JP7209288B2 - 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 a pair of rolling rolls.

Here, in the case of pressurization with rolls, the pressurizing force of the rolls tends to decrease at the ends in the width direction of the powder material during rolling, and there are more unsintered portions than in the central portion in the width direction, and the density tends to be low. . Therefore, the density in the width direction of the sintered body becomes uneven. In order to solve such a problem, Patent Document 2 proposes a method of using a pair of rolls in which one roll is provided with protrusions and the other roll is provided with grooves.

In the pair of rolls disclosed in Patent Literature 2, tapered portions are provided at both ends of each of the protrusions and grooves. By combining the roll protrusions and roll grooves having such tapered portions, it is possible to prevent the pressure force of the rolls from decreasing at the widthwise end portions of the powder material, and to prevent the density from decreasing at the widthwise end portions of the sintered body. It is intended to suppress.

Special table 2003-520292 JP 2000-234105

However, in the method disclosed in Patent Document 2, the powder material bites into the grooves of the roll, making it difficult to release the sintered compact. Further, it is disclosed that the width of the powder material can be changed by dividing the roll and adjusting the spacing of the spacers, but it is necessary to install a roll for the dividing system, and the roll cannot be used. The operating rate drops due to replacement. Therefore, it is difficult to achieve high productivity.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a powder sintering apparatus capable of achieving high productivity through continuous production while increasing the uniformity of density in the width direction of a sintered body.

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 and a pair of rolls facing each other with a gap therebetween, wherein the powder A pair of rolls for placing the powder material conveyed by a conveying mechanism in the gap and heating and pressurizing it, and a conveying path for the powder material being heated and pressurized by the pair of rolls is partially formed in the gap. A gap forming part that forms a gap along the conveying direction in the sintered body of the powder material by blocking, and a cutting part that cuts the sintered body along the gap formed by the gap forming part. And prepare.

According to the powder sintering apparatus of the present invention, it is possible to achieve high productivity through continuous production while improving the uniformity of density in the width direction of the sintered body.

Schematic diagram of powder sintering apparatus in embodiment Sectional drawing which shows the positional relationship of a pair of roll and wire in embodiment A-A' cross-sectional view of FIG. B-B' cross-sectional view of FIG. C-C' sectional view of Fig. 1 DD' sectional view of Fig. 1

According to the first aspect of the present invention, a powder conveying mechanism for conveying a powder material in a conveying direction and a pair of rolls facing each other with a gap therebetween, wherein the powder conveyed by the powder conveying mechanism A pair of rolls that heat and pressurize the body material placed in the gap, and a conveying path of the powdery material that is heated and pressed by the pair of rolls are partially blocked by the gap, so that the powdery material a gap forming section for forming gaps in the sintered body along the conveying direction; and a cutting section for cutting the sintered body along the gaps formed by the gap forming section. Provide a connection device.

According to a second aspect of the present invention, there is provided the powder sintering apparatus according to the first aspect, wherein the gap forming section includes a wire crossing the gap between the pair of rolls in the conveying direction.

According to the third aspect of the present invention, the gap forming section includes a first supporting section that supports the wire from above on the upstream side of the gap in the conveying direction, and a first supporting section on the downstream side of the gap in the conveying direction. and a second support for supporting the wire from above.

A fourth aspect of the present invention provides the powder sintering apparatus according to the third aspect, wherein the first supporting portion and the second supporting portion are configured to be capable of winding the wire.

According to the fifth aspect of the present invention, the wires are arranged on one side in the width direction of the powder material being conveyed in the conveying direction, and the first wire is arranged on the other side in the width direction. The powder sintering apparatus according to any one of the second aspect to the fourth aspect, comprising a second wire.

According to a sixth aspect of the present invention, the powder sintering apparatus according to any one of the second to fifth aspects, wherein the diameter of the wire is smaller than the gap between the pair of rolls offer.

According to the seventh aspect of the present invention, any one of the first aspect to the sixth aspect, wherein the gap forming part forms a groove extending along the conveying direction on the surface of the sintered body as the gap. A powder sintering apparatus according to 1 is provided.

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

FIG. 1 is a diagram showing a schematic configuration of a powder sintering apparatus 50 according to an embodiment. A powder sintering apparatus 50 shown in FIG. 1 is an apparatus for obtaining a sintered body 2 by sintering a powder material 1 . The powder sintering apparatus 50 includes a powder conveying mechanism 101 , a heating and pressurizing mechanism 201 , a gap forming section 301 , a cutting section 401 and a material recovery mechanism 501 .

The powder material 1 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 1 may be preliminarily subjected to a molding process to make the thickness and width uniform. As the molding process, for example, a method of compressing the powder into a sheet using a pair of rolls, or a method of pressing the powder using a mold can be used.

The powder conveying mechanism 101 is a mechanism for conveying the powder material 1 in the conveying direction X. As shown in FIG. The powder conveying mechanism 101 has a function of supplying the powder material 1 to the heating/pressurizing mechanism 201 . The transport direction X in the embodiment is horizontal. 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 1 while heating it. The heating and pressurizing mechanism 201 includes a first roll 11 and a second roll 12 as a pair of rolls. The first roll 11 and the second roll 12 sandwich the powder material 1 conveyed in the conveying direction X from both sides while applying heat and pressure. In the embodiment, the first roll 11 and the second roll 12 are arranged vertically, and the powder material 1 is vertically sandwiched between the upper first roll 11 and the lower second roll 12 to heat and press.

A gap 52 is formed between the first roll 11 and the second roll 12 . The gap 52 is the point where the first roll 11 and the second roll 12 come closest. In the gap 52 , the powder material 1 is heated and pressed by the first roll 11 and the second roll 12 to produce the sintered body 2 .

The powder conveying mechanism 101 described above has a function of supplying the sintered compact 2 to the cutting section 401 and the material recovery mechanism 501 .

The material of the rolls 11 and 12 is not particularly limited, but metals such as stainless steel, carbon steel, and high-speed tool steel, and ceramics such as silicon nitride, silicon carbide, alumina, sialon, and zirconia can be used. can. Furthermore, a structure combining these materials can also be used.

The heating temperature of the rolls 11 and 12 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 powder material 1 can be sufficiently raised, and a high-density sintered body 2 can be obtained. Also, by setting the temperature to 700° C. or less, it is possible to suppress the temperature rise of the shaft portions of the rolls 11 and 12 and extend the life of the bearings that support the shaft portions.

Although not shown, it is also possible to preheat the powder material 1 before reaching the heating/pressurizing mechanism 201 . The preheating means is not particularly limited, but a heating furnace, a sheathed heater, a ceramic heater, a halogen lamp heater, a carbon heater, a flash lamp heater, or the like can be used.

The heating and pressurizing mechanism 201 further includes a first heating device 13 and a second heating device 14 as members for heating the rolls 11 and 12 . The first heating device 13 is a member that heats the first roll 11 , and the second heating device 14 is a member that heats the second roll 12 . The heating devices 13 and 14 are not particularly limited, but induction heating coils, sheathed heaters, halogen lamp heaters, carbon heaters, flash lamp heaters, and the like can be used.

The atmosphere in which the powder material 1 is heated can be controlled to an inert atmosphere using nitrogen (N ₂ ) or the like, if necessary.

The gap forming part 301 is a member that forms gaps in the sintered body 2 by partially blocking the conveying path of the powder material 1 that is being heated and pressed by the rolls 11 and 12 . By forming such a gap, the end portion of the sintered body 2 in the width direction can be easily cut by a cutting portion 401, which will be described later. To obtain a sintered body 2 having a more uniform density by suppressing variations in the density in the width direction of the sintered body 2 by cutting the widthwise end of the sintered body 2 where the density tends to be low. can be done. A detailed configuration of the gap forming portion 301 will be described later.

The cutting part 401 is a member that cuts the sintered body 2 along the gap formed by the gap forming part 301 . As the cutting part 401, a means for separating by mechanical impact such as a hammer, rotary blade, air jet, sandblasting, dry ice blasting, or a means for applying thermal shock without contact such as laser cutting or flash lamp may be used. can be done. The cutting part 401 functions as an edge separation mechanism that separates the width direction edge of the sintered body 2 .

The material recovery mechanism 501 is a mechanism for recovering the sintered body 2 after being cut by the cutting section 401 . For example, the material recovery mechanism 501 may cut the sintered body 2 to a certain length and then recover it in a sheet form. Also, the sintered body 2 can be pulverized into flakes from the sheet form and then recovered.

Next, a detailed configuration of the gap forming portion 301 will be described.

As shown in FIG. 1 , the gap forming section 301 includes a wire 21 , a winding mechanism 22 , an unwinding mechanism 23 , and guide rolls 24 and 25 .

The wire 21 is a linear member passed through the gap 52 between the pair of rolls 11 and 12 . A gap is formed in the sintered body 2 by partially closing the conveying path of the powder material 1 with the gap 52 of the wire 21 .

The wire 21 of this embodiment is a metal wire made of metal. Although the material of the metal wire is not particularly limited, stainless steel can be used.

The winding mechanism 22 and the unwinding mechanism 23 are members that allow the wire 21 to be wound. The wire 21 unwound by the unwinding mechanism 23 is wound by the winding mechanism 22 .

The winding mechanism 22 and the unwinding mechanism 23 function as a first support section and a second support section for supporting the wire 21, respectively. The winding mechanism 22 is a first support that supports the wire 21 from above on the upstream side in the transport direction X of the gap 52 . The unwinding mechanism 23 is a second support section that supports the wire 21 from above on the downstream side in the transport direction X of the gap 52 . The wire 21 is passed through the gap 52 while suspended from above by the winding mechanism 22 and the unwinding mechanism 23 . The wire 21 provided in this manner traverses the gap 52 in the transport direction X. As shown in FIG.

Guide rolls 24 and 25 are rolls that guide the wire 21 .

The positional relationship between the pair of rolls 11 and 12 and the wire 21 will be described with reference to FIG. 2 is a cross-sectional view showing the pair of rolls 11 and 12 and the wire 21 in the gap 52 when viewed from the transport direction X. FIG.

In FIG. 2, the powder material 1 placed in the gap 52 is indicated by dotted lines.

As shown in FIG. 2, the wire 21 of this embodiment includes a first wire 21A and a second wire 21B as a pair of wires. The first wire 21A is a wire provided on one side in the width direction Y, and the second wire 21B is a wire provided on the other side in the width direction Y. As shown in FIG. The first wire 21A is arranged near one end in the width direction Y of the powder material 1 , and the second wire 21B is arranged near the other end in the width direction Y of the powder material 1 . By providing such a pair of first wire 21A and second wire 21B, gaps can be formed at both ends of the sintered body 2 in the width direction Y. As shown in FIG.

As shown in FIG. 2, the two wires 21A, 21B are arranged so as to contact the lowermost surface of the first roll 11. As shown in FIG. As a result, the voids formed in the sintered body 2 become grooves exposed on the surface of the sintered body 2 . In addition, not only when contacting the lowermost surface of the first roll 11, but also when the wire 21 is arranged at a distance from the lowermost surface of the first roll 11, a groove exposed on the surface of the sintered body 2 can be formed. can also

The diameter D2 of the wire 21 is designed to be smaller than the interval D1 of the gap 52 which is the distance between the rolls 11 and 12 . Thereby, the wire 21 can be reliably arranged in the gap 52 . Also, when performing maintenance on the wire 21, the wire 21 can be taken out from between the rolls 11 and 12 without changing the positions of the rolls 11 and 12 and the like.

3A to 3D show the A-A' cross section, the B-B' cross section, the C-C' cross section, and the D-D' cross section shown in FIG. 3A shows the A-A' cross section, FIG. 3B shows the B-B' cross section, FIG. 3C shows the C-C' cross section, and FIG. 3D shows the D-D' cross section.

As shown in FIG. 3A, the powder material 1 conveyed to the gap 52 by the powder conveying mechanism 101 is conveyed in a sheet-like form having a rectangular cross section. The thickness of the powder material 1 is substantially constant in the width direction Y.

The cross section shown in FIG. 3B corresponds to the gap 52 where the rolls 11 and 12 heat and press the powder material 1 . The powder material 1 is heated and pressed by rolls 11 and 12 to form a sintered body 2 . As shown in FIG. 3B, two wires 21A and 21B are provided so as to partially block the conveying path of the powder material 1. As shown in FIG. Voids 54 are formed in the sintered body 2 where the wires 21A and 21B are positioned. By forming such a gap 54 , the sintered body 2 is divided into ends 31 and 32 in the width direction Y and a central portion 33 located between the ends 31 and 32 .

