阅读说明：本技术 一种密闭状态下控制热传导变形的组合结构 (Composite structure for controlling heat conduction deformation in closed state ) 是由 王海涛 孙年俊 刘旭东 李初晔 李栋芳 于 2019-09-27 设计创作，主要内容包括：本发明涉及一种密闭状态下控制热传导变形的组合结构。该结构包括打印基板、支撑平台、成形箱体、滑枕和导轨,所述打印基板和所述滑枕均通过紧固件分别设在所述支撑平台的上部和下部,连接为整体结构,所述滑枕与所述成形箱体之间设有竖向导轨,所述滑枕通过所述导轨带动所述支撑平、打印基板在成形箱体的密闭空间内上下运动,在所述支撑平台内部装有嵌入式的预热元件,在所述滑枕和所述支撑平台之间设置有隔热层和热变形自动调整结构,所述隔热层用于隔离热量向所述滑枕和导轨传导,在预热时,所述热变形自动调整结构用于调节所述支撑平台与所述滑枕的竖向安装间隙,以消除因热传导引起的所述打印基板的热变形。(The invention relates to a combined structure for controlling heat conduction deformation in a closed state. The structure comprises a printing substrate, a supporting platform, a forming box body, a ram and a guide rail, wherein the printing substrate and the ram are respectively arranged at the upper part and the lower part of the supporting platform through fasteners and are connected into an integral structure, a vertical guide rail is arranged between the ram and the forming box body, the ram drives the supporting flat and printing substrate to move up and down in the closed space of the forming box body through the guide rail, an embedded preheating element is arranged in the supporting platform, a heat insulation layer and a thermal deformation automatic adjusting structure are arranged between the ram and the supporting platform, the heat insulation layer is used for isolating heat to be conducted to the ram and the guide rail, during preheating, the automatic thermal deformation adjusting structure is used for adjusting a vertical installation gap between the supporting platform and the ram so as to eliminate thermal deformation of the printing substrate caused by heat conduction.)

1. A composite structure for controlling heat conduction deformation in a closed state is characterized by comprising a printing substrate (2), a supporting platform (3), a forming box body (4), a ram (5) and a guide rail (7), wherein the printing substrate (2) and the ram (5) are respectively arranged on the upper portion and the lower portion of the supporting platform (3) through fasteners and are connected into an integral structure, a vertical guide rail (7) is arranged between the ram (5) and the forming box body (4), the ram (5) drives the supporting platform (3) and the printing substrate (2) to move up and down in a closed space of the forming box body (4) through the guide rail (7), an embedded preheating element (9) is arranged in the supporting platform (3), a heat deformation heat insulation layer (6) and an automatic thermal deformation adjusting structure (8) are arranged between the ram (5) and the supporting platform (3), the heat insulation layer (6) is used for isolating heat to be conducted to the ram (5) and the guide rail (7), and when the printing substrate is preheated, the thermal deformation automatic adjusting structure (8) is used for adjusting a vertical installation gap between the supporting platform (3) and the ram (5) so as to eliminate thermal deformation of the printing substrate (2) caused by heat conduction.

2. The composite structure for controlling thermal conduction deformation in a sealed state according to claim 1, wherein the multiple sets of the automatic thermal deformation adjusting structures (8) are arranged at the connecting portion of the support platform (3) and the ram (5) in a centrosymmetric manner.

3. The composite structure for controlling thermal conduction deformation in a closed state according to claim 1 or 2, wherein the automatic thermal deformation adjusting structure (8) comprises a sealing cover (10), an upper flat pad (11), an elastic body (12), a lower flat pad (13) and an adjusting screw (14), the adjusting screw (14) penetrates through the holes of the supporting platform (3) and the thermal insulation layer (6) and then is in threaded connection with the ram (5), the head of the adjusting screw (14) is rigidly connected with the sealing cover (10), the upper end face of the sealing cover (10) is connected with the printing substrate (2), the elastic body (12) is arranged in the middle section of the rod part of the adjusting screw (14), and the upper flat pad (11) and the lower flat pad (13) are respectively sleeved on the rod parts at two sides of the elastic body (12).

