional powder spreading, thereby improving the powder spreading efficiency.

[0033] The 3D printing equipment provided by the present invention can improve printing efficiency by applying the above-mentioned two-way powder spreading device. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0035] Figure 1 A flow chart of a two-way powder spreading method provided by an embodiment of the present invention;

[0036] Figure 2 A schematic diagram of the structure of a bidirectional powder spreading device provided in an embodiment of the present invention;

[0037] Figure 3 One of the cross-sectional views of the bidirectional powder spreading device provided in an embodiment of the present invention;

[0038] Figure 4 A second cross-sectional view of the bidirectional powder spreading device provided in an embodiment of the present invention;

[0039] Figure 5 A schematic diagram of the structure of a reversing mechanism provided by an embodiment of the present invention;

[0040] Figure 6 An exploded diagram of a reversing mechanism provided by an embodiment of the present invention;

[0041] Figure 7 A schematic diagram of the structure of a scraper provided in an embodiment of the present invention;

[0042] Figure 8 One of the state diagrams in the bidirectional powder spreading process provided by an embodiment of the present invention;

[0043] Fig. 9 The second state diagram of the two-way powder spreading process provided by the embodiment of the present invention;

[0044] Fig.10 The third state diagram of the two-way powder spreading process provided by the embodiment of the present invention;

[0045] Fig.11 The fourth state diagram of the two-way powder spreading process provided by the embodiment of the present invention;

[0046] Fig.12 The fifth state diagram of the two-way powder spreading process provided by the embodiment of the present invention;

[0047] Fig.13 The sixth state diagram of the two-way powder spreading process provided by the embodiment of the present invention;

[0048] Fig.14 The seventh state diagram of the two-way powder spreading process provided by the embodiment of the present invention;

[0049] Fig.15 The eighth state diagram of the two-way powder spreading process provided by the embodiment of the present invention;

[0050] Fig.16 The ninth state diagram of the two-way powder spreading process provided by the embodiment of the present invention;

[0051] Fig.17 The tenth state diagram of the two-way powder spreading process provided by an embodiment of the present invention.

[0052] Reference numerals:

[0053] 100. Two-way powder spreading device;

[0054] 10. Abutment;

[0055] 20. scraper; 21. upper part of scraper; 211. abutting protrusion; 212. guide groove; 213. guide hole; 22. lower part of scraper;

[0056] 30. Reversing mechanism; 31. Mounting seat; 32. Depressing tongue; 321. Horizontal portion; 322. Elevated portion; 3221. First clamping groove; 3222. Second clamping groove; 323. Transition portion; 324. Abutting portion; 33. First elastic clamping member; 34. Second elastic clamping member; 35. First elastic member; 36. Rotating shaft;

[0057] 40. a second elastic member;

[0058] 50. guide mechanism; 51. mounting member; 511. mounting groove; 52. ball bearing;

[0059] 200. Powder. DETAILED DESCRIPTION

[0060] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0061] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0062] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0063] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0064] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0065] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0066] like Figure 1 As shown, this embodiment provides a two-way powder spreading method, including:

[0067] The powder from the two powdering processes falls behind the scraper 20;

[0068] The scraper 20 moves backwards to spread the powder 200 on the printing platform, completing the first powder spreading;

[0069] The scraper 20 continues to move backward, and the scraper 20 abuts against the reversing mechanism 30, the reversing mechanism 30 includes a pressing tongue 32, and the scraper 20 moves upward along the upper surface of the pressing tongue 32, and the second layer of powder 200 is left on the printing platform;

[0070] The scraper 20 continues to move backward and upward at the same time. When the scraper 20 abuts against the base 10, the scraper 20 presses the pressing tongue 32 downward. At this time, the pressing tongue 32 drops to the second clamping position.

[0071] The scraper 20 moves forward at the height of the second clamping position to spread the second layer of powder 200 on the printing platform, completing the second powder spreading.

[0072] In the above-mentioned two-way powder spreading method, after the scraper 20 completes the first powder spreading, the scraper 20 is lifted by the reversing mechanism 30, thereby leaving the second layer of powder 200 on the printing platform, and then the scraper 20 is lowered to the second clamping position by the reversing mechanism 30, so that the scraper 20 maintains the height of the second clamping position and moves forward to complete the second powder spreading, thereby improving the powder spreading efficiency and further improving the printing efficiency.

[0073] Furthermore, the distance from the bottom of the scraper 20 to the bottom of the base 10 is a first height, the height of the powder pile of the powder 200 is a second height, and the first height is greater than the second height to prevent the base 10 from interfering with the powder pile and affecting the powder spreading quality.