As shown in FIG. 3B, the sintered body 2 has a thickness D3. The diameter D2 of the wire 21 is set to 1/2 or more of the thickness D3 of the sintered body 2 . Thereby, the gap 54 having a desired size can be formed.

The cross section shown in FIG. 3C corresponds to a position downstream of the gap 52 and upstream of the cut portion 401 . As shown in FIG. 3C, the wires 21A and 21B are separated from the sintered body 2, but the voids 54 formed by the gaps 52 are continuously formed. By continuously feeding the powder material 1 and the sintered body 2 in the conveying direction X, voids 54 continuously extending along the conveying direction X are formed in the sintered body 2 .

The gap 54 is utilized for cutting by the aforementioned cutting section 401 (FIG. 1). Specifically, the cutting portion 401 cuts the sintered body 2 along the gap 54 .

In FIG. 3D, the state after cutting by the cutting part 401 is shown. As shown in FIG. 3D, the ends 31 and 32 of the sintered body 2 in the width direction Y are cut and separated from the central portion 33 . At the ends 31 and 32 in the width direction Y, there is a space for the powder material 1 to escape to the outside, which is where the pressure applied by the rolls 11 and 12 is weakened. Therefore, the end portions 31 and 32 tend to have unsintered portions that have not been sufficiently sintered, and tend to have a lower density than the central portion 33 . On the other hand, by forming gaps 54 near both ends of the sintered body 2 in the width direction Y and cutting the ends 31 and 32 along the gaps 54, the ends 31 of the sintered body 2 having a low density , 32 can be removed. As a result, the central portion 33 having a smaller unsintered portion and a more uniform density can be recovered as the sintered body 2 .

In this embodiment, the gap 54 is formed only by arranging the wire 21 between the rolls 11 and 12 . Therefore, the gap 54 can be formed in the process of continuous production by the rolls 11 and 12, and high productivity can be achieved. Moreover, since cutting by the cutting unit 401 is also performed in the process of continuous production, high productivity can be achieved.

If a void is formed in the powder material 1 on the upstream side of the gap 52, the void cannot be formed because the void will be buried by the material flow during the subsequent heat and pressure treatment. In this embodiment, the gap 54 is formed in the sintered body 2 by passing the wire 21 through the gap 52 where the heating and pressurizing process is performed.

As described above, the powder sintering apparatus 50 of this embodiment includes the powder conveying mechanism 101 , the pair of rolls 11 and 12 , the gap forming section 301 and the cutting section 401 . The gap forming part 301 partially blocks the conveying path of the powder material 1 that is being heated and pressed by the pair of rolls 11 and 12 with the gap 52 , thereby forming a gap 54 along the conveying direction X in the sintered body 2 . to form The cutting section 401 cuts the sintered body 2 along the gap 54 formed by the gap forming section 301 . According to such a configuration, by cutting the sintered body 2 along the gap 54, it is possible to remove the width direction Y end portions 31 and 32 of the sintered body 2 where the density tends to be low. As a result, the central portion 33 , which is a portion with less variation in density in the width direction Y, can be recovered as the sintered body 2 . In addition, since the gap 54 can be formed and cut during the continuous production process using the pair of rolls 11 and 12, high productivity can be achieved.

Further, according to the powder sintering apparatus 50 of the embodiment, the gap forming section 301 includes the wire 21 that crosses the gap 52 between the pair of rolls 11 and 12 in the transport direction X. As shown in FIG. With such a configuration, the gap 54 can be formed with a simple configuration.

Further, according to the powder sintering apparatus 50 of the embodiment, the gap forming section 301 includes the winding mechanism 22 and the unwinding mechanism 23 . The winding mechanism 22 is a first support that supports the wire 21 from above on the upstream side in the transport direction X of the gap 52 , and the unwinding mechanism 23 is on the downstream side in the transport direction X of the gap 52 . is a second support portion that supports from above. With such a configuration, the wire 21 can be hung from above, and interference of the wire 21 with other members can be suppressed.

