Metal rotating part grafting printing method and 3D printing device

Abstract

The invention relates to the technical field of selective laser melting printing, in particular to a metal rotating part grafting printing method and a 3D printing device.The metal rotating part grafting printing method comprises the following steps that a rotating part model to be machined is split into a basic body and a grafting body, and the basic body is obtained through machining or 3D printing; a positioning piece matched with the bottom face of the base body in shape is arranged on a base plate through 3D printing, and the positioning piece is concentric with the base plate; the basic body is installed on the substrate through the positioning piece, and the contour parameters of the combination surface of the basic body are scanned to print the first layer contour of the grafting body for positioning comparison; and printing is carried out on the combination surface of the basic body according to the preset number of printing layers until the grafting body and the basic body are formed through grafting and printing. Through the arrangement, the printing efficiency and the printing quality are improved while the printing cost is reduced, the size range of the printed rotating part is wide, and the applicability of the printing device is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of selective laser melting printing, and in particular to a metal rotating part grafting printing method and a 3D printing device. Background Art

[0002] Selective laser melting technology SLM uses a 30-100μm fine laser spot to scan the selected area on the newly laid powder layer point by point, and after forming the surface contour, it stacks the layers to form and manufacture, and directly obtains functional parts of almost any shape. SLM can form parts of any complex structure, improve design freedom, break through traditional processing constraints, and create more added value for products based on the functionality of the parts. At present, SLM technology has been widely used in aerospace, molds, medical, automotive and other industrial fields.

[0003] SLM directly molded parts are processed layer by layer through laser scanning. The processing efficiency is slower than that of traditional machining, and the cost of equipment and materials and the unit processing time cost are relatively high. For some large parts that only require partial functional characteristics and other relatively simple structures, if they are printed as a whole, the printing time is long and the cost is high. Therefore, the grafting printing method is considered. The simple structure part is completed by traditional machining, and the complex structure and functional part is completed by 3D printing. 3D printing is combined with traditional processing to give full play to the advantages of 3D printing and reduce the cost and production efficiency of printing large parts with some complex structures. However, the existing grafting printing method has poor connection strength at the grafting part, which cannot meet the functional requirements of torque transmission, vibration reduction, etc. of the rotating parts in the working state and the requirements of heterogeneous metal bonding used to reduce the production and manufacturing costs. In addition, the traditional grafting method is to first machine the grafting matrix, and at the same time specially design a base plate fixed to the grafting matrix, and then fix the grafting matrix on the base plate by bolts or by printing the grafting matrix and the base plate together, and then perform grafting printing. There are problems such as complex operation, inaccurate positioning, high manufacturing cost, and unsuitability for industrial mass production. Therefore, it is of practical significance to design a new type of metal rotating parts grafting printing method and 3D printing device. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a metal rotating part grafting printing method and a 3D printing device.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: a method for grafting and printing metal rotating parts, comprising the following steps: splitting the model of the rotating parts to be processed into a basic body and a grafted body, and obtaining the basic body by machining or 3D printing; setting a positioning piece that is adapted to the bottom surface shape of the basic body on the substrate by 3D printing, and the positioning piece is set concentrically with the substrate; installing the basic body on the substrate by the positioning piece, scanning the contour parameters of the basic body joint surface to print the first layer contour of the grafted body for positioning comparison; printing on the basic body joint surface according to a preset number of printing layers until the grafted body and the basic body are grafted and printed.

[0006] Furthermore, a scale line is arranged on the surface of the bonding surface between the basic body and the grafted body, and during the model slicing process, the grafted body and the basic body are arranged concentrically with the substrate.

[0007] Furthermore, a plurality of linear grafting grooves are evenly arranged around the center of the surface layer of the bonding surface, and the number of the linear grafting grooves is the same as the number of the scale lines and coincides with the scale lines.

[0008] Furthermore, one end of the linear grafting groove close to the center of the bonding surface is at a certain distance from the center of the bonding surface, and the area occupied by a plurality of the linear grafting grooves is 0.65-0.85 times the area of ​​the bonding surface.

[0009] Furthermore, the surface layer of the bonding surface is provided with a plurality of annular grafting grooves having the same center as the bonding surface and intersecting with the linear grafting grooves, the annular grafting grooves have the same shape and different inner diameters, and the difference in inner diameters of adjacent annular grafting grooves is the same.

