KR102490874B1 - Zirconia furnace for dental prosthesis - Google Patents

Abstract

The present invention relates to a zirconia sintering furnace for dental prosthetics, and more particularly, to a structure in which a heat generating means is installed in the center of a sintering chamber to minimize heat loss of the heat generating means, and uniform temperature distribution is achieved without heat loss inside the chamber. and by allowing the sintered body to be positioned radially around the heating means with the highest thermal efficiency in the chamber, an environment in which zirconia for dental prosthesis can be sintered under optimal conditions is created, and the transparency, strength, hardness, Mechanical properties such as abrasion resistance and brittle resistance are further improved, and furthermore, the defect rate is reduced, the marketability is greatly improved, and since one heating means is used, the number of parts is reduced, the structure and design are simplified, and the complexity is improved. The present invention relates to a zirconia sintering furnace for dental prosthesis, which can be expected to reduce the manufacturing cost of the furnace and further improve power efficiency.

Description

Zirconia furnace for dental prosthesis}

The present invention relates to a zirconia sintering furnace for dental prosthetics, and more particularly, by installing a heating means in the center of a sintering chamber to form a uniform temperature distribution in the chamber without heat loss in the heating means, and to achieve the highest thermal efficiency in the chamber. By allowing the sintered body to be positioned radially around a good heating means, an environment in which dental prosthetic zirconia can be sintered under optimal conditions is created, and mechanical properties such as transparency, strength, hardness, wear resistance, and corrosion resistance of the sintered zirconia are created. It can be further improved, and furthermore, the defect rate is reduced, the marketability is greatly improved, and since one heating means is used, it is expected to reduce the manufacturing cost of the sintering furnace with effects such as reducing the number of parts, simplifying the structure and design, and improving complexity. It relates to a zirconia sintering furnace for dental prosthesis, which can further improve power efficiency.

A dental prosthesis refers to an artificial restoration installed in the oral cavity to functionally and aesthetically restore missing or partially removed teeth.

Dental prostheses have been generally made of metal or synthetic resin, but they do not satisfy strength and aesthetics at the same time, and discoloration and fracture occur due to color stability and strength deterioration. It has downsides that are not good. For example, noble metal alloys such as gold (Au) alloys have been widely used for prosthetics such as veneers, inlays, onlays, stumps, and crowns. However, precious metal alloys such as gold (Au) alloys are expensive, and gold (Au) values have risen rapidly in accordance with global trends in recent years, and accordingly, the cost of manufacturing noble metal alloy prostheses has also increased very steeply. In addition, since the noble metal alloy has a different color from natural teeth, many users are reluctant to use it for aesthetic reasons.

As a dental prosthesis to overcome these disadvantages, a porcelain prosthesis, also known as a porcelain prosthesis, has been applied. It had to go through a complicated and inefficient work process of cutting to fit the shape of the tooth.

Therefore, since the conventional dental prosthesis had to be manufactured solely by hand, productivity was very low, and the quality of the dental prosthesis was greatly influenced by the skill level of the operator.

Recently, with technological development, an automation system has been introduced in the field of dental prosthesis manufacturing, and one of them is the introduction of the CAD CAM system.

The CADCAM system refers to a system that uses a CAD program to 3D model a prosthetic appliance with a computer and transmits the modeling file to a processing machine so that the prosthetic appliance is automatically sculpted.

Raw materials used in the processing machine include synthetic resin, wax, zirconia, etc. In the case of zirconia, it can be made by sintering in a zirconia sintering furnace at a temperature of about 1500 ° C for an average of 9 hours after being carved into a certain shape in the processing machine. there is.

That is, in the CADCAM system, the zirconia sintering furnace is treated as an essential equipment.

In a typical sintering furnace, at least two or more heating wires are installed facing each other on facing walls in the chamber to realize the target temperature, or most of the heating wires are spirally wound around the wall. As a result, the heat transfer in the chamber could not be even.

Accordingly, more energy is consumed to reach the target temperature in the chamber, and thermal efficiency is lowered, and heat distribution in the chamber cannot be uniformly formed.

