1. The utility model provides a two laser printing equipment of quick cooling type which characterized in that: the powder coating machine comprises a working cavity (1) arranged on a rack, wherein a heat-insulating cavity (2) is arranged above the working cavity (1), a laser head (3) is arranged at the top end of the heat-insulating cavity (2), a powder bed (4) is arranged at the bottom end of the heat-insulating cavity, and a powder spreading mechanism (5) for spreading powder on the powder bed (4) and a heating mechanism (6) for heating the interior of the heat-insulating cavity (2) are arranged in the heat-insulating cavity (2); a supporting plate (7) for placing a workpiece is arranged in the working cavity (1), the supporting plate (7) is fixedly arranged on the lifting mechanism (8), and the supporting plate (7) slides up and down along the inner wall of the working cavity (1);

the cooling mechanism is arranged in the working cavity (1) and used for cooling a formed area of the workpiece when the workpiece is machined.

2. A rapid cooling type dual laser printing apparatus according to claim 1, characterized in that: the cooling mechanism comprises a hollow layer (9) arranged on the inner wall of the working cavity (1) and a cooling pipeline (10) fixedly arranged in the supporting plate (7), the hollow layer (9) is used for storing cold air, the hollow layer (9) is divided into an air inlet area and an air outlet area, one side of the hollow layer (9) positioned in the air inlet area is communicated with an external cooler through an air inlet (11), and the other side of the hollow layer (9) is communicated with the inside of the working cavity (1) through a control unit; hollow layer (9) one side that is located the gas outlet district communicates through gas outlet (12) and external cooler, and the opposite side is linked together through another the control unit with work cavity (1) is inside, the control unit is used for communicating hollow layer (9) and cooling tube (10) when backup pad (7) downstream, and retractable's first intercommunication mouth (13) and second intercommunication mouth (14) are opened respectively to cooling tube (10) both sides, first intercommunication mouth (13) are close to hollow layer (9) of income gas district, and second intercommunication mouth (14) are close to hollow layer (9) of gas outlet district.

3. A rapid cooling type dual laser printing apparatus according to claim 2, characterized in that: the control unit includes sliding tray (15) and gliding switch board (16) in sliding tray (15) that vertical seting up on work cavity (1) inner wall, it has intercommunication hollow layer (9) and the inside through-hole (17) of work cavity (1) to open on switch board (16), and it has drive plate (18) still to fix on switch board (16), drive plate (18) are located through-hole (17) below, and wedge face (19) have been seted up to the upper end of drive plate (18), it has fixed plate (20) still to fix on work cavity (1), and fixed plate (20) are located the lower extreme of sliding tray (15), are provided with first compression spring (21) between fixed plate (20) and drive plate (18).

4. A rapid cooling type dual laser printing apparatus according to claim 3, wherein: the air outlet (12) is also provided with an adjusting unit, and the adjusting unit controls the opening size of the air outlet (12) according to the displacement of the supporting plate (7) and adjusts the flow rate of cold air.

5. The rapid cooling type dual laser printing apparatus according to claim 4, wherein: the adjusting unit comprises a rack (22) fixedly mounted on the air outlet area driving plate (18) and an air outlet valve (23) arranged on the air outlet (12), a gear (24) is coaxially mounted on the air outlet valve (23), and the rack (22) is meshed with the gear (24).

6. A rapid cooling type dual laser printing apparatus according to claim 5, wherein: the cooling pipelines (10) are arranged in a bow shape.

Background

3D Printing, one of the rapid prototyping technologies, is a technology for constructing an object by Printing layer by layer using an adhesive material such as powdered metal or plastic based on a digital model file. Selective Laser Sintering (SLS) is to lay a layer of non-metal powder material on a workbench in advance, sinter the powder of the solid part under the control of a computer according to interface profile information by Laser, and then circulate continuously and stack and form layer by layer. The forming method has the characteristics of simple manufacturing process, high flexibility, wide material selection range, low material price, high material utilization rate, high forming speed and the like. However, the method has the following defects: the articles printed by the 3D printer have high heat and can be taken out only after being cooled after being printed, so that the working time is prolonged, and the working efficiency is reduced; in addition, since 3D printing by sintering the non-metal powder material needs to be performed at a certain temperature, if cooling is performed while printing and molding, the sintering and molding effect of the non-metal powder material is affected, and the molding quality is reduced; the powder can fly due to the adoption of cold air for direct blowing and cooling, so that potential safety hazards are caused, and the forming quality is influenced.

