JP2000329477A - Burning furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently reduce work time even if there is only one burning stand by providing a pre-drying part for pre-drying a next object to be burned before burning while the object to be burned being placed on a burning stand is being burned in a furnace body. SOLUTION: When first burning is to be made, first dental porcelain D' is placed on a drying stand 15 and is pre-dried by an auxiliary heat source 16 so that the dental porcelain D' cannot be cracked in a later burning process. When dental porcelain D that has been pre-dried is placed on a burning stand 3 and a program is specified for starting, a furnace body 4 is lowered by an elevation mechanism and the dental porcelain D is heated by a heater in the furnace body 4. When the burning of the dental porcelain D being placed on the burning stand 3 is completed, the furnace body 4 is raised by the elevation mechanism, and the dental porcelain D that has been burned is moved to another space for cooling. Then, the next dental porcelain D that has been pre-dried is placed on the burning stand 3, and burning control is immediately started, thus efficiently reducing work time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sintering furnace for dental use, which sinters an object to be sintered such as a denture in a vacuum or in the air.

[0002]

2. Description of the Related Art Generally, a baking furnace of this type includes one baking table provided at a fixed position on a base and one furnace body provided so as to be able to ascend and descend above the baking table. It is configured. The firing table is a table on which a firing target such as a ceramic tooth is placed. The furnace body has an internal space that opens downward, and has a built-in heater that raises the temperature of the internal space, and the lower edge of the furnace body at the lowered position is located at the peripheral edge of the stage on which the firing table is mounted. They are in close contact with each other via a seal rubber, are shut off from the outside air, and keep the inside airtight.

[0003] In such a firing furnace, very complicated firing such as dispersing, firing of a metal conditioner, firing of opaque porcelain, firing of crown-colored porcelain, and glazing are performed. The sintering is a complicated combination of maintaining the temperature at a predetermined temperature for a predetermined time, cooling after heating, and pre-drying. For this purpose, a control unit for controlling the contents of the processing is provided, and the operation of the electric heater in the furnace, the raising and lowering of the furnace, the supply and exhaust of the internal space, etc. are performed on the firing table in accordance with a predetermined program. One firing from placing the fired material to firing and taking out is automatically performed. Normally, the program can be set and input in any number of ways, and can be selectively used for each firing.

[0004] A series of steps up to the completion of porcelain tooth firing are exemplified as follows. (1) Call out the necessary program which is set and input in advance, place the ceramic-coated teeth on the firing table, and turn on the start switch. (2) The furnace body is lowered to a drying position determined at an appropriate position above the firing table. (3) The temperature inside the furnace body is adjusted to an appropriate temperature (generally 600 to 7).
(00 ° C.) and dried for 1 to several minutes. At this time, the temperature of the ceramic teeth on the firing table becomes 150 to 200 ° C. (4) Next, a drying step of gradually lowering the furnace body while maintaining the temperature of the internal space at 600 to 700 ° C. is performed over several minutes. (5) After the furnace body is completely lowered, the temperature of the internal space is increased at a rate of 30 to 100 ° C. per minute, and the temperature of the porcelain tooth is heated to a temperature range of 950 to 1100 ° C. over several minutes. (6) During heating of the ceramic tooth of (5) or 950 to 1100
When the temperature reaches the temperature range of ° C., the internal space maintained in the airtight state is evacuated to a vacuum of −55 to −76 cmHg (gauge pressure). In some cases, the vacuum is not applied. In this vacuum state or the atmosphere, the ceramic teeth are 2
Heated for 10 to 10 minutes. This heating is substantial baking. (7) Next, the furnace body is rapidly raised, the porcelain teeth are taken out of the firing table, placed on another porcelain application work table, and the porcelain is applied again to the porcelain teeth. During this time, the furnace body is at the highest position and the baking table is heated. (8) After the firing in (6) and before the operation in (7), a step of removing the porcelain teeth may be inserted depending on the type of porcelain and the firing method. In this case, set the temperature of the furnace internal space to 5
With the temperature maintained at 00 to 700 ° C., the furnace body is once raised to the highest position to expose the porcelain teeth on the firing table to the atmosphere, and then the furnace body is lowered again to be completely closed to a predetermined temperature ( The temperature is generally kept at 500 to 700 ° C.), followed by cooling. (9) After the above operation (7), the program previously set and input by the input means is called, and the same process as described above is usually repeated several times to complete the firing of the ceramic tooth.