In particular, if zirconia is not sintered under a uniform heat distribution, the transparency of the prosthesis decreases, distortion, fine cracks, etc. occur, resulting in significantly lower marketability.

In addition, since the heating wire must be provided on at least both side wall surfaces of the chamber, the structure of the sintering furnace becomes complicated and manufacturing cost increases.

Registered Patent No. 10-2027418

The present invention was created to solve this problem in view of the various problems in the prior art, by installing one heat generating means in the center of the sintering chamber to configure a uniform temperature distribution in the chamber without heat loss of the heat generating means, and to increase the thermal efficiency in the chamber By allowing the sintered body to be positioned radially around the best heating means, an environment in which dental prosthetic zirconia can be sintered under optimal conditions is created, thereby improving mechanical properties such as transparency, strength, hardness, wear resistance, and corrosion resistance of the sintered zirconia. The properties can be further improved, and furthermore, the defect rate is reduced, the marketability is greatly improved, and since one heating means is used, the manufacturing cost of the sintering furnace can be reduced through effects such as reducing the number of parts, simplifying structure and design, and improving complexity. It is an object of the present invention to provide a zirconia sintering furnace for dental prosthetics that can be expected and can further improve power efficiency.

The present invention is a means for achieving the above object, a sintering unit in which a cylindrical refractory material is provided inside and a chamber is formed with a downward opening to the inside of the refractory material; a heating unit extending vertically from the center of the chamber; a seating portion through which the heat generating unit passes through the center and configured to seat the zirconia sintered body around the passage hole; and a shelf part which lifts the seating part up and down while supporting the seating part to raise the seating part into the chamber or to separate the seating part from the bottom of the chamber.

In addition, when the shelf unit guides the seating unit into the chamber, the heat generating unit is inserted into the through hole of the seating unit, and the sintered bodies seated on the seating unit are arranged radially with the heating unit at the center.

In addition, a plurality of seating surfaces on which the sintered body is seated are provided in the form of concentric circles on the seating portion, and the plurality of seating surfaces are configured to gradually decrease in height as they are closer to the passage, forming a stepped structure.

In addition, each of the plurality of seating surfaces is characterized in that a downward gradient is formed toward the passage hole, and a drop prevention bump of a predetermined height is formed on the inner circumference.

In addition, in the seating portion, a driven gear is formed at the lower end exposed to the lower portion of the seating portion through the seating surface in the vertical direction, and a rotating shaft in which a fork for holding the sintered body is formed is installed at the upper end exposed to the upper portion of the seating surface. It is characterized in that the shelf unit is equipped with a servomotor that meshes with the driven gear and rotates the rotation shaft in the normal and reverse direction.

The present invention provides the following effects.

First, by arranging the heating part in the center of the chamber, it is configured to enable uniform temperature distribution in the chamber so that the sintered body can be sintered under more uniform temperature conditions, and the sintered body is arranged radially around the heating unit in the chamber. It has a structure that enables even heat transfer to the sintered body. Therefore, the mechanical properties of sintered zirconia, such as transparency, strength, hardness, abrasion resistance, and brittle resistance, are further improved, thereby reducing the defect rate and significantly improving marketability.

Second, since sufficient sintering is possible using one heating unit, manufacturing costs of the sintering furnace can be expected to be reduced due to effects such as reducing the number of parts, simplifying structure and design, and improving complexity, and power efficiency can be further improved.

1 is a front view of a zirconia sintering furnace for dental prosthesis according to the present invention.
2 and 3 are views schematically showing a cross-sectional configuration based on line AA shown in FIG. 1;
Figure 4 is a view showing the appearance of the seating portion.
5 is an enlarged view of a cross-sectional configuration of a main part of the present invention.
Figure 6 is a view schematically showing a cross-sectional configuration based on line AA shown in Figure 5;
Figure 7 is a view showing the appearance of the mounting portion of another embodiment.
FIG. 8 is a view schematically showing cross-sectional configurations of the seating portion and the elevator platform shown in FIG. 7;
9 is a partial cutaway view of a mounting portion of another embodiment;
FIG. 10 is a view schematically showing cross-sectional configurations of a seating portion and an elevator platform shown in FIG. 9;

In order to fully understand the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited to the examples described in detail below. This embodiment is provided to more completely explain the present invention to those skilled in the art. Accordingly, the shapes of elements in the drawings may be exaggerated to emphasize a clearer explanation. It should be noted that in each drawing, the same members are sometimes indicated by the same reference numerals. Detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention are omitted.

