Heating structure for selective laser melting equipment

Abstract

The utility model relates to the technical field of heating structures of melting equipment, in particular to a heating structure for selective laser melting equipment, which comprises a heating plate mounted on a substrate and provided with a wire slot on the front surface; the resistance wire is installed in the heating plate wire groove with the matched shape in a full welding and sealing mode through welding; the metal connecting part is arranged at the end part of the resistance wire and is connected with an external power supply; the insulating part is positioned at the end part of the resistance wire and is provided with a cavity for accommodating the metal connecting part; the sealing layer is installed on the front face of the heating plate and used for isolating the front face of the heating plate from the outside to seal the heating plate, and the technical problems that in the related technology, heating is not uniform, splashing explosion or short-circuit accidents are likely to happen, and the safety and stability are poor are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of heating structures of melting equipment, in particular to a heating structure for a selective laser melting equipment. Background Technique

[0002] Selective laser melting is a metal additive manufacturing technology. By irradiating metal powder with a high-energy laser beam, the metal powder is melted and stacked layer by layer to manufacture complex metal components. Before the selective laser melting process, it is necessary to heat the substrate. In small-scale equipment, usually the requirements for heating efficiency and uniformity are not high. However, in large-format equipment, usually the substrate is locally heated by multiple heating structures. Currently, the common problems in selective laser heating of the substrate are uneven heating, local high-temperature carbonization or abnormal local temperature of the substrate, etc. Since it works in a dust environment, it is extremely easy to cause electric sparks or short circuits at the heating ends due to poor sealing, resulting in material or gas splashing, seriously affecting the stability and reliability of the equipment operation.

[0003] A new patent with the publication number of CN215315723U and the name of a modular substrate heating device for a selective laser melting equipment includes a substrate, as well as a heat conduction plate, a heating component, a heating regular plate and a spring arranged below the substrate. It also includes a heat insulation block. The spring is arranged in a spring hole on the surface of the workbench, and a heating jacking plate is arranged thereon. The heat insulation block is arranged on the heating jacking plate. The heat insulation block is provided with a concave heating component setting cavity. The heating component is arranged in the heating component setting cavity. The upper surface of the heating component is slightly higher than the upper surface of the heat insulation block. The heat insulation block drives the heating component to move up and down under the push of the heating jacking plate. The upper surface of the heating component is highest to completely fit the heat conduction plate, which can reliably and efficiently realize selective laser melting operation. However, the related technologies including the above technical solutions still have many problems: ① The layout of the heating structure in the heating component is unreasonable. The temperature at the terminal interface wiring at the edge of the heating plate is relatively low, resulting in uneven heating of the entire heating plate, and the consistency and quality stability of the product cannot be guaranteed; ② Selecting the side wire outlet method is also prone to the phenomenon of local overheating or overcooling, which is extremely easy to cause product defects, and uneven heating is very likely to lead to inaccurate temperature detection data, resulting in too long heating time and causing phenomena such as local high-temperature carbonization; ③ Since the working scenario of the heating structure is in a dust environment, when materials or gases leak along the gaps into the working environment of the resistance wire during the heating process, it is extremely easy to generate electric sparks, resulting in safety accidents such as splashing or explosion, and there are relatively large potential safety hazards; ④ Dust is easy to enter the processing cavity along the gaps during the working process and float inside. If there is a lot of dust, it is very easy to form a spark between the positive and negative poles and the air in the middle, resulting in a short circuit at the heating end, leading to equipment damage or production interruption. Combining the above, there is an urgent need for a heating structure for a selective laser melting equipment to solve the technical problems existing in the above related technologies. Summary of the Invention

[0004] The purpose of the present utility model is to provide a heating structure for a selective laser melting equipment, which is used to solve the technical problems of poor safety and stability such as uneven heating, easy occurrence of splashing explosion or short - circuit accidents in the related art.

[0005] To achieve the above purpose, the present utility model provides the following technical solutions:

[0006] A heating structure for a selective laser melting equipment, comprising:

[0007] A heating plate, which is installed on a substrate and has wire grooves on its front surface;

[0008] A resistance wire, which is installed in the wire grooves of the heating plate with a shape - matching full - weld seal through welding;

[0009] A metal connecting part, which is installed at the end of the resistance wire for connecting to an external power supply;

[0010] An insulating part, which is located at the end of the resistance wire and has a cavity for accommodating the metal connecting part;

[0011] A sealing layer, which is installed on the front surface of the heating plate and is used to isolate and seal the front surface of the heating plate from the outside.