[0005] Depending on the type of ceramic tooth and the difference in firing method, (1)
In the steps (9) to (9), the step (7) may be omitted, and after the steps (6) and (8), the furnace may be raised to complete the firing only once.

[0006]

SUMMARY OF THE INVENTION A firing furnace composed of one firing table and one furnace body corresponding to the firing table,
There are the following problems. The dental porcelain build-up is wet in the unfired state, and as a pre-firing stage, it is gradually dried on the firing table using the radiant heat of the furnace body. The firing table required sufficient cooling to prevent bursting of the build-up due to rapid heating. In other words, since the firing table immediately after taking out the fired product is in a high temperature state, it takes a long time to cool the firing table, and the inconvenience that the next fired product cannot be dried immediately after the previous firing is completed. there were.

[0007] Such a problem is inherent in the firing furnace having two firing tables disclosed in Japanese Patent Publication No. 5-1020. The dental firing furnace includes a plurality of firing tables on which objects to be fired are placed, a furnace body formed to have a size that opens downward and can cover any of the firing tables, A state in which any one of the plurality of firing tables provided for one or both of the furnace bodies is selected and located immediately below the furnace body, and a state in which the furnace body covers the selected one of the firing tables. And a moving device configured to be able to change and move. And this baking furnace is to use one furnace body in combination with a moving device for each of a plurality of baking tables, and then tries to bake next to a baking table not used in combination with the furnace body. The object to be fired is placed in a standby state, and it is intended to be able to shift to firing in another firing table following completion of firing in one firing table. (4) The drying step is required, and the working time cannot be reduced efficiently. Further, a mechanism for moving the furnace body is required, and two baking tables need to be prepared. Therefore, disadvantages in terms of cost and installation occupation area become greater than the advantage of continuous baking.

Accordingly, an object of the present invention is to provide a firing furnace capable of efficiently shortening the operation time even with one firing table.

[0009]

In order to achieve the above object, the present invention takes the following technical measures. That is, the present invention provides a firing furnace including a firing table on which an object to be fired is mounted, and a furnace body opened downward and formed to have a size capable of covering the firing table. It has a pre-drying unit for pre-drying the next object to be fired before firing during firing of the fired material in the furnace.

[0010] According to this, during the firing of one object to be fired, the drying of the next built-up product is performed in the pre-drying section, whereby the drying step in the firing cycle can be omitted. Work time can be reduced. Further, even with one baking table, the working time can be reduced, and the working efficiency can be improved at low cost. further,
Since the drying can be completed in advance, even if the build-up product, which is an object to be fired, is placed on a high-temperature firing table immediately after the previous firing, the building is prevented from bursting, and the firing table is cooled. Therefore, it is not necessary to wait, so that the working time can be further reduced.

The pre-drying section is not limited to a specific structure, but may have various structures. For example, the pre-drying unit may include a drying table provided on a side of the baking table, and an auxiliary heat source for heating the object before firing placed on the drying table. As an auxiliary heat source,
A heater, a halogen bulb, or the like can be used, and the output and the like can be adjusted in advance so that the temperature of the built-up product does not rupture, and the temperature becomes suitable for drying.

It is also possible to pre-dry the object to be fired using heat generated from the furnace body instead of the auxiliary heat source. That is, the pre-drying unit includes a drying chamber provided on a side portion of the furnace body, and is configured to dry an object to be fired before firing installed in the drying chamber by heat radiated from the furnace body. can do.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a dental firing furnace 1 according to a first embodiment of the present invention. The firing furnace 1 includes a firing table 3 provided at a fixed position on a base 2.
And a furnace body 4 that can be moved up and down above the baking table 3.
And a pre-drying section 5 provided on the base 2 at a position lateral to the firing table 3.

