Heating equipment for metal 3D printing
By designing a heating device for metal 3D printing, and adopting fan-assisted heat dissipation and waste heat recovery, the problems of high-temperature damage and low flexibility of the equipment have been solved. The device's heat dissipation and flexible adjustment have been achieved, extending the equipment's lifespan and recovering waste heat resources.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHUZHOU VOCATIONAL & TECHN COLLEGE
- Filing Date
- 2025-05-26
- Publication Date
- 2026-04-24
AI Technical Summary
Existing metal 3D printing equipment does not provide auxiliary heat dissipation after completing the job, resulting in a long-term high-temperature working environment that is prone to damage to the equipment, and the overall equipment has low flexibility of use.
A heating device for metal 3D printing was designed, comprising components such as a sealed box, mounting base, limiting guide rail, fan, temperature sensor and motor. The device uses a fan to assist in heat dissipation and utilizes a temperature conduction plate and a cold water pipe to recover waste heat, thereby achieving flexible adjustment and heat dissipation of the device.
It effectively reduces equipment temperature, extends equipment lifespan, improves equipment flexibility and ease of use, and enables the recovery and utilization of waste heat resources.
Smart Images

Figure CN224157763U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of 3D printing equipment technology, and in particular to a heating device for metal 3D printing. Background Technology
[0002] 3D printing, also known as additive manufacturing, is a type of rapid prototyping technology. It is a technology that uses digital model files as a basis and employs powdered metal or plastic and other bondable materials to construct objects layer by layer. 3D printing is usually achieved using digital material printers and is often used in mold making, industrial design and other fields to create models. Later, it was gradually used for the direct manufacturing of some products.
[0003] In practice, existing printing equipment does not provide auxiliary heat dissipation after completing its work, resulting in a prolonged high-temperature working environment that can easily cause varying degrees of damage to the equipment. Furthermore, the overall printing equipment cannot be flexibly adjusted, leading to low overall flexibility and numerous inconveniences.
[0004] Therefore, this utility model provides a heating device for metal 3D printing. Utility Model Content
[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a heating device for metal 3D printing.
[0006] To achieve the above objectives, this utility model adopts the following technical solution: a heating device for metal 3D printing, including a sealed box.
[0007] The sealed box is equipped with a fixing frame inside. First limiting guide rails are installed on both sides of the fixing frame. Fourth limiting guide rails are installed on the top of both fixing frames. A reciprocating lead screw is installed on one side of each of the two fourth limiting guide rails. A fixing plate is installed on the outer side of each of the two reciprocating lead screws. A positioning plate is installed on one side of each fixing plate. A fixing block is installed on the other side of each of the two positioning plates. A third limiting guide rail is installed between the two fixing blocks. An installation side plate is installed on the outer side of the third limiting guide rail. An installation seat is installed on the outer side of the installation side plate. A printing device is installed inside the installation seat. A print head is installed at the bottom of the printing device.
[0008] A second limiting guide rail is installed between the first limiting guide rail and the fixed frame. Second limiting rollers are installed on both sides of the second limiting guide rail at equal intervals. A mounting base plate is installed on the top of each of the second limiting rollers. A mounting horizontal plate is installed above the mounting base plate. A mounting box is installed on the top of the mounting horizontal plate. A processing table is installed on the top of the mounting box. The processing table has air outlet slits that are evenly distributed and used in conjunction with the mounting box.
[0009] A fan is installed inside the mounting box. First positioning plates are installed between the mounting horizontal plate and the processing table, and around the perimeter of the mounting box. A first damper is installed on the top of each of the four first positioning plates. A buffer spring is fitted on the outside of each first damper. The tops of the first dampers and the buffer springs are connected to the bottom of the processing table. Second positioning plates are installed at equal intervals on the bottom of the mounting horizontal plate, and on the outside of the mounting base plate. A second damper is installed between each second positioning plate and the mounting horizontal plate. A buffer spring of the same structure is fitted on the outside of each second damper. The processing table is located below the mounting base.
