Unpowered single-blade bidirectional powder spreading device

Abstract

The application belongs to the technical field of laser stereolithography and relates to a non-powered single-knife bidirectional powder spreading device, which comprises a scraper holder, a powder temporary storage box, a powder pushing mechanism and a powder pushing driving mechanism; the powder pushing driving mechanism and the powder temporary storage box are arranged at the tail end of the scraper holder along the powder spreading operation direction; the powder pushing mechanism is arranged in the powder temporary storage box; the powder pushing driving mechanism is connected with the powder pushing mechanism; along the powder spreading direction, the scraper holder drives the powder pushing mechanism to move downward in the powder temporary storage box through the powder pushing driving mechanism; along the powder returning direction, the scraper holder drives the powder pushing mechanism to move upward in the powder temporary storage box through the powder pushing driving mechanism. The application provides the non-powered single-knife bidirectional powder spreading device which does not need to additionally increase a power source, reduces the equipment cost and can improve the equipment operation reliability.

Description

Technical Field

[0001] This invention belongs to the field of laser stereolithography technology, and relates to a single-blade bidirectional powder spreading device, and more particularly to a non-powered single-blade bidirectional powder spreading device used in SLM additive manufacturing equipment. Background Technology

[0002] Currently, single-blade bidirectional powder spreading technology has been gradually adopted. It is currently divided into three main categories: 1) powered by a power source, storing a certain amount of powder on the scraper frame for return powder spreading; 2) unpowered, storing a certain amount of powder on the scraper frame for return powder spreading; and 3) powered by a power source, storing a certain amount of powder on the bottom plate in the return direction for return powder spreading. The method of storing powder on the scraper frame carries the risk of powder leakage during the spreading process; while the method of storing powder on the bottom plate in the return direction requires an additional power source, corresponding driver, and operating system, undoubtedly increasing the cost of the equipment. Summary of the Invention

[0003] In order to solve the above-mentioned technical problems in the background art, the present invention provides a non-powered single-blade bidirectional powder spreading device that does not require an additional power source, reduces equipment costs, and improves equipment operating reliability.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A non-powered single-blade bidirectional powder spreading device is characterized in that: the non-powered single-blade bidirectional powder spreading device includes a scraper frame, a powder storage box, a powder pushing mechanism, and a powder pushing drive mechanism; the powder pushing drive mechanism and the powder storage box are both located at the tail end of the scraper frame as it spreads powder along the outward direction; the powder pushing mechanism is located in the powder storage box; the powder pushing drive mechanism is connected to the powder pushing mechanism; along the outward powder spreading direction, the scraper frame drives the powder pushing mechanism to descend freely in the powder storage box via the powder pushing drive mechanism; along the return powder spreading direction, the scraper frame drives the powder pushing mechanism to rise freely in the powder storage box via the powder pushing drive mechanism.

[0006] The aforementioned powder-pushing drive mechanism is a gear-type drive mechanism or a linkage-type drive mechanism.

[0007] When the aforementioned powder-pushing drive mechanism is a gear-type drive mechanism, the gear-type drive mechanism includes a gear and rack transmission mechanism and a bidirectional differential gear and rack mechanism; the bidirectional differential gear and rack mechanism is mounted on the scraper frame and moves synchronously with the scraper frame; the gear and rack transmission mechanism is located at the tail end of the scraper frame as it travels along the outward powder spreading direction; the gear and rack transmission mechanism is connected to the powder-pushing mechanism; along the outward powder spreading direction, the scraper frame drives the gear and rack transmission mechanism through the bidirectional differential gear and rack mechanism, causing the powder-pushing mechanism to descend freely in the powder storage box; along the return powder spreading direction, the scraper frame drives the gear and rack transmission mechanism through the bidirectional differential gear and rack mechanism, causing the powder-pushing mechanism to rise freely in the powder storage box.

[0008] The aforementioned bidirectional differential gear rack mechanism includes a first bidirectional differential gear rack mechanism and a second bidirectional differential gear rack mechanism. The structures of the first bidirectional differential gear rack mechanism and the second bidirectional differential gear rack mechanism are completely identical. The first bidirectional differential gear rack mechanism and the second bidirectional differential gear rack mechanism are arranged opposite to each other on the scraper holder.

[0009] The gear and rack transmission mechanism includes a first gear transmission mechanism, a pusher, a first transmission shaft, and a second gear transmission mechanism. The first gear transmission mechanism is connected to the second gear transmission mechanism via the first transmission shaft. The structure of the first gear transmission mechanism is exactly the same as that of the second gear transmission mechanism. The powder pushing mechanism is mounted on the first transmission shaft via the pusher. During rotation, the first transmission shaft drives the powder pushing mechanism to move freely up and down in the powder storage box via the pusher. When the scraper frame gradually moves to the end of the outgoing powder spreading direction, or gradually moves away from the end of the outgoing powder spreading direction along the return powder spreading direction, the first bidirectional differential gear and rack mechanism drives the first transmission shaft to rotate via the first gear transmission mechanism. At the same time, the second bidirectional differential gear and rack mechanism drives the first transmission shaft to rotate via the second gear transmission mechanism.