The firing table 3 is a table on which dentures (hereinafter referred to as "porcelain teeth") such as ceramic teeth or original casts to be ceramic teeth are placed. The furnace body 4 has an internal space 4a opened downward, and incorporates a heater (not shown) for raising the temperature of the internal space 4a. It is in close contact with the peripheral portion of the stage 6 on which it is mounted via a seal rubber 7, so that it is shut off from the outside air so that the inside is kept airtight. These configurations are the same as those of the above-described conventional firing furnace. In addition, separately from the one shown in the drawing, the furnace body is provided at a fixed position, and when the baking table is raised, the stage peripheral portion is in close contact with the furnace body lower end peripheral portion via the seal rubber to maintain airtightness. You can also.

The firing table 3 is provided on a stage 6 on which a seal rubber 7 is provided on the upper surface. On the firing table 3, a tray 14 on which the ceramic teeth D to be fired are placed is provided. Also, the stage 6 includes a cushion rubber 8
And is provided on the base 2 via.

The furnace body 4 is formed to have a size capable of covering the baking table 3 and is opened downward, and has a space 4a in which baking is performed. In addition,
In the figure, reference numeral 9 indicates a supply / exhaust port communicating with the space 4a, and reference numeral 10
Is a binding body such as a hose and an electric wire, and reference numeral 11 is a viewing window.

The furnace body 4 is provided with guide rails 13 attached vertically to a support 12 erected on the base 2.
And is raised and lowered by a lifting mechanism (not shown).

Although not shown, a control unit is incorporated in the base 2, and a numeric keypad, a power switch, a display, and the like are provided on the front portion of the base 2 as an operation unit, and a setting input is performed. The temperature, air supply and exhaust, and the operation of each part are controlled in the same manner as in the prior art in accordance with the programmed program.

The pre-drying unit 5 heats a drying table 15 provided on the base 2 at a position lateral to the firing table 3 and an object D 'to be fired before firing, which is placed on the drying table 15. Auxiliary heat source 16
And As the auxiliary heat source 16, a heater or the like can be used in addition to the halogen lamp.
The on / off switching of the auxiliary heat source 16 can be performed by the control unit, but can be performed by an independent switch. According to this, simplification of the configuration and cost reduction are achieved.

In the baking furnace 1 of the present embodiment, several programs for a series of steps are set and input in advance, and necessary ones are called and used. The usage can be, for example, as follows.

First, when performing the first baking, the porcelain teeth D ′ coated with porcelain are placed on a drying stand 15 and dried so that the porcelain teeth D ′ do not burst in a subsequent baking step. The ceramic tooth D ′ is pre-dried by the auxiliary heat source 16 set to a temperature suitable for the temperature.

When the pre-dried porcelain tooth D is placed on the baking table 3 and started by designating a program, the furnace body 4 is lowered by the elevating mechanism and the heater in the furnace body 4 is used to lower the porcelain tooth D. Is heated, and each of the steps (1) to
(9) is performed. Since the pre-drying has already been completed, the drying step can be omitted.
The height position of the furnace body 4 during the firing step is sequentially changed by controlling the elevating mechanism according to a program. During this process, the worker builds and places the next ceramic tooth D 'on the drying stand 15 until the firing of the ceramic tooth D is completed, and pre-drys the ceramic tooth D'.

When the firing of the ceramic teeth D placed on the firing table 3 is completed, the furnace body 4 is raised by the elevating mechanism, and the fired ceramic teeth D are transferred to another space for cooling. Then, the next ceramic tooth D after the pre-drying is placed on the firing table 3, and firing control is started immediately. In this way, even if the firing of the next ceramic material D, which is the object to be fired, is performed immediately after the completion of the previous firing, since the ceramic tooth D has already been preheated, the furnace body 4 has a high heat. Also, the ceramic tooth D does not burst, and the working time can be reduced efficiently.

Further, according to the present embodiment, the drying table 15
Need only be able to place the object to be fired D ′, does not require a cushion structure like the firing table 3, and does not require heat resistance as high as the firing table 3. According to this, it is very advantageous in terms of cost as compared with the case where two firing tables 3 are provided, and it is possible to reduce the size of the entire structure.

FIG. 3 shows a dental firing furnace according to a second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted. Will be described.

