Furnace having vertical arrangement of the combustion chamber for dental components and heat-resistant base

Abstract

The invention relates to a furnace (1) having a vertical orientation for dental components (11), comprising a combustion chamber (2), which is open at the bottom and the opening (2.1) of which can be closed by means of a furnace door (3), which is lowered in the vertical direction in the open position, and comprising a depositing region (10) for the heated component (11), which depositing region is arranged at a distance from the opening (3) in the combustion chamber (2). The depositing region is part of the furnace, and a cooling device that acts on the depositing region is arranged on or in the furnace. A heat-resistant base (21) has a heat-resistant support (12) arranged in a housing (22), which support has an active or passive cooling device, which, for example, has a Peltier element (30).

Description

Technical field

[0001] The invention relates to an oven with a vertical arrangement of the combustion chamber for dental components.

[0002] Ovens for dental components are often designed as tabletop units, resulting in a significantly smaller form factor than conventional industrial ovens. A particular advantage is that they do not require a separate high-voltage power connection for operation. These ovens are not limited to sintering processes; they can also be used for drying, crystallization, or glazing. These ovens differ, among other things, in their temperature ranges. Sintering typically requires a temperature range of 1500°C to 1600°C, while the crystallization of glass ceramics and glazing (coating zirconia with glass ceramic) take place at temperatures of 800°C. Drying a dental component after wet machining occurs within a temperature range of 150°C to 200°C. State of the art

[0003] From DE 10 2012 213 279 A1, a sintering furnace for dental components is known in which a component mounted on a carrier is removed from the combustion chamber after sintering, together with the carrier, and placed on a refractory surface at room temperature. The carrier acts as a temperature buffer to compensate for any potential thermal shock. In this cooling zone, the component mounted on the carrier cools from a temperature between 275 and 600 degrees Celsius to a temperature between 100 and 200 degrees Celsius. The component is then removed from the carrier and placed on a metallic surface at room temperature, where it is lukewarm to the touch after a maximum of two minutes and can be further processed.

[0004] From DE 10 2013 226 497 it is known to operate a dental oven with a temperature profile including a cooling phase.

[0005] From DE 10 2006 032 655 A1, a dental technology furnace is known in which a temperature-dependent position control of the sealing plate is provided. The drying process prior to firing takes place independently of the heating or cooling phase of the firing chamber, and the drying time of the material placed on the sealing plate before firing can be reduced.

[0006] A dental furnace with a hinged upper section is known from EP 0 775 883 A1 and EP 1 593 922 A1. Storage plates for temporarily holding the material to be fired for cooling or preheating extend to the sides of a lower section.

[0007] It is known that zirconium oxide and aluminum oxide require short cooling times and can even be cooled in water. Glass ceramics are damaged when cooled in water, but cooling in ambient air at room temperature is unproblematic.

[0008] The object of the invention is to shorten the cooling time of a component after sintering, crystallizing, glazing or drying. Description of the invention

[0009] Thanks to the inventive design of a vertically oriented oven for dental components, with a downwardly open combustion chamber, the opening of which can be closed by means of an oven door lowered vertically in the open position, having a storage area for the heated component arranged at a distance from the opening in the combustion chamber, wherein the storage area is part of the oven and wherein a cooling device acting on the storage area is arranged on or in the oven, the cooling time of the component removed from the oven and arranged on the storage area can be reduced compared to cooling the component by pure convection at room temperature.

[0010] The storage area is positioned outside the heat radiation field of the open combustion chamber. For example, in a vertical oven, this could be below the oven door or on top of the oven itself. This allows cooling to occur without the continued heat input via radiant heat from the combustion chamber.

[0011] A storage area as part of the oven also includes a shelf connected to the oven that can only be extended when needed.

[0012] The storage area features a heat-resistant shelf for the heated component, and the cooling device acts on the shelf.

[0013] A material is considered heat-resistant if it is resistant to thermal stress. Specifically, this means that the tray, when used at the intended temperatures of the component, does not undergo any changes that would permanently impair its use. Of particular importance is the fact that, for example, after a sintering process, a dental component heated to 1000°C can be placed directly onto the tray instead of waiting approximately 5 minutes for it to cool to around 400°C, thus accelerating the overall cooling process.

