Cooling device for sintered components

Abstract

The invention relates to a cooling device (10) for sintered components (9), comprising a stand block (14) having a receptacle (16), and comprising a cover block (20) which can be placed onto the stand block (14) and peripherally covers a component (9) deposited in the receptacle (16), wherein at least the cover block (16) has a porous structure (24).

Description

[0001] Cooling device for sintered components

[0002] Field of the invention

[0003] The invention relates to a cooling device for sintered components.

[0004] State of the art

[0005] Sintered components, such as milled ceramic teeth, are cooled after sintering, which carries the risk of cracking if the components cool down too quickly. Therefore, the furnace is shut down and cooled down while the components are still in the furnace. This, in turn, leads to longer furnace operating times, as it cannot be used for new sintered components during the cooling period.

[0006] Cooling devices for sintered ceramics are not known.

[0007] Description of the invention

[0008] The object of the invention is therefore to provide a possibility for optimal cooling of a sintered component, which allows a more efficient use of the sintering furnace.

[0009] This object is achieved with a cooling device according to claim 1. Further features which develop the invention are contained in the subclaims.

[0010] A cooling device for sintered components comprises a support block with a receptacle, which is designed in particular as a trough in the support block, and a cover block, in particular a multi-part cover block, which is placed on the support block and which circumferentially covers a component placed on the receptacle. At least the cover block, in particular a multi-part cover block, is designed with a porous structure. This cooling device allows the component to be cooled at a speed ideal for the component, while simultaneously eliminating the need for storage space in a furnace.

[0011] The support block preferably comprises legs for positioning the support block at a distance from the support surface, in particular at least 0.5 cm, more preferably at least 1.5 cm, 3 cm, 5 cm, or 10 cm, and / or preferably at most 5-10 cm from the support surface. This allows for suitable heat dissipation even beneath the cooling device, thus ensuring more uniform cooling of the sintered product.

[0012] Preferably, the cover block of the cooling device is formed from two or more block parts. This allows for precise placement of the sintered component using simple tools such as pliers, while still allowing the cooling device to be easily assembled. This applies in particular to a design in which the cover block has two substantially symmetrical parts and / or at least two stackable block parts.

[0013] The porous structure is preferably formed as a geometric pattern in cross-section that extends longitudinally. In particular, it is formed as a polygonal or round pattern, e.g., square, rectangular, diamond-shaped, hexagonal, triangular, or even circular or oval. More preferably, the base block is also formed from the porous structure. These regular structures enable good heat dissipation while simultaneously simplifying the production of the base and lid blocks.

[0014] The cooling device preferably further comprises a receiving device for inserting a transport tool, particularly in the stationary block. This allows the sintered component to be heated at least in the stationary block of the cooling device and then removed from the furnace with the aid of the receiving device and a transport tool. The receiving devices are preferably designed as holes, projections, hooks, or brackets, which allow the cooling device to be picked up using simple tools.

[0015] The cooling device preferably comprises a silicate ceramic, such as cordierite ceramic. This material is ideally suited for the required heat conduction while also being sufficiently heat-resistant to accommodate the sintered components or to hold them in the furnace.

[0016] External ribs can be formed on at least some sections of the base block and / or the cover block. This further improves heat dissipation.

[0017] The porous structure is preferably formed by a plurality of layered plates spaced apart from one another. This ensures optimal heat dissipation with the lowest possible weight.

[0018] The spacing between the plates is preferably equal to or greater than the thickness of the plates (1.2 to 1.5 times) and preferably a maximum of three to twice the thickness of the plates. Making the slots slightly thicker than the plates increases the insulating properties of the cooling device.

[0019] The cooling device preferably further comprises a frame that accommodates the base block and the cover block. This enables easy handling and quick loading of the cooling device, so that a sintering tray removed from the furnace does not have to remain exposed to air for long periods. The frame preferably has movable hoods that accommodate the cover block.

[0020] A cooling device according to the invention for sintered components thus comprises a standing block with a receptacle and a cover block which can be placed on the standing block and which circumferentially covers a component placed in the receptacle, wherein at least the cover block is formed from a plurality of layered plates.

[0021] The base block preferably withstands a temperature of 1450°C, i.e., it will not be damaged if a sintering tray or sintered component at this temperature is placed in or on the base block holder. This is often the case when the sintered components are transferred from the furnace to the cooling device. The base block preferably withstands a temperature of 1500°C to 1650°C. The cover block preferably withstands at least a temperature of 1300°C, more preferably 1400-1500°C. The cover block does not require the same temperature resistance because it does not normally come into direct contact with the sintered ceramic or the sintering tray.