Therefore, it is necessary to provide a rapid cooling type dual laser printing device, which can rapidly cool a formed area of a workpiece while the device prints the workpiece, and does not affect the temperature of an unformed area of the workpiece, and does not make powder fly, so that the workpiece can be synchronously cooled when printing is completed, and the forming efficiency of the workpiece is improved.

Disclosure of Invention

The object of the present invention is to provide a fast cooling type dual laser printing apparatus to solve the problems of the above background art that address the shortcomings of the prior art.

In order to achieve the purpose, the invention provides the following technical scheme: a rapid cooling type double-laser printing device comprises a working cavity mounted on a rack, wherein a heat insulation cavity is arranged above the working cavity, a laser head is arranged at the top end of the heat insulation cavity, a powder bed is arranged at the bottom end of the heat insulation cavity, and a powder spreading mechanism for spreading powder on the powder bed and a heating mechanism for heating the inside of the heat insulation cavity are arranged inside the heat insulation cavity; a supporting plate for placing a workpiece is arranged in the working cavity, the supporting plate is fixedly arranged on the lifting mechanism, and the supporting plate slides up and down along the inner wall of the working cavity;

the cooling mechanism is arranged in the working cavity and used for cooling a formed area of the workpiece when the workpiece is machined.

Selective Laser Sintering (SLS) is to lay a layer of non-metal powder material on a workbench in advance, sinter the powder of the solid part under the control of a computer according to interface profile information by Laser, and then circulate continuously and stack and form layer by layer. The forming method has the characteristics of simple manufacturing process, high flexibility, wide material selection range, low material price, high material utilization rate, high forming speed and the like. However, the method has the following defects: the articles printed by the 3D printer have high heat and can be taken out only after being cooled after being printed, so that the working time is prolonged, and the working efficiency is reduced; in addition, since 3D printing by sintering the non-metal powder material needs to be performed at a certain temperature, if cooling is performed while printing and molding, the sintering and molding effect of the non-metal powder material is affected, and the molding quality is reduced. Therefore, as shown in fig. 1 and fig. 2, when the powder spreading mechanism works, a layer of uniform non-metal powder material is firstly spread on a powder bed, then laser emitted by a laser head moves along a track, so that the non-metal powder material on the track is sintered to form a slice shape and falls on a support plate, then the support plate moves downwards under the driving of a lifting mechanism, and the non-metal powder material is sintered layer by layer to finally form a complete three-dimensional object. In the sintering process, the heating mechanism heats the heat-insulating cavity under the control of the temperature control system, and the temperature of the heat-insulating cavity is controlled within a certain range. When the equipment prints a workpiece, the printed area falls on the supporting plate and moves down together with the supporting plate, at the moment, the formed area of the workpiece is quickly cooled by the cooling mechanism, and the formed area of the workpiece is cooled while the laser head prints, so that the final cooling time is reduced, and the quick cooling effect is achieved.

As a further scheme of the invention, the cooling mechanism comprises a hollow layer arranged on the inner wall of the working cavity and a cooling pipeline fixedly arranged in the supporting plate, the hollow layer is used for storing cold air, the hollow layer is divided into an air inlet area and an air outlet area, one side of the hollow layer positioned in the air inlet area is communicated with an external cooler through an air inlet, and the other side of the hollow layer is communicated with the inside of the working cavity through a control unit; the well hollow layer that is located the gas zone communicates through gas outlet and external cooler mutually on one side, the opposite side through another the control unit with work cavity internal portion communicate, hollow layer and cooling tube way are opened respectively to the control unit when the backup pad moves down, cooling tube way both sides have open retractable first intercommunication mouth and second intercommunication mouth, first intercommunication mouth is close to the well hollow layer in the gas zone, and second intercommunication mouth is close to the well hollow layer in the gas zone.

