JP7162171B2 - Powder sintering equipment - Google Patents

Description

The present invention relates to a powder sintering apparatus for sintering powder.

By heat-treating at a temperature below the melting point after compacting ceramics or metal powders, bonding occurs between the powders and a sintered body can be obtained. This method is the main method for manufacturing ceramic products, ceramics, powder metallurgy, cermets, and the like.

Sintering methods include normal pressure sintering method, gas pressure sintering method, hot press method, hot isostatic pressure method (HIP), electric pressure method, millimeter wave method and the like.

In order to obtain a denser sintered body, it is effective to heat the powder compact under pressure by a gas pressure sintering method, a hot press method, a hot isostatic pressure method, an electric pressure method, or the like.

These methods are batch processing, and continuous processing is effective for increasing productivity. For example, Patent Literature 1 discloses that a sheet can be formed by heating metal powder and pressing it with pressure rolls.

Here, in order to increase the density during sintering, it is important to heat the rolling rolls and keep the workpiece at a high temperature. Means for heating the roll include heater heating, induction heating, lamp heating and the like. In order to obtain a sintered body with a higher density and to prevent the workpiece from adhering to the roll, the roll must have high hardness, and a roll having a ceramic surface is effective. Lamp heating is effective for efficiently heating a ceramic roll. For example, Patent Document 2 discloses a method of heating a roll with a lamp heater.

Japanese Patent Publication No. 2003-520292 JP 2018-94586 A

However, when the lamp heater is used, if the powder material flies around the lamp heater and adheres to the lamp heater, the light from the lamp heater may be blocked and the heating of the roll by the lamp heater may be hindered. In such a case, the rolls cannot be efficiently heated, the powder material cannot be sufficiently heated, and the resulting sintered body may have a low density.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a powder sintering apparatus capable of efficiently heating rolls to obtain a sintered body of high density.

In order to achieve the above object, the powder sintering apparatus of the present invention comprises: a powder conveying mechanism for conveying a powder material in a conveying direction; a box-shaped member covering the pair of rolls, the box portion having a gap for allowing the powder material being conveyed in the conveying direction to pass; a lamp heater that heats at least one roll of a pair of rolls, and a lamp heater that is attached to the box portion at a position between the at least one roll and the lamp heater, and directs light from the lamp heater to the box portion. and a window leading to the inside.

According to the powder sintering apparatus of the present invention, it is possible to efficiently heat the rolls and obtain a sintered body with high density.

Schematic diagram of powder sintering apparatus in Embodiment 1 Schematic diagram of powder sintering apparatus in Embodiment 2 Schematic diagram of a powder sintering apparatus in a modified example

According to the first aspect of the present invention, a powder conveying mechanism for conveying a powder material in a conveying direction, a pair of rolls for heating and pressurizing the powder material being conveyed in the conveying direction, and the pair of rolls A box-shaped member covering a box portion having a gap for allowing the powder material being conveyed in the conveying direction to pass; and at least one of the pair of rolls disposed outside the box portion. and a window portion attached to the box portion at a position between the at least one roll and the lamp heater to introduce light from the lamp heater into the box portion; A powder sintering apparatus is provided, comprising:

According to the second aspect of the present invention, the powder sintering apparatus according to the first aspect, wherein the window portion is arranged on the upstream side in the conveying direction from the closest point where the pair of rolls are closest to each other. I will provide a.

According to the third aspect of the present invention, the window portion has a main surface facing the at least one roll, and the main surface faces in the horizontal direction or downward from the horizontal direction. A powder sintering apparatus according to two aspects is provided.

According to a fourth aspect of the present invention, there is provided the powder sintering apparatus according to the third aspect, wherein the main surface of the window extends vertically so as to face the horizontal direction.

According to the fifth aspect of the present invention, the box portion is provided with a first gas introduction port for introducing gas into the inside of the box portion, and the first gas introduction port directs the gas in a direction along the surface of the window portion. to provide a powder sintering apparatus according to any one of the first to fourth aspects.

According to a sixth aspect of the present invention, the powder according to the fifth aspect, wherein the first gas introduction port is arranged on the upstream side in the conveying direction of the point where the pair of rolls are closest to each other. A sintering apparatus is provided.

According to the seventh aspect of the present invention, the box portion is provided with a second gas introduction port for introducing gas into the inside of the box portion, and the second gas introduction port blows gas downstream in the conveying direction. , provides a powder sintering apparatus according to any one of the first to sixth aspects.

According to an eighth aspect of the present invention, the powder according to the seventh aspect, wherein the second gas introduction port is arranged on the upstream side in the conveying direction of the closest point where the pair of rolls are closest to each other. A sintering apparatus is provided.

