Sintering furnace for components consisting of a sintering material, in particular for dental components, and a method for sintering such components

Patent metadata

Field	Value
Publication number	US-10101088-B2
Application number	US-201314417453-A
Country	US
Kind code	B2
Filing date	Jul 24, 2013
Priority date	Jul 27, 2012
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

The invention relates to a sintering furnace for components consisting of sintering material, especially dental components and in particular components consisting of ceramic, and a method for sintering such components. The sintering furnace 1 comprises a heatable furnace chamber 2 for the component 9 to be sintered, the furnace chamber 2 having a wall section 6 to be opened for inserting the component 9 to be sintered into the furnace chamber 2 . Drive means 10 are provided for mechanized opening and closing of the wall section 6 , and a control 11 is provided for the drive means 10 that has an actuation element 12 for the drive means 10 . Furthermore, a heating device 5 for the furnace chamber 2 is provided, and the control 11 causes the furnace chamber 2 to be heated. Actuating the control element 12 triggers the loading sequence of the control 11 , and the drive means 10 are automatically actuated by the control 11 corresponding to the loading sequence. An additional subject is a method for operating the sintering furnace, as well as a computer program therefor.

First claim

The invention claimed is:

1. A sintering furnace for dental components, comprising:
a furnace chamber that includes a movable wall section configured to move between an opened position and a closed position, the wall section includes a seat for a component to be sintered;
a heating device configured to heat the furnace chamber;
a controller configured to control the heating device so as to control a temperature in the furnace chamber; and
a memory storing a plurality of temperature profiles for a sintering process,
wherein the controller is constructed to:
(i) execute a loading sequence, while the furnace chamber is heated by the heating device, that includes steps of:
opening the wall section of the furnace chamber for a first time,
holding the wall section of the furnace chamber in the opened position while a component to be sintered is loaded on the seat, and
closing the wall section of the furnace chamber,

(ii) measure time periods for one or more of the opening, holding, and closing steps of the loading sequence,
(iii) detect one or more temperature drops within the furnace chamber during one or more of the opening, holding, and closing steps of the loading sequence,
(iv) select a temperature profile for the sintering process from the plurality of temperature profiles based on one or more of the measured time periods and/or one or more of the detected temperature drops within the furnace chamber,
(iv) execute the sintering process of:
heating the furnace chamber, after the loading sequence is completed, to a holding temperature over a first time period based on selected temperature profile, and
maintaining the holding temperature over a second time period, and

(v) execute a cooling process of:
opening the wall section of the furnace chamber for a second time to bring the seat of the wall section into a heated first cooling zone for a first cooling period, and
causing a signal indicating an expiration of the first cooling period and a transition to a second cooling period corresponding to a second cooling zone to be emitted, wherein a temperature in the second cooling zone is lower than a temperature in the first cooling zone.

2. The sintering furnace according to claim 1 , further comprising:
a control element,
wherein actuation of the control element causes the controller to execute the loading sequence, measure the time periods, and detect the one or more temperature drops.

3. The sintering furnace according to claim 1 , further comprising:
a drive unit constructed to move the wall section between the opened position and the closed position,
wherein the drive unit is controlled by the controller according to the loading sequence in response to actuation of a control element.

4. The sintering furnace according to claim 1 , wherein the heating device is controlled to heat the furnace chamber at an average heating rate of at least 1.0° C./s.

5. The sintering furnace according to claim 1 , wherein the controller is further configured to select the temperature profile from the plurality of temperature profiles stored in the memory based on at least one of: (i) a size of a component to be sintered, (ii) one or more geometric features of the component to be sintered, including: a maximum wall thickness, a maximum component cross-section, and a volume of the component to be sintered, and (iii) a material type of the component to be sintered.

6. The sintering furnace according to claim 1 , further comprising:
an evaluation unit configured to acquire information on a component to be sintered,
wherein the controller is further configured to select the temperature profile based on the acquired information.

7. The sintering furnace according to claim 1 , wherein the heating device is controlled to heat the furnace chamber at a maximum heating rate of 6° C./s.

8. A sintering furnace for dental components, comprising:
a furnace chamber that includes a movable wall section configured to move between an opened position and a closed position, the wall section includes a seat for the component to be sintered;
a heating device configured to heat the furnace chamber;
a memory storing:
(i) a preset loading sequence that includes steps of:
opening the wall section of the furnace chamber for a first time,
holding the wall section of the furnace chamber in the opened position while a component to be sintered is loaded on the seat, and
closing the wall section of the furnace chamber,
wherein the furnace chamber is heated by the heating device during the preset loading sequence, and

(ii) a temperature profile for a sintering process; and

a controller constructed to:
(i) control a temperature in the furnace chamber,
(ii) execute the preset loading sequence,
(iii) control the heating device during the sintering process in accordance with the temperature profile following the preset loading sequence, wherein the sintering process includes steps of:
heating the furnace chamber, after the loading sequence is completed, to a holding temperature over a first time period based on the temperature profile, and
maintaining the holding temperature over a second time period, and

(iv) perform a cooling sequence of:
opening the wall section of the furnace chamber for a second time to bring a seat of the wall section into a heated first cooling zone for a first cooling period, and
causing a signal indicating an expiration of the first cooling period and a transition to a second cooling period corresponding to a second cooling zone to be emitted, wherein a temperature in the second cooling zone is lower than a temperature in the first cooling zone.

9. The sintering furnace according to claim 8 , further comprising:
a drive unit constructed to move the wall section between the opened position and the closed position,
wherein the controller is further configured to control the drive unit according to the preset loading sequence in response to actuation of a control element.

10. The sintering furnace according to claim 8 ,
wherein the controller is further configured to control the drive unit to open the wall section such that the seat is located a predetermined distance from the furnace chamber.

11. The sintering furnace according to claim 10 , further comprising:
another heating device,
wherein the controller is further configured to operate the heating device or the other heating device to heat the seat of the wall section while the seat of the wall section is held in the first cooling zone.

12. The sintering furnace according to claim 11 , further comprising:
at least one temperature sensor configured to measure a temperature in at least one of the first cooling zone or the furnace chamber,
wherein the controller is further configured to issue a control signal when the at least one temperature sensor indicates that a cooling temperature has been reached.

13. The sintering furnace according to claim 8 , further comprising:
at least one signal indicator constructed to indicate which of the opening, holding, and closing steps is currently being performed.

14. A method for sintering a dental component, comprising:
opening a wall section of a furnace chamber for a first time;
loading the furnace chamber by placing a component to be sintered on a seat of the wall section while the wall section is opened;
closing the wall section of the furnace chamber;
heating the furnace chamber to a holding temperature over a first time period;
maintaining the holding temperature over a second time period;
opening the wall section of the furnace chamber for a second time to bring the seat of the w

Assignees

• Sirona Dental Systems Gmbh

Inventors

• Schmidt Christian
• Figge David
• Gleditzsch Siegfried
• Fornoff Peter

Classifications

• F27D19/00

  Arrangements of controlling devices · CPC title

• F27B17/025 Primary

  for dental workpieces · CPC title

• A61C13/20

  Methods or devices for soldering, casting, moulding or melting {(A61C13/04, A61C13/081 take precedence)} · CPC title

• F27D2019/0028

  Regulation · CPC title

• F27D2019/0081

  Controlling an air-lock chamber · CPC title