[0074] Furthermore, when the scraper 20 moves forward at the height of the second clamping position and spreads the second layer of powder 200 on the printing platform, the tongue 32 is switched to the first clamping position, so that the scraper 20 can continuously implement the above-mentioned two-way powder spreading process, further improving the powder spreading efficiency.

[0075] like Figure 2-Figure 4 As shown, the present embodiment also provides a bidirectional powder spreading device 100 for executing the above-mentioned bidirectional powder spreading method. Specifically, the bidirectional powder spreading device 100 includes a base 10, a scraper 20 and a reversing mechanism 30. The scraper 20 is slidably matched with the base 10, and the bottom of the scraper 20 protrudes from the bottom surface of the base 10. The scraper 20 is used to spread the powder 200; the reversing mechanism 30 is arranged on the left and right sides of the scraper 20. The reversing mechanism 30 includes a mounting seat 31 and a pressing tongue 32. The front end of the pressing tongue 32 is rotatably connected to the mounting seat 31 through a rotating shaft 36. The height of the pressing tongue 32 gradually increases from front to back. The scraper 20 can abut against the pressing tongue 32 to switch the pressing tongue 32 between the first clamping position and the second clamping position. During operation, the amount of powder from the two powder spreadings falls to the rear of the scraper 20. After the scraper 20 moves backward to complete the first powder spreading, the scraper 20 continues to move backward, and the scraper 20 abuts against the pressing tongue 32. As the height of the pressing tongue 32 gradually increases from front to back, the scraper 20 is gradually lifted, and the second layer of powder 200 is left on the printing platform. At this time, the pressing tongue 32 is in the first clamping groove 3221 position; the scraper 20 continues to move backward and moves upward at the same time. When the scraper 20 abuts against the base 10, the scraper 20 presses the pressing tongue 32 down. At this time, the scraper 20 drops to the second clamping position. The scraper 20 moves forward at the height of the second clamping position to spread the second layer of powder 200 on the printing platform to complete the second powder spreading.

[0076] It is understandable that the base 10 is mounted on a linear drive mechanism, which drives the base 10 to reciprocate in the front-to-back direction, thereby driving the scraper 20 to reciprocate in the front-to-back direction to complete the powder spreading. The linear drive mechanism can be any existing linear motor, electric push rod, etc.

[0077] like Figure 5 and Figure 6 As shown, the pressing tongue 32 includes a horizontal portion 321, an elevated portion 322, a transition portion 323 and abutting portion 324, which are connected to each other. The horizontal portion 321, the elevated portion 322, the transition portion 323 and the abutting portion 324 are arranged from front to back. When the scraper 20 moves backward, it first abuts against the horizontal portion 321, and is lifted upward to the transition portion 323 under the action of the elevated portion 322, and then moves to the abutting portion 324, and the scraper 20 presses the pressing tongue 32 into the second clamping position.

[0078] like Figure 2-Figure 6 As shown, the reversing mechanism 30 further includes a first elastic clamping member 33 and a second elastic clamping member 34. The horizontal portion 321 is provided with a first clamping groove 3221 and a second clamping groove 3222. The first elastic clamping member 33 can be clamped and matched with the first clamping groove 3221, and the second elastic clamping member 34 can be clamped and matched with the second clamping groove 3222. When the first elastic clamping member 33 is clamped and matched with the first clamping groove 3221, the scraper 20 is in the first clamping position; when the second elastic clamping member 34 is clamped and matched with the second clamping groove 3222, the scraper 20 is in the second clamping position. Specifically, the first elastic clamping member 33 and the second elastic clamping member 34 are spring plungers.

[0079] Alternatively, if Figure 2-Figure 6 As shown, the reversing mechanism 30 further includes a first elastic member 35, which is located at the rear end of the mounting seat 31, one end of the first elastic member 35 abuts against the pressing tongue 32, and the other end of the first elastic member 35 abuts against the mounting seat 31. The first elastic member 35 can play a buffering role on the pressing tongue 32, so that the pressing tongue 32 can switch between the first clamping position and the second clamping position more smoothly. The first elastic member 35 can be a spring.

[0080] like Figure 7 As shown, the scraper 20 includes a scraper upper portion 21 and a scraper lower portion 22, and the scraper upper portion 21 and the scraper lower portion 22 are detachably connected by a connecting piece, which facilitates the rapid disassembly of the scraper upper portion 21 and the scraper lower portion 22. The connecting piece can be a screw.