[0012] Furthermore, the wire grooves of the heating plate are distributed in a symmetrical shape, an intermediate groove is provided at the center of the heating plate, the starting ends of the wire grooves are all connected to the intermediate groove, both the metal connecting part and the insulating part are arranged in the intermediate groove, and the relationship between the depth S of the intermediate groove and the thickness T of the heating plate is: 0.5T < S < 0.8T.

[0013] Furthermore, a sealing groove is provided along the four - peripheral edges on the front surface of the heating plate, and the four - peripheral edges of the sealing layer are installed in the sealing groove for fixing, and the relationship between the width X and the depth Y of the sealing groove is: 1.4Y < X < 1.6Y.

[0014] Furthermore, a temperature detection part is installed in the intermediate groove, the temperature detection part is connected in series between the metal connecting part and the power supply, and a connecting part is provided on the sealing layer for the power line to pass through hermetically.

[0015] Furthermore, the shape of the wire groove includes two parallel and symmetrical groove segments. One of the groove segments includes a central vertical segment, an outer horizontal segment, an intermediate segment, an outer horizontal segment, and a central vertical segment that are connected in series in an E - shape. The intermediate segment includes several groups of edge vertical segments, intermediate horizontal segments, intermediate vertical segments, and intermediate horizontal segments that are connected in series in sequence. The intermediate horizontal segments are parallel to the outer horizontal segments and perpendicular to the edge vertical segments, intermediate vertical segments, and central vertical segments at the same time, and one end of each central vertical segment is connected to the central groove.

[0016] Furthermore, rounded segments are provided at the 90-degree corners of each slot section.

[0017] Furthermore, the relationship among the distance L between two adjacent central vertical segments, the length N of the outer horizontal segment, the length M of the middle horizontal segment, and the distance P between the outer vertical segment and the edge of the heating plate in the two slot sections is as follows: 1.3M < N < 1.5M, 0.11N < L < P < 0.12N. The relationship among the distance D between the outer horizontal segment and the adjacent middle horizontal segment, the distance H between two adjacent middle horizontal segments, and the distance W between the outer horizontal segment and the edge of the heating plate is: 2W < D = H < 2.5W.

[0018] Furthermore, the insulating part uses a ceramic insulating ring, the metal connecting part uses a brass column, the resistance wire uses a copper resistance wire, the heating plate uses a stainless steel material, the connecting part uses a gland, and the sealing layer uses a high-temperature resistant gasket.

[0019] Furthermore, several groups of stepped holes and setscrew holes are provided on the back of the heating plate. The stepped holes are used to install screws for positioning and installing the back of the heating plate and the substrate, and the setscrew holes are used to install setscrews for adjusting the distance and supporting the heat insulation plate on the front of the heating plate.

[0020] Compared with the prior art, the technical solution of the present utility model has the following beneficial effects:

[0021] (1). By welding the resistance wire in the wire groove of the heating plate in a full-welded manner, and arranging a metal connecting part, an insulating part, and a sealing layer at the end of the resistance wire, the present utility model can effectively reduce the leakage risk, prevent materials or gases from leaking along the gaps into the heating environment during the heating process and causing electric sparks, resulting in short-circuit phenomena. The good sealing performance effectively reduces the occurrence of safety accidents such as splashing and explosion, and improves the safety and stability during the operation of the equipment, reducing the maintenance cost hidden by the short-circuit risk and the equipment cost of replacement.

[0022] (2). By setting the shape of the wire groove of the heating plate and limiting the specific dimensions, the symmetric shape is beneficial to ensuring the uniformity of the heating plate. At the same time, by arranging the temperature detection part in the middle groove, it is beneficial to improve the accuracy of temperature detection, thereby avoiding the occurrence of local high temperature or even carbonization phenomena and effectively improving the heating efficiency. By setting the connecting part and the sealing layer to be hermetically connected, it is beneficial to ensure good sealing performance. By setting the relationship between the depth of the middle groove and the thickness of the heating plate, it is beneficial to improve the heating uniformity on the premise of ensuring the strength of the heating plate. By setting the relationship between the width and depth of the sealing groove, it is beneficial to ensure good sealing performance.

[0023] (3) By providing a ceramic insulating ring, a brass post, a copper resistance wire, a heating plate made of stainless steel, a gland, and a high-temperature resistant gasket, the stability and safety of the operation of the heating structure are improved as a whole; by providing a set screw hole and a stepped hole, it is convenient to fix the heating plate and effectively support the heat insulation plate, preventing the heat insulation plate from deforming due to high temperature and affecting the installation and matching relationship of the overall equipment, thus affecting the overall operation accuracy of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a three-dimensional structural schematic diagram of the present utility model;

[0025] Figure 2 is a rear view of the present utility model;

[0026] Figure 3 is a front view of the present utility model;

[0027] Figure 4 is Figure 3 a schematic cross-sectional view taken along line A-A in

[0028] Figure 5 is Figure 4 a partially enlarged schematic view at position B in

[0029] Figure 6 is the present utility model;

[0030] Figure 7 is a structural schematic diagram of the front mounting sealing layer of the present utility model.

[0031] In the figure, 100 is the heating plate; 101 is the front; 102 is the sealing groove; 103 is the wire groove; 1031 is the central vertical section; 1032 is the outer peripheral horizontal section; 1033 is the edge vertical section; 1034 is the middle vertical section; 1035 is the middle horizontal section; 1036 is the rounded corner section; 104 is the insulating part; 105 is the middle groove; 106 is the set screw hole; 107 is the stepped hole; 108 is the back.

[0032] 200 is the sealing layer;

[0033] 300 is the connecting piece. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0035] The accompanying drawings are only for illustrative purposes and should not be construed as limiting the patent.

[0036] The terms used in the embodiments of this application are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of this application. The singular forms "a", "the", and "said" used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0037] When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. On the contrary, they are merely examples of devices and methods consistent with some aspects of this application as detailed in the appended claims.

[0038] In the description of this application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects and do not have to be used to describe a specific order or sequence, nor can they be construed as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0039] In addition, in the description of this application, unless otherwise specified, "a plurality" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after. The following further elaborates on the present utility model in conjunction with the accompanying drawings and embodiments.

[0040] In order to solve the limitations of the prior art, this embodiment provides a technical solution. The following further illustrates the technical solution of the present utility model in conjunction with the accompanying drawings and embodiments.

[0041] The present utility model mainly aims at the heating structure for selective laser melting equipment in the related art. During normal use, due to being in a dust environment, dust is extremely likely to enter the heating environment through the gaps in the equipment installation. When the resistance wire is energized, it is extremely likely to generate sparks and cause a short - circuit phenomenon. In addition, the conventional heating structures generally have the phenomenon of uneven heating.

[0042] A heating structure for a selective laser melting device, comprising: a heating plate 100, a resistance wire (not shown in the figure) installed on the heating plate 100, a metal connector (not shown inside the insulating part 104) installed at the end of the resistance wire, an insulating part 104, a sealing layer 200 installed on the front surface 101 of the heating plate 100, and a temperature detection part installed on the heating plate 100. The specific structure is as follows:

[0043] See attached Figures 1-3 , the heating plate 100 is made of stainless steel, preferably 304 stainless steel. The heating plate 100 is installed on the substrate, and a wire groove 103 is provided on its front surface 101. It can be understood here that the back surface 108 of the heating plate 100 is in contact with the substrate for installation, and is used to conduct the generated heat to the substrate to heat the substrate material on the substrate; the wire grooves 103 on the heating plate 100 are distributed in a symmetrical shape. Here, the symmetrical shape is beneficial to ensuring the heating uniformity of the heating plate 100. An intermediate groove 105 is provided at the center of the heating plate 100. Here, the shape of the intermediate groove 105 is a square groove and is located at the center of the heating plate 100. The starting ends of the wire grooves 103 are all communicated with the intermediate groove 105, that is, both ends of the resistance wire are communicated with the intermediate groove 105. See attached Figure 4 , the relationship between the depth S of the intermediate groove 105 and the thickness T of the heating plate 100 is: 0.5T < S < 0.8T. Here, it is preferably S = 0.7T. By defining the relationship between the depth of the intermediate groove 105 and the thickness of the heating plate 100, it is not only beneficial to ensure the strength of the heating plate 100, but also can ensure the heating uniformity of the heating plate 100. The shape of the wire groove 103 includes two parallel and symmetrical groove segments. The main layout purpose of the groove segments is to cover the area of the heating plate 100 as much as possible. See attached Figure 6, where one slot section includes a central vertical section 1031, an outer peripheral horizontal section 1032, an intermediate section, an outer peripheral horizontal section 1032, and a central vertical section 1031 that are connected in series in sequence to form an "E" shape. The intermediate section includes several groups of edge vertical sections 1033, intermediate horizontal sections 1035, intermediate vertical sections 1034, and intermediate horizontal sections 1035 that are connected in series in sequence. The intermediate horizontal section 1035 is parallel to the outer peripheral horizontal section 1032 and perpendicular to the edge vertical section 1033, the intermediate vertical section 1034, and the central vertical section 1031. The other ends of the central vertical sections 1031 are all connected to the central slot. A rounded corner section 1036 is provided at each 90-degree corner of each slot section. The rounded corner section 1036 is provided to facilitate the smooth bending of the resistance wire and prevent the 90° corner from damaging the resistance wire. The relationship between the distance L between two adjacent central vertical sections 1031 in two slot sections, the length N of the outer peripheral horizontal section 1032, the length M of the intermediate horizontal section 1035, and the distance P between the outer peripheral vertical section and the edge of the heating plate 100 is: 1.3M < N < 1.5M, 0.11N < L < P < 0.12N. Preferably, N = 1.4M and P = 45 mm. L = 40 mm. Here, it can be understood that P + M + L / 2 = half of the side length of the heating plate. The heating plate is of a square structure. The relationship between the distance D between the outer peripheral horizontal section 1032 and the adjacent intermediate horizontal section 1035, the distance H between two adjacent intermediate horizontal sections 1035, and the distance W between the outer peripheral horizontal section 1032 and the edge of the heating plate 100 is: 2W < D = H < 2.5W. By limiting the distribution shape and size of the wire slot 103, the heating uniformity of the heating plate 100 is greatly improved.