The invention can quickly cool the formed area of the workpiece when the workpiece is printed by the equipment, and can not influence the temperature of the unformed area of the workpiece and make the powder fly. Therefore, as shown in fig. 1, 2 and 6, the cooling pipeline is arranged in the support plate, and the hollow layer for storing cold air is arranged in the working cavity. When the laser sintering machine works, nonmetal powder is sintered layer by laser, cold air enters the hollow layer from the air inlet of the air inlet area, flows out of the air outlet of the hollow layer of the air outlet area after flowing through the cold area pipeline in the support plate, so that the cold air flows through the cooling pipeline and cannot directly blow the powder, the powder cannot fly, the temperature of the hollow layer of the air outlet area is reduced and cooled from the support plate, only a formed area of a workpiece close to the support plate is reduced and cooled, so that cold air is positioned below, hot air of the heat insulation cavity is positioned above, the density of the hot air is low, the cold air and the hot air cannot generate convection under the condition of no external force, the powder flies, and heat exchange of the cold air and the hot air can only occur at a boundary, so that the formed area can be rapidly cooled, the temperature of the unformed area of the workpiece cannot be influenced, and the forming quality of the printed workpiece is guaranteed. According to the invention, the formed area of the workpiece on the supporting plate is cooled from bottom to top by using the cooling pipeline, so that not only is the potential safety hazard caused by direct powder blowing avoided, but also the convection of cold air and hot air is avoided, the temperature in the heat insulation cavity is not influenced by the cooling of the cooling pipeline, and the printing and forming effects are avoided while the cooling effect is improved.

As a further scheme of the present invention, the control unit includes a sliding groove vertically formed on an inner wall of the working cavity and a switch board sliding in the sliding groove, a through hole communicating the hollow layer and the inside of the working cavity is formed in the switch board, a driving board is further fixedly mounted on the switch board, the driving board is located below the through hole, a wedge surface is formed at an upper end of the driving board, a fixing plate is further fixedly mounted on the working cavity, the fixing plate is located at a lower end of the sliding groove, and a first compression spring is disposed between the fixing plate and the driving board.

Because the invention does not need to be cooled when just printing, the temperature in the heat-insulating cavity is prevented from being influenced, and the cooling is carried out only after the printing is carried out to a certain height. As shown in fig. 2, 3 and 8, the support plate of the invention is continuously lowered along with the printing in operation. At the beginning, the first connecting port and the second connecting port at the two ends of the cooling pipeline in the supporting plate are in a closed state. Along with the decline of backup pad, the backup pad can extrude the drive plate for the switch board slides downwards in the sliding tray, and the through-hole can move out from the sliding tray along with the downward removal of switch board like this and be linked together with first interface, and the air conditioning in the cavity of entering air zone can get into cooling duct like this. In a similar way, the second connecting port is also communicated with the hollow layer of the air outlet area, and cold air starts to flow circularly to cool the formed area of the workpiece on the supporting plate. After printing, the supporting plate rises and resets under the action of the lifting mechanism, the driving plate on the switch plate moves upwards and resets under the action of the first compression spring, and the through hole enters the sliding groove again to disconnect the hollow layer from the cooling pipeline. The purpose of the invention is to provide a wedge surface on the driving plate so as to press the first communication port and the second communication port when the driving plate is reset, and assist the first communication port and the second communication port to contract and disconnect.

As a further scheme of the invention, the air outlet is also provided with an adjusting unit, and the adjusting unit controls the size of the opening of the air outlet according to the displacement of the supporting plate and adjusts the flow rate of the cold air.

As a further scheme of the invention, the adjusting unit comprises a rack fixedly arranged on the air outlet area driving plate and an air outlet valve arranged at the air outlet, wherein a gear is coaxially arranged on the air outlet valve, and the rack is meshed with the gear.