1 is a front view of a zirconia sintering furnace for dental prosthesis according to the present invention, FIGS. 2 and 3 are views schematically showing a cross-sectional structure taken along the line A-A shown in FIG. 1, and FIG. It is a drawing showing the appearance of a part, FIG. 5 is an enlarged view of the cross-sectional configuration of a main part of the present invention, and FIG. 6 is a diagram schematically showing a cross-sectional configuration based on the line A-A shown in FIG.

The zirconia sintering furnace according to the present invention can be largely defined as including a sintering part 10, a heating part 20, a seating part 30 and a shelf part 40, as shown in FIGS. 1 to 6 there is.

As a result, a case 50 constituting the exterior of the zirconia sintering furnace is provided separately, and the configuration of the sintering part 10, the heating part 20, the seating part 30, and the shelf part 40 is arranged in place. A door 51 for opening and closing the inside of the case 50 may be installed on the front side of the case 50, and the heating unit 20 and the shelf unit 40 are driven under the door 51. An input means for inputting a signal for manipulation, a display means for monitoring the input signal, the temperature of the heating part 20, the temperature in the sintering part 10, the operating state of various devices, and the like may be provided. The input means and the display means may be integrated and implemented in the form of a known touch screen 52 .

First, the sintering unit 10 is built into the case 50 and constitutes a space for sintering a zirconia sintered body (hereinafter referred to as a sintered body), that is, a chamber 12 having a certain volume.

The sintering part 10 may include a cylindrical refractory material 11 with an open bottom, a chamber 12 is formed inside the refractory material 11, and an insulation housing 13 surrounds the outside of the chamber 12. become a structure

In addition, although not separately shown, the sintering unit 10 includes a cooling fan for rapidly cooling the chamber 12 when the temperature in the chamber 12 exceeds the critical temperature of zirconia sintering, and a gas generated during the sintering reaction of zirconia into the chamber. (12) may further include an air vent or the like for properly discharging.

Next, the heating unit 20 is provided in the form of a rod extending vertically at the center of the chamber 12 and is a means for heating the sintered body accommodated in the chamber 12 to a sintering temperature, and when power is supplied, to 1,600 ℃ or more. It is possible to use a known electric heating element in a line capable of being heated.

For example, the heating unit 20 may be installed by connecting a cable to a power supply unit provided in the case 50 . A thermometer 21 for measuring the temperature in the chamber 12 may be provided around the heating unit 20 .

Next, the seating part 30 is configured such that the passage hole 31 passes through the center so that the heat generating part 20 passes through and the zirconia sintered body is seated around the passage hole 31 .

The seating portion 30 is accommodated in the chamber 12 while supporting the sintered body, and is made of a ceramic material so as to have sufficient heat resistance, and in particular, may be formed of a ring-shaped disk structure.

A seating protrusion 32 having a certain height may be formed on the outer circumference of the seating portion 30 along the circumferential direction, and a receiving groove recessed to a certain depth is provided on the upper surface of the seating portion 30 by the seating protrusion 32. And, the sintered body can be seated on the seating surface 33, which is the bottom surface of the receiving groove.

The sintered body can be supported on the seating surface 33 in a state where zirconia beads are laid so as to enable even heat transfer to the sintered body and to prevent sintering defects that may occur due to close contact with the seating surface 33 .

When the shelf part 40 guides the seating part 30 into the chamber 12 for sintering of the sintered body, as shown in FIGS. ), and the sintered body seated on the seating portion 30 may be arranged radially with the heating portion 20 at the center.