In the firing furnace of the present embodiment, the predrying section 5
There is provided a drying chamber 20 provided on the side of the furnace body 4, and the ceramic teeth D ′, which are objects to be fired before firing, installed in the drying chamber 20 are heated by the heat radiated from the furnace body 4. It is configured to dry.

That is, the drying chamber 20 is provided in the housing of the furnace body 4 on the side of the firing chamber 4a, and heats the ceramic teeth D 'in the drying chamber 20 by using heat from a heater for firing. Drying can be done efficiently. The drying chamber 20 has an opening 21 on the side, and the ceramic teeth D ′ are put in and out of the drying chamber 20 through the opening 21. The opening 21 can be opened and closed by a lid 22. The lid 22 is attached to a housing of the furnace body 4 via a hinge 23.

According to the second embodiment, in addition to the above-mentioned functions and effects, an auxiliary heat source is not required, so that the cost can be further reduced and the heat is radiated from the furnace body 4 as heat for predrying. By using such a device, power consumption can be reduced.

FIG. 4 shows a dental firing furnace according to a third embodiment of the present invention. The same components as those in the second embodiment are denoted by the same reference numerals, detailed description thereof will be omitted, and different configurations will be described. The operation and effect will be described.

The firing furnace according to the present embodiment includes a plurality of firing tables 3.
And a moving mechanism for moving the plurality of firing tables 3 so as to be located immediately below the firing table. In the illustrated example, the moving mechanism includes a base 25 supported on the base 2 so as to be rotatable in a horizontal plane. On the substrate 25, each of the firing tables 3 is provided via a cushion rubber 8, a stage 6, and a seal rubber 7. It is assumed that each was installed. Then, by rotating the substrate 25 by a rotation drive mechanism (not shown) such as a motor, each firing table 3 can be sequentially positioned immediately below the furnace body 4. Note that a plurality of firing tables may be sequentially positioned directly below the furnace body 4 by horizontally moving the firing tables 3 in parallel, or a plurality of firing tables may be horizontally moved on the furnace body 4 side. It can also be configured to selectively cover the firing table.

The side of the furnace body 4 has a size capable of covering the firing table 3 which is not located immediately below the furnace body 4,
A drying chamber 20 is provided at the position. The drying chamber 20 has an opening at the bottom, and the furnace body 4 is moved down to cover the baking table 3 on which the next ceramic tooth D 'is placed.
Can be dried using the heat dissipated from the furnace body 4.

The present invention is not limited to the above-described embodiment, and can be modified as appropriate.

[0033]

According to the present invention, while one object to be fired is being fired in the furnace body, drying of the next built-up product is performed by an auxiliary heat source or heat radiated from the furnace body. It is possible to omit the drying step in the firing cycle, and to improve the working efficiency at low cost. Furthermore, even if the next built-up product is placed on a high-temperature baking table, since the built-up product is previously heated and dried, it is prevented from bursting even if it is rapidly heated in a furnace body, and after each baking process. It is not necessary to perform cooling, and by performing continuous firing, the working efficiency can be further improved.

[Brief description of the drawings]

FIG. 1 is a front view of a firing furnace according to a first embodiment of the present invention.

FIG. 2 is a right side view of the firing furnace.

FIG. 3 is a partially broken front view of a firing furnace according to a second embodiment of the present invention.

FIG. 4 is a front view of a firing furnace according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Firing furnace 2 Base 3 Firing table 4 Furnace body 5 Pre-drying unit 15 Drying table 16 Auxiliary heat source 20 Drying room D Firing object D 'Firing object before firing

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) // F27D 7/06 A61C 13/00 K

Claims (3)

[Claims] 1. A firing furnace comprising a firing table on which an object to be fired is mounted and a furnace body opened downward and formed to have a size capable of covering the firing table. A firing furnace, comprising: a pre-drying section for pre-drying a next object to be fired before firing while firing the object in the furnace. 2. The pre-drying unit includes a drying table provided on a side of the baking table, and an auxiliary heat source that heats an object to be fired before firing placed on the drying table. The firing furnace according to claim 1. 3. The pre-drying unit includes a drying chamber provided on a side portion of the furnace body, and the object to be fired before firing set in the drying chamber is dried by heat radiated from the furnace body. The firing furnace according to claim 1, wherein: