KR101396826B1 - Continuous type sintering and tempering furnace for wear resistance sintered material - Google Patents

Abstract

The present invention relates to a continuous sintering and tempering furnace for wearing-resistant sintered material. By continuously conducting sintering and tempering process of powder metal article, the working time for plasticizing the article and production costs can be reduced. The continuous sintering and tempering furnace according to the present invention comprises: a sintering unit comprising a pre-heating zone, a sintering zone, and a cooling zone to transfer the forming product by a conveyor; and a tempering unit comprising a tempering zone for tempering the forming product, and a second cooling zone for cooling the forming product.

Description

{CONTINUOUS TYPE SINTERING AND TEMPERING FURNACE FOR WEAR RESISTANCE SINTERED MATERIAL FOR HIGH Abrasion Resistance Sintering Material}

More particularly, the present invention relates to a continuous sintering tempering furnace, and more particularly, to a continuous sintering tempering furnace which is capable of continuously performing a sintering process and a tempering process of a powder metallurgical product, A valve seat and a TIP to stabilize the structure and improve the physical properties, and to improve the durability of the muffle by reinforcing the structure of the muffle, thereby improving the structure of the continuous sintering tempering furnace.

Generally, a sintering furnace is generally used for sintering a raw material obtained by compression-molding powders of cemented carbide, ceramics and metal in a vacuum or gas atmosphere to improve the mechanical properties and thermal stability of the material. In the case of an atmosphere sintering furnace, ₂ , H ₂ , Ar and the like are used, and the temperature is varied from room temperature to 1200 ° C.

Conventional powder metallurgy products are sintered after forming into product shape with press, tempering process is carried out on sintered products in order to increase hardness and toughness and have high abrasion resistance and high strength characteristics.

The above-mentioned products have high hardness and improved abrasion resistance and are applied to various automobile parts, machine parts and the like.

The powder metallurgy product is manufactured through a continuous sintering furnace, and the continuous sintering furnace is divided into a preheating zone, a sintering zone and a cooling zone according to a temperature pattern. The products are sequentially transferred to the respective chambers, Is performed in each of the chambers.

On the other hand, the sintered molded product is subjected to a tempering process through a tempering furnace to improve the quality of the product. The tempering furnace has a uniform temperature distribution throughout the furnace, and a temperature cycle in which the temperature is varied is applied The heating, holding and cooling steps of the molded article are repeated.

A conventional sintering furnace is divided into a preheating zone, a sintering zone and a cooling zone in which a space portion is formed, and a molded product placed on the conveying conveyor is driven by a driving force of a motor to drive a mesh belt, do.

The preheating zone and the sintering zone are wrapped with an insulating material to maximize thermal efficiency by minimizing the amount of radiated heat and heat. The preheating zone is formed by a curtain of carbon fiber material in order to block the inflow of outside air to the entrance of the molded product. Is installed.

The sintering zone is equipped with a thermocouple used as a heat source for the high temperature SiC HEATER, a thermoelectric thermometer and a radiometer used as a radiator in the chamber, and the preheated molded product from the preheat zone is heated and sintered at a high temperature using a heater.

The cooling zone is provided with a gas pipe for supplying an atmospheric gas (NH ₃ , H _2, etc.) to the sintering zone, and a drain and a supply pipe for injecting and circulating cooling water are arranged.

As one example of the prior art related to the conventional sintering furnace, as disclosed in Korean Patent No. 10-1069682 entitled " vacuum degreasing sintering furnace "(registered on September 27, 2011), a space portion is formed inside, , A heat insulating box provided in the sintering furnace main body, a tight box installed in the heat insulating box and filled with the metal powder molded article, a heating element provided between the heat insulating box and the tight box, a gas supply part for supplying gas into the sintering furnace body A vacuum exhausting means for evacuating the space portion of the sintering furnace body by vacuum, a vacuum exhausting means for exhausting the steam generated in the tight box, a liquefied degreasing means for liquefying the vapor discharged from the vacuum exhausting means, A movable member including a heat control box and a tight box is provided so as to include a control control unit that operates organically .