[0022] The support block preferably has a thickness of at least 40 mm below the receptacle, preferably 45 mm, 50 mm, or 55 mm. Furthermore, the cover block can have a thickness of at least 30 mm, preferably 40 mm, 45 mm, 50 mm, or 55 mm, above or to the side of a sintering tray or sintered ceramic placed in the cooling device. These thicknesses ensure that the cover block and the support block can absorb sufficient heat and that the heat from the sintering tray is not conducted undiminished by the support block to the outside of the cooling device.

[0023] The materials of the cover block preferably have a thermal conductivity of 10-20 W / mK, preferably 15-20 W / mK. In particular, the cover block or at least the individual layers (if present) comprise stainless steel or titanium, or are formed entirely from these materials.

[0024] Short description of the characters

[0025] Figure 1 shows an isometric exploded view of an embodiment of the cooling device according to the invention;

[0026] Figure 2 shows an isometric view of a cooling device in the closed state;

[0027] Figure 3 shows an isometric view of a cooling device in the open state;

[0028] Figure 4 shows a plan view of a cooling device in the open state; Figure 5 shows a longitudinal section of a cooling device in the open state;

[0029] Figure 6 shows a longitudinal section of a cooling device in the closed state; and

[0030] Figure 7 shows a cross section of a cooling device

[0031] Description of the preferred embodiments

[0032] A cooling device 10 according to the invention comprises a standing block 14 and a cover block 20. The standing block has a receptacle 16 for a sintered component or a component shell 9, into which the sintered component or the component shell 9 is placed for cooling. A sinter shell can be used to hold sintered components such as pre-milled dental ceramics. This allows smaller components in particular to be loaded into and removed from the furnace more easily, thus simplifying handling. Furthermore, the shell also serves as a heat reservoir, so that smaller sintered components in particular do not lose heat too quickly when transferred from the furnace to the cooling device 10.

[0033] The cover block 20 can be formed in one piece and preferably also has a recess 16? which is provided for receiving the sintered component or the component shell 9.

[0034] During use, the sintered component is typically placed in a sintering tray 9 and heated together with the tray for sintering. This tray can then be removed from the furnace and placed into the receptacle 16 of a provided support block 14. The cover block 20 is then placed onto the support block 12, and the sintered component is cooled in the cooling device 10. Alternatively, the sintered component 9 could also be sintered in the support block in the furnace, and then the support block 14 could be removed from the furnace. This is then placed on a storage location and closed with the cover block 20.

[0035] Figure 1 shows an embodiment of the cooling device whose cover block 20 is formed from several parts. Here, the cover block 20 has a lower part 21 and an upper part 22, which are placed one after the other on the support block. It is also possible to use multiple lower parts 21, for example, if larger sintered components or sintered shells 9 are to be cooled.

[0036] The cover block 20 can also comprise a different division. The cover block can, for example, consist of two halves 22' 22", as indicated by the dashed line in Figure 1. Such halves can be more easily placed on the support block. The halves can, of course, be provided like a cover block 20 without a lower part 21, but they can also be used with a lower part 21 and / or the lower part 21 can also be divided. Figure 1 shows a combined embodiment that has two stackable cover block parts 21, 22, each of which is also formed in two parts. The stackability of the cover block also allows different sized sintered components or sintered shells to be cooled with the same cooling device.

[0037] The support block 14 here has legs 12, which allow the support block to be placed on any surface. The legs 12 are schematically depicted here as pyramid-shaped stilts, but can also take other forms such as cuboids and simple rods, or even be designed as rails along one side. The number of legs 12 can also vary. Here, four legs 12 are preferred, but any number of legs can be used as long as a secure stand is guaranteed.

[0038] The material of the base block 14 and / or the cover block 20 comprises silicate ceramic, e.g. a cordierite ceramic, or is made entirely of this material.