[0010] The aforementioned first gear transmission mechanism includes a gear shaft, a gear shaft bearing housing, and a helical gear set. The gear shaft drives the first transmission shaft to rotate through the gear shaft bearing housing and the helical gear set. When the scraper holder gradually moves to the tail end of the outgoing powder spreading direction, or gradually moves away from the tail end of the outgoing powder spreading direction along the return powder spreading direction, the first bidirectional differential gear rack mechanism gradually meshes with the gear shaft and drives the gear shaft to rotate axially around the gear shaft. The pushing component includes a first rack, a torque limiting gear, and a rack connecting seat. The torque limiting gear is mounted on the first transmission shaft and rotates synchronously with the first transmission shaft. The first rack is connected to the powder pushing mechanism through the rack connecting seat. The torque limiting gear meshes with the first rack. When the first transmission shaft rotates, the torque limiting gear drives the first rack to push the powder pushing mechanism to move freely up and down in the powder storage box.

[0011] The aforementioned first bidirectional differential gear rack mechanism includes a gear guide seat, a second rack, a forward gear set, and a reverse gear set. The gear guide seat is mounted on the scraper holder and moves synchronously with it. The second rack includes an upper rack and a lower rack arranged parallel to the upper rack. The upper and lower racks extend from opposite sides of the gear guide seat. The forward and reverse gear sets are mounted on the gear shaft from top to bottom. When the scraper holder gradually moves along the outgoing powder spreading direction to the tail end of the outgoing powder spreading, the forward gear set gradually contacts the upper rack and... The upper rack meshes with the lower rack, which drives the gear shaft to rotate axially around the gear shaft via the forward gear set. As the scraper holder gradually moves away from the tail end of the outgoing powder spreading direction along the return powder spreading direction, the reverse gear set gradually contacts and meshes with the lower rack. The lower rack drives the gear shaft to rotate axially around the gear shaft via the reverse gear set. The structure of the forward gear set is exactly the same as that of the reverse gear set. The forward gear set includes a gear and a one-way bearing. The gear and the one-way bearing are sequentially mounted on the gear shaft from the outside to the inside. The gear meshes with the second rack.

[0012] When the aforementioned powder-pushing drive mechanism is a linkage-type drive mechanism, the linkage-type drive mechanism includes a linkage transmission mechanism and a bidirectional cam mechanism; the bidirectional cam mechanism is mounted on the scraper frame and moves synchronously with the scraper frame; the linkage transmission mechanism is located at the tail end of the scraper frame as it travels along the outgoing powder-spreading direction; the linkage transmission mechanism is connected to the powder-pushing mechanism; along the outgoing powder-spreading direction, the scraper frame drives the linkage transmission mechanism and the powder-pushing mechanism to descend freely in the powder storage box via the bidirectional cam mechanism; along the return powder-spreading direction, the scraper frame drives the linkage transmission mechanism and the powder-pushing mechanism to rise freely in the powder storage box via the bidirectional cam mechanism.

[0013] The aforementioned bidirectional cam mechanism includes a first bidirectional cam mechanism and a second bidirectional cam mechanism. The structure of the first bidirectional cam mechanism is exactly the same as that of the second bidirectional cam mechanism. The first bidirectional cam mechanism and the second bidirectional cam mechanism are arranged opposite to each other on the scraper holder. The linkage transmission mechanism includes a first linkage transmission mechanism, a pusher, a second transmission shaft, and a second linkage transmission mechanism. The first linkage transmission mechanism is connected to the second linkage transmission mechanism through the second transmission shaft. The structure of the first linkage transmission mechanism is exactly the same as that of the second linkage transmission mechanism. The powder pushing mechanism is arranged on the second transmission shaft through the pusher. During rotation, the second transmission shaft drives the powder pushing mechanism to move freely up and down in the powder storage box through the pusher. When the scraper holder gradually moves to the end of the outgoing powder spreading direction, or gradually moves away from the end of the outgoing powder spreading direction along the return powder spreading direction, the first bidirectional cam mechanism drives the second transmission shaft to rotate through the first linkage transmission mechanism. At the same time, the second bidirectional cam mechanism drives the second transmission shaft to rotate through the second linkage transmission mechanism.

[0014] The aforementioned first linkage transmission mechanism includes a cam guide shaft assembly, a bearing housing, a fourth linkage, and a third linkage; the cam guide shaft assembly is connected to the third linkage via the bearing housing and the fourth linkage; the third linkage is connected to the second transmission shaft and drives the second transmission shaft to rotate axially around the second transmission shaft; when the scraper holder gradually moves to the end of the outgoing powder spreading direction, or gradually moves away from the end of the outgoing powder spreading direction along the return powder spreading direction, the first bidirectional cam mechanism gradually connects to the first linkage transmission mechanism and drives the first linkage transmission mechanism to move synchronously; at the same time, the second bidirectional cam mechanism gradually connects to the second linkage transmission mechanism and drives the second linkage transmission mechanism to move synchronously.

[0015] The pushing component includes a first connecting rod and a second connecting rod; one end of the first connecting rod is mounted on a second transmission shaft and rotates synchronously with the second transmission shaft, and the other end is connected to the second connecting rod; the second connecting rod is connected to the powder pushing mechanism.

