JP4519302B2 - Sintered product manufacturing apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and a method for manufacturing a sintered product using a sintering furnace having an improved dewaxing portion.
[0002]
[Prior art]
Generally, in a sintering furnace, if the dewaxing gas flows into the sintering chamber, the furnace may be contaminated, so the lubricant in the green compact that is the molded product is removed prior to sintering. It has a dewaxing section.
Conventionally, a dewaxing section provided in a sintering furnace is burned or decomposed or decomposed by heating the lubricant in the green compact to prevent the furnace from being contaminated by the dewaxing gas. It is structured to discharge outside the furnace. FIG. 4 shows an example of the configuration of such a conventional sintering furnace.
In the figure, the sintering furnace 1 is provided with an endless belt 2, and when the molded product is carried into the dewaxing section 3 by driving the belt 2, the gas burner 4 disposed in the dewaxing section 3. However, the lubricant is burned or decomposed by directly heating the article to be molded. The burned or decomposed lubricant is exhausted from the exhaust duct 5 as dewaxing gas.
Further, the molded product dewaxed by the dewaxing portion 3 is conveyed downstream by the belt 2 and is sintered by passing through a sintering chamber (not shown) to become a sintered product.
[0003]
[Problems to be solved by the invention]
By the way, since the dewaxing part 3 of the sintering furnace 1 according to the prior art uses the gas burner 4, there is an advantage that an energy saving effect can be obtained as compared with the heater type.
However, in the method of manufacturing a sintered product using the sintering furnace 1, the molded product in the dewaxed portion is directly heated by the gas burner 4 to burn or decompose the lubricant in the molded product. There is a possibility that non-uniformity may occur in the combustion or decomposition of the agent, and if the sintering process is carried out as it is, defective products will be abnormally produced, resulting in a decrease in yield.
[0004]
The present invention has been made in view of the above-mentioned problems of the prior art. The lubricant contained in the molded product can be burned or decomposed substantially uniformly to obtain a high-quality sintered product and to improve the yield. An object of the present invention is to provide a sintered product manufacturing apparatus and a manufacturing method capable of achieving the above.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention employs the following means.
[0006]
In the invention according to claim 1, the molded product is conveyed to the sintered product by sequentially transporting the molded product to the dewaxing section, preheating chamber, sintering chamber, and cooling zone provided in the sintering furnace. An apparatus for manufacturing a sintered product, wherein the dewaxing portion includes a muffle disposed therein, and heating means for indirectly heating the inside of the muffle to obtain an indirect heating atmosphere temperature. The heating means faces the outer surface of the muffle, faces one gas burner disposed toward the upper portion of one side surface of the muffle, and moves toward the lower portion of the opposite side surface facing the one side surface. The other gas burner is arranged so that the flame flow by the one gas burner travels from the outer upper part of the side surface to the upper side of the muffle in the direction of the opposite side surface, and the flame by the other gas burner. The flow is opposite It is comprised so that it may go to the said side surface direction along the said muffle from the lower part of the outer side of a surface, and the lubricant contained in the said molded article is removed by burning or decomposing | disassembling in the said indirect heating atmosphere temperature. It is characterized by that.
The invention according to claim 2 is the sintered product manufacturing apparatus according to claim 1, wherein the one gas burner gradually moves upward as it approaches the one side surface of the muffle. The other gas burner is disposed so as to be inclined with respect to the opposing side surface so as to gradually move downward as it approaches the opposing side surface of the muffle. It is characterized by.
[0007]
According to the third aspect of the present invention, the molded product is transferred to the sintered product by sequentially conveying the molded product to the dewaxing section, preheating chamber, sintering chamber, and cooling zone provided in the sintering furnace. A method for manufacturing a sintered product, wherein the dewaxing portion has a muffle disposed therein, and heating means for indirectly heating the inside of the muffle to obtain an indirect heating atmosphere temperature. The heating means faces the outer surface of the muffle, faces one gas burner disposed toward the upper portion of one side surface of the muffle, and moves toward the lower portion of the opposite side surface facing the one side surface. The other gas burner is arranged so that the flame flow by the one gas burner travels from the outer upper part of the side surface to the upper side of the muffle in the direction of the opposite side surface, and the flame by the other gas burner. The flow is opposite Are composed of outer lower surface to turn into the side direction along the lower side of the muffle, is removed by combustion or to decompose the lubricant contained in the object to be molded article in the indirect heating atmosphere temperature It is characterized by that.
Furthermore, the invention according to claim 4 is the method for manufacturing a sintered product according to claim 3 , wherein the gas burner is disposed so as to incline along one of the outer peripheral directions of the muffle. It is characterized by being.