Under the same condition, the faster the flow rate of the cold air means that the more heat the cold air takes away, the better the cooling effect, so in order to achieve the purpose of rapid cooling, it is necessary to increase the flow rate of the cold air. However, when the printing is started, the distance between the support plate and the heat preservation cavity is too close, the flow speed of cold air is accelerated, the cooling effect is improved, the temperature in the heat preservation cavity is probably directly influenced, and the sintering forming quality is influenced. Therefore, the present invention requires adjusting the flow rate of the cold air in the cooling duct according to the distance that the support plate moves down. As shown in the figures 2, 4 and 10, when the air conditioner works, the driving plate of the air outlet area is driven by the supporting plate to move downwards along with the downward movement of the supporting plate, because the driving plate of the air outlet area is fixedly provided with a rack which drives a gear coaxially arranged on the air outlet valve to rotate, the gear rotates to adjust the size of the air outlet, when the rack rotates downwards, the gear rotates forwards to adjust the size of the air outlet, the cold air circulation is accelerated, and the cold air flow speed is accelerated. When the rack returns under the restoring force of the first compression spring, the rack driving gear rotates reversely, and the air outlet also returns. And (5) circulating and reciprocating. The flow velocity of cold air in the cooling pipeline is adjusted according to the downward moving distance of the supporting plate, and when the downward moving distance of the supporting plate is larger, the flow velocity of the cold air is improved, so that the temperature in the heat-insulating cavity is not influenced while the cooling effect is improved; the accelerated flow rate can ensure that the cooling can be completed quickly when the printing is finished, thereby saving the working time and improving the working efficiency. The bigger the downward moving distance of the supporting plate is, the closer the printing work is to be completed, so that the flow rate of cold air needs to be accelerated, the cooling efficiency is increased, the cooling and the temperature reduction can be timely completed after the printing is completed, the cooling time is saved, and the working efficiency is improved.

As a further aspect of the present invention, the cooling pipes are arranged in a zigzag shape. The cooling pipelines are arranged in the supporting plate in a bow shape, so that the heat exchange area of the cooling pipelines is increased, the cooling efficiency is improved, and the formed area of the workpiece on the supporting plate is cooled by the cooling pipelines conveniently.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention can quickly cool the formed area of the workpiece while the workpiece is printed by the equipment, does not influence the temperature of the unformed area of the workpiece, does not enable powder to fly, enables the workpiece to synchronously finish cooling when the printing is finished, and improves the forming efficiency of the workpiece.

2. According to the invention, the formed area of the workpiece on the supporting plate is cooled from bottom to top by using the cooling pipeline, so that not only is the potential safety hazard caused by direct powder blowing avoided, but also the convection of cold air and hot air is avoided, the temperature in the heat insulation cavity is not influenced by the cooling of the cooling pipeline, and the printing and forming effects are avoided while the cooling effect is improved.

3. The flow velocity of cold air in the cooling pipeline is adjusted according to the downward moving distance of the supporting plate, and when the downward moving distance of the supporting plate is larger, the flow velocity of the cold air is improved, so that the temperature in the heat-insulating cavity is not influenced while the cooling effect is improved; the accelerated flow rate can ensure that the cooling can be completed quickly when the printing is finished, thereby saving the working time and improving the working efficiency.

4. The hollow layer and the heat preservation cavity have a certain distance, so that the influence of cold air in the hollow layer on heat preservation of the heat preservation cavity can be avoided when the heat preservation cavity works, and the cooling pipeline in the support plate is not communicated with the hollow layers at the two ends when the heat preservation cavity and the work cavity start working, so that the support plate can effectively separate the heat preservation cavity from the work cavity, the heat dissipation of the heat preservation cavity is prevented, and the heat preservation cavity is favorably and quickly heated.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural view of a rapid cooling type dual laser printing apparatus;

FIG. 2 is a cross-sectional view of a printing apparatus of the present invention;

FIG. 3 is an enlarged view of a portion A of FIG. 2 according to the present invention;

FIG. 4 is an enlarged view of a portion B of FIG. 2 in accordance with the present invention;

FIG. 5 is a schematic structural view of the present invention with the heat-insulating chamber and the working chamber removed;

FIG. 6 is a schematic view of the structure of the support plate of the present invention;

FIG. 7 is a schematic structural diagram of a control unit according to the present invention;

FIG. 8 is an enlarged view of a portion C of FIG. 7 in accordance with the present invention;

FIG. 9 is a schematic view of the structure of the adjusting unit of the present invention;

fig. 10 is a partial enlarged view of portion D of fig. 9 according to the present invention.