[0016] Preferably, the first bidirectional differential cam mechanism includes a cam guide seat, a torsion spring assembly, a first paddle, a horizontal limiting plate, a second paddle, and a cam shaft; the cam guide seat is mounted on the scraper holder and moves synchronously with the scraper holder; the side wall of the cam guide seat is provided with a cam movement groove; the axial direction of the cam movement groove is parallel to the travel direction of the scraper holder; the first paddle, the horizontal limiting plate, and the second paddle are disposed in the cam movement groove, dividing the cam movement groove from bottom to top into a forward movement groove and a return movement groove; one end of the first paddle abuts against the cam movement groove. The top of the moving groove is connected to the horizontal limiting plate via a torsion spring assembly; one end of the second paddle rests against the bottom of the cam moving groove, and the other end is connected to the horizontal limiting plate via a torsion spring assembly; the camshaft is connected to the cam guide shaft assembly; when the scraper holder gradually moves to the end of the outgoing powder spreading direction, the camshaft moves in the outgoing moving groove along the direction from the first paddle to the second paddle; when the scraper holder gradually moves away from the end of the outgoing powder spreading direction along the return powder spreading direction, the camshaft moves in the return moving groove along the direction from the second paddle to the first paddle.

[0017] The powder pushing mechanism includes a powder pushing plate and a guide rail slider; the powder pushing plate is placed inside the powder storage box and can move freely up and down along the height direction of the powder storage box; the powder pushing drive mechanism is connected to the powder pushing plate through the guide rail slider.

[0018] Preferably, the powder pushing mechanism further includes a compression spring and a spring plate; the spring plate is placed at the bottom of the powder pushing plate; the compression spring is disposed between the spring plate and the powder pushing plate and is connected to the spring plate and the powder pushing plate respectively; the powder pushing drive mechanism is connected to the spring plate through a guide rail slider.

[0019] The advantages of this invention are:

[0020] This invention provides a non-powered single-blade bidirectional powder spreading device. It utilizes the residual power of the scraper holder to drive the powder storage mechanism, achieving the function of single-blade bidirectional powder spreading. This device is a purely mechanical structure, eliminating the need for a power source and driver, significantly reducing the cost of achieving single-blade bidirectional functionality. Simultaneously, it effectively utilizes the residual power of the scraper holder, avoiding the waste of excessive motor power. Specifically, the advantages of this invention are: 1. The device is a purely mechanical mechanism, eliminating the need for an additional power source to drive the powder pushing mechanism, reducing the cost of achieving single-blade bidirectional functionality, and effectively utilizing the residual power of the scraper holder, avoiding excessive motor power. 2. The bidirectional differential gear rack mechanism allows the scraper holder to trigger the powder pushing mechanism at a designated position and, conversely, trigger the mechanism at another designated position. Meanwhile, the bidirectional cam mechanism can convert linear motion in the horizontal direction into vertical motion, and can control the cam to move in a specified position and state, which can ensure the realization of the powder storage and removal actions of the scraper frame; the linkage transmission mechanism has a simple structure, requires no lubrication, and has an adjustable transmission ratio, which can effectively reduce costs and improve structural reliability in realizing the bidirectional powder spreading function; 3. For SLM equipment with double-sided powder collection ports, this device can recover all the powder spread in the outgoing process for the return process, which can replace the powder collection port on one side and simplify the powder collection structure of the equipment. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the gear-type unpowered single-blade bidirectional powder spreading device used in Example 1;

[0022] Figure 2 This is a schematic diagram of the powder pushing mechanism used in Example 1;

[0023] Figure 3 This is a schematic diagram of the gear and rack transmission mechanism used in Example 1;

[0024] Figure 4 This is a schematic diagram of the bidirectional differential gear rack mechanism used in Example 1;

[0025] Figure 5 This is a schematic diagram of the one-way gear used in Example 1;

[0026] Figure 6 This is a schematic diagram of the complete bidirectional powder spreading operation of the gear-type unpowered single-blade bidirectional powder spreading device used in Example 1.

[0027] Figure 7 This is a schematic diagram of the linkage-type unpowered single-blade bidirectional powder spreading device used in Example 2;

[0028] Figure 8 This is a schematic diagram of the powder pushing mechanism used in Example 2;

[0029] Figure 9 This is a schematic diagram of the linkage transmission mechanism used in Example 2;

[0030] Figure 10 This is a schematic diagram of the bidirectional differential cam mechanism used in Example 2;

[0031] Figure 11 This is a schematic diagram of the complete bidirectional powder spreading action of the linkage-type unpowered single-blade bidirectional powder spreading device used in Example 2;

[0032] in:

[0033] A1-Powder pushing mechanism; A11-Housing; A12-Powder pushing plate; A13-Guide rail slider; A14-Compression spring; A15-Spring plate; A2-Gear and rack transmission mechanism; A21-First rack; A22-Torque limiting gear; A23-Drive shaft bearing seat; A24-First drive shaft; A25-Helical gear set; A26-Gear shaft; A27-Rack connecting seat; A28-Gear shaft bearing seat; A3-Double-direction gear and rack mechanism; A31-Gear guide rail seat; A32-Second rack; A33-Forward gear set; A331-Gear; A332-One-way bearing; A34-Reverse gear set; A4-Scraper holder;

[0034] B1-Powder pushing mechanism; B11-Housing; B12-Powder pushing plate; B13-Guide rail slider; B2-Linkage transmission mechanism; B21-Bearing seat; B22-Second drive shaft; B23-First link; B24-Second link; B25-Third link; B26-Fourth link; B27-Cam guide shaft assembly; B28-Bearing seat; B3-Two-way differential cam mechanism; B31-Cam guide rail seat; B32-Torsion spring assembly; B33-First paddle; B34-Second paddle; B35-Camshaft; B4-Scraper holder. Detailed Implementation

[0035] The technical solution provided by the invention will be described in detail below with reference to specific implementation methods.