According to a ninth aspect of the present invention, there is provided the powder sintering apparatus according to any one of the first aspect to the eighth aspect, wherein the box portion is provided with an exhaust port.

According to a tenth aspect of the present invention, the powder sintering apparatus according to the ninth aspect, wherein the exhaust port is arranged downstream in the conveying direction from the closest point where the pair of rolls are closest to each other. I will provide a.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram showing a schematic configuration of a powder sintering apparatus 1 according to Embodiment 1. FIG. A powder sintering apparatus 1 shown in FIG. 1 is an apparatus for obtaining a sintered body 3 by sintering a powder material 2 . The powder sintering apparatus 1 includes a powder conveying mechanism 101 , a heating and pressurizing mechanism 201 , a box portion 301 and a material recovery mechanism 401 .

The powder material 2 is, for example, an aggregate of particles with a particle size of less than 100 μm, and its particle size distribution is not limited at all. The powder material 2 may be preliminarily subjected to a molding process to make the thickness and width uniform. The molding process includes, for example, a method of compressing the powder into a sheet using a pair of rolls, a method of pressing the powder using a mold, and the like.

The powder conveying mechanism 101 is a mechanism for conveying the powder material 2 in the conveying direction A. The powder conveying mechanism 101 has a function of supplying the powder material 2 to the heating/pressurizing mechanism 201 . The conveying direction A in Embodiment 1 is the horizontal direction. The powder conveying mechanism 101 is composed of, for example, a belt conveyor. A steel belt, a mesh belt, or the like can be used as the belt conveyor.

The heating and pressurizing mechanism 201 is a mechanism that pressurizes the powder material 2 while heating it. The heating and pressurizing mechanism 201 includes a first roll 21 and a second roll 22 as a pair of rolls. As shown in FIG. 1, the rolls 21 and 22 are housed inside the box portion 301 . The first roll 21 and the second roll 22 sandwich the powder material 2 conveyed in the conveying direction A from both sides while applying heat and pressure. In Embodiment 1, the first roll 21 and the second roll 22 are arranged vertically, and the powder material 2 is sandwiched between the upper first roll 21 and the lower second roll 22 while being heated and pressurized. . A close point 32 is a point where the first roll 21 and the second roll 22 are closest to each other.

The material of the rolls 21 and 22 is not particularly limited, but in order to prevent the powder material 2 from sticking, ceramics or a composite material of metal and ceramics may be used. For example, silicon nitride, silicon carbide, alumina, sialon, zirconia, etc. may be used. Furthermore, different materials may be used for the surface material of the rolls 21 and 22 that contact the powder material 2 and the shaft material for rotating the rolls 21 and 22 . For example, ceramics may be used as the surface material, and carbon steel, stainless steel, high-speed tool steel, chromium steel, or the like may be used as the shaft material. As a combination of ceramics and shaft material, a structure in which a ceramic film is formed on the shaft material by direct thermal spraying or vapor deposition, or a structure in which ceramics with a sleeve structure are combined on the outside of the shaft can be used.

The heating temperature of the rolls 21 and 22 may be set to, for example, 400° C. or higher and 700° C. or lower. By setting the temperature to 400° C. or higher, the temperature of the sintered body 3 can be sufficiently raised, and a high-density sintered body 3 can be obtained. Further, by setting the temperature to 700° C. or less, it is possible to suppress the temperature rise of the shaft portions of the rolls 21 and 22 and extend the life of the bearings that support the shaft portions.

Although not shown, it is also possible to preheat the powder material 2 before it reaches the heating and pressurizing mechanism 201 . The preheating means is not particularly limited, but may be a heating furnace, a sheathed heater, a ceramic heater, a halogen lamp heater, a carbon heater, a flash lamp heater, or the like.

The powder sintering apparatus 1 further includes a first lamp heater 23 and a second lamp heater 24 as members for heating the rolls 21 and 22 . The first lamp heater 23 is a member that heats the first roll 21 , and the second lamp heater 24 is a member that heats the second roll 22 . A halogen lamp heater, a carbon heater, a flash lamp heater, or the like may be used as the lamp heaters 23 and 24 .

As shown in FIG. 1, the lamp heaters 23 and 24 are arranged outside the box portion 301 . Both the lamp heaters 23 and 24 of Embodiment 1 are provided on the upstream side in the transport direction A with respect to the box portion 301 .

The box portion 301 is a box-shaped member that covers and accommodates the pair of rolls 21 and 22 . As shown in FIG. 1, the box portion 301 has a gap 33 through which the powder material 2 being conveyed in the conveying direction A is allowed to pass. Box portion 301 in Embodiment 1 has a substantially rectangular parallelepiped shape.