In the drawings, the components represented by the respective reference numerals are listed below:

1-working cavity, 2-heat preservation cavity, 3-laser head, 4-powder bed, 5-powder laying mechanism, 6-heating mechanism, 7-supporting plate, 8-lifting mechanism, 9-hollow layer, 10-cooling pipeline, 11-air inlet, 12-air outlet, 13-first communicating port, 14-second communicating port, 15-sliding groove, 16-switch plate, 17-through hole, 18-driving plate, 19-wedge surface, 20-fixing plate, 21-first compression spring, 22-rack, 23-air outlet valve and 24-gear.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-10, a rapid cooling type dual laser printing apparatus includes a working cavity 1 mounted on a frame, a heat-insulating cavity 2 is disposed above the working cavity 1, a laser head 3 is disposed at the top end of the heat-insulating cavity 2, a powder bed 4 is disposed at the bottom end of the heat-insulating cavity 2, and a powder spreading mechanism 5 for spreading powder on the powder bed 4 and a heating mechanism 6 for heating the interior of the heat-insulating cavity 2 are disposed inside the heat-insulating cavity 2; a supporting plate 7 for placing a workpiece is arranged in the working cavity 1, the supporting plate 7 is fixedly arranged on the lifting mechanism 8, and the supporting plate 7 slides up and down along the inner wall of the working cavity 1;

a cooling mechanism is arranged in the working cavity 1 and used for cooling a formed area of a workpiece when the workpiece is machined.

Selective Laser Sintering (SLS) is to lay a layer of non-metal powder material on a workbench in advance, sinter the powder of the solid part under the control of a computer according to interface profile information by Laser, and then circulate continuously and stack and form layer by layer. The forming method has the characteristics of simple manufacturing process, high flexibility, wide material selection range, low material price, high material utilization rate, high forming speed and the like. However, the method has the following defects: the articles printed by the 3D printer have high heat and can be taken out only after being cooled after being printed, so that the working time is prolonged, and the working efficiency is reduced; in addition, since 3D printing by sintering the non-metal powder material needs to be performed at a certain temperature, if cooling is performed while printing and molding, the sintering and molding effect of the non-metal powder material is affected, and the molding quality is reduced. Therefore, as shown in fig. 1 and fig. 2, when the powder spreading mechanism 5 of the invention works, a layer of non-metal powder material is firstly spread on the powder bed 4, then the laser head 3 emits laser to move along a track, so that the non-metal powder material on the track is sintered to form a slice shape and falls on the support plate 7, then the support plate 7 moves downwards under the driving of the lifting mechanism 8, and the non-metal powder material is sintered layer by layer to finally form a complete three-dimensional object. In the sintering process, the heating mechanism 6 heats the interior of the heat-insulating cavity 2 under the control of the temperature control system, and controls the temperature of the heat-insulating cavity 2 within a certain range. When the equipment prints a workpiece, the printed area falls on the supporting plate 7 and moves down together with the supporting plate 7, at the moment, the formed area of the workpiece is quickly cooled by the cooling mechanism, the formed area of the workpiece is cooled while the laser head 3 prints, the final cooling time is shortened, and the quick cooling effect is achieved.

As a further scheme of the invention, the cooling mechanism comprises a hollow layer 9 arranged on the inner wall of the working cavity 1 and a cooling pipeline 10 fixedly arranged inside the support plate 7, the hollow layer 9 is used for storing cold air, the hollow layer 9 is divided into an air inlet area and an air outlet area, one side of the hollow layer 9 positioned in the air inlet area is communicated with an external cooler through an air inlet 11, and the other side is communicated with the inside of the working cavity 1 through a control unit; the hollow layer 9 that is located the gas outlet district communicates with external cooler through gas outlet 12 one side, and the opposite side is linked together through another the control unit with 1 inside with the working cavity, the control unit is used for communicating hollow layer 9 and cooling tube 10 when backup pad 7 moves down, and retractable's first intercommunication mouth 13 and second intercommunication mouth 14 have been opened respectively to cooling tube 10 both sides, first intercommunication mouth 13 is close to the hollow layer 9 in the gas inlet district, and second intercommunication mouth 14 is close to the hollow layer 9 in the gas outlet district.