[0036] This invention provides a non-powered single-blade bidirectional powder spreading device, including a scraper holder, a powder storage box, a powder pushing mechanism, and a powder pushing drive mechanism. Both the powder pushing drive mechanism and the powder storage box are located at the tail end of the scraper holder during its outward powder spreading operation. The powder pushing mechanism is housed within the powder storage box. The powder pushing drive mechanism is connected to the powder pushing mechanism. Along the outward powder spreading direction, the scraper holder drives the powder pushing mechanism to descend freely within the powder storage box via the powder pushing drive mechanism. Along the return powder spreading direction, the scraper holder drives the powder pushing mechanism to rise freely within the powder storage box via the powder pushing drive mechanism. For example, the powder pushing drive mechanism can be a gear-type drive mechanism or a linkage-type drive mechanism. The non-powered single-blade bidirectional powder spreading device with two different powder pushing drive structures will be described in detail below. Example

[0037] See Figure 1 This embodiment provides a gear-type unpowered single-blade bidirectional powder spreading device for SLM equipment with single powder bucket powder dispensing, realizing bidirectional powder spreading function. The device consists of a powder pushing mechanism A1, a gear and rack transmission mechanism A2, a bidirectional differential gear and rack mechanism A3, and a scraper holder A4, wherein the bidirectional differential gear and rack mechanism A3 is connected to the scraper holder A4; the gear and rack transmission mechanism A2 and the bidirectional differential gear and rack mechanism A3 together constitute the gear-type drive mechanism adopted in this invention. A bidirectional differential gear rack mechanism A3 is mounted on the scraper holder and moves synchronously with it; a gear rack transmission mechanism A2 is mounted at the tail end of the scraper holder as it travels along the outward powder spreading direction; the gear rack transmission mechanism A2 is connected to the powder pushing mechanism; along the outward powder spreading direction, the scraper holder drives the gear rack transmission mechanism A2 and the powder pushing mechanism to descend freely in the powder storage box via the bidirectional differential gear rack mechanism A3; along the return powder spreading direction, the scraper holder drives the gear rack transmission mechanism A2 and the powder pushing mechanism to rise freely in the powder storage box via the bidirectional differential gear rack mechanism A3.

[0038] See Figure 2 The powder pushing mechanism A1 used in this invention includes a housing A11, a powder pushing plate A12, a guide rail slider A13, a compression spring A14, and a spring plate A15. The guide rail slider A13 is located below the powder pushing plate A12 and guides the powder pushing plate A12 to achieve the powder pushing action (the powder pushing plate A12 moves upward to achieve powder pushing). The compression spring A14 initially applies a certain preload to ensure that the powder pushing plate A12 will not descend due to the gravity of the powder pushing plate A12 in a free state.

[0039] See Figure 4The bidirectional differential gear rack mechanism A3 used in this invention includes a first bidirectional differential gear rack mechanism and a second bidirectional differential gear rack mechanism. The structures of the first and second bidirectional differential gear rack mechanisms are completely identical. The first and second bidirectional differential gear rack mechanisms are arranged opposite to each other on the scraper holder. Taking the first gear transmission mechanism as an example, the first gear transmission mechanism includes a gear guide seat A31, a second rack A32, a forward gear set A33, and a reverse gear set A34. See also... Figure 5 The forward gear set A33 and the reverse gear set A34 have the same structure, both consisting of gear A331 and one-way bearing A332. The forward gear set is mounted on the gear shaft in the forward direction, and the reverse gear set is mounted on the gear shaft after being rotated 180°. That is, when the scraper holder A4 moves in the forward direction (along the outgoing direction), the forward gear set A33 meshes with the upper second rack A32. When the scraper holder A4 moves in the reverse direction (along the return direction), the reverse gear set A34 meshes with the lower second rack A32, thereby enabling the scraper holder A4 to drive the powder pusher plate A12 to move at the designated position. The number of meshing teeth of the gear and rack determines the stroke of the powder pusher plate. With a fixed number of teeth and a fixed stroke, if the initial position of the powder pusher mechanism is not at the upper or lower limit of the powder pusher plate's stroke due to gravity or other resistance, the gear and rack cannot mesh at the designated position, resulting in the stroke not being completed and the mechanism getting stuck. In this case, a torque limiting gear A22 is introduced. When the torque of the first transmission shaft A24 reaches a certain value, the torque limiting gear A22 will idle, thereby preventing the mechanism from getting stuck. This ensures that no matter where the powder pusher mechanism is in the stroke, the rack A32 on the scraper holder A4 will eventually return to the correct position after meshing with the forward gear set A33 and the reverse gear set A34.

[0040] See Figure 3 The gear and rack transmission mechanism A2 used in this invention includes a first gear transmission mechanism, a pusher, a first transmission shaft A24, and a second gear transmission mechanism. The first gear transmission mechanism is connected to the second gear transmission mechanism via the first transmission shaft A24. The structure of the first gear transmission mechanism is exactly the same as that of the second gear transmission mechanism. The powder pushing mechanism is mounted on the first transmission shaft A24 via the pusher. During rotation, the first transmission shaft A24 drives the powder pushing mechanism to move freely up and down in the powder storage box via the pusher. When the scraper frame gradually moves to the end of the outgoing powder spreading direction, or gradually moves away from the end of the outgoing powder spreading direction along the return powder spreading direction, the first bidirectional differential gear and rack mechanism drives the first transmission shaft A24 to rotate via the first gear transmission mechanism. At the same time, the second bidirectional differential gear and rack mechanism drives the first transmission shaft A24 to rotate via the second gear transmission mechanism.