On the other hand, as the tempering, a heater is provided inside the furnace for heating the furnace, and the furnace has a structure in which a fan is attached to keep the furnace temperature uniform.

As an example of the prior art relating to the tempering furnace, as disclosed in Korean Registered Utility Model Registration No. 20-0148520 entitled " Waste Gas Combustion Furnace by Tempering "(registered on March 18, 1999) A chamber formed to be capable of housing a metal product in the interior of the main body by tempering, a chamber cover for sealing the upper end of the chamber, and a blower installed in the chamber cover, An exhaust pipe provided in the main body by tempering so as to discharge the waste gas in the chamber, and a combustor installed on the outlet side of the discharge pipe to burn waste gas discharged to the outside through the discharge pipe.

Since the sintering process and the tempering process are separately performed in the conventional sintering furnace and the tempering process, the waiting time between the sintering furnace and the tempering process becomes longer, and the sintering process of the powder metallurgy process and the tempering process And the manufacturing cost is increased.

Korean Patent No. 10-1069682 entitled "Vacuum degreasing and sintering furnace" (registered on September 27, 2011) Korean Registered Utility Model Registration No. 20-0148520 entitled "Waste Gas Combustion Apparatus by Tempering" (Registered on March 18, 1999)

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a powder metallurgy molded article improved in structure so that a sintering process and a tempering process in a molding process of a powder metallurgical product are continuously performed in a sequential order. And to provide a molding apparatus of the same.

Another object of the present invention is to provide a molding apparatus for a powder metallurgy molded article in which the structure is improved so as to significantly shorten the waiting time during the sintering and tempering process of a powder metallurgical product.

In order to accomplish the above object, the present invention provides a sintering apparatus comprising: a sintering section composed of a preheating zone, a sintering zone and a cooling zone having respective chambers and sintered and formed while a molded product is conveyed by a conveyor;

A tempering zone disposed on the conveyor and having a muffle disposed therein for tempering a shaped article continuously passed through the first cooling zone and a second cooling zone for cooling the tempered product passing through the tempering zone, And a tempering part formed of a metal material.

The upper and lower surfaces of the muffle are formed so as to be bent with respect to the left and right side walls, and the bent upper and lower surfaces are welded to the left and right side walls.

The muffle is formed by integrally welding a reinforcing plate in the form of a lattice on the outer surface.

The roto body is further provided with an opening / closing means provided on the entrance side for opening / closing the entrance,

The opening / closing means includes a door gate provided so as to be vertically movable up and down on the furnace inlet side of the tempering section to open and close the inlet of the furnace body, and a cylinder for imparting upward and downward force to the door gate.

And an air injection nozzle provided in the door gate for spraying compressed air to a molded product entering the inside of the muffle.

As the sintering and tempering process of the powder metallurgical product is continuously performed on the single conveyor while passing through the sintering portion and the tempering portion, the waiting time between the sintering process and the tempering process can be shortened and workability is improved It has a useful effect.

Further, according to the present invention, by using the air injection nozzle disposed at the inlet side or the door gate of the furnace, the temperature of the molded article is cooled to the temperature range in which the temperature of the molded article is to be thermally tempered by the jetting force of the compressed air, It has an advantage that it can be cooled quickly to a desired temperature.

The upper and lower surfaces of the muffle are integrally welded to the left and right walls by integrally welding the reinforcing plate of the grid pattern to the outer circumferential surface of the muffle of the present invention to improve the durability due to the reinforcing structure of the muffle .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural view showing a structure of a continuous sintering tempering according to the present invention; FIG.
2 is a schematic view of the tempering furnace according to the present invention.
3 is a cross-sectional view showing a loose-fitting structure of the tempering portion
4 is a perspective view showing the opening and closing means of the present invention.
Fig. 5A and Fig. 5B are explanatory views showing the operation of the opening and closing means of the present invention. Fig.

The present invention enables continuous sintering and tempering of a powder metallurgy molded article to greatly shorten the working time of the sintered molded article.