4. The composite structure for controlling thermal conduction deformation in a sealed state according to claim 3, wherein 4 sets of the automatic thermal deformation adjusting structures (8) are symmetrically arranged on 4 mounting corners of the supporting platform (3) in pairs.

5. The composite structure for controlling thermal conduction deformation in a sealed state according to claim 3, wherein the sealing cover (10) is embedded in a mounting hole on the supporting platform (3), and the sealing cover (10) is in interference fit with the mounting hole.

6. The composite structure for controlling thermal conduction deformation in a closed state according to claim 3, wherein the elastic body (12) is a plurality of annular elastic sheets provided with mounting through holes, the annular surfaces of the annular elastic sheets are inclined towards the same side of the central axis to form concave sheets with holes at the bottoms, and at least 2 annular elastic sheets are pairwise overlapped and penetrated on the adjusting screws (14) to form the composite elastic body (12).

7. The composite structure for controlling thermal conduction deformation in a sealed state according to claim 6, wherein the elastic body (12) is made of spring steel.

8. The composite structure for controlling thermal conduction deformation in a closed state according to claim 1, wherein a plurality of threaded holes are symmetrically formed in the outer edge of the printing base (2) in the circumferential installation direction, and screws (1) penetrate into the threaded holes to detachably connect the printing base (2) and the supporting platform (3).

9. The combination structure for controlling thermal conduction deformation in a sealed state according to claim 1, wherein the thermal insulation layer (6) is made of a non-metallic material, and has a thermal conductivity of 0.1-0.12W/m.K and a thermal expansion coefficient of 25-28 x 10^-6/℃。

10. The composite structure for controlling heat conduction deformation in a closed state according to claim 1, wherein the preheating element (9) is a heating tube, a heating sheet or a heater, a groove is formed on the mounting surface of the supporting platform (3) on the side close to the ram (5), and the preheating element (9) is mounted in the groove.

Technical Field

The invention relates to the technical field of additive manufacturing, in particular to a combined structure for controlling heat conduction deformation in a closed state.

Background

Selective laser melting is an important rapid forming technology, and laser is used for irradiating powder materials to realize forming and solidification of workpieces. In the selective laser melting and rapid forming process, preheating is an important link, and if preheating is not performed or is not performed properly, the forming time is increased, so that the performance of a formed part is low, the precision is poor, and even the normal operation of the printing process is influenced. Therefore, a preheating process for the printing substrate is indispensable. As a result of the preheating, heat conduction will occur, and thermal deformation of the relevant parts of the apparatus will occur, which will ultimately affect the operational stability, accuracy and printing accuracy of the apparatus.

The existing method for solving the thermal deformation of the substrate is to apply a certain prestress on the substrate, but the method mainly aims to reduce the influence of a laser heat source on the deformation of the substrate, does not consider the influence generated by preheating, and has great limitation.

In order to improve and ensure the precision of equipment and parts, the thermal deformation amount needs to be controlled within a reasonable range by reducing or blocking a heat conduction path through structural design or adopting corresponding measures so as to meet the requirement of product printing.

Accordingly, the inventors have provided a composite structure that controls thermal conduction deformation in a sealed state.

Disclosure of Invention

The embodiment of the invention provides a combined structure for controlling heat conduction deformation in a closed state, which is characterized in that a heat-insulating layer and a thermal deformation automatic adjusting structure are arranged to block a heat conduction path, so that the functions of heat conduction control and thermal deformation adjustment in the closed state are realized, the operation precision of equipment is effectively improved, and the quality and precision of a formed part are improved.