[0039] The cover block 20 and preferably also the standing block 14 are porous, i.e. there are a large number of air spaces 24 in the material. This allows the heat radiated from the sintered component to be efficiently dissipated. The porous structure 24 is preferably a regular structure, such as the grid of regular air spaces shown in Figure 1 (here with rectangular or square air spaces) that extend along the individual components, for example here along the height of the cover block 20, but also along the width or length is possible. Ribs can also be formed on the outside of the standing block 14 and / or the cover block 20 for better heat dissipation. These can be made from the material of the corresponding block, but can also be made from a different material, e.g. a metal.For this purpose, metal ribs can extend into the cover block 20 and / or the stand block 14 or have projections that are incorporated into the cover block 20 and / or the stand block 14. The cover block 20 and / or the stand block 14 can also have through-holes for receiving the support 16 if cooling is to be further accelerated.

[0040] Figures 2-7 show a more specific embodiment of the present invention. The cooling device 10 shown in these figures has a standing block 14 and a two-part cover block 20. The receptacle 16 of the standing block 14 is designed here merely as a support surface on which the sintered ceramic or a sintering tray can be placed. The standing block 14 is preferably made of a ceramic, in particular one of the ceramics mentioned above, and it can be accommodated in a frame 30 that can comprise the support legs 12. The frame 30 preferably accommodates the standing block 14 and the cover block 20. The cover block does not have a lower part 21 here.

[0041] Figure 2 shows an isometric view of the frame 30. In the embodiment shown here, the frame 30 has a lower support 32, a middle support 34, and an upper support 36. The legs 12 are formed in the lower support 32, the standing block 14 is received in the middle support 34, and the upper support 36 is designed as a hood 37 in which the cover block 20 is mounted. The hood 37 preferably has two movable hood halves, each of which receives a cover block half 22', 22", wherein the cover block halves 22', 22" are moved with the hood halves. For manual handling of the hood, the hood halves have handles 38 with which the hood halves can be moved back and forth. The frame 30 is in particular made of a metal and more preferably formed with closed, opening-free plates in order to prevent the occurrence of an air flow at the receptacle 16.

[0042] Figure 3 shows an isometric view of the frame in an open state. Here, the receptacle 16 for the sintering tray and one half of the cover block 22" can be seen, which is mounted in the hood 37 and moves with the hood. In this embodiment, the cover block 20 has a layered construction, which creates the porous structure. A plurality of plate-shaped individual layers 26 are arranged spaced apart from one another. These individual layers 26 are preferably made of a metal. A recess is provided in the cover block 22" in which the sintering tray 9 can be received. The lower level 32 and the middle level 34 of the frame 30 are spaced apart from one another by means of spacers 40, so that the hood engages in the distance between the lower and middle levels with sliding surfaces 39, which can be formed, for example, by inwardly bent ends of the openingless plates.Preferably, the underside of the sliding surface 39 and / or the upper side of the lower support 34 has a coating (e.g., Teflon) at least in the area on which the sliding surfaces 39 can run. The spacers 40 can be used as stops that limit the movement of the hood halves. However, such stops can also be formed separately. A recess is formed in the middle support 34 to accommodate the support block 14, into which the support block 14 can be inserted.

[0043] Figure 4 shows a plan view of the frame 30 and the standing block 14, which is received in the recess in the central support 34. The recess in the central support 34 ensures that the standing block has a predetermined position relative to the cover block 20 mounted in the hood. This can be assisted by stops 33 (see Figure 5). Figure 5 shows the cooling device 10 and the frame 30 in a longitudinal section in an open state. The preferred cover block 20 is clearly visible here. The cover block is designed in layers so that parallel plates 26 are attached at a distance from one another. The parallel and spaced arrangement of the plates 26 creates the porous structure of the cover block 20, through which the heat is dissipated at the correct heat dissipation rate, so that the dental ceramic cools without cracking or tearing.Preferably, the distance between the plates is equal to or greater than the thickness of the plates 26 (e.g., 1.2 to 1.5 times greater), but at most three or twice as large. The plates 26 thus retain the heat in the receptacle for the sintering tray 9, allowing cooling to proceed sufficiently slowly.

[0044] A plate 26 preferably has a thickness of 1-3 mm, preferably 1.7-2.3 mm. The distance between such plates 26 is accordingly the same or up to three times as large. The resulting heat dissipation cools a sintered component from approximately 900-1200 °C to approximately 400-600 °C within 15 minutes and then to 100-120 °C in approximately another 75 minutes. This cooling rate prevents cracks and damage in the sintered ceramic.

[0045] The plates are made of metal, especially stainless steel or titanium.