[0010] Furthermore, the cross-sectional profile of the linear grafting groove and / or the annular grafting groove is a trapezoid with an open top.

[0011] Furthermore, the bottom angles on both sides of the trapezoidal cross-sectional profile of the linear grafting groove and / or the circular grafting groove are equal, and the relationship between the height H1 of the trapezoidal cross-sectional profile and the bottom angle α of the trapezoidal cross-sectional profile satisfies the following formula: H1=0.08α-1.8, wherein the unit of H1 is mm, the range of H1 is 0.6 mm-3 mm, the unit of α is degree, the range of α is 30°-60°, and the number of printing layers of the linear grafting groove and / or the circular grafting groove is set to 5-8 layers.

[0012] Furthermore, an energy absorption zone formed by stacking lattice structures is printed on the graft, and the relationship between the height H2 of the energy absorption zone and the height H1 of the trapezoidal cross-sectional profile satisfies the following formula: H2=3.75H1-0.25, wherein the unit of H2 is mm, and the range of H2 is 3 mm-10 mm.

[0013] Further, the lattice structure unit cell size is T, in mm, and the relationship between the lattice structure unit cell size T, the height H1 of the trapezoidal cross-sectional profile and the height H2 of the bonding area satisfies the following formula:

[0014] T=0.13(H1-0.6)+0.04(H2-3)+0.2.

[0015] The present invention also provides a 3D printing device, which uses the above-mentioned metal rotating part grafting printing method for printing.

[0016] The beneficial effects of the present invention are:

[0017] (1) While ensuring that the functional characteristics of rotating parts remain unchanged, the printing cost of some rotating parts with complex structures is reduced, the printing efficiency is improved, and the printing time is shortened.

[0018] (2) In view of the characteristics of the rotating parts, the present invention innovatively sets a positioning part on the substrate, which eliminates the need to separately design a substrate fixed to the basic body, further reducing the printing cost and avoiding the basic body being directly connected to the substrate by printing more supporting structures. This avoids post-processing steps such as cutting and polishing after the rotating parts are printed, further improving the printing efficiency and ensuring better surface forming quality. Compared with the existing printing method, it is more suitable for mass production in industry. Therefore, by setting the positioning part, the printing cost is reduced while the printing efficiency and printing quality are improved.

[0019] (3) By arranging the positioning member concentrically with the substrate, a wide range of sizes of rotating members can be printed within a certain printing space, thereby improving the applicability of the printing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram of the structure of a rotating member provided in an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of a three-dimensional structure of a basic body provided by an embodiment of the present invention;

[0023] Figure 3 A schematic diagram of the three-dimensional structure of a graft provided by an embodiment of the present invention;

[0024] Figure 4 A schematic diagram of a bonding surface structure with scale lines provided in an embodiment of the present invention;

[0025] Figure 5 A top view of a basic body provided by an embodiment of the present invention;

[0026] Figure 6 A schematic diagram of the three-dimensional structure of the bonding surface provided by an embodiment of the present invention;

[0027] Figure 7 A schematic cross-sectional view of a linear grafting groove and a circular grafting groove provided in an embodiment of the present invention;

[0028] Figure 8 A plan view of a lattice structure provided for an embodiment of the present invention.

[0029] Figure numerals: 1. basic body; 11. bonding surface; 12. linear grafting groove; 13. circular grafting groove; 121. lower bottom; 122. side; 2. grafting body; 21. energy absorption area; 3. positioning member; 4. substrate; 5. scale line. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0032] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; 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. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0033] In the present invention, unless otherwise clearly specified and limited, a first feature being above or below a second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, a first feature being above, above, and above a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being below, below, and below a second feature includes the first feature being directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0034] Example 1

[0035] like Figure 1-3 As shown, the present invention provides a metal rotating part grafting printing method, the printing method comprising the following steps:

[0036] The model of the rotating part to be processed is split into a basic body 1 and a grafted body 2, and the basic body 1 is obtained by machining or 3D printing;

[0037] A positioning member 3 adapted to the bottom surface shape of the basic body 1 is arranged on the substrate 4 by 3D printing, and the positioning member 3 is arranged concentrically with the substrate 4;

[0038] The basic body 1 is mounted on the substrate 4 by the positioning member 3, and the contour parameters of the bonding surface 11 of the basic body 1 are scanned to print the first layer contour of the grafted body 2 for positioning comparison;

[0039] Printing is performed on the joint surface 11 of the basic body 1 according to a preset number of printing layers until the grafting body 2 and the basic body 1 are grafted and printed into shape.