[0014] To prevent dental components, especially restorations, from suffering thermal shock at the contact points, it is advantageous to use a material whose temperature quickly adapts to the hot component, such as an aluminum support plate. Furthermore, using a black anodized aluminum support plate largely prevents discoloration.

[0015] The shelf has ventilation openings through which a cooling airflow is directed onto the component placed on it. Furthermore, the ventilation openings are aerodynamically connected to a fan to provide a cooling airflow. This enables active cooling of the component on the shelf.

[0016] Advantageously, an air-permeable, heat-insulating insert can be placed between the fan and the shelf to prevent the component's heat radiation from affecting the fan.

[0017] In addition to an airflow, the tray can be cooled by means of a Peltier element that is thermally coupled directly to the tray.

[0018] Advantageously, the storage area or the storage unit can have means for measuring the temperature in the storage area or the storage unit or of the component to be cooled, such as a temperature sensor or a thermal imaging camera.

[0019] Advantageously, comparison and display devices can be provided to compare the temperature of the component being cooled with a predefined limit temperature and to display this information when the limit temperature is reached. With continuous thermal monitoring of the dental component using a thermal sensor or thermal imaging camera throughout its entire cooling phase, the earliest possible time for handling the component for further processing can be indicated or communicated to the user in any conceivable way after a limit temperature has been reached, for example, as an acoustic and / or visual signal or via email or other electronic notification.

[0020] Advantageously, the cooling device can deliver a cooling output dependent on the means of temperature measurement by means of a control unit.

[0021] Advantageously, several shelves with multiple cooling devices can be located within a single housing. Such a designed oven or base then allows for the storage of several heated components for cooling.

[0022] Advantageously, the cooling capacity of each shelf can be individually controlled. This allows the multiple cooling units to be operated individually, depending on the temperature, via a single control system. Brief description of the drawings

[0023] Exemplary embodiments of the invention are shown in the drawing. It shows: Fig. 1 shows a lower part of a dental furnace with an open combustion chamber and a storage area arranged in front of it; Fig. 1 shows the storage area made of Fig. 1 in detail with component placed on top; Fig. 2 a dental oven with an open combustion chamber and a storage area arranged on the combustion chamber; Fig. 3 a non-inventive heat-resistant base, designed independently of a dental oven; Fig. 4 a dental oven with an open combustion chamber and a storage area arranged below the open oven door; Fig. 5 a dental oven with an open combustion chamber and a storage area arranged in front of the combustion chamber with free convection; Fig. 6 a dental oven with an open combustion chamber and a storage area arranged in front of the combustion chamber with a Peltier element; Fig. 7 the dental oven made of Fig. 1 with automatic repositioning of the hot component by means of a gripper arm or robot arm; Fig. 8 the dental furnace made of Fig. 1 with an automatic repositioning of the hot component by means of a plunger (e.g. linear actuator or compressed air pipe), a chute and a collection basket; Fig. 9 a dental oven with two oven doors and with ventilation installed in the oven housing; Fig. 10 several shelves with several cooling devices arranged in a housing not according to the invention; Fig. 11 a base not according to the invention with a control unit. Exemplary embodiment of the invention

[0024] Fig. 1 Figure 1 shows the lower part of a vertically oriented dental furnace 1 with a downward-facing combustion chamber 2, the opening of which can be closed by means of a furnace door 3 lowered vertically in the open position. The lowered furnace door 3, in a loading position, comprises a plate-shaped wall section 4 on which a lower and an upper door block 5, 6 are provided for insulating the combustion chamber. The upper door block 6 has a support surface 7 on its upper side for a component to be heat-treated in the combustion chamber 2. To load the furnace, the component is placed on the support surface 7 of the furnace door in the loading position, and the furnace door is moved vertically upwards, closing the combustion chamber in the closed position.After completion of the heat treatment in the closed combustion chamber 2, the furnace door is opened by lowering it downwards, and once the loading position is reached, the component, which still exhibits residual heat, is removed from the support surface 7 and placed in a storage area 10. This storage area 10 is part of the furnace 1 and is located at a distance from the opening 2.1 of the combustion chamber 2, in this case in front of the opening 2.1 of the combustion chamber 2. However, it is equally conceivable to position the storage area 10 to the side of the opening 2.1 of the combustion chamber.