[0008]
According to the third aspect of the present invention, the molded product is transferred to the sintered product by sequentially conveying the molded product to the dewaxing section, preheating chamber, sintering chamber, and cooling zone provided in the sintering furnace. A method for manufacturing a sintered product, wherein the dewaxing portion has a muffle disposed therein, and heating means for indirectly heating the inside of the muffle to obtain an indirect heating atmosphere temperature. The heating means faces the outer surface of the muffle, faces one gas burner disposed toward the upper portion of one side surface of the muffle, and moves toward the lower portion of the opposite side surface facing the one side surface. The other gas burner is arranged so that the flame flow by the one gas burner travels from the outer upper part of the side surface to the upper side of the muffle in the direction of the opposite side surface, and the flame by the other gas burner. The flow is opposite It is comprised so that it may go to the said side surface direction along the said muffle from the lower part of the outer side of a surface, and the lubricant contained in the said molded article is removed by burning or decomposing | disassembling in the said indirect heating atmosphere temperature. It is characterized by that.
Furthermore, the invention according to claim 4 is the method for manufacturing a sintered product according to claim 3, wherein the one gas burner gradually moves upward as it approaches the one side surface of the muffle. The other gas burner is disposed so as to be inclined with respect to the opposing side surface so as to gradually move downward as it approaches the opposing side surface of the muffle. It is characterized by.
[0009]
Further, if the heating means is constituted by a gas burner and the flame flow by the gas burner is moved along the outer periphery direction of the muffle of the dewaxing portion, the inside of the muffle can be easily brought to a uniform indirect heating atmosphere temperature. It is possible to make the combustion or decomposition of the lubricant in the molded article more uniform.
[0010]
Furthermore, if the gas burner is disposed so as to be inclined along one of the outer peripheral directions of the muffle, the flame flow can be easily moved along the outer peripheral direction of the muffle.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a sintered product manufacturing apparatus and manufacturing method according to the present invention will be described below with reference to FIGS. FIG. 1 is a schematic view showing a manufacturing apparatus, that is, a sintering furnace for carrying out a method for manufacturing a sintered product according to the present invention, and FIG. 2 is a cross-sectional explanatory view showing a dewaxing portion in the sintering furnace.
[0012]
The sintering furnace (manufacturing apparatus) 10 is applied to, for example, a muffle type mesh belt furnace, and as shown in FIG. Then, the lubricant contained in is burned or decomposed, then passed through the preheating chamber 12, the molded product is heated to a predetermined temperature, further sintered in the sintering chamber 13, and then downstream of the sintering chamber 13. By passing through the cooling zone 15 through the slow cooling section 14, a molded product having predetermined physical and mechanical characteristics and dimensional accuracy is obtained. Accordingly, the molded product is conveyed from the left side to the right side in FIG. 1 by the mesh belt, and sequentially passes through the dewaxing portion 11, the preheating chamber 12, the sintering chamber 13, the slow cooling portion 14, and the cooling zone 15.
[0013]
And the dewaxing part 11 heats the muffle (furnace core tube) 21 provided inside, and makes the inside of the dewaxing part an indirect heating atmosphere temperature, thereby burning or decomposing the lubricant in the molded product. It has a heating means.
As the heating means, for example, as shown in FIG. 2, two gas burners 22 and 23 are provided in the dewaxing portion 11 so as to face the outer surface portion of the muffle 21 disposed inside. Of the two burners, one gas burner 22 is arranged so as to go to the upper part of one side surface 21a of the muffle 21, and the other gas burner 23 is arranged so as to go to the lower part of the side surface 21b facing it. When each of the burners 22 and 23 heats the outside of the muffle 21, the flame flow caused by one gas burner 22 travels from the outer upper part of the side surface 21a through the top plate portion 21c toward the opposite side surface 21b, The flame flow caused by the other gas burner 23 is rotated from the opposite side surface 21b to the side surface 21a through the mesh belt 17 below, and the exhaust gas from the gas burner flame is exhausted from below as indicated by the arrow a from below. Exhaust by means (not shown).
[0014]
Accordingly, the heating means heats the muffle 21 from the outside by the two gas burners 22 and 23, and the flame flow of the gas burners 22 and 23 moves the muffle 21 along the circumferential direction from the outside, thereby The inside is generated at an indirect heating atmosphere temperature (about 600 to 700 ° C.), so that the indirect heating atmosphere temperature is substantially uniform in the region where the molded product is conveyed. Therefore, the gas burners 22 and 23 are disposed so as to face the muffle 21 straight so that the flame flow moves along the outer peripheral direction of the muffle 21.
Other than this, for example, as shown in FIG. 3, the gas burners 22 and 23 are arranged so as to have an inclination angle along one of the outer peripheral directions of the muffle 21, and the flame flow follows the outer peripheral direction of the muffle 21. The distance between the outer shell of the dewaxing portion 11 and the muffle 21 may be appropriately selected.
[0015]
The lubricant burned or decomposed in the muffle 21 is exhausted by a dewaxing gas exhausting means (not shown) as dewaxing gas. As this dewaxing gas exhaust means, for example, the same exhaust duct 5 as shown in FIG.