[0044] The resistance wire is hermetically installed in the wire slot 103 of the heating plate 100 with a shape adaptation by full welding. The resistance wire uses a copper resistance wire. Here, it can be understood that silver welding is used for full welding between the resistance wire and the heating plate 100, that is, except for the end part of the resistance wire, the rest is hermetically sealed in the wire slot 103 by welding.

[0045] The metal connection part uses a brass column and is installed at the end of the resistance wire for connecting to an external power supply; the insulating part 104 uses a ceramic insulating ring and is located at the end of the resistance wire and is provided with a cavity for accommodating the metal connection part; both the metal connection part and the insulating part 104 are arranged in the intermediate slot 105, that is, one end of the brass column is connected to the resistance wire and the other end is connected to the power supply, and the brass column is located inside the ceramic insulating ring. In addition, a temperature detection part is also installed in the intermediate slot 105. The temperature detection part is serially installed between the metal connection part and the power supply. The temperature detection part uses a temperature relay and is used to detect the real-time temperature of the heating plate 100, so as to timely and effectively control the on-off of the power supply of the resistance wire of the heating plate 100.

[0046] See the appendix Figure 4 、 5, 7. The sealing layer 200 is made of a high-temperature resistant gasket. Here, the high-temperature resistant gasket can be understood as a rubber sealing material that can withstand the heating temperature of the heating plate 100. The sealing layer 200 is installed on the front surface 101 of the heating plate 100 and is used to isolate and seal the front surface 101 of the heating plate 100 from the outside. A sealing groove 102 is provided along the four peripheral edges of the front surface 101 of the heating plate 100. The sealing groove 102 is used to install the four peripheral edges of the sealing layer 200 to fix it. The relationship between the width X and the depth Y of the sealing groove 102 is: 1.4Y < X < 1.6Y. Preferably, X = 1.5Y. The limitation of the size of the sealing groove 102 is beneficial to improving the sealing effect. A connecting piece 300 is provided on the sealing layer 200. The connecting piece 300 is used for the power wire to pass through hermetically. The connecting piece 300 adopts a gland. By welding the resistance wire in a full-weld manner in the wire groove 103 of the heating plate 100, and at the same time, a metal connecting part, an insulating part 104 and the sealing layer 200 are provided at the end of the resistance wire, it can effectively reduce the leakage risk and prevent materials or gases from leaking along the gap into the heating environment during heating to cause electric sparks and result in a short-circuit phenomenon. Good sealing effectively reduces the occurrence of safety accidents such as splash explosion, and at the same time improves the safety and stability during the operation of the equipment, and reduces the maintenance cost hidden by the short-circuit risk and the equipment cost of replacement and upgrade.

[0047] See the appendix Figures 2-5 , a plurality of groups of stepped holes 107 and set screw holes 106 are provided on the back surface 108 of the heating plate 100. The stepped holes 107 are used to install screws for positioning and installing the back surface 108 of the heating plate 100 and the substrate, and the set screw holes 106 are used to install set screws for adjusting the distance and supporting the heat insulation plate on the front surface 101 of the heating plate 100.

[0048] When the heating structure disclosed by the present utility model is in use, the power supply is energized. The wire passes through the sealing layer 200 through the gland and then passes through the temperature relay and the brass column and is connected in series with the resistance wire. The resistance wire is energized to generate heat. Since the resistance wire, the brass column, the ceramic insulating ring, the wire groove 103, and the stepped holes 107 and the set screw holes 106 are all located in the space between the sealing layer 200 and the heating plate 100, under the isolation of the sealing layer 200, the heating environment of the resistance wire is extremely safe. At the same time, since the resistance wire is installed in the wire groove 103 by means of full welding, the occurrence of short-circuit phenomena is eliminated. In addition, due to the distribution and size limitation of the wire groove 103, the resistance wire uniformly heats the heating plate 100, thereby avoiding the occurrence of phenomena such as too high or too low local temperature and improving the consistency of product quality.