The box portion 301 is provided with windows 25 and 26 . The first window portion 25 is a member that introduces the light of the first lamp heater 23 into the box portion 301 , and the second window portion 26 introduces the light of the second lamp heater 24 into the box portion 301 . It is a member. The first window portion 25 is attached to the box portion 301 at a position between the first roll 21 and the first lamp heater 23 , and the second window portion 26 is located between the second roll 22 and the second lamp heater 24 . It is attached to the box part 301 at a position between and. Both the windows 25 and 26 of Embodiment 1 are provided on the upstream side in the transport direction A from the proximity point 32 and the rolls 21 and 22 .

The windows 25, 26 have major surfaces 25A, 26A, respectively. Principal surfaces 25A and 26A face rolls 21 and 22, respectively. Principal surfaces 25A and 26A in Embodiment 1 both extend vertically so as to face the horizontal direction.

As a material for the windows 25 and 26, a transparent or translucent material such as quartz glass or neoceram may be used.

The box portion 301 is further provided with gas inlet ports 27 to 30 and an exhaust port 31 .

The gas introduction ports 27 to 30 are members for introducing gas into the inside of the box portion 301 . Any gas such as nitrogen or argon may be used as the gas. All of the gas introduction ports 27 to 30 of Embodiment 1 are provided on the upstream side in the transport direction A of the proximity point 32 .

The exhaust port 31 is a member for exhausting the atmosphere inside the box portion 301 to the outside. The exhaust port 31 of Embodiment 1 is provided downstream in the transport direction A from the proximity point 32 .

By providing the gas introduction ports 27 to 30 and the exhaust port 31, the atmosphere inside the box portion 301 can be circulated. The gas introduction ports 27 to 30, the exhaust port 31, and the box portion 301 function as an atmosphere control portion that controls the atmosphere inside the box portion 301. FIG.

The gas introduction ports 27-30 are provided with first gas introduction ports 27, 28 and second gas introduction ports 29, 30, respectively.

The first gas introduction ports 27 and 28 are members for blowing gas along the surfaces of the windows 25 and 26, respectively. The first gas introduction port 27 blows gas in a direction along the surface of the first window portion 25 and in a direction approaching the proximity point 32 . The second gas introduction port 28 blows gas in a direction along the surface of the second window portion 26 and in a direction approaching the proximity point 32 . The first gas introduction port 27 is arranged above the first window portion 25 and blows gas downward. The second gas introduction port 28 is arranged below the second window portion 26 and blows gas upward.

The second gas introduction ports 29 and 30 are members for blowing gas from the upstream side to the downstream side in the transport direction A, respectively. The second gas introduction port 29 blows gas toward the location where the first roll 21 contacts the powder material 2 . The second gas introduction port 30 blows gas toward the location where the second roll 21 contacts the powder material 2 . As shown in FIG. 1 , the second gas introduction port 29 is arranged below the first window portion 25 and the second gas introduction port 30 is arranged above the second window portion 26 .

The material recovery mechanism 401 is a mechanism for recovering the sintered body 3 that has passed through the box portion 301 . For example, the material recovery mechanism 401 may cut the sintered body 3 to a certain length and then recover it in a sheet form. Alternatively, the sintered body 3 may be pulverized into flakes from the sheet, and then recovered.

According to the configuration described above, the lamp heaters 23 and 24 for heating the rolls 21 and 22 are arranged outside the box portion 301 . Therefore, even if the powder material 2 flies inside the box portion 301 , it is possible to prevent the powder material 2 from adhering to the surfaces of the lamp heaters 23 and 24 . This prevents the powder material 2 from interfering with the heating of the rolls 21 and 22 by the lamp heaters 23 and 24 .

Further, in Embodiment 1, windows 25 and 26 are provided for introducing light from the lamp heaters 23 and 24 into the inside of the box portion 301 . By providing the windows 25 and 26 , the heat of the lamp heaters 23 and 24 can be efficiently transferred to the rolls 21 and 22 . In this way, the rolls 21 and 22 can be efficiently heated, the powder material 2 can be sufficiently heated, and the sintered body 3 with high density can be obtained.

Furthermore, according to the powder sintering apparatus 1 of Embodiment 1, the lamp heaters 23 and 24 are arranged on the upstream side in the transport direction A with respect to the box portion 301 . Therefore, the distance from the location where the rolls 21 and 22 are heated by the lamp heaters 23 and 24 to the location where the rolls 21 and 22 contact the powder material 2 can be shortened. Thereby, heat from the lamp heaters 23 and 24 can be efficiently transferred from the rolls 21 and 22 to the powder material 2 .