[0010] In a preferred embodiment, the mounting base has an internal cavity for mounting the printing device. A heating box is mounted on top of the printing device, and a valve extending to the outside of the mounting base is mounted on top of the heating box. Two first limiting rollers are mounted on one side of the mounting side plate, above the third limiting guide rail. These first limiting rollers limit the sliding motion of the mounting base. The mounting side plate has an L-shaped structure, and a third positioning bolt extending into the third limiting guide rail is located at the bottom of the mounting side plate. After moving to the work site, the third positioning bolt can position the mounting side plate and the third limiting guide rail, preventing the device from moving independently. The top of the mounting box... A filter screen is installed above the fan in the mounting box. A control compartment is installed inside the mounting box and on one side of the fan. A temperature sensor is fixedly connected inside the control compartment. A motor mounting plate is fixedly connected inside the mounting box and below the fan. A second drive motor is installed inside the motor mounting plate. The output end of the second drive motor is connected to the fan. The second drive motor is supported and installed by the motor mounting plate. When the second drive motor runs, it drives the fan to rotate. The air discharged through the filter screen provides auxiliary heat dissipation for the printing site. It can also recover heat from the site into the mounting box, conduct the temperature through temperature conduction plates, and recover and utilize waste heat resources through cold water pipes.
[0011] In a preferred embodiment, a first drive motor is installed on one side of each of the two fourth limiting guide rails and above the first limiting guide rail. The output end of each first drive motor is fixedly connected to the bottom end of the corresponding reciprocating lead screw. A movable slide plate is threaded to the outer side of each reciprocating lead screw. One side of each movable slide plate is connected to a corresponding fixed plate. The operation of the first drive motor drives the corresponding reciprocating lead screw to rotate, thereby adjusting the height of the movable slide plate, thus adjusting the height of one side of the fixed plate, until finally adjusting the height of the third limiting guide rail, improving the final printing height. The other side of each of the two fixed plates is threaded with a second positioning bolt extending into the interior of the corresponding positioning plate. The positioning plate and the fixed plate... A third limiting roller is installed between the fixed plates to cooperate with the fourth limiting guide rail. A first mounting slide is installed on one side of the first drive motor. The first mounting slide is slidably connected to the first limiting guide rail. A first positioning bolt extending into the fourth limiting guide rail is threaded on the outer side of the first mounting slide. The first positioning bolt positions and installs the first mounting slide and the fourth limiting guide rail, thereby ensuring that when the first mounting slide is moved to one side, the fourth limiting guide rail and the first mounting slide will move to one side simultaneously. The overall installation position of the fourth limiting guide rail can be flexibly adjusted. The fixed plate and the positioning plate are positioned and installed by the second positioning bolt. The third limiting roller is used to limit the movement when sliding on the outer side of the fourth limiting guide rail.
[0012] In a preferred embodiment, a control panel is fixedly connected inside the sealed box and to one side of one of the first limiting guide rails. A storage box is fixedly connected inside the sealed box and to one side of the other first limiting guide rail. An electrical control box is installed on the top of the storage box. The electrical control box, valves, printing equipment, print head, first drive motor, second drive motor, and temperature sensor are all electrically connected to the control panel. The control panel is used to control the operation of the electrical control box, valves, printing equipment, print head, first drive motor, second drive motor, and temperature sensor, realizing unified management of electrical equipment. The storage box is used for storing some items for easy access during use.
[0013] In a preferred embodiment, a shock-absorbing base plate is fixedly connected to the bottom of the sealed box, and a viewing window is provided on the outside of the sealed box. The shock-absorbing base plate supports the entire equipment, and the viewing window is used to observe the operation of the equipment inside the sealed box.