That is, the heating unit 20 penetrates the center of the seating unit 30 vertically, and thus, the sintered bodies are arranged in all directions of the heating unit 20 .

In addition, since the structure allows the heating unit 20 to pass through the passage 31 of the seating unit 30, even if the seating unit 30 rises in the chamber 12, it is directly connected to the heating unit 20. Contact interference can be avoided, so that the seating portion 30 can rise to a sufficient height within the chamber 12 .

In particular, since the heating unit 20 dissipates heat in the center of the chamber 12 without being biased toward the wall surface of the chamber 12, a uniform temperature distribution inside the chamber 12 can be configured.

If the heating unit 20 is configured in close contact with the refractory material 11, the heat of the heating unit 20 is absorbed by the refractory material 11 and consequent heat loss cannot be avoided, and the heating unit 20 is on one side As the temperature is biased, the temperature of the other side is lowered to generate a minute temperature difference in the chamber 12 . In order to compensate for this, there are cases in which the heating unit 20 is provided as a pair on the wall surface of the chamber 12 facing at least, or a heating element is spirally wound around the inner circumferential surface of the refractory material 11, but this is the case of the heating unit 20 The increase in the number of parts caused the increase in manufacturing cost, and also caused the structure of the sintering unit 10 to become very complicated.

In addition, if the temperature distribution in the chamber 12 is not uniform or the heat transfer is not uniform to the sintered body, the shrinkage rate of the sintered body is different from each other due to uneven heat transfer in the process of shrinking at a certain shrinkage rate due to the nature of the sintering reaction of zirconia. As it wears out, distortion of the prosthesis occurs. This causes a problem that it is completely impossible to set the sintered prosthesis in the oral cavity.

However, in this embodiment, the heating unit 20 is placed in the center of the chamber 12 to enable uniform temperature distribution in the chamber 12 so that the sintered body can be sintered under more uniform temperature conditions, and the chamber ( 12) has a structure that enables even heat transfer to the sintered body by arranging the sintered body in a radial form around the heating part 20.

Accordingly, the transparency of the sintered zirconia is improved, and mechanical properties such as strength, hardness, wear resistance, and brittle resistance are further improved, thereby reducing the defect rate and significantly improving marketability.

In addition, since sufficient sintering is possible using one heat generating unit 20, manufacturing costs of the sintering furnace can be expected to be reduced due to effects such as reducing the number of parts, simplifying structure and design, and improving complexity, and power efficiency can be further improved.

Next, the shelf part 40 moves up and down while supporting the seating part 30 to raise the seating part 30 into the chamber 12 or to separate it from the lower part of the chamber 12 .

To this end, the shelf unit 40 may include a platform 41 supporting the seating unit 30 and a driving unit providing a driving force for moving the platform 41 up and down.

The platform 41 may close the lower part of the open chamber 12, and a part thereof is provided to be inserted into the chamber 12.

In the center of the platform 41, a communication port 41a communicating with the passage port 31 of the seating portion 30 seated on the platform 41 may be recessed at a predetermined depth, and the seating portion 30 is placed in a chamber ( When the lift platform 41 is raised to guide to 12), the lower end of the heating unit 20 can be accommodated in the communication port 41a.

Accordingly, a structure in which the seating portion 30 can rise without difficulty from the chamber 12 to a certain height is provided.

The driving means may be implemented in various ways along the line capable of reciprocally lifting the lift table 41 in the vertical direction. For example, in the present embodiment, the lift motor 42 rotates forward and reverse by the lift motor 42. A screw shaft 43, a guide block 44 connected to the screw shaft 43 and guided up and down by the screw shaft 43, and a connecting bracket 45 connecting the guide block 44 and the platform 41 It is illustrated as including.

That is, when a drive signal is input, the lift motor 42 rotates the screw shaft 43, and the guide block 44 moves up or down, and the lift platform 41 integrated with the connection bracket 45 interlocks with this. ) can move up or down.

Therefore, in order to sinter the sintered body, the user moves the platform 41 to the bottom dead center, places the seating portion 30 containing the sintered body on the upper surface of the platform 41, and moves the platform 41 upward to place the seating portion ( 30) can control the sintering furnace so that it is guided into the chamber 12.

