JP2004076067A - Die, punch and molding apparatus and manufacturing method of them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die in which the degree of smoothness and flatness of a product is increased when base-material powder is compressed for molding and to provide a punch, a molding apparatus and a method for manufacturing it. <P>SOLUTION: A sintered die 11, a lower punch 12 and an upper punch 13 are formed so that respective surfaces have a minute and flat face. That is, the sintered die 11 consists of ultrafine particles of a sintered hard metal having average particle diameter of 0.2-0.5 μm as base-material powder, for example ultrafine particles such as tungsten carbide. The lower punch 12 and the upper punch 13 consist of ultrafine particles of a conductive ceramics having average particle diameter of 0.2-0.5 μm as the base-material powder, for example, zirconia base ultrafine particles. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a die and a punch for sintering for compressing and molding a base material powder, a molding apparatus having the die and the punch, and a method of manufacturing the same.
[0002]
[Prior art]
2. Description of the Related Art As a molding apparatus, particularly a molding apparatus for molding a small module product (molded product), there is a molding device in which a die and a punch are formed by a sintering process. These sintered dies and punches are each formed of a base material powder having an average particle size of about several μm in order to increase the surface accuracy of the surface of the small module product.
In other words, the base material powder of a cemented carbide having an average particle size of about several μm is compressed to form a die compact, and the base material powder of an alloy tool steel having the same average particle size is compressed. After the molded bodies for punches are formed, they are sintered to form an intermediate for die from a molded body for die, and an intermediate for punch from the molded body for punch. A sintered die and a sintered punch are formed.
[0003]
When the molding device molds a small module using the sintering die and the sintering punch formed as described above, the surface accuracy of the molding hole of the sintering die is transferred to the outer peripheral surface of the small module. At the same time, the surface accuracy of the front end surface of the sintered punch is transferred to the upper and lower surfaces of the small module product, so that the surface of the small module product can obtain good surface accuracy.
[0004]
[Problems to be solved by the invention]
However, when a conventional molding apparatus molds a small module product having an outer diameter of several mm as a molded product, for example, a sintering die and a sintering punch formed of a base material powder having an average particle size of about several μm are used. Even with the use of (1), there is a problem that the unevenness of the surface of the module product becomes conspicuous because the molded module product is small.
That is, even if the sintering die and the sintering punch are formed of the base material powder having the above-mentioned particle diameter, as shown in FIG. 4, holes b (open pores) are generated between the base material powders a. Since the cavities b are present between the respective base material powders a, even if the surface is finished no matter how much the surface can be finished, it can only be finished to a certain surface roughness or more. It was difficult to make the surface irregularities smaller than that.
[0005]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a sintering die, a sintering punch, and a molding apparatus capable of improving the smoothness of a molded product. The purpose is to provide a method for its manufacture.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention proposes the following means.
The invention according to claim 1 is a die which has been subjected to a sintering process for forming a desired molded product by compressing a molded product raw material powder filled in a molding hole with a punch, and having an average of 0.2 to 0.5 μm. It is characterized by being formed of a base material powder having a particle size.
[0007]
According to the die according to the present invention, since the die is formed of the base material powder having an average particle size of 0.2 to 0.5 μm, the size of the open pores generated between the particles is minimized, and the open pores are conspicuous. There is no danger, and the peripheral surface of the forming hole can be formed with a fine flatness. Thereby, the surface roughness of the molded article formed by using the above-mentioned die can be improved, and as a result, the densification between particles of the molded article can be provided. Further, when the molded product is extracted from the die, the frictional resistance between the molded product and the die can be reduced, so that the life of the die can be extended.
[0008]
The invention according to claim 2 is a sintered punch which is inserted into a molding hole of a die and compresses a raw material powder filled in the molding hole of the die to form a desired molded product. ,
It is characterized by being formed of a base material powder having an average particle size of 0.2 to 0.5 μm.
[0009]
According to the punch according to the present invention, since the punch is formed of the base material powder having an average particle diameter of 0.2 to 0.5 μm, the tip of the punch can be formed with a fine flatness. As a result, the surface roughness of a molded article formed by using the punch can be improved, and as a result, a high density between particles of the molded article can be provided.