The embodiment of the invention provides a combined structure for controlling heat conduction deformation in a closed state, which comprises a printing substrate, a supporting platform, a forming box body, a ram and a guide rail, wherein the printing substrate and the ram are respectively arranged at the upper part and the lower part of the supporting platform through fasteners and are connected into an integral structure, a vertical guide rail is arranged between the ram and the forming box body, the ram drives the supporting platform and the printing substrate to move up and down in a closed space of the forming box body through the guide rail, an embedded preheating element is arranged in the supporting platform, a heat insulation layer and an automatic thermal deformation adjusting structure are arranged between the ram and the supporting platform, the heat insulation layer is used for isolating heat to be conducted to the ram and the guide rail, and the automatic thermal deformation adjusting structure is used for adjusting a vertical installation gap between the supporting platform and the ram during preheating, so as to eliminate thermal deformation of the printing substrate caused by thermal conduction.

Furthermore, the multiple groups of thermal deformation automatic adjusting structures are arranged at the connecting part of the supporting platform and the ram in a central symmetry manner.

Further, heat altered shape automatic adjustment structure includes sealed lid, last flat pad, elastomer, lower flat pad and adjusting screw, adjusting screw passes supporting platform with behind the hole of insulating layer with ram threaded connection, adjusting screw's head rigid connection sealed lid, just the up end of sealed lid is connected print the base plate, the elastomer is established adjusting screw's pole portion middle section, go up flat pad and lower flat pad cover respectively and establish the pole portion of elastomer both sides.

Further, 4 groups of the automatic thermal deformation adjusting structures are symmetrically arranged on 4 installation angles of the supporting platform in pairs.

Further, the sealing cover is arranged in the mounting hole in the supporting platform in an embedded mode, and the sealing cover and the mounting hole are in interference fit.

Furthermore, the elastic body is a plurality of annular elastic sheets provided with mounting through holes, the annular surfaces of the annular elastic sheets incline towards the same side of the central shaft to form concave sheets with holes at the bottom, and at least 2 annular elastic sheets are folded and penetrated on the adjusting screws in a pairwise manner to form a combined elastic body.

Furthermore, the elastic body is made of spring steel.

Furthermore, a plurality of threaded holes are symmetrically formed in the outer edge of the periphery of the printing base, and screws penetrate into the threaded holes to detachably connect the printing base and the supporting platform.

Furthermore, the heat insulation layer (6) is made of non-metal material, and has a heat conductivity coefficient of 0.1-0.12W/m.K and a thermal expansion coefficient of 25-28 multiplied by 10^-6/℃。

Furthermore, the preheating element adopts a heating pipe, a heating sheet or a heater, a groove is formed in the mounting surface of the supporting platform on the side close to the ram, and the preheating element is mounted in the groove

In conclusion, the beneficial effects of the invention are as follows:

1. the heat insulation layer structure is adopted, so that the heat conduction between the connecting pieces can be effectively blocked, and the thermal deformation of the heat-related connecting pieces is greatly reduced, so that the whole structure is simple, the realization is easy, and the heat insulation effect is obvious;

2. the thermal deformation automatic adjusting structure can release internal stress caused by heat conduction, and can dynamically adjust in real time according to the combined state of the supporting platform and the printing substrate, so that the horizontal precision of the printing substrate during the operation of the equipment is ensured;

3. the comprehensive influence of two factors of heat conduction uplink and downlink is fully considered, and the design method of a combined structure mode is adopted to achieve and meet the index target of equipment.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic view of an assembly structure of a composite structure for controlling thermal conduction deformation in a sealed state according to an embodiment of the present invention.

FIG. 2 is a schematic structural view of a partially-concealed forming box according to an embodiment of the present invention.

Fig. 3 is a schematic cross-sectional view of a composite structure of an embodiment of the invention.

FIG. 4 is an enlarged schematic view of the thermal deformation automatic adjustment structure according to an embodiment of the present invention.