In addition to the above-described embodiment, the driving means may be configured in various ways along the line capable of vertically lifting the platform 41, so a detailed description thereof will be omitted.

If necessary, the seating portion 30 seated on the platform 41 may be rotated in place while the seating portion 30 is guided into the chamber 12. A stage may be provided and a motor capable of rotating the stage may be installed inside the platform 41 so as to rotate and move the seating portion 30 seated on the stage.

On the other hand, when the number of sintered bodies increases on the seating portion 30 and a plurality of sintered bodies are overlapped with each other on a straight line L toward the heat generating unit 20, the projected area of the heat between the sintered bodies crosses each other, causing the seating portion ( 30), there is a possibility that the heat transfer will be reduced as it goes to the outside.

That is, as the sintered body moves further away from the heating unit 20, it is covered by a sintered body closer to the heating unit 20, resulting in loss in heat transfer.

Therefore, in the following embodiment, the seating portion 30 is configured in a stepped structure so that the sintered bodies seated on the seating portion 30 do not overlap each other on a straight line and more evenly heat transfer is possible to the plurality of sintered bodies. Examples are described.

To this end, as shown in FIGS. 7 and 8 , a plurality of seating surfaces 33 on which the sintered body is seated are provided in the form of concentric circles on the seating portion 30, and the plurality of seating surfaces 33 have a passage hole 31 It is characterized in that the height is gradually lowered as it is closer to form a stepped structure.

That is, since each seating surface 33 is configured in the form of a stair with a height difference between the top and bottom, it is possible to secure a sufficient heat projection area without sintered bodies seated on each seating surface 33 being covered by each other.

In addition, each of the plurality of seating surfaces 33 may have a downward slope toward the passage hole 31 and a drop prevention bump 34 of a certain height may be formed on the inner circumference.

This is a structure in which the sintered material seated on the seating surface 33 is guided to the anti-fall bump 34 by its own weight and can be fixed in position at a 'V'-shaped depression between the seating surface 33 and the anti-fall bump 34. to be.

If unavoidable vibration due to the operation of the machine is applied to the seating part 30 in the process of the elevator platform 41 moving up and down, the sintered body seated on the seating surface 33 or the zirconia beads spread on the seating surface 33 pass through the passage. A problem of being guided to (31) and discharged to the outside through the passage (31) may occur.

In addition, even if the sintered body is not discharged to the passage hole 31, when it is guided around the passage hole 31, it is unnecessarily disposed adjacent to the heating unit 20 in the chamber 12 in an airtight manner, and thus excessive heat is generated in the sintered body. There is a problem in that microcracks due to oversintering occur in the absorbed and sintered prosthetic appliance.

Therefore, in this embodiment, simply by placing the sintered body on the seating surface 33, the sintered body rides the seating surface 33 and is guided by its own weight to the part of the anti-falling shoulder 34, and then moves beyond the anti-falling shoulder 34. Since this may be limited, even if vibration is applied to the seating part 30 itself, it does not flow and maintains an appropriate distance from the heating part 20.

On the other hand, when a specific sintered body having a relatively large volume or a thick thickness is included, only the specific sintered body is rotated inside the chamber 12 so that the entire surface of the specific sintered body can evenly view the heating part 20. that can be effective.

Accordingly, in order to configure only a specific sintered body on the seating portion 30 to rotate instead of rotating the entire seating portion 30, the seating portion 30 has a seating surface 33 as shown in FIGS. 9 to 10 A driven gear 36 is formed at the lower end exposed to the lower portion of the seating portion 30 by penetrating in the vertical direction, and a rotating shaft at the upper end exposed to the upper portion of the seating surface 33 is formed with a fork 37 for holding the sintered body. 35 is installed, and the shelf part 40 has a structure in which a servomotor 46 that meshes with the driven gear 36 and rotates the rotation shaft 35 in the normal and reverse direction is built-in.