[0014] Compared with the prior art, the advantages and positive effects of this utility model are as follows:
[0015] By setting up a sealed box, mounting base, fourth limit guide rail, and processing table, the second drive motor drives the fan to rotate, providing auxiliary heat dissipation for the printing site through the filter. Heat can also be recovered from the site and transferred to the mounting box for heat conduction via temperature conductive plates and waste heat recovery via cold water pipes. A temperature sensor monitors temperature changes in real time, and when a preset value is reached, the fan provides cooling. The fan is bidirectional and can switch between blowing and suction. The first drive motor drives the corresponding reciprocating screw to rotate, thereby adjusting the height of the moving slide plate, which in turn adjusts the height of the fixed plate on one side, ultimately adjusting the height of the third limit guide rail. This improves the final printing height. The storage box is used for some items... The device features convenient storage and easy access. The first mounting plate and the fourth limiting guide rail are positioned and installed using the first positioning bolt. This ensures that moving the first mounting plate to one side will simultaneously move both the fourth limiting guide rail and the first mounting plate to one side. The overall installation position of the fourth limiting guide rail can be flexibly adjusted. The fixing plate and positioning plate are positioned and installed using the second positioning bolt. The third limiting roller, in conjunction with the fourth limiting guide rail, provides limiting action when sliding outside. A shock-absorbing base plate supports the entire device. A viewing window allows visibility of the device's operation within the sealed enclosure and provides auxiliary cooling after printing. This design facilitates easy access for staff and offers a degree of protection, extending the device's lifespan. Attached Figure Description
[0016] Figure 1 A schematic diagram of the overall structure of a heating device for metal 3D printing provided by this utility model;
[0017] Figure 2 Internal schematic diagram of the overall structure of a heating device for metal 3D printing provided by this utility model. Figure 1 ;
[0018] Figure 3 Internal schematic diagram of the overall structure of a heating device for metal 3D printing provided by this utility model. Figure 2 ;
[0019] Figure 4 An enlarged schematic diagram of the processing table structure of a heating device for metal 3D printing provided by this utility model;
[0020] Figure 5 A schematic diagram of the internal structure of the mounting box for a heating device for metal 3D printing provided by this utility model;
[0021] Figure 6 An enlarged schematic diagram of the mounting base structure for a heating device for metal 3D printing provided by this utility model;
[0022] Figure 7 The present invention provides a heating device for metal 3D printing. Figure 3 Enlarged schematic diagram of the structure at point A in the middle.
[0023] Legend:
[0024] 1. Sealed box; 11. Shock-absorbing base plate; 12. Viewing window; 13. Control panel; 14. Fixing frame; 15. Storage box; 16. Electrical control box; 17. First limit guide rail; 18. Second limit guide rail;
[0025] 2. Mounting base; 21. Valve; 22. First limit roller; 23. Third limit guide rail; 24. Mounting side plate; 25. Heating box; 26. Mounting cavity; 27. Printing equipment; 28. Print head;
[0026] 3. Fourth limit guide rail; 31. First mounting slide plate; 32. First positioning bolt; 33. First drive motor; 34. Reciprocating lead screw; 35. Moving slide plate; 36. Fixed plate; 37. Positioning plate; 38. Second positioning bolt; 39. Fixed block;
[0027] 4. Processing table; 41. Air outlet slit; 42. First positioning plate; 43. First damper; 44. Buffer spring; 45. Mounting horizontal plate; 46. Second limit roller; 47. Mounting base plate; 48. Second positioning plate; 49. Second damper;
[0028] 5. Mounting box; 51. Control compartment; 52. Motor mounting plate; 53. Second drive motor; 54. Fan; 55. Filter screen; 56. Cold water pipe; 57. Temperature conductive plate; 58. Temperature sensor. Detailed Implementation
[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0030] like Figures 1-7As shown, this embodiment provides a technical solution: a heating device for metal 3D printing, including a sealed box 1, a fixing frame 14 installed inside the sealed box 1, first limiting guide rails 17 installed on both sides of the fixing frame 14, fourth limiting guide rails 3 installed on the top of the two fixing frames 14, a reciprocating lead screw 34 installed on one side of the two fourth limiting guide rails 3, a fixing plate 36 installed on the outer side of the two reciprocating lead screws 34, a positioning plate 37 installed on one side of the fixing plate 36, a fixing block 39 installed on the other side of the two positioning plates 37, a third limiting guide rail 23 installed between the two fixing blocks 39, an installation side plate 24 installed on the outer side of the third limiting guide rail 23, an installation seat 2 installed on the outer side of the installation side plate 24, a printing device 27 installed inside the installation seat 2, and a print head 28 installed at the bottom of the printing device 27;
[0031] In this scheme, a second limiting guide rail 18 is installed between one of the first limiting guide rails 17 and the fixed frame 14. The second limiting guide rail 18 is equipped with equidistant second limiting rollers 46 on both sides. The top of the second limiting rollers 46 is equipped with a mounting base plate 47. The mounting base plate 47 is installed above the mounting base plate 47. The mounting box 5 is installed on the top of the mounting box 45. The top of the mounting box 5 is equipped with a processing table 4. The processing table 4 has equidistant air outlet slits 41 that are used in conjunction with the mounting box 5.