[0046] The plates 26 can be cast with small webs, but it is preferred that the plates 26 be kept apart from one another using spacers 27 (e.g. ring plates) which are mounted on one or more pins 28. The pins 28 can be designed with threads or as threaded screws and hold the layered plates 26 with one or two nuts. Each cover half 20', 22' preferably has three such pins 28, one in the middle on the closed side and two at the edges on the side with the recess 23. This ensures the stability of the cover block. Furthermore, the recess is preferably only formed in the lower plates 26 so that the sintering shell 9 is received but is covered at the top. Preferably, a maximum of half to two-thirds of the plates 26 have a recess 23. The recess is present in a symmetrical design in both cover halves 22', 22".

[0047] Figure 6 shows the cooling device 10 and the frame 30 in a longitudinal section in a closed state. Both cover halves 22', 22" are mounted in the hood 37. This is achieved in particular by fastening elements 35, which are attached both to the cover block halves 22', 22" and to the hood 37. More preferably, the fastening elements 35 are plate-shaped and cover the longitudinally extending slots on the rear and sides. In particular, these fastening elements 35 are attached to the pins 28. When the hood is then slid along the sliding surfaces 39 on the lower support 32, the cover halves 22', 22" are moved with the hood 37, and the receptacle 16 of the support block 14 is released. The legs 12 of the frame 30 are formed by the sides of the lower support 32. The legs 12 are bent inward, particularly at the lower end, similar to the sliding surfaces 39.In the embodiment shown, the upper support 36 is not rigidly connected to the middle support, but can move along the middle support 34. The lower support 32, on the other hand, is rigidly connected to the middle support 34.

[0048] List of reference symbols

[0049] 9 Sintering tray

[0050] 10 Cooling device 12 Leg

[0051] 14 Stand block

[0052] 16 recording

[0053] 17 recording

[0054] 20 cover block

[0055] 21 Lower part

[0056] 22 Top

[0057] 22', 22" lid half

[0058] 23 Lid holder

[0059] 24 porous structure

[0060] 25 distance

[0061] 26 plate-shaped single layer

[0062] 27 spacers

[0063] 28 pin

[0064] 30 frame

[0065] 32 lower support

[0066] 33 stop

[0067] 34 medium carrier

[0068] 35 Fastening element

[0069] 36 upper carrier

[0070] 37 hood

[0071] 38 handle

[0072] 39 Sliding surface

[0073] 40 spacers

Claims

Patent claims 1. A cooling device (10) for sintered components (9), comprising a support block (14) with a receptacle (16); a cover block (20) which can be placed on the support block (14) and which circumferentially covers a component (9) placed in the receptacle (16); wherein at least the cover block (16) is formed with a porous structure (24).

2. Cooling device (10) according to claim 1, wherein the stand block comprises legs which position the stand block at a distance from the support surface.

3. Cooling device (10) according to one of the preceding claims, wherein the cover block is formed from two or more block parts.

4. Cooling device (10) according to claim 3, wherein the cover block has two substantially symmetrical parts and / or at least two stackable block parts.

5. Cooling device (10) according to one of the preceding claims, wherein the perforated structure is formed as a geometric pattern in cross section extending in the longitudinal direction.

6. Cooling device (10) according to one of the preceding claims, further comprising a receiving device for inserting a transport tool.

7. Cooling device (10) according to one of the preceding claims, wherein the cooling device comprises a silicate ceramic.

8. Cooling device (10) according to one of the preceding claims, in which ribs are formed at least in sections on the standing block and / or the cover block.

9. Cooling device according to one of the preceding claims, wherein the porous structure is formed by a plurality of plates (26) stacked one above the other or next to the other and spaced apart from one another.

10. Cooling device according to claim 9, wherein the spacing between the plates (26) is equal to or greater than the thickness of the plates (26). Preferably, at most twice as large as the plates.

11. Cooling device according to claim 9 or 10, further comprising a frame (30) which receives the stand block and the cover block.

12. Cooling device according to claim 11, wherein the frame has movable hoods which receive the cover block.

13. Cooling device according to one of the preceding claims, wherein the standing block can withstand a temperature of 1450°C.

14. Cooling device according to one of the preceding claims, in which the standing block under the receptacle has a thickness of at least 40 mm.

15. Cooling device according to one of the preceding claims, in which the cover block (20) has a thickness of at least 30 mm above or to the side of a sintered shell (9) or sintered ceramic placed in the cooling device.

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