[0040] It should be pointed out that the printing method of the present invention is based on the selective laser melting 3D printer for printing. The splitting position of the rotating part to be processed should avoid the splitting at the assembly position. Preferably, the structural transition is used as the splitting position to try to maintain a certain feature integrity. In order to maintain the functional integrity of the rotating part and the subsequent processing efficiency, the splitting position is preferably provided with distinguishing alignment features. The alignment features are holes with contour shapes, squares, circles, etc., and the subsequent grafting printing positioning work is facilitated by setting the alignment features. Rotating parts generally adopt a shape that rotates symmetrically around the axis to obtain better running stability, such as Figure 1 As shown, the embodiment of the present invention uses a rotating part with a cylindrical cross section for illustration. In actual operation, it can also be a square rotating part. According to the structural characteristics of the basic body 1, the machining or 3D printing processing method is selected. If the basic body 1 has a simple structure and no functional characteristics, or the rotating part is large and the processing time is long, the machining method can be used. If the basic body 1 has a complex structure, the processing time is relatively short, and it has certain functional characteristics, the 3D printing method can be used.

[0041] The base plate 4 is square or round, and "adaptation" means that after the base body 1 is installed in place, the positioning member 3 provides good support for the base body 1. Figure 1 As shown, the present invention grafts and prints a cylindrical rotating part, and the basic body 1 and the positioning part 3 are installed by direct assembly. The size and shape of the positioning part 3 can be specifically designed according to the actual rotating part to be processed;

[0042] By adjusting and printing the outline of the graft body 2 for multiple times, it is ensured that the alignment positions of the basic body 1 and the graft body 2 are within the required range;

[0043] Through the above settings, firstly, under the premise of ensuring that the functional characteristics of the rotating parts remain unchanged, the printing cost of some rotating parts with complex structures is reduced, the printing efficiency is improved, and the printing time is shortened; secondly, the present invention innovatively sets a positioning member 3 on the substrate 4 in view of the characteristics of the rotating parts, and there is no need to separately design the substrate 4 fixed to the basic body 1, which further reduces the printing cost and avoids the basic body 1 being directly connected to the substrate 4 by printing more supporting structures, which not only avoids the post-processing steps such as cutting and polishing after the rotating parts are printed, further improves the printing efficiency, but also ensures better surface forming quality. Compared with the existing printing methods, the grafting printing method of the present invention is more suitable for mass production in industry. Therefore, by setting the positioning member 3, the printing efficiency and printing quality are improved while reducing the printing cost; finally, by setting the positioning member 3 concentrically with the substrate 4, a wide range of rotating parts can be printed within a certain printing space, thereby improving the applicability of the printing device.

[0044] Specifically, Figure 4 As shown, a scale mark 5 is arranged on the surface of the bonding surface 11 between the basic body 1 and the grafted body 2 . When the model is sliced, the grafted body 2 and the basic body 1 are arranged concentrically with the substrate 4 . It should be pointed out that the scale lines 5 are used to mark angles. Preferably, as shown in the figure, the scale lines 5 are arranged around the center of the substrate 4, and the angle marked between adjacent scale lines 5 is 10°, which is convenient for observation and processing. When the rotating part model is sliced, the bonding surface 11 of the grafted body 2 and the basic body 1 is arranged to be the same center as the substrate 4. When positioning and aligning the basic body 1 and the grafted body 2, it is no longer necessary to adjust the rotating part model to be processed in the slicing processing software in the X and Y directions (wherein the X direction is perpendicular to the Y direction, and the X direction and the Y direction are both perpendicular to the extension direction of the central axis of the rotating part, and the Z direction is parallel to the extension direction of the central axis of the rotating part). It is only necessary to adjust the rotation angle in the Z direction in the slicing processing software according to the measured offset angle, that is, rotate around the central axis of the rotating part, which reduces the difficulty of positioning and printing errors, realizes precise positioning, and makes alignment simpler, faster and more accurate. By setting the scale lines 5, it plays a role of intuitive reference, and it is possible to intuitively judge whether the Z-direction adjustment setting is correct, without the need for repeated measurements to determine whether the adjustment is correct.