[0032] In this design, a fan 54 is installed inside the mounting box 5. First positioning plates 42 are installed between the mounting plate 45 and the processing table 4 and around the mounting box 5. First dampers 43 are installed on the top of each of the four first positioning plates 42. Buffer springs 44 are fitted on the outside of each of the first dampers 43. The tops of the first dampers 43 and the buffer springs 44 are connected to the bottom of the processing table 4. Second positioning plates 48 are installed at equal intervals at the bottom of the mounting plate 45 and outside the mounting base plate 47. Second dampers 49 are installed between each of the second positioning plates 48 and the mounting plate 45. Buffer springs 44 of the same structure are fitted on the outside of each of the second dampers 49. The processing table 4 is located below the mounting base 2.
[0033] Going further, such as Figures 1-2 , Figure 6As shown: In this solution, the mounting base 2 has an internal mounting cavity 26 for mounting the printing device 27. A heating box 25 is mounted on the top of the printing device 27. A valve 21 extending to the outside of the mounting base 2 is mounted on the top of the heating box 25. Two first limiting rollers 22 are mounted on one side of the mounting side plate 24 and above the third limiting guide rail 23. The first limiting rollers 22 limit the sliding of the mounting base 2. The mounting side plate 24 has an L-shaped structure. The bottom of the mounting side plate 24 has a third positioning bolt extending into the third limiting guide rail 23. After moving to the work site, the mounting side plate 24 and the third limiting guide rail 23 can be positioned by the third positioning bolt to prevent the equipment from moving on its own.
[0034] Going further, such as Figures 1-7 As shown: In this solution, a filter 55 is installed on the top of the mounting box 5 above the fan 54. A control compartment 51 is installed inside the mounting box 5 and to one side of the fan 54. A temperature sensor 58 is fixedly connected inside the control compartment 51. A motor mounting plate 52 is fixedly connected inside the mounting box 5 and below the fan 54. A second drive motor 53 is installed inside the motor mounting plate 52. The output end of the second drive motor 53 is connected to the fan 54. The second drive motor 53 is supported and installed by the motor mounting plate 52. When the second drive motor 53 runs, it drives the fan 54 to rotate. The air discharged through the filter 55 provides auxiliary heat dissipation for the printing site. It can also recover the heat from the site to the inside of the mounting box 5. The temperature is conducted through the temperature conduction plate 57, and the waste heat is recovered and utilized through the cold water pipe 56.
[0035] In this design, a control panel 13 is fixedly connected inside the sealed box 1 and to one side of one of the first limiting guide rails 17. A storage box 15 is fixedly connected inside the sealed box 1 and to one side of the other first limiting guide rail 17. An electrical control box 16 is installed on the top of the storage box 15. The electrical control box 16, valve 21, printing device 27, print head 28, first drive motor 33, second drive motor 53, and temperature sensor 58 are all electrically connected to the control panel 13. The control panel 13 is used to control the operation of the electrical control box 16, valve 21, printing device 27, print head 28, first drive motor 33, second drive motor 53, and temperature sensor 58, realizing unified management of electrical equipment. The storage box 15 is used for storing some items for easy access.
[0036] Going further, such as Figures 1-3 , Figure 7As shown, in this scheme, a first drive motor 33 is installed on one side of each of the two fourth limiting guide rails 3 and above the first limiting guide rail 17. The output end of each first drive motor 33 is fixedly connected to the bottom end of the corresponding reciprocating lead screw 34. A movable slide plate 35 is threadedly connected to the outer side of each reciprocating lead screw 34. One side of each movable slide plate 35 is connected to the corresponding fixed plate 36. When the first drive motor 33 is running, it drives the corresponding reciprocating lead screw 34 to rotate, thereby driving the movable slide plate 35 to adjust its height, thereby adjusting the height of the fixed plate 36 on one side, until finally adjusting the height of the third limiting guide rail 23, thus improving the final printing requirements.