In the figure:

1-a fastening screw; 2-printing the substrate; 3-supporting the platform; 4-forming a box body; 5-ram; 6-a heat insulation layer; 7-a guide rail; 8-a thermal deformation automatic adjustment structure; 9-heating a tube; 10-sealing cover; 11-upper flat cushion; 12-an elastomer; 13-lower flat cushion; 14-adjusting the screw.

Detailed Description

The embodiments of the present invention will be described in further detail with reference to the drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the invention and are not intended to limit the scope of the invention, i.e., the invention is not limited to the embodiments described, but covers any modifications, alterations, and improvements in the parts, components, and connections without departing from the spirit of the invention.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

In the selective laser melting and rapid forming process, preheating is an important link, and if preheating is not performed or is not performed properly, the forming time is increased, so that the performance of a formed part is low, the precision is poor, and even the normal operation of the printing process is influenced. Therefore, a preheating process for the printing substrate is indispensable. As a result of the preheating, heat conduction will occur, and thermal deformation of the relevant parts of the apparatus will occur, which will ultimately affect the accuracy of the operation of the apparatus and the accuracy of the printing.

As shown in fig. 1 to 3, a composite structure for controlling thermal conduction deformation in a sealed state according to an embodiment of the present invention at least includes a printing substrate 2, a supporting platform 3, a forming box 4, a ram 5 and a guide rail 7, the printing substrate 2 and the ram 5 are respectively disposed on the upper portion and the lower portion of the supporting platform 3 through fasteners, and are connected to form an integral structure, a vertical guide rail 7 is disposed between the ram 5 and the forming box 4, and the ram 5 drives the supporting platform 3 and the printing substrate 2 to move up and down in a sealed space of the forming box 4 through the guide rail 7, so as to complete a lifting printing process. The printing substrate preheating device is characterized in that an embedded preheating element 9 is arranged inside the supporting platform 3, a heat insulation layer 6 and a thermal deformation automatic adjusting structure 8 are arranged between the ram 5 and the supporting platform 3, the heat insulation layer 6 is used for isolating heat to conduct to the ram 5 and the guide rail 7, and the thermal deformation automatic adjusting structure 8 is used for adjusting a vertical installation gap between the supporting platform 3 and the ram 5 during preheating so as to eliminate thermal deformation of the printing substrate 2 caused by heat conduction.

It should be noted that only the components related to the present invention are shown in the drawings of the embodiments of the present invention, and other components not directly related to the present invention are not shown.

It can be seen that the combined structure of the present invention mainly comprises two parts of heat insulation and adjustment, the preheating of the printing substrate 2 is performed by the preheating element 9 embedded in the supporting platform 3, in order to reduce and avoid the downward heat conduction generated by the direct contact between the ram 5 and the supporting platform 3, the heat insulation layer 6 meeting the rigidity requirement is arranged between the ram 5 and the supporting platform 3, which can effectively reduce the heat conductivity, thereby greatly reducing the thermal deformation of the lifting systems such as the ram 5 and the guide rail 7, and improving the operation precision of the equipment.

Specifically, the heat insulation layer (6) is made of a nonmetal heat insulation plate, the heat conductivity coefficient of the heat insulation layer is preferably 0.12W/m.K, the lower heat conductivity coefficient of the heat insulation plate ensures better heat insulation effect, and the thermal expansion coefficient is 28 multiplied by 10^-6The temperature is lower than the temperature of the insulating board, so that the better thermal stability of the insulating board is guaranteed. The preheating element 9 is a heating pipe, a heating sheet or a heater, a groove is formed in the mounting surface of the supporting platform 3 close to one side of the ram 5, and the preheating element 9 is mounted in the groove.

Because the supporting platform 3 and the printing substrate 2 are connected and fastened together through the fastener (the screw 1), heat generated by the preheating element 9 during preheating can be quickly transferred to the printing substrate 2 so as to meet the temperature requirement required by printing. In addition, because the preheating element 9 is installed inside the supporting platform 3, when preheating is carried out, heat up conduction causes thermal deformation of the supporting platform 3, so that the printing substrate 2 deforms along with the heating, and in order to eliminate the deformation, a thermal deformation automatic adjusting structure 8 is designed between the ram 5 and the supporting platform 3, so that connection of the two parts can be realized, and dynamic adjustment of the working posture of the substrate can also be realized.