[0010]
According to a third aspect of the present invention, there is provided a molding apparatus including the die according to the first aspect and the punch according to the second aspect.
According to the molding apparatus according to the present invention, by providing the above-described die and punch, a molded article having a high surface smoothness can be obtained, so that not only a high-quality molding apparatus can be obtained, but also various small module products. Can be easily dealt with. Further, as a result, the frictional resistance between the die and the punch is reduced, so that the life of the die and the punch can be extended.
[0011]
According to a fourth aspect of the present invention, in the molding apparatus according to the third aspect, the die and the punch are configured for molding a molded product having an outer diameter of φ2 to φ6 mm.
ADVANTAGE OF THE INVENTION According to the shaping | molding apparatus which concerns on this invention, since a small-sized molded article can be formed in a dense and smooth surface, even if it is small, there is no possibility that an open pore will stand out and a favorable molded article can be formed.
[0012]
The invention according to claim 5 is the molding apparatus according to claim 3 or 4, wherein the sintered die and the sintered punch are configured for gear molding.
According to the forming apparatus of the present invention, since the gear is formed by the die and the punch, the entire surface of the gear, that is, the outer peripheral surface and both end surfaces of the gear can be formed into a dense flat surface. Thereby, especially the hardness of the gear portion of the gear can be increased, and a good gear can be obtained even if the gear is small.
[0013]
The invention according to claim 6 is to form a molded body for die by compressing the base material powder, and then sinter the molded body for die to form an intermediate for die. In a die manufacturing method for manufacturing a die by performing a straightening finish, the die compact is formed of a base material powder having an average particle diameter of 0.2 to 0.5 μm.
[0014]
According to the method of manufacturing a die according to the present invention, it is only necessary to change the average particle size of the base material powder, so that a high-density flat die can be reliably obtained.
[0015]
The invention according to claim 7 is that the base material powder is compressed to form a molded body for punch, and then, the molded body for punch is sintered to form an intermediate for punch. A method for manufacturing a punch, wherein a punch is formed by performing a correction finish, wherein the molded body for punch is formed of a base material powder having an average particle diameter of 0.2 to 0.5 μm.
[0016]
According to the method for manufacturing a sintered punch according to the present invention, it is only necessary to change the average particle size of the base material powder, so that a high-density flat-surface sintered punch can be reliably obtained.
[0017]
The invention according to claim 8 is a molding step of compressing a base material powder to form a molded body for a die and a molded body for a punch, and sintering the molded body for a die and the molded body for a punch to form an intermediate for a die. A sintering step of forming a body and a punch intermediate, and a straightening step of straightening and finishing a die intermediate and a punch intermediate. Is characterized in that a base material powder having an average particle size of 0.2 to 0.5 μm is compressed to form a molded body for a die and a molded body for a punch, respectively.
[0018]
ADVANTAGE OF THE INVENTION According to the manufacturing method of the shaping | molding apparatus which concerns on this invention, since only the average particle diameter of the base material powder handled in a shaping | molding process was changed, a high-density die and a punch can be easily manufactured without changing a manufacturing process. it can.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 3 are views showing a molding apparatus according to an embodiment of the present invention. FIG. 1 is a schematic diagram showing the molding apparatus, FIG. 2 is an enlarged sectional view showing a main part of the molding apparatus, and FIG. FIG. 3 is a cross-sectional view showing a molded product formed by a sintering die and a sintering punch of the forming apparatus, corresponding to the line AA in FIG. 2.
The sintering apparatus 10 according to this embodiment is roughly provided with a sintering die (die) 11 and a sintering punch (punch) including a lower punch 12 and an upper punch 13 as shown in FIG. ing.
The sintered die 11 is provided with a forming hole 11a for forming the outer periphery of the molded product, and is fitted to, for example, a die mounting body 14 and fixed by shrink fitting or the like. The die attaching body 14 is attached to the lower holder 15 via bolts B, and the upper holder 16 is fixed on the upper surface so as to overlap.