[0037] In this design, the other side of each of the two fixed plates 36 is threaded with a second positioning bolt 38 extending into the corresponding positioning plate 37. A third limiting roller is installed between the positioning plate 37 and the fixed plate 36 to cooperate with the fourth limiting guide rail 3. A first mounting slide plate 31 is installed on one side of the first drive motor 33. The first mounting slide plate 31 is slidably connected to the first limiting guide rail 17. The outer side of the first mounting slide plate 31 is threaded with a first positioning bolt 32 extending into the fourth limiting guide rail 3. The first positioning bolt 32 is used to position and install the first mounting slide plate 31 and the fourth limiting guide rail 3, thereby ensuring that when the first mounting slide plate 31 is moved to one side, the fourth limiting guide rail 3 and the first mounting slide plate 31 will move to one side simultaneously, allowing for flexible adjustment of the overall installation position of the fourth limiting guide rail 3. The fixed plate 36 and the positioning plate 37 are positioned and installed using the second positioning bolt 38, and the third limiting roller is used to limit the movement when sliding on the outer side of the fourth limiting guide rail 3.
[0038] Going further, such as Figures 1-2 As shown, in this scheme, a shock-absorbing base plate 11 is fixedly connected to the bottom of the sealed box 1, and a viewing window 12 is provided on the outside of the sealed box 1. The shock-absorbing base plate 11 supports the entire equipment, and the viewing window 12 is used to see through the internal equipment operation status of the sealed box 1.
[0039] Working principle:
[0040] like Figures 1-7 As shown:
[0041] By setting up a sealed box 1, mounting base 2, fourth limit guide rail 3, and processing table 4, when in use, the control panel 13 is opened, and the first limit roller 22 limits the sliding of the mounting base 2. The mounting side plate 24 has an L-shaped structure, and the bottom of the mounting side plate 24 is provided with a third positioning bolt extending into the third limit guide rail 23. After moving to the work site, the mounting side plate 24 and the third limit guide rail 23 can be positioned by the third positioning bolt to prevent the equipment from moving on its own.
[0042] The second drive motor 53 is supported and installed by the motor mounting plate 52. The operation of the second drive motor 53 drives the fan 54 to rotate. The air is discharged through the filter 55 to provide auxiliary heat dissipation for the printing site. It can also recover the heat from the site to the installation box 5. The temperature is conducted through the temperature conduction plate 57 and the waste heat is recovered and utilized through the cold water pipe 56. The temperature sensor 58 monitors the temperature changes in real time. When the preset value is reached, the fan 54 can be used for heat dissipation. The fan 54 is a bidirectional fan that can be used to switch between blowing and suction.
[0043] The first drive motor 33 rotates, driving the corresponding reciprocating lead screw 34 to rotate, thereby driving the moving slide plate 35 to adjust its height, thus adjusting the height of the fixed plate 36 on one side, until finally adjusting the height of the third limit guide rail 23, improving the final printing requirements.
[0044] The control panel 13 is used to control the operation of the electrical control box 16, valve 21, printing equipment 27, print head 28, first drive motor 33, second drive motor 53 and temperature sensor 58, realizing unified management of electrical equipment.
[0045] Storage box 15 is used for storing certain items, making them easy to access when needed.
[0046] The first mounting plate 31 and the fourth limiting guide rail 3 are positioned and installed by the first positioning bolt 32, thereby ensuring that when the first mounting plate 31 is moved to one side, the fourth limiting guide rail 3 and the first mounting plate 31 will move to one side simultaneously, and the overall installation position of the fourth limiting guide rail 3 can be flexibly adjusted. The fixing plate 36 and the positioning plate 37 are positioned and installed by the second positioning bolt 38, and the third limiting roller is used to limit the movement when sliding on the outside of the fourth limiting guide rail 3.