Further, according to the powder sintering apparatus 1 of Embodiment 1, the windows 25 and 26 are arranged on the upstream side in the conveying direction A of the proximity point 32 between the rolls 21 and 22 . According to such a configuration, it becomes difficult for the powder material 2 flying in the box portion 301 to adhere to the surfaces of the windows 25 and 26, thereby suppressing a decrease in the light transmittance of the windows 25 and 26. can be done.

Furthermore, according to the powder sintering apparatus 1 of Embodiment 1, the windows 25 and 26 have main surfaces 25A and 26A facing the rolls 21 and 22, and the main surfaces 25A and 26A are oriented horizontally. extends vertically to By orienting the main surfaces 25A, 26A of the windows 25, 26 in this way, even if the powder material 2 flying in the box portion 301 reaches the main surfaces 25A, 26A, it does not reach the main surfaces 25A, 26A. Easy to fall off without accumulating. Thereby, it is possible to suppress the decrease in the light transmittance of the windows 25 and 26 . Furthermore, by arranging the main surfaces 25A and 26A vertically, a simple layout can be adopted.

Furthermore, according to the powder sintering apparatus 1 of Embodiment 1, the box portion 301 is provided with the first gas introduction ports 27 and 28 for introducing gas into the inside of the box portion 301 . The first gas introduction ports 27 and 28 blow gas along the surfaces of the windows 25 and 26 . According to such a configuration, it becomes difficult for the powder material 2 flying in the box portion 301 to adhere to the surfaces of the windows 25 and 26, thereby suppressing a decrease in the light transmittance of the windows 25 and 26. can be done.

Furthermore, according to the powder sintering apparatus 1 of Embodiment 1, the first gas introduction ports 27 and 28 are arranged on the upstream side in the conveying direction A of the proximity point 32 between the rolls 21 and 22 . According to such a configuration, it is possible to promote the generation of an air current from the upstream side to the downstream side in the transport direction A inside the box portion 301 . This makes it difficult for the powdery material 2 floating in the box portion 301 to adhere to the surfaces of the windows 25 and 26 , thereby suppressing deterioration in the light transmittance of the windows 25 and 26 .

Furthermore, according to the powder sintering apparatus 1 of Embodiment 1, the box portion 301 is provided with the second gas introduction ports 29 and 30 for introducing gas into the inside of the box portion 301 . The second gas introduction ports 29 and 30 blow gas downstream in the transport direction A. As shown in FIG. According to such a configuration, it is possible to promote the generation of an air current from the upstream side to the downstream side in the transport direction A inside the box portion 301 . This makes it difficult for the powdery material 2 floating in the box portion 301 to adhere to the surfaces of the windows 25 and 26 , thereby suppressing deterioration in the light transmittance of the windows 25 and 26 .

Furthermore, according to the powder sintering apparatus 1 of Embodiment 1, the second gas introduction ports 29 and 30 are arranged on the upstream side in the conveying direction A of the proximity point 32 between the rolls 21 and 22 . According to such a configuration, it is possible to promote the generation of an air current from the upstream side to the downstream side in the transport direction A inside the box portion 301 . This makes it difficult for the powdery material 2 floating in the box portion 301 to adhere to the surfaces of the windows 25 and 26 , thereby suppressing deterioration in the light transmittance of the windows 25 and 26 .

Further, according to the powder sintering apparatus 1 of Embodiment 1, the box portion 301 is provided with the exhaust port 31 . According to such a configuration, the atmosphere inside the box portion 301 can be circulated.

Furthermore, according to the powder sintering apparatus 1 of Embodiment 1, the exhaust port 31 is arranged downstream in the conveying direction A from the proximity point 32 between the rolls 21 and 22 . According to such a configuration, it is possible to promote the generation of an air current toward the downstream side in the transport direction A inside the box portion 301 . This makes it difficult for the powdery material 2 floating in the box portion 301 to adhere to the surfaces of the windows 25 and 26 , thereby suppressing deterioration in the light transmittance of the windows 25 and 26 .

(Embodiment 2)
A powder sintering apparatus 501 according to Embodiment 2 of the present invention will be described with reference to FIG. In addition, in Embodiment 2, mainly different points from Embodiment 1 will be described. Also, the same or equivalent configurations are denoted by the same reference numerals, and descriptions thereof are omitted.

FIG. 2 is a diagram showing a schematic configuration of a powder sintering apparatus 501 according to Embodiment 2. As shown in FIG. The powder sintering apparatus 501 shown in FIG. 2 includes a powder conveying mechanism 101, a heating and pressurizing mechanism 201, and a material recovery mechanism 401 as the same configuration as in Embodiment 1, but differs from Embodiment 1. As a configuration, a box portion 601 is provided.