[0020]
At the time of molding a molded product using the sintering apparatus 10, the lower punch 12 of the sintering punch passes through the guide member 17 provided on the lower holder 15 so that the upper end face 12 a of the lower punch 15 forms the forming hole of the sintering die 11. 11a is inserted into a predetermined position. The upper punch 13 faces downward when the lower punch 12 is fitted and inserted into the molding hole 11a and the molding material raw powder 19 for forming a molding is filled in the molding hole 11a as shown in FIG. Is pressed down into the forming hole 11a to compress the raw material powder 19 in the forming hole 11a and is defined by the forming hole 11a, the lower punch 12, and the upper punch 13. The molded article is formed in the space.
[0021]
In this embodiment, as shown in FIG. 3, the molded product is a gear 20 having an outer diameter of about 2 mm having a gear portion 21 on the outer periphery. Therefore, the peripheral surface of the molding hole 11a of the sintered die 11 is While being formed in a shape corresponding to the outer periphery of the gear portion 21 of the gear 20, the tip surfaces 12a, 13a of the lower punch 12 and the upper punch 13 are also formed in a shape corresponding to the forming hole 11a. Then, when the gear 20 is formed, it is heated and sintered in a sintering furnace, and then is subjected to a correction finish, thereby finally being formed as a sintered gear.
[0022]
The lower punch 12 and the upper punch 13 are formed with holes 12b and 13b on the axis thereof, and the core rod 18 is inserted into these holes. The insertion hole 22 is provided by being located. The forming hole 11a of the sintering die 11 is finished by, for example, applying a shape by, for example, electric discharge machining and then processing it with a special wrap (finishing) rod.
[0023]
The sintered die 11 and the sintered punches of the lower punch 12 and the upper punch 13 are formed through the same processing steps as the gear 20 described above. In other words, the sintered die 11 is first formed into a molded body for a die by compressing the base material powder (molding step), and then subjected to a sintering process on the molded body for a die to form an intermediate for the die. Is formed (sintering step), and then, the die intermediate is subjected to corrective finishing (sizing) (corrective finishing step) to form a sintered die 11 having a predetermined size. The same applies to the lower punch 12 and the upper punch 13, where a molded body for punch is formed by the base material powder (molding step), and then the molded body for punch is sintered to form an intermediate for punch. (Sintering step) After that, the punch intermediate is subjected to corrective finishing (sizing) (corrective finishing step), so that it is formed on the lower punch 12 and the upper punch 13 of a predetermined size.
[0024]
In this embodiment, the surface of each of the sintered die 11, the lower punch 12, and the upper punch 13 is formed as a dense flat surface. That is, the sintering die 11 is formed using ultrafine particles of a cemented carbide having an average particle size of 0.2 to 0.5 μm as a base material powder, and is made of, for example, tungsten carbide type ultrafine particles. The lower punch 12 and the upper punch 13 are also made of conductive ceramic ultrafine particles having an average particle diameter of 0.2 to 0.5 μm as a base material powder, and are made of, for example, zirconia-based ultrafine particles.
Therefore, the sintered die 11 is formed by molding a die molded body with a base material powder having an average particle size of 0.2 to 0.5 μm, and the lower and upper punches 12 and 13 have the same base material. It is formed by molding a compact for punching with powder.
[0025]
As described above, if the peripheral surface of the forming hole 11a of the sintering die 11 and the tip surfaces 12a, 13a of the lower punch 12 and the upper punch 13 are formed on a dense flat surface, the gear formed by them is formed. 20 can surely be increased in smoothness.
In other words, when the sintered die 11 and the punches 12 and 13 are formed of a base material powder having an average particle size of 0.2 to 0.5 μm and are finished, the particle density can be increased accordingly. In addition, not only do the particles gather densely, but also the size of the open pores generated between the particles is reduced (see FIG. 4), and the open pores are not likely to be conspicuous. The surface and the tip portions of both punches 12 and 13 can be formed into a dense flat surface.
[0026]
Therefore, by transferring the peripheral surface of the sintered die 11 forming the forming hole 11a to the outer peripheral surface of the gear portion 21 of the gear 20, the outer peripheral surface of the gear portion 21 can be reliably formed into a dense smooth surface. Can be. In addition, since the tip surfaces of the lower punch 12 and the upper punch 13 are transferred to the upper and lower surfaces of the gear 20, the upper and lower surfaces of the gear 20 can be reliably formed into a dense and smooth surface.