[0047] The shock-absorbing base plate 11 supports the entire equipment, and the viewing window 12 allows the equipment to be viewed through the sealed box 1 to monitor its operation. It also provides auxiliary heat dissipation for the equipment after printing, making it convenient for staff to handle and providing a certain degree of protection for the equipment, thus extending its service life.
[0048] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.
Claims
1. A heating device for metal 3D printing, comprising a sealed box (1), characterized in that, The sealed box (1) is equipped with a fixing frame (14) inside. The fixing frame (14) is equipped with a first limiting guide rail (17) on both sides. The top of the two fixing frames (14) is equipped with a fourth limiting guide rail (3). The two fourth limiting guide rails (3) are equipped with a reciprocating screw (34) on one side. The two reciprocating screws (34) are equipped with a fixing plate (36) on the outside. The fixing plate (36) is equipped with a positioning plate (37) on one side. The two positioning plates (37) are equipped with a fixing block (39) on the other side. The two fixing blocks (39) are equipped with a third limiting guide rail (23). The third limiting guide rail (23) is equipped with an installation side plate (24) on the outside. The installation side plate (24) is equipped with an installation seat (2) on the outside. The installation seat (2) is equipped with a printing device (27) inside. The printing device (27) is equipped with a print head (28) at the bottom. A second limiting guide rail (18) is installed between the first limiting guide rail (17) and the fixed frame (14). The second limiting guide rail (18) is equipped with second limiting rollers (46) that are evenly distributed on both sides. The top of the second limiting rollers (46) is equipped with a mounting plate (45). The top of the mounting plate (45) is equipped with a mounting box (5). The top of the mounting box (5) is equipped with a processing table (4). The inside of the mounting box (5) is equipped with a fan (54).
2. The heating device for metal 3D printing according to claim 1, characterized in that: The top of the printing device (27) is equipped with a heating box (25), and the top of the heating box (25) is equipped with a valve (21) extending to the outside of the mounting base (2). Two first limiting rollers (22) are installed on one side of the mounting side plate (24) and above the third limiting guide rail (23).
3. The heating device for metal 3D printing according to claim 2, characterized in that: A filter screen (55) is installed on the top of the mounting box (5) and above the fan (54). A control compartment (51) is installed inside the mounting box (5) and on one side of the fan (54). A temperature sensor (58) is fixedly connected inside the control compartment (51). A motor mounting plate (52) is fixedly connected inside the mounting box (5) and below the fan (54). A second drive motor (53) is installed inside the motor mounting plate (52). The output end of the second drive motor (53) is connected to the fan (54).
4. The heating device for metal 3D printing according to claim 3, characterized in that: A first drive motor (33) is installed on one side of each of the two fourth limiting guide rails (3) and above the first limiting guide rail (17). The output end of the first drive motor (33) is fixedly connected to the bottom end of the corresponding reciprocating screw (34). The outer side of the reciprocating screw (34) is threaded with a movable slide plate (35). One side of the movable slide plate (35) is connected to the corresponding fixed plate (36).
5. The heating device for metal 3D printing according to claim 4, characterized in that: The other side of each of the two fixed plates (36) is threaded with a second positioning bolt (38) extending into the interior of the corresponding positioning plate (37). A first mounting plate (31) is installed on one side of the first drive motor (33). The first mounting plate (31) is slidably connected to the first limiting guide rail (17). The outer side of the first mounting plate (31) is threaded with a first positioning bolt (32) extending into the interior of the fourth limiting guide rail (3).
6. The heating device for metal 3D printing according to claim 3, characterized in that: A control panel (13) is fixedly connected inside the sealed box (1) and on one side of one of the first limiting guide rails (17). A storage box (15) is fixedly connected inside the sealed box (1) and on one side of the other first limiting guide rail (17). An electrical control box (16) is installed on the top of the storage box (15). The electrical control box (16), valve (21), printing device (27), print head (28), first drive motor (33), second drive motor (53) and temperature sensor (58) are all electrically connected to the control panel (13).
7. The heating device for metal 3D printing according to claim 6, characterized in that: The bottom of the sealed box (1) is fixedly connected to a shock-absorbing base plate (11), and a viewing window (12) is provided on the outside of the sealed box (1).