In the first embodiment, the box portion 301 is provided with the gas introduction ports 27 to 30 and the exhaust port 31, whereas in the second embodiment, the box portion 601 is not provided with the gas introduction port and the exhaust port. is different.

Even if the box portion 601 is not provided with the gas introduction port and the exhaust port, the window portions 25 and 26 are provided while the lamp heaters 23 and 24 are arranged outside the box portion 601 as in the first embodiment. Therefore, the same effect as in the first embodiment can be obtained.

Although the present invention has been described above with reference to the first and second embodiments, the present invention is not limited to the first and second embodiments. For example, in Embodiments 1 and 2 above, the lamp heaters 23 and 24 and the windows 25 and 26 are both provided upstream in the conveying direction A with respect to the rolls 21 and 22, but in such a case is not limited to For example, the lamp heaters and windows may be provided at positions as shown in FIG.

In the example shown in FIG. 3 , a first lamp heater 803 and a first window portion 805 are provided on the upper side of the box portion 801 . On the other hand, the arrangement of the second lamp heater 24 and the second window portion 26 is the same as in the first embodiment. Even in such a case, by providing the lamp heater 803 outside the box portion 801 and providing the window portion 805 between the lamp heater 803 and the first roll 21, the roll 21 can be efficiently heated. , a sintered body 3 having a high density can be obtained.

A main surface 805A of the window 805 shown in FIG. 3 faces vertically downward toward the first heating roll 21 and extends horizontally. According to such a configuration, even if the powder material 2 dancing in the box portion 801 reaches the main surface 805A of the window portion 805, it does not accumulate on the main surface 805A and easily falls downward.

As shown in this modified example and the first embodiment, the main surface of the window may be set to face the horizontal direction or downward from the horizontal direction. According to such arrangement, adhesion of the powder material 2 to the window can be suppressed, and the roll can be efficiently heated.

INDUSTRIAL APPLICABILITY The present invention is applicable to a powder sintering apparatus for sintering powder material.

1 powder sintering device 2 powder material 3 sintered body 21 upper roll 22 lower roll 23, 24 lamp heater 25, 26 window 25A, 26A main surface 27, 28 first gas introduction port 29, 30 second gas introduction Mouth 31 Exhaust port 32 Adjacent point 33 Gap 101 Powder conveying mechanism 201 Heating and pressurizing mechanism 301 Box part 401 Material recovery mechanism 501 Powder sintering device 601 Box part 701 Powder sintering device 801 Box part 803 Lamp heater 805 Window part 805A main surface

Claims (10)

a powder conveying mechanism for conveying the powder material in the conveying direction;
a pair of rolls for heating and pressurizing the powder material being conveyed in the conveying direction;
a box-shaped member covering the pair of rolls, the box portion having a gap through which the powder material being conveyed in the conveying direction passes;
a lamp heater disposed outside the box portion for heating at least one roll of the pair of rolls;
a window portion attached to the box portion at a position between the at least one roll and the lamp heater for introducing light from the lamp heater into the inside of the box portion. 2. The powder sintering apparatus according to claim 1, wherein said window portion is arranged on the upstream side in said conveying direction of a point where said pair of rolls are closest to each other. 3. The powder sintering apparatus according to claim 1, wherein said window has a main surface facing said at least one roll, said main surface facing in the horizontal direction or downward from the horizontal direction. 4. The powder sintering apparatus according to claim 3, wherein said main surface of said window portion extends vertically so as to face in a horizontal direction. A first gas introduction port for introducing gas into the inside of the box portion is provided in the box portion,
The powder sintering apparatus according to any one of claims 1 to 4, wherein said first gas introduction port blows gas in a direction along the surface of said window. 6. The powder sintering apparatus according to claim 5, wherein said first gas introduction port is arranged on the upstream side in said conveying direction of a point where said pair of rolls are closest to each other. A second gas introduction port for introducing gas into the inside of the box portion is provided in the box portion,
The powder sintering apparatus according to any one of claims 1 to 6, wherein said second gas inlet blows gas downstream in said conveying direction. 8. The powder sintering apparatus according to claim 7, wherein said second gas introduction port is arranged on the upstream side in said conveying direction of a point where said pair of rolls are closest to each other. The powder sintering apparatus according to any one of claims 1 to 8, wherein the box portion is provided with an exhaust port. 10. The powder sintering apparatus according to claim 9, wherein said exhaust port is arranged downstream in said conveying direction of a point where said pair of rolls are closest to each other.

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