Further, the molded product dewaxed by the dewaxing section 11 is then conveyed downstream, preheated in the preheating chamber 12 and then sintered in the sintering chamber, and gradually cooled in the slow cooling section 14 and the cooling zone 15. And it is cooled to room temperature and becomes a sintered product.
[0016]
In the sintered product manufacturing apparatus and manufacturing method according to the present embodiment, the muffle 21 in the dewaxing section 11 is heated from the outside by gas burners 22 and 23 as heating means, whereby the inside of the muffle 21 is indirectly heated. Since the ambient temperature is set, the temperature inside the muffle 21 can be made uniform, unlike the case where the lubricant in the molded article is directly burned or decomposed by the gas burner as in the prior art. The gas flow of the dewaxing gas is not disturbed, and the preheating effect can be enhanced.
Therefore, it becomes possible to remove the lubricant in the molded article carried into the dewaxing portion 11 almost uniformly by combustion or decomposition, and as a result, a high-quality sintered product can be obtained, Yield can be improved.
[0017]
Further, since the flame flow by the gas burners 22 and 23 is moved along the outer peripheral direction of the muffle 21, the inside of the muffle 21 can be easily set to a uniform indirect heating atmosphere temperature, and the molded product The combustion or decomposition of the lubricant in the inside can be made more uniform.
[0018]
Furthermore, if the gas burners 22 and 23 are arranged so as to be inclined along one of the outer peripheral directions of the muffle 21, the flame flow can be easily moved along the outer peripheral direction of the muffle 21, A predetermined indirect heating atmosphere temperature can be achieved in a short time, and a higher energy saving effect can be obtained.
[0019]
【The invention's effect】
As described above, according to the sintered product manufacturing apparatus and manufacturing method of the present invention, the lubricant contained in the molded product can be burned or decomposed substantially uniformly to obtain a high-quality sintered product. At the same time, it is possible to provide a method for producing a sintered product that can improve the yield.
[Brief description of the drawings]
FIG. 1 is a side view of a sintered product manufacturing apparatus according to an embodiment of the present invention, that is, a sintering furnace.
FIG. 2 is a cross-sectional view showing a dewaxing portion of the sintering furnace in FIG.
FIG. 3 is a cross-sectional view showing another example of the dewaxing portion in FIG. 2;
FIG. 4 is a side sectional view showing an example of a dewaxing portion in a conventional sintering furnace.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Sintering furnace (manufacturing apparatus), 11 ... Dewaxing part, 21 ... Muffle (furnace core tube), 22, 23 ... Gas burner (heating means)

Claims (4)

An apparatus for manufacturing a sintered product, in which the molded product is sequentially conveyed to a dewaxing section, a preheating chamber, a sintering chamber, and a cooling zone provided in the sintering furnace. The dewaxing portion has a muffle disposed therein, and heating means for indirectly heating the inside of the muffle to obtain an indirect heating atmosphere temperature,
The heating means faces the outer surface of the muffle, faces one gas burner disposed toward the upper part of one side of the muffle, and faces the lower part of the opposite side facing the one side. And the other gas burner is arranged so that the flame flow caused by the one gas burner travels from the outer upper part of the side surface over the muffle toward the opposite side surface and the flame flow caused by the other gas burner. Is configured to rotate in the lateral direction along the lower side of the muffle from the lower outer side of the opposing side surface,
An apparatus for producing a sintered product, wherein the lubricant contained in the molded article is removed by burning or decomposing at the indirect heating atmosphere temperature. The one gas burner is disposed so as to be inclined with respect to the one side surface so as to gradually move upward as it approaches the one side surface of the muffle,
2. The sintering according to claim 1, wherein the other gas burner is disposed so as to be inclined with respect to the opposite side surface so as to gradually move downward as it approaches the opposite side surface of the muffle. Product manufacturing equipment. This is a method for producing a sintered product in which the molded product is sequentially conveyed to a dewaxing section, a preheating chamber, a sintering chamber, and a cooling zone provided in the sintering furnace. The dewaxing portion has a muffle disposed therein, and heating means for indirectly heating the inside of the muffle to obtain an indirect heating atmosphere temperature,
The heating means faces the outer surface of the muffle, faces one gas burner disposed toward the upper part of one side of the muffle, and faces the lower part of the opposite side facing the one side. And the other gas burner is arranged so that the flame flow caused by the one gas burner travels from the outer upper part of the side surface over the muffle toward the opposite side surface and the flame flow caused by the other gas burner. Is configured to rotate in the lateral direction along the lower side of the muffle from the lower outer side of the opposing side surface,
A method for producing a sintered product, characterized in that the lubricant contained in the article to be molded is burned or decomposed and removed in the indirectly heated atmosphere temperature. The one gas burner is disposed so as to be inclined with respect to the one side surface so as to gradually move upward as it approaches the one side surface of the muffle,
The other gas burner, sintering according to claim 3, characterized in that it is arranged so as to be inclined with respect to the opposite sides as gradually directed downward according to proximity to the opposite sides of the muffle Product manufacturing method.

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