[0045] Specifically, Figure 2 , 3As shown in Figures 5, 6, a plurality of linear grafting grooves 12 are evenly arranged on the surface of the bonding surface 11 around its center, and the number of the linear grafting grooves 12 is the same as the number of the scale lines 5 and coincides with the scale lines 5. Based on the use environment of rotating parts, the rotating parts have high requirements for strength, torque transmission, vibration reduction and other performances. By setting the linear grafting grooves 12, during grafting printing, the grafted body 2 prints the surface structure that matches the linear grafting grooves 12, so that the grafted body 2 and the surface structure of the basic body 1 are mutually embedded, which can increase the contact area between the grafted body 2 and the basic body 1 and improve the bonding strength between the grafted body 2 and the basic body 1. The design of the grooves also enhances the torsional resistance of the basic body 1 and the grafted body 2 under rotating conditions, further ensuring the connection strength between the grafted body 2 and the basic body 1. In addition, because in some special working conditions, the performance requirements for rotating parts are very high, it is often necessary to select special metals as manufacturing materials, which will lead to a sharp increase in production costs. Therefore, considering the two parts being connected by grafting printing, The grafting of different metal materials uses special metal materials at the working position under special working conditions, but the bonding strength of the grafting printing of dissimilar metal materials using the existing technology cannot meet the performance requirements and is prone to cracking. The above settings ensure the bonding strength of the printed grafting of dissimilar metal materials, so that the performance of the grafted dissimilar metal materials after printing meets the required performance indicators, greatly reducing the production cost. Finally, by setting the number of the linear grafting grooves 12 to be the same as the number of the scale lines 5 and coinciding with the scale lines, the linear grafting grooves 12 play the role of angle indication, and there is no need to process the scale lines 5 separately, further simplifying the production process. Therefore, through the above settings, while improving the bonding strength and reducing the cracking probability of the bonding surface 11 between the graft body 2 and the basic body 1, the production process is simplified and the printing efficiency is improved.

[0046] It should be pointed out that for the functional characteristics of rotating parts, such as Figure 5-6 As shown, the embodiment of the present invention is provided with 36 straight-line grafting grooves 12, where the straight-line shape refers to a grafting groove whose projection shape is a long straight line. The number of the straight-line grafting grooves 12 can be set according to the actual use environment and performance requirements, and is not limited to the embodiments in the drawings of this application.

[0047] Specifically, Figure 5-6As shown, one end of the linear grafting groove 12 close to the center of the bonding surface 11 is at a certain distance from the center of the bonding surface 11. By setting the linear grafting groove 12 at a certain distance from the center of the bonding surface 11, so that the center of the bonding surface 11 has a certain area not covered by the linear grafting groove 12, during grafting printing, this area can disperse stress to avoid stress concentration at the grafting joint, and also play a deformation correction and heat conduction role for the linear grafting groove 12, avoiding the linear grafting groove 12 from being deformed by thermal stress due to heat transfer during the grafting printing process because the ends of the linear grafting groove 12 close to the center of the bonding surface 11 are too close to each other. , which makes the subsequent printing powder laying uneven in thickness, affecting the printing flatness of the bonding surface 11 and the concentricity of the rotating part, and further affecting the performance of the rotating part; preferably, the area of ​​the region surrounded by the plurality of said linear grafting grooves 12 is 0.65-0.85 times the area of ​​the bonding surface 11. It should be pointed out that the area of ​​the region surrounded by the plurality of said linear grafting grooves 12 refers to the annular area between the circle formed by connecting one end of the plurality of linear grafting grooves 12 close to the center of the bonding surface 11 and the circle formed by connecting the other end opposite to the plurality of linear grafting grooves 12. The limitation of the above area parameters further ensures that the bonding strength meets the performance requirements of the rotating part, and avoids deformation at the linear grafting grooves 12.