FIG. 3 is a cross-sectional view showing the loose bonding structure of the tempering part, and FIG. 4 is a cross-sectional view showing the sintering tempering according to the present invention Fig. 5A and Fig. 5B are explanatory diagrams showing the use state of the opening and closing means of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 5, a continuous sintering tempering apparatus according to the present invention includes a preheating zone 110, a sintering zone 120, and a first cooling zone 130 for sintering a powder metallurgy product, (100) for transferring the molded article to the mold (310); A tempering zone 230 disposed to be positioned on the conveyor 310 for heat treatment of the molded product passing through the sintering unit 100 and for tempering the molded product and a tempering zone 230 for cooling the tempered molded product while passing through the tempering zone 230 And a tempering section 200 composed of two cooling zones 240.

Referring to FIG. 1, the preheating zone 110 and the sintering zone 120 have respective chambers, and the furnace body of the sintered body 100 is formed of a welded structure of a steel plate and a steel plate in contrast to thermal stress, And has a structure in which an insulating material is surrounded to maximize thermal efficiency by minimizing the amount of radiated heat and heat.

In the preheating zone 110, a curtain of carbon fiber material is disposed to block the inflow of outside air into the entrance side of the molded product. The sintering zone 120 is formed of a hydrocarbon (SiC) heating element, which is a type of electric heater, thermo couple is installed as a heat source.

The first cooling zone 130 is provided with a supply pipe of NH ₃ and N ₂ gas for supplying an atmospheric gas to the sintering zone 120 and performs cooling for the product passing through the first cooling zone 130 A cooling water supply unit 135 is provided to inject cooling water.

The cooling water supply unit 135 has a known configuration composed of a supply pipe for supplying cooling water and a cooling water injection nozzle.

The conveyor 310 adopts a method in which a mesh belt is circulatingly driven to transport a molded article in a lateral direction.

In order to maximize thermal efficiency on the inner circumferential surface of the furnace body 210, a heat insulating material is disposed on the bottom surfaces of the upper and lower portions and the side walls 225, and a muffle 220 in the form of a tunnel muffle.

The tempering section 200 has a known configuration having a heating section for heating the molded article in an air atmosphere and a cooling section for cooling the tempered molded article.

Referring to FIG. 3, the muffle 220 has a structure in which a reinforcing plate 231 for reinforcing is integrally welded to the outer peripheral surface.

It is preferable that the reinforcing plate 231 is configured in a lattice pattern so as to have a sufficient rigidity with respect to the load transmitted in the longitudinal direction and the transverse direction.

Referring to FIG. 3, the muffle 220 has a structure in which the upper and lower surfaces 222 and 224 are formed to be bent in the directions in which the upper and lower surfaces 222 and 224 are integrally welded after being superimposed to overlap with the side wall 225.

The upper surface 222 and the lower surface 224 of the muffle 220 are hermetically welded to the side wall 225 to improve the durability of the muffle 220.

4, it is preferable that the present invention further includes opening / closing means 400 provided at the inlet side of the roaster 210 for opening and closing the inlet, and the opening / A door gate 410 which is provided so as to be vertically movable up and down on the inlet side of the body 210 and which opens and closes the inlet of the body 210 and a rod 425 linked to the door gate 410, And a cylinder 420 to which the gas is supplied.

The cylinder 420 is provided on the inlet of the rotor 210 and has a structure in which the rod 425 is operated up and down by hydraulic pressure or pneumatic pressure.

The door gate 410 is made of refractory material and a groove 412 is formed at the lower center to prevent interference with the conveyor 310 when the rod 425 is lowered.

The present invention is also applicable to an air injection nozzle 510 for ejecting compressed air to a molded product entering the inside of the muffle 220 to remove cooling water when the cooling water is present in the molded product conveyed through the first cooling zone 130 ).

The air injection nozzle 510 may be disposed in the groove 412 or may be disposed at the entrance side of the roaster 210 or the door gate 410 to inject the roaster 210 in the tempering portion 200, It is possible to quickly cool the molded article to the desired temperature in the tempering section 200 before entering the mold.