[0041] Taking the first gear transmission mechanism as an example, the first gear transmission mechanism includes a gear shaft A26, a gear shaft bearing seat A28, and a helical gear set A25; the gear shaft A26 drives the first transmission shaft A24 to rotate through the gear shaft bearing seat A28 and the helical gear set A25; the pushing component includes a first rack A21, a torque limiting gear A22, and a rack connecting seat A27; the torque limiting gear A22 is mounted on the first transmission shaft A24 and rotates synchronously with the first transmission shaft A24; the first rack A21 is connected to the powder pushing mechanism through the rack connecting seat A27; the torque limiting gear A22 meshes with the first rack A21; when the first transmission shaft A24 rotates, the torque limiting gear A22 drives the first rack A21 to push the powder pushing mechanism to move freely up and down in the powder storage box. The drive shaft bearing seat A23 is fixed on the housing A11. The first rack A21 is fixed on the slider of the guide rail slider A13 through the rack connecting seat A27 and meshes with the torque limiting gear A22. They are symmetrically arranged at both ends of the powder pushing plate A12. The first drive shaft A24 is connected to the gear shaft A26 through the helical gear set A25 to form a gear and rack transmission chain, which converts the torque of the gear shaft A26 into the torque of the first drive shaft A24, and then into the thrust of the powder pushing plate A12. The gear shaft A26 is arranged at both ends of the powder pushing mechanism to ensure that the first drive shaft A24 and the scraper holder A4 are subjected to uniform force.

[0042] See Figure 6 The gear-type unpowered single-blade bidirectional powder spreading device provided by the present invention can realize the function of unpowered single-blade bidirectional powder spreading. Its overall functional principle and specific implementation steps are as follows:

[0043] (1) Initial state: The scraper holder A4 is initially located at the powder dropping position, dropping a powder amount that is twice the thickness of the powder layer. Under the action of the spring A14, the powder pushing mechanism A1 is by default at the upper limit position within the movement stroke of the powder pushing plate A12.

[0044] (2) Spreading powder on the outgoing journey: See Figure 6 a. When the scraper holder A4 extends outward and spreads powder to the edge of the powder pushing plate A12, the forward gear set A33 meshes with the upper second rack A32 for transmission, and the reverse gear set A34 meshes with the lower second rack A32 and then idles under the action of the one-way bearing without transmitting power. The scraper holder A4 continues to move to the right ( Figure 6 As shown in Figure a, the right side (i.e., the direction of powder spreading at the outlet) moves downwards, driven by the gear and rack transmission mechanism A2, which in turn drives the powder pushing plate A12 to move downwards. The scraper holder A4 scrapes excess powder into the powder trough. Figure 6 b and Figure 6 As shown in c;

[0045] (3) Return trip spreading powder: See Figure 6d. When the scraper holder A4 returns and spreads powder to the edge of the powder pushing plate A12, the reverse gear set A34 meshes with the lower second rack A32 for transmission, and the forward gear set A33 meshes with the upper second rack A32 and then idles under the action of the one-way bearing without transmitting power. The scraper holder A4 continues to move to the left ( Figure 6 As shown in d, the left side is the left, i.e., the return powder spreading direction. The movement is driven by the gear and rack transmission mechanism A2, which drives the powder pushing plate A12 to move upward, as shown in d. Figure 6 e and Figure 6 As shown in f, the powder pusher plate A12 pushes the powder out for the return powder spreading of the scraper holder A4, thus completing the entire bidirectional powder spreading action. Example

[0046] See Figure 7 This invention provides a linkage-type, unpowered, single-blade, bidirectional powder spreading device, applicable to SLM equipment with a single powder bin, achieving bidirectional powder spreading function. It comprises a powder pushing mechanism B1, a linkage transmission mechanism B2, a bidirectional eccentric cam mechanism B3, and a scraper frame B4. The linkage transmission mechanism B2 and the bidirectional eccentric cam mechanism B3 together constitute the linkage-type drive mechanism used in this invention. The bidirectional eccentric cam mechanism B3 is mounted on the scraper frame and moves synchronously with it. The linkage transmission mechanism B2 is located at the tail end of the scraper frame during the outward powder spreading operation. The linkage transmission mechanism B2 is connected to the powder pushing mechanism. Along the outward powder spreading direction, the scraper frame, through the bidirectional eccentric cam mechanism B3, drives the linkage transmission mechanism B2 and the powder pushing mechanism to descend freely in the powder storage box. Along the return powder spreading direction, the scraper frame, through the bidirectional eccentric cam mechanism B3, drives the linkage transmission mechanism B2 and the powder pushing mechanism to rise freely in the powder storage box.

[0047] See Figure 8 The powder pushing mechanism B1 used in this invention consists of a housing B11, a powder pushing plate B12, and a guide rail slider B13. The guide rail slider B13 is located below the powder pushing plate B12 and guides the powder pushing plate B12 to achieve the powder pushing action.