[0049] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present utility model. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present utility model. Therefore, the present utility model will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

[0050] The foregoing is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A heating structure for laser selective melting equipment, characterized in that: include: A heating plate (100), the heating plate (100) being mounted on a substrate and having a wire groove (103) disposed on a front surface (101); The resistance wire is installed in a wire groove (103) of a heating plate (100) with a matching shape by full welding and sealing; A metal connection part, installed at the end of the resistance wire for connecting an external power source; An insulating portion (104) is located at the end of the resistance wire and is provided with a cavity for accommodating the metal connecting portion; A sealing layer (200) is installed on the front side (101) of the heating plate (100) and is used to isolate the front side (101) of the heating plate (100) from the outside to make it sealed.

2. A heating structure for laser selective melting equipment according to claim 1, characterized in that: The wire grooves (103) of the heating plate (100) are distributed in a symmetrical shape, a middle groove (105) is arranged at the center of the heating plate (100), the starting ends of the wire grooves (103) are connected to the middle groove (105), and the metal connection part and the insulating part (104) are arranged in the middle groove (105).

3. A heating structure for laser selective melting equipment according to claim 2, characterized in that: The front side (101) of the heating plate (100) is provided with sealing grooves (102) along the four edges. The sealing grooves (102) are used to install the four edges of the sealing layer (200) to fix it. The relationship between the width X and the depth Y of the sealing grooves (102) is: 1.4Y<X<1.6Y.

4. The heating structure for selective laser melting equipment according to claim 3, characterized in that: A temperature detection unit is installed in the middle groove (105), and the temperature detection unit is installed in series between the metal connection unit and the power supply. A connector (300) is provided on the sealing layer (200), and the connector (300) is used to allow the power line to pass through in a sealed manner. The relationship between the depth S of the middle groove (105) and the thickness T of the heating plate (100) is: 0.5T<S<0.8T.

5. The heating structure for selective laser melting equipment according to claim 4, characterized in that: The shape of the wire trough (103) comprises two parallel and symmetrical trough sections, wherein one of the trough sections comprises a central vertical section (1031), a peripheral horizontal section (1032), a middle section, a peripheral horizontal section (1032) and a central vertical section (1031) which are sequentially connected in series and form an E shape, wherein the middle section comprises a plurality of groups of edge vertical sections (1033), a middle horizontal section (1035), a middle vertical section (1034) and a middle horizontal section (1035) which are sequentially connected in series, wherein the middle horizontal section (1035) is parallel to the peripheral horizontal section (1032) and perpendicular to the edge vertical section (1033), the middle vertical section (1034) and the central vertical section (1031), and one end of the central vertical section (1031) is connected to the central trough.

6. The heating structure for selective laser melting equipment according to claim 5, characterized in that: A rounded corner section (1036) is provided at the 90-degree corner of each slot section.

7. The heating structure for selective laser melting equipment according to claim 6, characterized in that: The relationship between the distance L between two adjacent central vertical sections (1031) in two slot sections and the length N of the peripheral horizontal section (1032), the length M of the middle horizontal section (1035), and the distance P between the peripheral vertical section and the edge of the heating plate (100) is: 1.3M<N<1.5M, 0.11N<L<P<0.12N, and the relationship between the distance D between the peripheral horizontal section (1032) and the adjacent middle horizontal section (1035), the distance H between two adjacent middle horizontal sections (1035), and the distance W between the peripheral horizontal section (1032) and the edge of the heating plate (100) is: 2W<D=H<2.5W.

8. The heating structure for selective laser melting equipment according to claim 7, characterized in that: The insulating part (104) is made of a ceramic insulating ring, the metal connecting part is made of a brass column, the resistance wire is made of a copper resistance wire, the heating plate (100) is made of stainless steel, the connecting piece (300) is made of a cable gland, and the sealing layer (200) is made of a high temperature resistant sealing gasket.

9. A heating structure for a laser selective melting device according to any one of claims 1 to 8, characterized in that: The back side (108) of the heating plate (100) is provided with a plurality of groups of stepped holes (107) and top screw holes (106); the stepped holes (107) are used for installing screws to position and install the back side (108) of the heating plate (100) and the substrate; the top screw holes (106) are used for installing top screws to adjust the distance and support the heat insulation board on the front side (101) of the heating plate (100).

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