[0081] Furthermore, abutment protrusions 211 are provided at the left and right ends of the scraper upper portion 21 . The abutment protrusions 211 protrude from the outer surface of the base 10 , and the lower ends of the abutment protrusions 211 are arc-shaped, so as to better abut against the pressing tongue 32 .

[0082] like Figure 2-Figure 7 As shown, the bidirectional powder spreading device 100 further includes a second elastic member 40, one end of which abuts against the scraper 20, and the other end of which abuts against the base 10. The second elastic member 40 can ensure that the abutting protrusion 211 abuts against the pressing tongue 32. The second elastic member 40 can be a spring.

[0083] like Figure 4 As shown, the scraper upper portion 21 is provided with a guide hole 213 , and at least a portion of the second elastic member 40 is located in the guide hole 213 , so that the second elastic member 40 is guided by the guide hole 213 , thereby ensuring the accuracy of the elastic force provided by the second elastic member 40 .

[0084] like Figure 4 As shown, the bidirectional powder spreading device 100 further includes a guide mechanism 50, which is disposed between the scraper 20 and the base 10 and is configured to move the scraper 20 in the up and down direction. The guide mechanism 50 makes the process of the scraper 20 moving up and down relative to the base 10 more stable and smooth.

[0085] Specifically, if Figure 4 and Figure 7 As shown, the guide mechanism 50 includes a mounting member 51 and a plurality of balls 52. The mounting member 51 is disposed on the base 10 and is provided with a mounting groove 511 extending in the up-down direction. The plurality of balls 52 are installed in the mounting groove 511 in the up-down direction. The scraper 20 is provided with a guide groove 212 extending in the up-down direction. The balls 52 are rollingly matched with the guide groove 212. Optionally, the cross section of the guide groove 212 is arc-shaped, and the arc-shaped guide groove 212 matches with the balls 52, which has a better guiding effect.

[0086] This embodiment also provides a 3D printing device, which includes a printing device and a two-way powder spreading device 100. The printing device is used to sinter the powder 200 spread on the printing platform by the two-way powder spreading device 100. By applying the two-way powder spreading device 100, a higher printing efficiency is achieved. It should be noted that the specific structure and working principle of the printing device are all prior art and will not be repeated here.

[0087] For ease of understanding, combined Figure 8-Figure 17 The working process of the bidirectional powder spreading device 100 is described as follows:

[0088] 1) If Figure 8 As shown, the powder feeding device (not shown in the figure) drops the powder of the two powder spreading to the rear of the scraper 20; the linear drive mechanism (not shown in the figure) drives the scraper 20 to move backward, spreads the powder 200 on the printing platform, and completes the first powder spreading;

[0089] 2) If Fig. 9As shown, the scraper 20 continues to move backward, and the abutting protrusion 211 abuts against the pressing tongue 32. At this time, the clamping force of the first elastic clamping member 33 on the pressing tongue 32 is greater than the elastic force of the second elastic member 40, and the scraper 20 moves upward under the action of the raised portion 322 of the pressing tongue 32, and the second elastic member 40 is compressed;

[0090] 3) If Fig.10 and Fig.11 As shown, the scraper 20 continues to move backward and upward at the same time, and when the abutting protrusion 211 moves to the transition portion 323 of the pressing tongue 32, the second layer of powder 200 is left on the printing platform;

[0091] 4) If Fig.12 As shown, the scraper 20 continues to move backward, and the abutting protrusion 211 abuts against the abutting portion 324 of the rear end of the pressing tongue 32. At this time, the scraper upper portion 21 abuts against the base 10, pressing the first elastic clamping member 33 out of the first clamping groove 3221;

[0092] 5) If Fig.13 As shown, the elastic force of the second elastic member 40 is greater than the elastic force of the first elastic member 35, the second elastic clamping member 34 is pressed into the second clamping groove 3222, and the clamping force of the second elastic clamping member 34 on the pressing tongue 32 is greater than the elastic force of the first elastic member 35. At this time, the scraper 20 is in the second clamping position; at this time, the horizontal portion 321 at the front end of the pressing tongue 32 is tilted;

[0093] 6) If Fig.14 and Fig.15 As shown, the scraper 20 moves forward, while pushing the second layer of powder 200 left on the printing platform forward;

[0094] 7) If Fig.16 As shown, the abutting protrusion 211 abuts against the raised horizontal portion 321, pressing the second elastic clamping member 34 out of the second clamping groove 3222; at the same time, the elastic force of the second elastic member 40 is greater than the clamping force of the second elastic clamping member 34 on the pressing tongue 32;

[0095] 8) If Fig.17 As shown, the second elastic member 40 pushes the pressing tongue 32, so that the first elastic clamping member 33 is pressed into the second clamping groove 3222; the scraper 20 continues to move forward to complete the second powder spreading.