[0048] See Figure 9The linkage transmission mechanism B2 used in this invention includes a bearing seat B21, a second transmission shaft B22, and a first connecting rod B23. The bearing seat B21 is fixed to the side of the housing B11. The first connecting rod B23 and the second connecting rod B24 connect the second transmission shaft B22 and the powder pushing plate B12, converting the torque of the second transmission shaft B22 into thrust and transmitting it to the powder pushing plate B12. There are two sets of the first connecting rod B23 and the second connecting rod B24, which are respectively arranged symmetrically at both ends of the powder pushing plate B12 to ensure the horizontal state of the powder pushing plate B12 and prevent it from jamming on the housing B11 due to uneven force. The third link B25 and the fourth link B26 connect the second drive shaft B22 and the cam guide shaft assembly B27. The cam guide shaft assembly B27 is mounted on the bearing housing B28, allowing the cam guide shaft assembly B27 to move in the vertical direction. The thrust of the camshaft B35 is converted into the torque of the second drive shaft B22 through the linkage mechanism. Different transmission ratios can be achieved by adjusting the lengths of the third link B25 and the fourth link B26. The third link B25 and the fourth link B26 are respectively arranged symmetrically at both ends of the second drive shaft B22 to ensure that the second drive shaft B22 is subjected to uniform force.

[0049] See Figure 10 The bidirectional differential cam mechanism B3 provided by this invention includes a cam guide seat B31, a torsion spring assembly B32, a first paddle B33, a second paddle B34, and a cam shaft B35. Cam grooves are mounted on scraper seats at both ends of the scraper holder B4. The first paddle B33 and the second paddle B34 are both mounted on the cam grooves via pins. The torsion spring assembly B32 fixes the initial positions of the first paddle B33 and the second paddle B34, allowing the torsion spring to quickly return to its original position after being triggered. The first paddle B33 and the second paddle B34 move intermittently on the cam grooves, thereby converting the horizontal linear motion of the scraper holder B4 into vertical linear motion. The cam inlets in both directions of the cam groove are large openings, covering the entire stroke of the camshaft. No matter where the powder pusher plate B12 is, the camshaft B35 can quickly cut into the cam groove, allowing the powder pusher plate B12 to return to the correct position. Under the action of the first paddle B33 and the second paddle B34, the cam can only follow a fixed trajectory when cutting into the cam groove from one direction. That is, the cam of the scraper holder B4 will follow different trajectories during the outgoing and return powder spreading. Thus, when the scraper holder B4 is about to spread powder into the range of the powder pusher plate, the powder pusher plate B12 moves downward, and when the scraper holder B4 is about to spread powder into the range of the powder pusher plate, the powder pusher plate B12 moves upward.

[0050] See Figure 11 The linkage-type unpowered single-blade bidirectional powder spreading device provided by this invention can realize the function of single-blade bidirectional powder spreading. Its overall functional principle and specific implementation steps are as follows:

[0051] (1) Initial state: The scraper holder B4 is initially located at the powder dropping position, and the amount of powder dropping is double the amount of powder. The default position of the powder pushing mechanism can be any position within its movement stroke.

[0052] (2) Spreading powder on the outgoing journey: See Figure 11 a. When the scraper holder B4 spreads powder to the edge of the powder-pushing plate B12, the cam guide rail seat B31 moves to the camshaft B35. The scraper holder B4 continues to move along the outward powder-spreading direction, and the camshaft B35 moves along the first track formed by the first deflector B33 and the cam guide rail seat B31, driving the powder-pushing plate B12 to move downward; see also Figure 11 b. When the movement reaches the second shifter B34 position, the cam pushes the second shifter B34 up and through the cam guide seat. Then, under the action of the torsion spring, the second shifter B34 quickly returns to its original position. Figure 11 As shown in c, at this time, the excess powder from the outgoing powder spreading is pushed into the powder pushing mechanism for use during the return powder spreading;

[0053] (3) Return trip spreading powder: See Figure 11 d. When the scraper holder B4 returns and spreads powder to the edge of the powder-pushing plate B12, the cam guide seat B31 moves to the camshaft B35. The scraper holder B4 continues to move in the return powder-spreading direction, and the camshaft B35 moves along the second track formed by the second paddle B34 and the cam guide seat B31, driving the powder-pushing plate B12 to move upward. The powder-pushing plate B12 pushes the powder onto the platform, and the scraper holder B4 continues to move and scrapes away the powder for return powder spreading. See [link to relevant documentation]. Figure 11 e. When the scraper holder B4 moves to the position of the first lever B33, the camshaft pushes the first lever B33 up and through the cam guide seat B31. Then, the first lever B33 quickly returns to its original position under the action of the torsion spring. Figure 11 As shown in f, the entire bidirectional powder spreading process is now complete.

Claims

1. A non-powered single-blade bidirectional powder spreading device, characterized in that: The non-powered single-blade bidirectional powder spreading device includes a scraper frame, a powder storage box, a powder pushing mechanism, and a powder pushing drive mechanism. Both the powder pushing drive mechanism and the powder storage box are located at the tail end of the scraper frame as it spreads powder along the outward path. The powder pushing mechanism is located in the powder storage box. The powder pushing drive mechanism is connected to the powder pushing mechanism. Along the outward powder spreading direction, the scraper frame drives the powder pushing mechanism to descend freely within the powder storage box via the powder pushing drive mechanism. Along the return powder spreading direction, the scraper frame drives the powder pushing mechanism to rise freely within the powder storage box via the powder pushing drive mechanism. The powder pushing drive mechanism is a gear-type drive mechanism or a linkage drive mechanism. When the powder pushing drive mechanism is a gear-type drive mechanism, the gear-type drive mechanism includes a gear and rack transmission mechanism (A2) and a bidirectional non-gear gear and rack mechanism (A3); the bidirectional non-gear gear and rack mechanism (A3) is mounted on the scraper frame and moves synchronously with the scraper frame; the gear and rack transmission mechanism (A2) is mounted at the tail end of the scraper frame as it spreads powder along the outgoing stroke; the gear and rack transmission mechanism (A2) is connected to the powder pushing mechanism; When the powder pushing drive mechanism is a linkage drive mechanism, the linkage drive mechanism includes a linkage transmission mechanism (B2) and a bidirectional cam mechanism (B3); the bidirectional cam mechanism (B3) is mounted on the scraper frame and moves synchronously with the scraper frame; the linkage transmission mechanism (B2) is mounted at the tail end of the scraper frame as it spreads powder along the outgoing path; the linkage transmission mechanism (B2) is connected to the powder pushing mechanism.