The invention can quickly cool the formed area of the workpiece when the workpiece is printed by the equipment, and can not influence the temperature of the unformed area of the workpiece and make the powder fly. Therefore, as shown in fig. 1, 2 and 6, the present invention has a cooling duct 10 in the support plate 7 and a hollow layer 9 for storing cool air in the working chamber 1. When the invention works, the laser sinters the non-metal powder layer by layer, the cold air enters the hollow layer 9 from the air inlet 11 of the air inlet area, after flowing through the cold area pipeline in the supporting plate 7, flows out from the air outlet 12 at the hollow layer 9 of the air outlet area, thus, the cold air flowing through the cooling duct 10 does not directly blow the powder, does not fly the powder, and the temperature is reduced and cooled from the position of the supporting plate 7, only the formed area of the workpiece close to the position of the supporting plate 7 is cooled, thus, the cold air is positioned at the lower part, the hot air of the heat preservation cavity 2 is positioned at the upper part, the density of the hot air is lower, the cold and hot air can not generate convection under the condition of no external force, so that the powder flies upward, and the heat exchange of the cold and hot air can only occur at the boundary, therefore, the formed area can be rapidly cooled, the temperature of the unformed area of the workpiece cannot be influenced, and the forming quality of the printed workpiece is guaranteed. According to the invention, the formed area of the workpiece on the supporting plate 7 is cooled from bottom to top by using the cooling pipeline 10, so that not only is the potential safety hazard caused by direct powder blowing avoided, but also the convection of cold air and hot air is avoided, the temperature in the heat-insulating cavity 2 is ensured not to be influenced by the cooling of the cooling pipeline 10, and the printing and forming effects are avoided while the cooling effect is improved.

As a further scheme of the present invention, the control unit includes a sliding groove 15 vertically formed on an inner wall of the working cavity 1 and a switch board 16 sliding in the sliding groove 15, a through hole 17 communicating the hollow layer 9 and the inside of the working cavity 1 is formed in the switch board 16, a driving board 18 is further fixedly mounted on the switch board 16, the driving board 18 is located below the through hole 17, a wedge surface 19 is formed at an upper end of the driving board 18, a fixing plate 20 is further fixedly mounted on the working cavity 1, the fixing plate 20 is located at a lower end of the sliding groove 15, and a first compression spring 21 is disposed between the fixing plate 20 and the driving board 18.

Because the invention does not need to be cooled when just printing, the temperature in the heat-insulating cavity 2 is prevented from being influenced, and the temperature is cooled only after printing to a certain height. As shown in fig. 2, 3 and 8, the support plate 7 is continuously lowered along with the printing in the operation of the invention. At the beginning, the first connection port and the second connection port at the two ends of the cooling pipeline 10 in the support plate 7 are in a closed state. As the support plate 7 descends, the support plate 7 presses the driving plate 18, so that the switch plate 16 slides downward in the sliding groove 15, and thus the through hole 17 moves out of the sliding groove 15 to communicate with the first connection port as the switch plate 16 moves downward, so that the cool air in the hollow layer 9 of the air inlet region can enter the cooling duct 10. Similarly, the second connecting port is also communicated with the hollow layer 9 of the air outlet area, and the cold air starts to flow circularly to cool the formed area of the workpiece on the supporting plate 7. After printing, the supporting plate 7 is lifted and reset by the lifting mechanism 8, the driving plate 18 on the switch plate 16 is moved upwards and reset by the first compression spring 21, and the through hole 17 enters the sliding groove 15 again to disconnect the hollow layer 9 from the cooling pipeline 10. The purpose of the present invention is to provide a wedge surface 19 on the drive plate 18 in order to press the first communication port 13 and the second communication port 14 when the drive plate 18 is returned, and to assist the first communication port 13 and the second communication port 14 in contracting and disconnecting.