[0048] Specifically, Figure 5-6As shown, the surface of the bonding surface 11 is provided with a plurality of annular grafting grooves 13 having the same center as the bonding surface 11 and intersecting with the linear grafting grooves 12. The annular grafting grooves 13 have the same shape and different inner diameters, and the difference in inner diameters of adjacent annular grafting grooves 13 is the same. By providing the annular grafting grooves 13, firstly, by providing a larger number of grafting grooves, the bonding strength, vibration reduction and torsion resistance between the basic body 1 and the grafting body 2 can be further improved. Secondly, the provision of the annular grafting grooves 13 also plays a role in flow guidance and heat conduction. In the process of grafting printing in the grooves, the linear grafting grooves 12 are not connected to each other. If the printing thickness in some linear grafting grooves 12 is greater than that in other linear grafting grooves 12 due to powder spreading errors, after multiple powder spreading and printing, it will affect the printing flatness and the concentricity of the rotating parts, resulting in poor bonding strength, The vibration reduction and torsion resistance performance do not meet the requirements. After the annular grafting groove 13 is set, the linear grafting grooves 12 are connected to each other, which can not only better conduct heat and avoid thermal deformation, but also make the molten metal evenly distributed in the linear grafting groove 12 and the annular grafting groove 13, avoiding the problem of uneven printing thickness and ensuring that the bonding strength meets the performance requirements. In particular, by setting the inner diameter difference of adjacent annular grafting grooves 13 to be the same, the annular grafting groove 13 divides the linear grafting groove 12 into several sections, further improving the bonding strength, vibration reduction and torsion resistance. Preferably, the diameter difference between adjacent annular grafting grooves 13 is 1 / 8-1 / 10 of the diameter of the bonding surface 11. This setting can further coordinate the effect achieved by the annular grafting grooves 13 to avoid the problem of insufficient bonding strength due to too few annular grafting grooves 13 or easy deformation of the grooves due to too many annular grafting grooves 13. It should be pointed out that in the actual grafting printing process, the number of annular grafting grooves 13 can be reasonably determined based on the size of the rotating part to be processed and the above-mentioned parameter range, and is not limited to the number shown in the embodiments in the drawings of the present application.

[0049] Specifically, Figure 7As shown, the cross-sectional profile shape of the linear grafting groove 12 and / or the circular grafting groove 13 is a trapezoid with an opening at the top. It should be pointed out that the cross-sectional profiles of the linear grafting groove 12 and the circular grafting groove 13 described in the embodiment of the present invention are both trapezoids with an opening at the top. The cross-sectional profile shape can also be a polygon with an opening at the top. For ease of processing, the present application preferably has a trapezoidal cross-sectional profile. It can be understood that the width of the upper base of the trapezoid (the top opening, the side close to the surface of the bonding surface 11) is smaller than the width of the lower base 121 of the trapezoid (the side away from the surface of the bonding surface 11). The two side edges 122 of the trapezoid connect the upper base and the lower base 121, so that the volume of the trapezoid gradually expands from the top opening toward the lower base 121. By setting the cross-sectional profile to a trapezoid, a limiting and fixing effect is achieved. , so that the combination between the basic body 1 and the grafted body 2 is tighter, and under the conditions of rotation and vibration, when the grafted body 2 tends to separate from the basic body 1, the two side surfaces of the grafting groove (the two inclined edges of the trapezoidal cross-sectional profile) exert a force toward the inside of the printed part on the printed part of the grafted body 2 located in the grafting groove, so that the maximum force-bearing area of ​​the printed part located in the grafting groove moves from its surface to its inside, thereby improving the pressure-bearing capacity, avoiding the problem of surface cracking and fracture of the part of the grafted body 2 located in the grafting groove, and improving the torsional resistance of the rotating part, further ensuring the bonding strength between the basic body 1 and the grafted body 2.