2. The non-powered single-blade bidirectional powder spreading device according to claim 1, characterized in that: When the powder pushing drive mechanism is a gear-type drive mechanism, along the outward powder spreading direction, the scraper frame drives the gear and rack transmission mechanism (A2) through the bidirectional differential gear and rack mechanism (A3) to move, so that the powder pushing mechanism can descend freely in the powder storage box; along the return powder spreading direction, the scraper frame drives the gear and rack transmission mechanism (A2) through the bidirectional differential gear and rack mechanism (A3) to move, so that the powder pushing mechanism can rise freely in the powder storage box.

3. The non-powered single-blade bidirectional powder spreading device according to claim 2, characterized in that: The bidirectional differential gear rack mechanism (A3) includes a first bidirectional differential gear rack mechanism and a second bidirectional differential gear rack mechanism. The structures of the first bidirectional differential gear rack mechanism and the second bidirectional differential gear rack mechanism are completely identical. The first bidirectional differential gear rack mechanism and the second bidirectional differential gear rack mechanism are arranged opposite to each other on the scraper holder. The gear and rack transmission mechanism (A2) includes a first gear transmission mechanism, a pusher, a first transmission shaft (A24), and a second gear transmission mechanism. The first gear transmission mechanism is connected to the second gear transmission mechanism via the first transmission shaft (A24). The structure of the first gear transmission mechanism is exactly the same as that of the second gear transmission mechanism. The powder pushing mechanism is mounted on the first transmission shaft (A24) via the pusher. During rotation, the first transmission shaft (A24) drives the powder pushing mechanism to move freely up and down in the powder storage box via the pusher. When the scraper frame gradually moves to the end of the outgoing powder spreading direction, or gradually moves away from the end of the outgoing powder spreading direction along the return powder spreading direction, the first bidirectional gear and rack mechanism drives the first transmission shaft (A24) to rotate via the first gear transmission mechanism. At the same time, the second bidirectional gear and rack mechanism drives the first transmission shaft (A24) to rotate via the second gear transmission mechanism.

4. The non-powered single-blade bidirectional powder spreading device according to claim 3, characterized in that: The first gear transmission mechanism includes a gear shaft (A26), a gear shaft bearing housing (A28), and a helical gear set (A25). The gear shaft (A26) drives the first transmission shaft (A24) to rotate through the gear shaft bearing housing (A28) and the helical gear set (A25). When the scraper holder gradually moves to the tail end of the outgoing powder spreading direction, or gradually moves away from the tail end of the outgoing powder spreading direction along the return powder spreading direction, the first bidirectional differential gear rack mechanism gradually meshes with the gear shaft (A26) and drives the gear shaft (A26) to rotate axially around the gear shaft (A26). The pushing component includes a first rack (A21), a torque limiting gear (A22), and a rack connecting seat (A27); the torque limiting gear (A22) is mounted on the first drive shaft (A24) and rotates synchronously with the first drive shaft (A24); the first rack (A21) is connected to the powder pushing mechanism through the rack connecting seat (A27); the torque limiting gear (A22) meshes with the first rack (A21); when the first drive shaft (A24) rotates, the torque limiting gear (A22) drives the first rack (A21) to push the powder pushing mechanism to move freely up and down in the powder storage box.

5. The non-powered single-blade bidirectional powder spreading device according to claim 4, characterized in that: The first bidirectional differential gear rack mechanism includes a gear guide seat (A31), a second rack (A32), a forward gear set (A33), and a reverse gear set (A34). The gear guide seat (A31) is mounted on the scraper holder and moves synchronously with it. The second rack (A32) includes an upper rack and a lower rack arranged parallel to it. The upper and lower racks extend from opposite sides of the gear guide seat (A31). The forward gear set (A33) and the reverse gear set (A34) are mounted on the gear shaft (A26) from top to bottom. When the scraper holder gradually moves along the outgoing powder spreading direction to the tail end of the outgoing powder spreading, the forward gear set (A33) gradually contacts and meshes with the upper rack. The upper rack moves forward... The gear set (A33) drives the gear shaft (A26) to rotate axially around the gear shaft (A26); as the scraper holder gradually moves away from the tail end of the outgoing powder spreading along the return powder spreading direction, the reverse gear set (A34) gradually contacts and meshes with the lower rack, and the lower rack drives the gear shaft (A26) to rotate axially around the gear shaft (A26) through the reverse gear set (A34); the structure of the forward gear set (A33) is exactly the same as that of the reverse gear set (A34); the forward gear set (A33) includes a gear (A331) and a one-way bearing (A332); the gear (A331) and the one-way bearing (A332) are sequentially mounted on the gear shaft (A26) from the outside to the inside; the gear (A331) meshes with the second rack (A32).