As a further aspect of the present invention, the air outlet 12 is further provided with an adjusting unit that controls the opening size of the air outlet 12 according to the displacement of the support plate 7, and adjusts the flow rate of the cold air.

As a further scheme of the invention, the adjusting unit comprises a rack 22 fixedly arranged on the air outlet area driving plate 18 and an air outlet valve 23 arranged on the air outlet 12, a gear 24 is coaxially arranged on the air outlet valve 23, and the rack 22 is meshed with the gear 24.

Under the same condition, the faster the flow rate of the cold air means that the more heat the cold air takes away, the better the cooling effect, so in order to achieve the purpose of rapid cooling, it is necessary to increase the flow rate of the cold air. However, when the printing is started, the distance between the support plate 7 and the heat preservation cavity 2 is too close, the flow speed of the cold air is accelerated, the cooling effect is improved, the temperature in the heat preservation cavity 2 is probably directly influenced, and the sintering forming quality is influenced. The present invention requires the flow rate of the cold air in the cooling duct 10 to be adjusted according to the distance by which the support plate 7 is moved downward. As shown in fig. 2, 4 and 10, when the air conditioner works, as the support plate 7 moves downwards, the drive plate 18 of the air outlet area is driven by the support plate 7 to move downwards, because the drive plate 18 of the air outlet area is fixedly provided with the rack 22, the rack 22 drives the gear 24 coaxially arranged on the air outlet valve 23 to rotate, the gear 24 rotates to adjust the size of the air outlet 12, when the rack 22 rotates downwards, the gear 24 rotates forwards to adjust the size of the air outlet 12, the cold air circulation is accelerated, and the cold air flow rate is accelerated. When the rack 22 is returned by the restoring force of the first compression spring 21, the rack 22 drives the gear 24 to rotate reversely, and the air outlet 12 is also returned. And (5) circulating and reciprocating. The flow velocity of cold air in the cooling pipeline is adjusted according to the downward moving distance of the supporting plate, and when the downward moving distance of the supporting plate is larger, the flow velocity of the cold air is improved, so that the temperature in the heat-insulating cavity is not influenced while the cooling effect is improved; the accelerated flow rate can ensure that the cooling can be completed quickly when the printing is finished, thereby saving the working time and improving the working efficiency. The larger the downward moving distance of the supporting plate 7 is, the closer the printing work is to the completion, so that the flow rate of cold air needs to be accelerated, the cooling efficiency is increased, the cooling and the temperature reduction can be timely completed after the printing is completed, the cooling time is saved, and the working efficiency is improved.

As a further aspect of the present invention, the cooling pipes 10 are arranged in a zigzag shape. The cooling pipelines 10 are arranged in the supporting plate 7 in a bow shape, so that the heat exchange area of the cooling pipelines 10 is increased, the cooling efficiency is improved, and the formed area of the workpiece on the supporting plate 7 is cooled by the cooling pipelines 10 conveniently.

The working principle is as follows: as shown in fig. 1 and 2, in the invention, when working, a powder spreading mechanism 5 firstly spreads a layer of non-metal powder material on a powder bed 4, then a laser head 3 emits laser to move along a track, so that the non-metal powder material on the track is sintered to form a slice shape and falls on a support plate 7, then the support plate 7 moves downwards under the driving of a lifting mechanism 8, and the non-metal powder material is sintered layer by layer to finally form a complete three-dimensional object. The heating mechanism 6 heats the interior of the heat-insulating cavity 2 in the sintering process, and the temperature of the heat-insulating cavity 2 is controlled within a certain range. The invention uses the cooling mechanism to rapidly cool the formed area of the workpiece while the equipment prints the workpiece, thereby achieving the effect of rapid cooling.