Reference numeral 150 denotes a driving unit 150 for driving the conveyor 310. [

In the continuous sintering tempering according to the present invention having such a configuration, the driving unit 150 circulates the conveyor 310, and when the plastic molded product is placed on the conveyor 310 circulatingly driven by the driving unit 150, 310 through the sintered portion 100 and the tempering portion 200 in a state where the molded product is seated.

The molded product passing through the sintering section 100 is preheated in a preheating zone 110 of the sintering section 100 at a temperature higher than a predetermined temperature and then heated by the SiC heating element and the thermocouple in the sintering zone 120, A sintering treatment operation is performed.

At this time, when the sintering zone 120 reaches the temperature of 700 to 800 ° C, the NH ₃ gas is supplied after the N ₂ gas is supplied and then the H ₂ gas is continuously supplied to cut off the outside air.

Thereafter, the sintered molded article is cooled before entering the tempering section 200 due to the cooling water injected from the cooling water supply section 135 in the course of passing through the first cooling zone 130.

The molded article cooled by the cooling water is rapidly cooled to a temperature range in which the temperature of the molded article is to be tempered by the injection of the compressed air injected from the air injection nozzle 510, And enters the interior.

5A, the door gate 410 is moved by the rod 425 to the conveyor 310 before the molded product is advanced into the loose body 210 of the tempering part 200. At this time, It is possible to eliminate the interference with the molded product which enters the interior of the rotor 210 of the tempering part 200. After the molded product enters the interior of the rotor 210, The rod 425 of the rod body 210 is lowered and the door gate 410 interlocked with the lowering motion of the rod 425 is lowered to seal the inlet of the rod body 210.

Accordingly, the door gate 410 can open and close the inlet, which is a passage through which the molded product enters the interior of the interior of the interior of the interior of the interior of the interior of the interior of the interior of the interior of the interior of the interior of the interior space 210, .

Thereafter, the tempering unit 200 heats the molded product that has entered the muffle 220 in an air atmosphere by raising the internal temperature by using a SiC heating element, which is heating means provided in the furnace body 210 of the tempering part 200 And a tempering process in which cooling is performed while passing through the second cooling zone 240 which is the cooling zone after performing the tempering process.

Accordingly, the present invention can be applied to a sintering and tempering process of a powder metallurgical product through a sintering process and a tempering process, The time can be shortened and the workability can be improved.

100: Sintered part 110: Preheating zone
120: sintering zone 130: first cooling zone
135: cooling water supply unit 150:
200: Tempering section 210:
220: muffle 222, 224: upper and lower surfaces
225: side wall 230: tempering zone
231: reinforcement plate 240: second cooling zone
310: Conveyor 400: opening / closing means
410: door gate 412: groove
420: cylinder 425: rod
510: air jet nozzle

Claims (5)

A sintering section 100 consisting of a preheating zone 110 having respective chambers, a sintering zone 120, and a first cooling zone 130, and the sintered body being sintered while being conveyed by the conveyor 310; And
A tempering zone 230 disposed on the conveyor 310 and provided with a muffle 220 inside the furnace 210 for tempering the continuously transported product through the first cooling zone 130, And a second cooling zone (240) through which the tempered product is cooled while passing through the tempering zone (230)
The opening and closing means 400 is provided on the inlet side of the furnace body 210 of the tempering unit 200 so that the furnace body 210 can be lifted up and down A door gate 410 for opening and closing the inlet of the loose body 210 and a cylinder 420 for applying the upward and downward force to the door gate 410. In the continuous sintering tempering, The method according to claim 1,
The upper surface 222 and the lower surface 224 of the muffle 220 are formed to be bent with respect to the left and right side walls 225 and the bent upper and lower surfaces 222 and 224 are welded to the left and right side walls 225 Wherein the sintering temperature of the sintered body is in the range of from about 1 to about 10 seconds. The method according to claim 1,
Wherein a reinforcing plate (231) in the form of a lattice is integrally welded to the outer surface of the muffle (220). The method according to claim 1,
Further comprising an air injection nozzle (510) provided in the door gate (410) for spraying compressed air to a molded product entering into the muffle (220). The method of claim 4,
Wherein the air injection nozzle (510) is disposed in a groove (412) provided in the door gate (410).

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