Specifically, as shown in fig. 4, the automatic thermal deformation adjusting structure 8 includes a sealing cover 10, an upper flat pad 11, an elastic body 12, a lower flat pad 13, and an adjusting screw 14, wherein the adjusting screw 14 penetrates through the holes of the supporting platform 3 and the thermal insulation layer 6 and is in threaded connection with the ram 5, the head of the adjusting screw 14 is rigidly connected to the sealing cover 10, the upper end surface of the sealing cover 10 is connected to the printing substrate 2, the elastic body 12 is disposed in the middle section of the rod portion of the adjusting screw 14, and the upper flat pad 11 and the lower flat pad 13 are respectively sleeved on the rod portions on two sides of the elastic body 12.

When the support platform 3 for connecting and fixing the printing substrate 2 generates thermal deformation, the support platform and the ram 5 are connected with each other equivalently through prestress, so that the connection flexibility is improved, when the temperature rises, due to the existence of prestress at the connection part, the thermal stress is released, most of thermal deformation is counteracted, the thermal deformation is uniform finally, and the printing substrate 2 is prevented from being irregularly warped. Meanwhile, each automatic adjusting structure 8 is caused by thermal deformation to be adjusted in real time, and the horizontal precision and the flatness precision of the printing substrate 2 are kept through relative displacement and free extension and retraction of the elastic body 12, so that the working precision of the printing substrate is guaranteed, and the precision and quality requirements of a printed product are met. The elastic body 12 is a plurality of annular elastic pieces provided with mounting through holes, the annular surfaces of the annular elastic pieces incline towards the same side of the central axis to form concave pieces with holes at the bottom, and at least 2 annular elastic pieces are folded and penetrated on the adjusting screw 14 in pairs to form the combined elastic body 12. Preferably, the spring steel is used to make the elastomer 12 in the present embodiment. The special elastic body 12 can effectively meet the requirement of effective adjustment according to thermal deformation, adopts a combined structure, and has the advantages of large load, short stroke, small required space, easy maintenance, disassembly and assembly and the like.

As another preferred embodiment, the multiple groups of automatic thermal deformation adjusting structures 8 are arranged at the connecting position of the supporting platform 3 and the ram 5 in a central symmetry manner, so that the symmetrical thermal deformation adjustment is realized, and the adjustment is more uniform and efficient. In this embodiment, it is preferable that 4 sets of the automatic thermal deformation adjusting structures 8 are symmetrically arranged on 4 installation corners of the supporting platform 3 in pairs.

In conclusion, the heat source device is realized by the heat insulation layer 6 and the automatic thermal deformation adjusting structure 8 which complement each other and act together, wherein the heat insulation layer 6 separates the heat source body from the lifting mechanism, so that the contact type conduction of heat is avoided, and the effect of reducing the thermal deformation of the lifting part is achieved. And the automatic thermal deformation adjusting structure 8 automatically adjusts the thermal deformation of the printing substrate 2 caused by heat conduction in real time under the action of the pre-stressing mechanism according to the deformation of the supporting platform 3 caused by temperature change, so as to ensure the preheating function and the working precision of the printing substrate 2, and finally ensure the realization of the lifting operation precision, the powder laying precision and the printing precision of a forming part of the selective laser melting forming equipment.

It should be clear that the embodiments in this specification are described in a progressive manner, and the same or similar parts in the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the drawings. Also, a detailed description of known process techniques is omitted herein for the sake of brevity.

The above description is only an example of the present application and is not limited to the present application. Various modifications and alterations to this application will become apparent to those skilled in the art without departing from the scope of this invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.