[0050] Specifically, Figure 7As shown, the bottom angles on both sides of the trapezoidal cross-sectional profile of the linear grafting groove 12 and / or the annular grafting groove 13 are equal, and the relationship between the height H1 of the trapezoidal cross-sectional profile and the bottom angle α of the trapezoidal cross-sectional profile satisfies the following formula: H1=0.08α-1.8, wherein the unit of H1 is mm, the range of H1 is 0.6 mm-3 mm, the unit of α is degree, the range of α is 30°-60°, and the number of printing layers of the linear grafting groove 12 and / or the annular grafting groove 13 is set to 5-8 layers. It can be understood that the bottom angle α is the angle between the side 122 of the trapezoidal profile and the lower bottom 121. When calculating, the angle α only takes the numerical value, not the angle unit. For example, when calculating the value of H1 when the angle α is 30°, just substitute 30 into the formula. During the grafting printing process, it is necessary to control the molten metal to fully fill the grafting groove to avoid affecting the bonding strength due to insufficient filling. If the height H1 is less than 0.6 mm, the size of the grafting groove is too small and the pressure-bearing performance of the printed part in the grafting groove is insufficient, resulting in weak bonding strength. If the height H1 is greater than 3 mm, although the bonding strength is ensured, correspondingly, because the height is too large, it is necessary to increase the power of the printing laser to ensure uniform melting and filling, but correspondingly, the increase in thermal stress can easily lead to deformation of the grafting groove. Therefore, it is impossible to simultaneously meet the uniform filling of the molten metal and control the deformation of the grafting groove. Although it is possible to avoid deformation of the grafting groove by reducing the laser power and setting multiple printings for control, the height is too large, which will also make the printing Too many printing layers will greatly reduce the printing efficiency and make it more difficult to control the printing error, which cannot meet the requirements of mass industrial production. By coordinating the relationship between the angle α and the height H1, the angle α increases with the increase of the height H1, so as to avoid the problem that the height H1 is too small and the angle α is too large, resulting in insufficient bonding strength or the height H1 is too large and the angle α is too small, resulting in uneven melting of the edge of the metal powder near the angle and a loose printed structure. Further coordination ensures the bonding strength while reducing the printing difficulty and improving the printing efficiency. By setting the number of printing layers to 5-8, the normal printing efficiency can be met while the molten metal can better fill the grafting groove. It should be pointed out that for grafting grooves of different heights, the thickness of the powder can be adjusted to meet the above-mentioned printing layer requirements. Preferably, when the grafting groove is grafted and filled, the power of the printing laser is set to gradually change from weak to strong, and the scanning printing speed is set to gradually change from slow to fast. Through this setting, a preheating effect is played during the printing process of the first few layers to avoid deformation caused by excessive local thermal stress in the scanning and printing area. As the number of printing layers increases, the printing laser power is increased accordingly and the scanning and printing speed is accelerated to avoid thermal stress deformation of the grafting groove while ensuring that the metal powder is fully melted and the entire grafting groove is fully filled with molten metal.

[0051] Preferably, the angle α between the trapezoidal profile side 122 and the lower bottom 121 is set to a rounded angle. Through this setting, stress concentration at the angle α is avoided. Moreover, because the molten metal has surface tension, the surface tension causes the metal droplets to develop into a spherical shape. By setting the angle α to a rounded angle, the angle position of the grafting groove can be fully filled under the automatic regulation of the molten metal tension, further ensuring that the performance of the rotating part meets the required performance indicators.

[0052] Specifically, Figure 1 , 3 As shown, an energy absorption zone 21 formed by stacking lattice structures is printed on the graft 2, and the relationship between the height H2 of the energy absorption zone 21 and the height H1 of the trapezoidal cross-sectional profile satisfies the following formula: H2=3.75H1-0.25, wherein the unit of H2 is mm, and the range of H2 is 3 mm-10 mm. Preferably, the energy absorption zone 21 is printed from the same metal material as the grafted body 2, and the grafted printed portion of the grafted body 2 located in the linear grafting groove 12 and the annular grafting groove 13 is a solid structure. After the grafted body 2 completes printing of the portion located in the grafting groove, the energy absorption zone 21 is continued to be printed according to a preset height. After the energy absorption zone 21 is printed, the printing of the entire grafted body 2 is continued according to the set printing parameters. It should be pointed out that the lattice structure is directly printed after being designed by the lattice design software, and the shape and distribution of the lattice can be freely designed according to performance requirements. By setting the energy absorption zone 21, the energy generated during the operation of the rotating part can be absorbed. During operation, the portion of the grafted body 2 located in the grafting groove plays an impact protection role, further improving the vibration reduction performance and torsion resistance of the rotating part, and by setting the energy absorption zone 21, manufacturing raw materials are saved, the rotating part is lightweight, and it is very helpful to improve transmission efficiency and reduce costs. In order to better provide impact protection for the grafted printed part in the grafting groove, the height H2 of the energy absorption zone 21 varies with the height H1 of the trapezoidal cross-sectional profile of the linear grafting groove 12 and / or the annular grafting groove 13. Preferably, the range of H2 is 3 mm-10 mm. If H2 is too large, such as greater than 10 mm, it will not only extend the printing time, but also increase the subsequent processing steps, so that the printing efficiency is affected.