Further, according to the powder sintering apparatus 50 of the embodiment, the winding mechanism 22 and the unwinding mechanism 23 are configured to be able to wind the wire 21 . By configuring the wire 21 so as to be wound up in this manner, the position in the longitudinal direction at which the wire 21 contacts the powder material 1 can be varied according to the degree of use of the wire 21 or the like.

Further, according to the powder sintering apparatus 50 of the embodiment, the wire 21 includes the first wire 21A and the second wire 21B. The first wire 21A is arranged on one side in the width direction Y of the powder material 1, and the second wire 21B is arranged on the other side in the width direction Y. As shown in FIG. By providing such a pair of wires 21, it is possible to form a gap 54 on both sides of the sintered body 2 in the width direction Y, and both ends (ends 31, 32) in the width direction Y where the density tends to be low can be formed. can be disconnected. As a result, variations in the density of the sintered body 2 after cutting can be further suppressed.

Further, according to the powder sintering apparatus 50 of the embodiment, the diameter D2 of the wire 21 is smaller than the distance D1 of the gap 52 between the pair of rolls 11 and 12 . With such a configuration, the wire 21 can be easily and reliably arranged in the gap 52 between the rolls 11 and 12 .

Further, according to the powder sintering apparatus 50 of the embodiment, the diameter D2 of the wire 21 is set to 1/2 or more of the thickness D3 of the sintered body 2 . With such a setting, a large gap 54 can be provided, and the sintered body 2 can be easily cut.

Further, according to the powder sintering apparatus 50 of the embodiment, the gap forming part 301 forms grooves extending along the conveying direction X on the surface of the sintered body 2 as the gaps 54 . By forming grooves as the gaps 54 in this way, the gaps 54 can be easily confirmed from the outside and can be easily cut.

Although the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments. For example, in the above embodiment, the case where the gap forming portion 301 includes the wire 21 has been described, but the present invention is not limited to such a case. Any configuration other than the wire 21 may be adopted as long as it can form a gap in the sintered body 2 along the transport direction X.

INDUSTRIAL APPLICABILITY The powder sintering apparatus of the present invention is useful as a powder sintering apparatus for obtaining a sintered body by sintering a powder material.

1 powder material 2 sintered body 11 first roll (upper roll)
12 second roll (lower roll)
13 First heating device 14 Second heating device 21 Wire (metal wire)
21A first wire 21B second wire 22 winding mechanism (first support)
23 unwinding mechanism (second support)
24, 25 guide rolls 31, 32 end portion 33 central portion 50 powder sintering device 52 gap (proximity point)
54 air gap (groove)
101 Powder Conveying Mechanism 201 Heating and Pressurizing Mechanism 301 Gap Forming Part (Groove Forming Mechanism)
401 cutting section (end separation mechanism)
501 material recovery mechanism D1 spacing D2 diameter D3 thickness X transport direction Y width direction

Claims (7)

a powder conveying mechanism for conveying the powder material in the conveying direction;
A pair of rolls facing each other with a gap is provided, the powder material conveyed by the powder conveying mechanism is placed in the gap between the pair of rolls, and the powder material is heated and pressed. A pressure heating mechanism for generating a sintered body by
a gap forming part that partially closes the conveying path of the powder material in the gap between the pair of rolls and forms a gap along the conveying direction in the sintered body;
and a cutting section that cuts the sintered body along the gap formed along the conveying direction . 2. The powder sintering apparatus according to claim 1, wherein said gap forming part includes a wire that crosses said gap between said pair of rolls in said conveying direction. The gap forming part includes a first supporting part that supports the wire from above on the upstream side of the gap in the conveying direction, and a second supporting part that supports the wire from above on the downstream side of the gap in the conveying direction. 3. The powder sintering apparatus according to claim 2, further comprising a support. 4. The powder sintering apparatus according to claim 3, wherein said first support part and said second support part are configured to be able to wind said wire. The wire comprises a first wire arranged on one side in the width direction of the powder material being conveyed in the conveying direction, and a second wire arranged on the other side in the width direction. 5. The powder sintering apparatus according to any one of 2 to 4. The powder sintering apparatus according to any one of claims 2 to 5, wherein the diameter of the wire is smaller than the gap between the pair of rolls. The powder sintering apparatus according to any one of claims 1 to 6, wherein the gap forming portion forms a groove extending along the conveying direction on the surface of the sintered body as the gap.

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