As shown in fig. 1, 2 and 6, the present invention has a cooling duct 10 in the support plate 7 and a hollow layer 9 for storing cool air in the working chamber 1. When the invention works, the laser sinters the non-metal powder layer by layer, the cold air enters the hollow layer 9 from the air inlet 11 of the air inlet area, after flowing through the cold area pipeline in the supporting plate 7, flows out from the air outlet 12 at the hollow layer 9 of the air outlet area, thus, the cold air flowing through the cooling duct 10 does not directly blow the powder, does not fly the powder, and the temperature is reduced and cooled from the position of the supporting plate 7, only the formed area of the workpiece close to the position of the supporting plate 7 is cooled, thus, the cold air is positioned at the lower part, the hot air of the heat preservation cavity 2 is positioned at the upper part, the density of the hot air is lower, the cold and hot air can not generate convection under the condition of no external force, so that the powder flies upward, and the heat exchange of the cold and hot air can only occur at the boundary, therefore, the formed area can be rapidly cooled, the temperature of the unformed area of the workpiece cannot be influenced, and the forming quality of the printed workpiece is guaranteed. According to the invention, the formed area of the workpiece on the supporting plate 7 is cooled from bottom to top by using the cooling pipeline 10, so that not only is the potential safety hazard caused by direct powder blowing avoided, but also the convection of cold air and hot air is avoided, the temperature in the heat-insulating cavity 2 is ensured not to be influenced by the cooling of the cooling pipeline 10, and the printing and forming effects are avoided while the cooling effect is improved.

As shown in fig. 2, 3 and 8, the support plate 7 is continuously lowered along with the printing in the operation of the invention. At the beginning, the first connection port and the second connection port at the two ends of the cooling pipeline 10 in the support plate 7 are in a closed state. As the support plate 7 descends, the support plate 7 presses the driving plate 18, so that the switch plate 16 slides downward in the sliding groove 15, and thus the through hole 17 moves out of the sliding groove 15 to communicate with the first connection port as the switch plate 16 moves downward, so that the cool air in the hollow layer 9 of the air inlet region can enter the cooling duct 10. Similarly, the second connecting port is also communicated with the hollow layer 9 of the air outlet area, and the cold air starts to flow circularly to cool the formed area of the workpiece on the supporting plate 7. After printing, the supporting plate 7 is lifted and reset by the lifting mechanism 8, the driving plate 18 on the switch plate 16 is moved upwards and reset by the first compression spring 21, and the through hole 17 enters the sliding groove 15 again to disconnect the hollow layer 9 from the cooling pipeline 10. The purpose of the present invention is to provide a wedge surface 19 on the drive plate 18 in order to press the first communication port 13 and the second communication port 14 when the drive plate 18 is returned, and to assist the first communication port 13 and the second communication port 14 in contracting and disconnecting.

As shown in fig. 2, 4 and 10, when the air conditioner works, as the support plate 7 moves downwards, the drive plate 18 of the air outlet area is driven by the support plate 7 to move downwards, because the drive plate 18 of the air outlet area is fixedly provided with the rack 22, the rack 22 drives the gear 24 coaxially arranged on the air outlet valve 23 to rotate, the gear 24 rotates to adjust the size of the air outlet 12, when the rack 22 rotates downwards, the gear 24 rotates forwards to adjust the size of the air outlet 12, the cold air circulation is accelerated, and the cold air flow rate is accelerated. When the rack 22 is returned by the restoring force of the first compression spring 21, the rack 22 drives the gear 24 to rotate reversely, and the air outlet 12 is also returned. And (5) circulating and reciprocating. The flow velocity of cold air in the cooling pipeline is adjusted according to the downward moving distance of the supporting plate, and when the downward moving distance of the supporting plate is larger, the flow velocity of the cold air is improved, so that the temperature in the heat-insulating cavity is not influenced while the cooling effect is improved; the accelerated flow rate can ensure that the cooling can be completed quickly when the printing is finished, thereby saving the working time and improving the working efficiency. The larger the downward moving distance of the supporting plate 7 is, the closer the printing work is to the completion, so that the flow rate of cold air needs to be accelerated, the cooling efficiency is increased, the cooling and the temperature reduction can be timely completed after the printing is completed, the cooling time is saved, and the working efficiency is improved.

The cooling pipes 10 are arranged in a bow shape. The cooling pipelines 10 are arranged in the supporting plate 7 in a bow shape, so that the heat exchange area of the cooling pipelines 10 is increased, the cooling efficiency is improved, and the formed area of the workpiece on the supporting plate 7 is cooled by the cooling pipelines 10 conveniently.