A plurality of rotation axes 35 may be provided with a certain angular phase difference, and for convenience of explanation, an embodiment in which one rotation axis 35 is applied will be illustrated and described.

The fork 37 exposed to the upper portion of the seating surface 33 is configured to be curved in a substantially 'U' shape, so that the sintered body can be effectively held without shaking.

When the sintered body is placed on the fork 37, it may float upward at a predetermined distance from the seating surface 33.

Normally, a crown dental prosthesis has a cup shape with one side open, so when the cup-shaped sintered body is placed on the fork 37 using this open portion, contact points are created in at least two parts so that the sintered body can be more stably placed. .

The servomotor 46 may be embedded in the shelf 40, more specifically, the platform 41. At this time, an installation groove 41b of a certain depth is provided on the upper surface of the platform 41, and the installation groove 41b ), the driving gear 47 integrated with the drive shaft of the servo motor 46 is provided.

That is, the seating portion 30 can be fitted into the installation groove 41b, and the driven gear 36 exposed to the lower portion of the seating portion 30 is the prime mover 47 provided in the installation groove 41b. It is threaded and the power transmission system is connected.

Accordingly, when the servo motor 46 is driven, this driving force is transmitted to the driving gear 47, the driven gear 36, and the rotating shaft 35, so that the rotating shaft 35 can be rotated in place while holding the sintered body. do.

In summary, the present invention arranges a heating unit in the center of the chamber to enable a uniform temperature distribution in the chamber so that the sintered body can be sintered under more uniform temperature conditions, and the sintered body is formed in a radial shape around the heating unit in the chamber. It is arranged to have a structure that enables even heat transfer to the sintered body. Therefore, the mechanical properties of sintered zirconia, such as transparency, strength, hardness, abrasion resistance, and brittle resistance, are further improved, thereby reducing the defect rate and significantly improving marketability.

In addition, since sufficient sintering is possible using one heating unit, manufacturing costs of the sintering furnace can be expected to be reduced due to effects such as reducing the number of parts, simplifying structure and design, and improving complexity, and power efficiency can be further improved.

The embodiments of the present invention described above are merely exemplary, and those skilled in the art will appreciate that various modifications and equivalent other embodiments are possible therefrom. Therefore, it will be well understood that the present invention is not limited to the forms mentioned in the detailed description above. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims. It is also to be understood that the present invention includes all modifications, equivalents and alternatives within the spirit and scope of the present invention as defined by the appended claims.

10: sintering unit
20: heating part
30: seating part
40: shelf
11: fireproof material
12: chamber

Claims (5)

A sintering unit in which a cylindrical refractory material is provided inside and a chamber with a downward opening is formed inside the refractory material;
a heating unit installed inside the chamber;
a seating portion through which the heat generating unit passes through the center and configured to seat the zirconia sintered body around the passage hole; and
A shelf portion that moves up and down while supporting the seating portion to raise the seating portion into the chamber or spaced apart from the lower portion of the chamber,
The heating unit is installed extending vertically from the center of the chamber,
When the shelf guides the seating part into the chamber, the heat generating part is inserted into the passage of the seating part, and the sintered body seated on the seating part is arranged radially with the heating part at the center,
A plurality of seating surfaces on which the sintered body is seated are provided in the form of concentric circles on the seating portion, and the plurality of seating surfaces are gradually lowered in height as they are closer to the passage, forming a stepped structure,
The zirconia sintering furnace for dental prosthesis, characterized in that each of the plurality of seating surfaces has a downward gradient toward the passage hole and a drop prevention bump of a predetermined height is formed on the inner circumference. delete delete delete The method of claim 1,
In the seating portion, a driven gear is formed at the lower end exposed to the lower portion of the seating portion by penetrating the seating surface in the vertical direction, and a rotating shaft in which a fork for holding the sintered body is formed at the upper end exposed to the upper portion of the seating surface. Is installed,
The zirconia sintering furnace for dental prosthesis, characterized in that the shelf part is built-in a servomotor that meshes with the driven gear to rotate and drive the rotation shaft in the normal and reverse direction.

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