[0025] On this storage area 10, the component 11, which is to be or has been subjected to heat treatment in the combustion chamber 2, can be placed.

[0026] As from Fig. 1A As can be seen, the storage area 10 has a heat-resistant shelf 12 on which the heated component 11 can be placed. The storage area 10 is designed as part of a housing 13 of the dental oven 1, more precisely as part of a base plate.

[0027] Storage area 10 contains a cooling device 14 that acts on the shelf 12. This device includes a fan 15 attached to the housing 13, which directs an airflow 17 through ventilation slots 16 in the shelf 12 onto the component 11, which has been removed from the combustion chamber and is placed on the shelf. When the oven is placed on a base, storage area 10 has a gap between it and the base. Cooling air can reach the underside of the shelf through this gap, or be drawn in by the fan, thus cooling the shelf.

[0028] Between the fan 15 and the shelf 12, an air-permeable, heat-insulating insert 18 is arranged to prevent the heat radiation of the component 11 from affecting the fan 15.

[0029] Fig. 2 Figure 1 shows a dental furnace 1 with the furnace door 3 of the combustion chamber 2 open and a storage area 10 arranged on the combustion chamber 2 at a distance from the opening 2.1 of the combustion chamber 2, with a storage area 12 which is provided with ventilation slots 16, through which an airflow 17 is directed towards the component 11.

[0030] Fig. 3Figure 1 shows a heat-resistant support 21 for a heated dental component 11, which is designed independently of a dental oven and has a heat-resistant tray arranged in a housing 22 with an active or passive cooling device. As a passive cooling device, ventilation slots 16 are provided in the tray through which an airflow can reach the component 11. The airflow 17 can be intensified by a fan (not shown) in the housing 22, resulting in an active cooling device.

Claims

1. A furnace having vertical orientation for dental components (11), comprising a combustion chamber (2) which is open at the bottom and has an opening (2.1) that can be closed by means of a furnace door (3), which in the open position is lowered in the vertical direction, having a support region (10) for the heated component (11), which support region is arranged at a distance from the opening (3) in the combustion chamber (2), is part of the furnace and is arranged outside a heat radiation field of the open combustion chamber (2), characterised in that a cooling device (14) acting on the support region (10) is arranged on or in the furnace, wherein the support region (10) has a heat-resistant support (12) for the heated component (11) and that the cooling device (14) acts on the support (12) and wherein the support (12) has ventilation openings (16), by means of which a cooling air flow (17) is directed onto a component (11) to be arranged on the support (12) in the support region (10), wherein the ventilation openings (16) are fluidically connected to a fan (15) for providing a cooling air flow (17).

2. The furnace according to claim 1, characterised in that an air-permeable, heat-insulating insert part (18) is arranged between the fan (15) and the support (12).

3. The furnace (1) according to one of claims 1 to 2, characterised in that the support region (10) or the support (12) has means for measuring the temperature (42) in the support region (10) or of the support (12) or of the component to be cooled (11).

4. The furnace (1) according to claim 3, characterised in that comparison means (81) and display means (82) are provided to compare the temperature of the component (11) to be cooled with a predetermined limit temperature and to display same when the limit temperature is reached.

5. The furnace (1) according to claim 3 or 4, characterised in that the cooling device delivers a cooling output dependent on the signal of the means for measuring the temperature (42) by means of a control unit (83).

6. The furnace (1) according to one of claims 1 to 5, characterised in that a plurality of supports (71-74, 75, 76) having a plurality of cooling devices is provided in a housing (13; 22).

7. The furnace (1) according to claim 6, characterised in that the cooling output of each support (71-74, 75, 76) can be controlled individually.

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