[0053] Specifically, Figure 8 As shown, the lattice structure unit cell size is T, in mm, and the relationship between the lattice structure unit cell size T, the height H1 of the trapezoidal cross-sectional profile and the height H2 of the bonding area satisfies the following formula: T = 0.13 (H1-0.6) + 0.04 (H2-3) + 0.2. It should be noted that the attached Figure 8 It is only used to illustrate the unit cell size T. The specific shape and distribution of the lattice can be freely designed according to performance requirements and is not limited to the attached Figure 8The shape and distribution shown in . By limiting the above relationship, while ensuring printing efficiency and reducing production costs, the functional characteristics of the rotating parts such as the bonding strength, vibration reduction performance, and torsion resistance are improved; preferably, the range of the cell size T of the lattice structure is 0.3㎜-0.5㎜. By limiting the range of the cell size T, the printing time is shortened and the material consumption is reduced while ensuring the printing accuracy and the mechanical properties of the lattice structure.

[0054] Example 2

[0055] The present invention provides a 3D printing device, which uses the metal rotating part grafting printing method described in Example 1 for printing.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A metal rotating part grafting printing method, characterized in that: The printing method comprises the following steps: Splitting the model of the rotating part to be processed into a basic body and a grafted body, and obtaining the basic body by machining or 3D printing; A positioning piece adapted to the shape of the bottom surface of the basic body is arranged on the substrate by 3D printing, and the positioning piece is arranged concentrically with the substrate; The basic body is mounted on the substrate by the positioning member, and the contour parameters of the basic body joint surface are scanned to print the contour of the first layer of the graft body for positioning comparison; Printing is performed on the combined surface of the basic body according to a preset number of printing layers until the grafted body and the basic body are grafted and printed into shape.

2. The metal rotating part grafting printing method according to claim 1, characterized in that: Graduation lines are arranged on the surface of the bonding surface between the basic body and the grafted body. When the model is sliced, the grafted body and the basic body are arranged concentrically with the substrate.

3. The metal rotating part grafting printing method according to claim 2, characterized in that: A plurality of linear grafting grooves are evenly arranged around the center of the surface layer of the bonding surface, and the number of the linear grafting grooves is the same as the number of the scale lines and coincides with the scale lines.

4. The metal rotating part grafting printing method according to claim 3, characterized in that: One end of the linear grafting groove close to the center of the bonding surface is at a certain distance from the center of the bonding surface, and the area occupied by a plurality of the linear grafting grooves is 0.65-0.85 times the area of ​​the bonding surface.

5. The metal rotating part grafting printing method according to claim 3, characterized in that: The surface layer of the bonding surface is provided with a plurality of annular grafting grooves having the same center as the bonding surface and intersecting with the linear grafting grooves. The annular grafting grooves have the same shape but different inner diameters, and the difference in inner diameters of adjacent annular grafting grooves is the same.

6. The metal rotating part grafting printing method according to claim 5, characterized in that: The cross-sectional profile of the linear grafting groove and / or the annular grafting groove is a trapezoid with an open top.

7. The metal rotating part grafting printing method according to claim 6, characterized in that: The bottom angles on both sides of the trapezoidal cross-sectional profile of the linear grafting groove and / or the circular grafting groove are equal, and the relationship between the height H1 of the trapezoidal cross-sectional profile and the bottom angle α of the trapezoidal cross-sectional profile satisfies the following formula: H1=0.08α-1.8, wherein the unit of H1 is mm, the range of H1 is 0.6 mm-3 mm, the unit of α is degree, the range of α is 30°-60°, and the number of printing layers of the linear grafting groove and / or the circular grafting groove is set to 5-8 layers.

8. The metal rotating part grafting printing method according to claim 7, characterized in that: An energy absorption zone formed by stacking lattice structures is printed on the grafted body, and the relationship between the height H2 of the energy absorption zone and the height H1 of the trapezoidal cross-sectional profile satisfies the following formula: H2=3.75H1-0.25, wherein the unit of H2 is mm, and the range of H2 is 3 mm-10 mm.

9. The metal rotating part grafting printing method according to claim 8, characterized in that: The cell size of the lattice structure is T, in mm. The relationship between the cell size T of the lattice structure, the height H1 of the trapezoidal cross-sectional profile and the height H2 of the bonding area satisfies the following formula: T=0.13(H1-0.6)+0.04(H2-3)+0.

2.

10. A 3D printing device, characterized in that: Printing is performed using the metal rotating part grafting printing method as described in any one of claims 1 to 9.

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