6. The non-powered single-blade bidirectional powder spreading device according to claim 1, characterized in that: When the powder pushing drive mechanism is a linkage drive mechanism, along the outward powder spreading direction, the scraper frame drives the linkage transmission mechanism (B2) and the powder pushing mechanism to descend freely in the powder temporary storage box through the bidirectional differential cam mechanism (B3); along the return powder spreading direction, the scraper frame drives the linkage transmission mechanism (B2) and the powder pushing mechanism to rise freely in the powder temporary storage box through the bidirectional differential cam mechanism (B3).

7. The non-powered single-blade bidirectional powder spreading device according to claim 6, characterized in that: The bidirectional cam mechanism (B3) includes a first bidirectional cam mechanism and a second bidirectional cam mechanism, the structure of which is identical to that of the second bidirectional cam mechanism; the first and second bidirectional cam mechanisms are arranged opposite to each other on the scraper holder; the linkage transmission mechanism (B2) includes a first linkage transmission mechanism, a pusher, a second transmission shaft (B22), and a second linkage transmission mechanism; the first linkage transmission mechanism is connected to the second linkage transmission mechanism via the second transmission shaft (B22); the structure of the first linkage transmission mechanism is identical to that of the second linkage transmission mechanism. The structures are completely identical; the powder pushing mechanism is mounted on the second transmission shaft (B22) via a pusher; during rotation, the second transmission shaft (B22) drives the powder pushing mechanism to move freely up and down in the powder storage box via the pusher; when the scraper frame gradually moves to the end of the outgoing powder spreading direction, or gradually moves away from the end of the outgoing powder spreading direction along the return powder spreading direction, the first bidirectional cam mechanism drives the second transmission shaft (B22) to rotate via the first linkage transmission mechanism, and at the same time, the second bidirectional cam mechanism drives the second transmission shaft (B22) to rotate via the second linkage transmission mechanism.

8. The non-powered single-blade bidirectional powder spreading device according to claim 7, characterized in that: The first linkage transmission mechanism includes a cam guide shaft assembly (B27), a bearing housing (B28), a fourth link (B26), and a third link (B25). The cam guide shaft assembly (B27) is connected to the third link (B25) through the bearing housing (B28) and the fourth link (B26). The third link (B25) is connected to the second transmission shaft (B22) and drives the second transmission shaft (B22) to rotate around the axial direction of the second transmission shaft (B22). When the scraper frame gradually moves to the end of the outgoing powder spreading direction, or gradually moves away from the end of the outgoing powder spreading direction along the return powder spreading direction, the first bidirectional cam mechanism gradually connects with the first linkage transmission mechanism and drives the first linkage transmission mechanism to move synchronously. At the same time, the second bidirectional cam mechanism gradually connects with the second linkage transmission mechanism and drives the second linkage transmission mechanism to move synchronously. The pushing component includes a first connecting rod (B23) and a second connecting rod (B24); one end of the first connecting rod (B23) is mounted on the second transmission shaft (B22) and rotates synchronously with the second transmission shaft (B22), and the other end is connected to the second connecting rod (B24); the second connecting rod (B24) is connected to the powder pushing mechanism.

9. The non-powered single-blade bidirectional powder spreading device according to claim 8, characterized in that: The first bidirectional differential cam mechanism includes a cam guide seat (B31), a torsion spring assembly (B32), a first paddle (B33), a horizontal limiting plate, a second paddle (B34), and a camshaft (B35). The cam guide seat (B31) is mounted on the scraper holder and moves synchronously with it. The side wall of the cam guide seat (B31) is provided with a cam movement groove. The axial direction of the cam movement groove is parallel to the travel direction of the scraper holder. The first paddle (B33), the horizontal limiting plate, and the second paddle (B34) are disposed in the cam movement groove, dividing the cam movement groove from bottom to top into a forward movement groove and a return movement groove. One end of the first paddle (B33) rests against the top of the cam movement groove. The other end is connected to the horizontal limiting plate via a torsion spring assembly (B32); one end of the second paddle (B34) rests against the bottom of the cam moving groove, and the other end is connected to the horizontal limiting plate via a torsion spring assembly (B32); the camshaft (B35) is connected to the cam guide shaft assembly (B27); when the scraper holder gradually moves to the end of the outgoing powder spreading direction, the camshaft (B35) moves in the outgoing moving groove along the direction from the first paddle (B33) to the second paddle (B34); when the scraper holder gradually moves away from the end of the outgoing powder spreading direction along the return powder spreading direction, the camshaft (B35) moves in the return moving groove along the direction from the second paddle (B34) to the first paddle (B33).

10. The non-powered single-blade bidirectional powder spreading device according to any one of claims 1-9, characterized in that: The powder pushing mechanism includes a powder pushing plate and a guide rail slider; the powder pushing plate is placed inside the powder storage box and can move freely up and down along the height direction of the powder storage box; the powder pushing drive mechanism is connected to the powder pushing plate through the guide rail slider.

11. The non-powered single-blade bidirectional powder spreading device according to claim 10, characterized in that: The powder pushing mechanism also includes a compression spring and a spring plate; the spring plate is placed at the bottom of the powder pushing plate; the compression spring is disposed between the spring plate and the powder pushing plate and is connected to the spring plate and the powder pushing plate respectively; the powder pushing drive mechanism is connected to the spring plate through a guide rail slider.

Images