[0096] Note that in the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0097] The above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A two-way powder spreading method, characterized in that: include: The powder from the two powdering processes falls behind the scraper (20); The scraper (20) moves backwards to spread the powder (200) on the printing platform, completing the first powder spreading; The scraper (20) continues to move backwards, the scraper (20) abuts against a reversing mechanism (30), the reversing mechanism (30) comprises a pressing tongue (32), the scraper (20) moves upwards along the upper surface of the pressing tongue (32), and a second layer of the powder (200) is left on the printing platform; The scraper (20) continues to move backwards and upwards at the same time, and when the scraper (20) contacts the base (10), the scraper (20) presses the pressing tongue (32) downwards, and at this time, the pressing tongue (32) descends to a second clamping position; The scraper (20) moves forward at the height of the second clamping position to spread a second layer of the powder (200) on the printing platform, thereby completing the second powder spreading.

2. The two-way powder spreading method according to claim 1, characterized in that: The distance from the bottom of the scraper (20) to the bottom of the base (10) is a first height, the height of the powder pile of the powder (200) is a second height, and the first height is greater than the second height.

3. The two-way powder spreading method according to claim 1, characterized in that: When the scraper (20) moves forward at the height of the second clamping position to spread a second layer of the powder (200) on the printing platform, the tongue pressing (32) is switched to the first clamping position.

4. A two-way powder spreading device, used to perform the two-way powder spreading method according to any one of claims 1 to 3, characterized in that: The two-way powder spreading device comprises: abutment(10); a scraper (20), the scraper (20) being in sliding cooperation with the base (10), and the bottom of the scraper (20) protruding from the bottom surface of the base (10), and the scraper (20) being used to spread the powder (200); A reversing mechanism (30) is arranged on the left and right sides of the scraper (20), the reversing mechanism (30) comprising a mounting seat (31) and a pressing tongue (32), the front end of the pressing tongue (32) being rotatably connected to the mounting seat (31) via a rotating shaft (36), the height of the pressing tongue (32) gradually increasing from front to back, and the scraper (20) can abut against the pressing tongue (32) so that the pressing tongue (32) switches between a first clamping position and a second clamping position.

5. The two-way powder spreading device according to claim 4, characterized in that: The reversing mechanism (30) further comprises: A first elastic clamping member (33) and a second elastic clamping member (34); a first clamping groove (3221) and a second clamping groove (3222) are provided on the pressing tongue (32); the first elastic clamping member (33) can be clamped and matched with the first clamping groove (3221); and the second elastic clamping member (34) can be clamped and matched with the second clamping groove (3222).

6. The two-way powder spreading device according to claim 4, characterized in that: The reversing mechanism (30) further comprises: A first elastic member (35), one end of the first elastic member (35) abuts against the pressing tongue (32), and the other end of the first elastic member (35) abuts against the mounting seat (31).

7. The two-way powder spreading device according to claim 4, characterized in that: The two-way powder spreading device also includes: A second elastic member (40), one end of the second elastic member (40) abuts against the scraper (20), and the other end of the second elastic member (40) abuts against the base (10).

8. The bidirectional powder spreading device according to claim 4, characterized in that: The two-way powder spreading device also includes: The guide mechanism (50) is disposed between the scraper (20) and the base (10), and is configured to move the scraper (20) in an up-down direction.

9. The bidirectional powder spreading device according to claim 8, characterized in that: The guiding mechanism (50) comprises: A mounting member (51) and a plurality of ball bearings (52), wherein the mounting member (51) is arranged on the base (10) and is provided with a mounting groove (511) extending in the up-down direction, wherein the plurality of ball bearings (52) are installed in the mounting groove (511) in the up-down direction, and the scraper (20) is provided with a guide groove (212) extending in the up-down direction, wherein the ball bearings (52) are in rolling engagement with the guide groove (212).

10. 3D printing equipment, characterized in that The printing device comprises a printing device and also comprises a bidirectional powder spreading device as claimed in any one of claims 4 to 9, wherein the printing device is used to sinter and mold the powder (200) spread on the printing platform by the bidirectional powder spreading device.

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