SINTERING DEVICE

Abstract

A sintering device comprising a tray including a tray part in which metallic workpieces to be sintered (not represented here) are placed during the sintering operation and a base part in which the tray is located including gas-flowing holes and side wall extended upwardly from the edge of the upper surface of the base part, and a sintering chamber including side wall extended downwardly from the upper surface for covering the tray part and at least one gas flow passage between the inner surface thereof and outer surface of the side wall of the tray part;

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Korean Patent Application No. 10-2016-0005990 filed Jan, 18, 2016, the entirety of the disclosure of which is expressly incorporated herein by reference.

STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT

Not Applicable

BACKGROUND

The present invention relates to a sintering device, and more particularly to a sintering device comprising a cylindrical member formed of titanium or titanium alloy to restrain oxidation of metallic workpieces to be sintered in the sintering device. Furthermore, the present invention relates to a sintering device in which a tray may be arranged on a base plate in a chamber member in a gas-tight manner without using any separate cover.

A conventional sintering device of the above-mentioned type comprises a base part, a tray placed on the base part, a cover for covering the tray accommodating the sinter product and a tray chamber surrounding the tray and support plate.

As one example of such sintering device, U.S. patent application Publication No. 2013/0149186 discloses a structure that a tray is disposed on a base plate with a space each other for flowing a gas.

U.S. patent application Publication No. 2014/0299195 discloses a sintering device wherein a sintering material compartment member is placed on a base part and a cover is arranged in the sintering material compartment member.

Also, the present applicant has suggested a sintering device in Korean Patent Application No. 10-2015-0021470 filed on Feb. 12, 2015, which is incorporated herein for reference. As depicted in FIGS. 1 and 2, the sinter device comprises a tray 20 placed on the base plate 10, a cover member 30 for covering the tray and base plate. The cover member 30 includes a lower end engaged with a stepped portion of the base plate 10 and a middle stepped portion 32 supported on the upper end 23 of the tray 20. A recessed portion 12 is formed at the edge of the base plate 10 for engaging the lower end 31 of the cover member 30. A hole for gas inflow and outflow is formed in the center portion of the base plate. The tray 20 is sealed by the base plate 10 and cover member 30. The tray 20 includes a gas flow passage which comprises a ring-shaped protrusion 21 formed at the bottom surface and recesses 22 in the ring-shaped protrusion 21. The tray 20 is separated from the base plate 10 by the protrusion 21.

However, there is a problem in the conventional sintering devices mentioned above that an oxygen in the residual gas in the cavity formed by the cover 20 oxidize the sintering material in the cavity surrounded by the cover member 30 in the sintering process.

Furthermore, in the conventional sintering devices, a sintering chamber should be formed by a least two elements arranged on the base plate, thereby causing an increase of manufacturing costs and complexity of structure.

BRIEF SUMMARY

In order to accomplish the above-mentioned object, according to the present invention there is provided a sintering device comprising a tray including a tray part in which metallic workpieces to be sintered (not represented here) are placed during the sintering operation and a base part in which the tray is located including gas-flowing holes and side wall extended upwardly from the edge of the upper surface of the base part, and a sintering chamber including side wall extended downwardly from the upper surface for covering the tray part and at least one gas flow passage between the inner surface thereof and outer surface of the side wall of the tray part,

wherein the tray part and base part are integrally formed;

wherein the base part includes at the lower portion through holes in horizontal and longitudinal directions for gas inflowing and discharging, a hole at crossover point of the through holes for penetrating the center portion of the base plate and extended to the exterior, and

wherein the lower end of the sinter chamber is disposed on the lowered and stepped surface of the base part and the stepped portion formed in the middle of the side wall of the sintering chamber is supported by the upper end of the side wall of the tray for allowing the gas to flow.

According to the present invention, a cylindrical member for the prevention of oxidization may be disposed on the base part between the side walls of the tray part and sintering chamber to prevent the oxygen contacting the metallic workpiece.

The cylindrical member for the prevention of oxidization is preferably formed in a sheet made from titanium or titanium allow.

The inner diameter of the sidewall of the sintering chamber is bigger than the outer diameter of the side wall of the tray part to form a cylindrical space as a gas flow passage between the side walls of the tray part and sintering chamber, and the cylindrical space is communicated with the through holes in horizontal and longitudinal directions formed at the base part.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects, other features and advantages of the present invention will become more apparent by describing the preferred embodiments thereof with reference to the accompanying drawings, in which:

FIG. 1 is a cross-section view of the conventional exploded sintering device in an exploded state which was filed by the present applicant;

FIG. 2 is a cross-section view of the assembled sintering device in FIG. 1;

FIG. 3 is an exploded perspective view showing the improved sintering device according to the preferred embodiment of the present invention, in which a tray part and a base part are integrally formed;

FIG. 4 is a partial cross section view of the sintering device in FIG. 3;

FIG. 5 is a cross section view of the assembled sintering device in FIG. 4; and

FIG. 6 is a cross section view of the variant embodiment of FIG. 5.

DETAILED DESCRIPTION

The present invention will be hereafter described in detail with reference to the accompanying drawings.

The sintering device according to the first embodiment of the present invention FIGS. 3, 4, 5 includes a tray comprising a tray part 330 and a base part 331 integrally formed therewith and a sintering chamber 340 covering the tray part 330, the upper portion of the tray part 330 being opened. That is, the tray part and the base part are different from a tray and a base plate in the FIGS. 1 and 2 in that the tray part and base part are integrally formed in one piece.

The tray part 330 is provided with a cylindrical side wall 332 formed upwardly on the bottom surface to form an inner space for accommodating workpieces therein and the base part 331 is formed with through holes 334 in horizontal and longitudinal directions for gas inflowing and discharging, and a hole 335 at crossover point of the through holes 334 for penetrating the center portion of the base plate and extended to the exterior. Also, a lowered and stepped surface 333 is formed at the edge portion of the base part 331.

The through holes 334 work as a gas passage for inflowing the argon gas and discharging the residual gas in the inner space of the tray part and the hole 335 works as an gas inlet and an gas outlet connected to the gas supply and discharging means provided in the conventional sintering device.

The sintering chamber 340 is mounted on the lowered and stepped surface of the base part for covering the tray part 330 and is provided with a cylindrical side wall 342 formed in the downward direction and a stepped portion 341 in the middle of the side wall to increase the inner diameter at the lower portion of the side wall.

When the sintering chamber 340 is mounted for covering the tray part 330, the lower end of the side wall 342 seats on the stepped surface 333 of the base part and the stepped portion 341 of the side wall 342 seats on the upper end of the side wall of the tray part 330, so that gas may follow through a fine gap between them.

The inner diameter of the side wall 342 of the sintering chamber 340 is bigger than that of the side wall 332 of the tray part 330, so that a ring shaped space 336 is formed as a gas passage between the side walls 332 and 334. The space 336 is connected to the horizontal and longitudinal through holes 334 formed at the base part.

The argon gas supplied by (not shown) a gas supplying apparatus may flow into the ring shaped space 336 between the side walls 332 and 334 through the hole 335 and through holes 334 formed at the base part and the residual gas in the inner space of the tray part may be discharged via the same gas flowing paths mentioned above.

In this embodiment, the tray part and the base part are integrate in one piece, where the hole 335 and through holes 334 are formed at the base part 331 for the gas inflow and discharging and the stepped surface 333 of the base part is formed at the base part 331 for mounting the sintering chamber 340, so that the sintering device may be compacted in virtue of the decrease of the number of parts and the manufacturing cost may be decreased. Accordingly, the sintering device according to the invention is improved as compared with the prior sintering device in which the tray and the base plate are separated, a spacer should be formed at the bottom for a space as a gas passage.

Referring to FIG. 6, the sintering device according to the variant embodiment of the invention includes a cylindrical member 250 provided between the side wall of the tray part 330 and the side wall of the sintering chamber 340 for the prevention of oxidization. The cylindrical member 250 has a diameter which is bigger than that of tray part and smaller than that of the sintering chamber, so that the cylinder member may be arranged on the base part 331 and between the side walls of the tray part and sintering chamber. At this time, it is desirable that the cylinder member is separated from the side wall of the tray part 330 not to prevent the inflow and discharging of the gas.

Accordingly, the argon gas supplied by the gas supplying apparatus may be flowed in the space 336 between the side walls 332 and 334 through the hole 335 and flows in the inner space of the tray part 330, thereby urging the residual gas in the inner space of the tray part to be discharged and the argon atmosphere is formed in the inner space of the tray part. Therefore, in the sintering operation, the oxygen remained in the space 336 may be first contacted with the cylindrical member 250 and the oxidation of the metallic workpiece may be prevented.

The cylindrical member 250 is preferably formed in a sheet made from titanium or titanium allow and is first oxidized by the residual oxygen in the space 336 to prevent from the metallic workpiece to oxidation. Accordingly, the quality of the sintered workpiece may be improved.

The forgoing embodiments are merely exemplary and are not to be construed as limiting the present invention. The present teachings can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.

Claims

1. A sintering device comprising a tray including a tray part in which metallic workpieces to be sintered (not represented here) are placed during the sintering operation and a base part in which the tray is located including gas-flowing holes and side wall extended upwardly from the edge of the upper surface of the base part, and a sintering chamber including side wall extended downwardly from the upper surface for covering the tray part and at least one gas flow passage between the inner surface thereof and outer surface of the side wall of the tray part; wherein the tray part and base part are integrally formed;wherein the base part includes at the lower portion through holes in horizontal and longitudinal directions for gas inflowing and discharging, a hole at crossover point of the through holes for penetrating the center portion of the base plate and extended to the exterior, andwherein the lower end of the sinter chamber is disposed on the lowered and stepped surface of the base part and the stepped portion formed in the middle of the side wall of the sintering chamber is supported by the upper end of the side wall of the tray for allowing the gas to flow.

2. The sintering device as claimed in claim 1, wherein a cylindrical member for the prevention of oxidization is disposed on the base part between the side walls of the tray part and sintering chamber to prevent the oxygen contacting the metallic workpiece.

3. The sintering device as claimed in claim 2, wherein the cylindrical member is formed in a sheet made from titanium or titanium allow.

4. The sintering device as claimed in claim 1, wherein the inner diameter of the sidewall of the sintering chamber is bigger than the outer diameter of the side wall of the tray part to form a cylindrical space as a gas flow passage between the side walls of the tray part and sintering chamber, and the cylindrical space is communicated with the through holes in horizontal and longitudinal directions formed at the base part.