[0027]
As a result, as compared with the conventional molded product formed by the sintered die 11 and the punches 12 and 13 formed of the base material powder having an average particle size of several μm, the gear 20 is a small module product of about 2 mm. Even so, the smoothness of the entire surface of the gear 20 can be reliably increased. Further, when the gear 20 is extracted from the die 11, the frictional resistance between the gear 20 and the die 11 can be reduced, so that the life of the die 11 can be extended. In addition, since the frictional resistance between the die 11 and the punches 12 and 13 is reduced, the life of the punches 12 and 13 as well as the sintered die 11 can be extended.
[0028]
Since the molding apparatus 10 includes the above-described sintering die 11 and the sintering punch, the gear 20 having a surface with high smoothness can be obtained, so that a high-quality molding apparatus 10 can be manufactured. In addition, various small module products can be easily dealt with.
In particular, in this embodiment, when the entire surface of the gear 20, that is, the outer peripheral surface and both end surfaces of the gear 20 are formed into a dense and smooth surface, the gear portion of the gear 20 is particularly applied to the gear 20 as a small module product. The hardness of the gear 21 can be increased, and a good gear 20 can be obtained even if it is small.
[0029]
According to the molding apparatus 10, both the sintering die 11 and both the punches 12 and 13 can be formed only by changing the average particle diameter of the base material powder. 11 and both punches 12 and 13 can be reliably obtained. In addition, since only the average particle size of the base material powder handled in the molding process is changed, both the high-density sintering die 11 and both the punches 12 and 13 can be easily manufactured without changing the manufacturing process. Can be manufactured.
[0030]
In this embodiment, an example is shown in which all of the sintered die 11, the lower punch 12, and the upper punch 13 are formed of the base material powder having the above-described average particle diameter. However, it is sufficient that at least a portion for forming the gear 20 is made of the same material. Therefore, in the sintered die 11, the peripheral surface for forming the forming hole 11a, and the tip surface for the lower punch 12 and the upper punch 13 The portions forming 12a and 13a may be made of the base material powder having the above-described average particle size.
In addition, although an example in which the gear 20 is formed to have an outer diameter of 2 mm has been described, in the present invention, a gear having a smaller diameter can be reliably manufactured. This is extremely useful for the production of gears consisting of:
[0031]
【The invention's effect】
As described above, according to the first aspect of the invention, the die is formed of the base material powder having an average particle size of 0.2 to 0.5 μm, and the particle density can be increased. Is not only densely packed, but also the size of the open pores generated between the particles is reduced and the open pores are not likely to be conspicuous, so that the effect that the peripheral surface of the forming hole can be formed to a fine flatness can be obtained. can get. Further, when the molded product is extracted from the die, the frictional resistance between the molded product and the die can be reduced, so that the life of the die can be extended.
[0032]
According to the second aspect of the present invention, the punch is also formed of the base material powder having the same average particle size as in the first aspect, so that the particle density can be increased and the open pores are not likely to be conspicuous. The effect is obtained that the portion can be reliably formed on a dense smooth surface.
[0033]
According to the third aspect of the present invention, a molded product having a high surface smoothness can be obtained by providing the above-mentioned die and punch, so that not only a high-quality molding device can be obtained, but also various small module products. This also provides an effect that can be easily dealt with. Further, since the frictional resistance between the die and the punch is reduced, the life of the die and the punch can be extended.
[0034]
According to the fourth aspect of the present invention, since a small-sized molded product can be formed on a dense and smooth surface, even if it is a small-sized product, there is no fear that open pores are conspicuous, and an effect of forming a good molded product can be obtained.
[0035]
According to the invention according to claim 5, since the gear is formed by the die and the punch, the outer peripheral surface and both end surfaces of the gear can be formed into a dense flat surface. Thus, the effect that a good gear can be obtained is obtained.
[0036]
According to the invention of claim 6, since it is only necessary to change the average particle size of the base material powder, the effect of reliably obtaining a high-density flat surface die can be obtained.
[0037]
According to the invention according to claim 7, since it is only necessary to change the average particle size of the base material powder, an effect of reliably obtaining a high-density flat surface punch can be obtained.
[0038]
According to the invention of claim 8, since only the average particle size of the base material powder handled in the molding process is changed, the effect that the high-density die and punch can be easily manufactured without changing the manufacturing process is obtained. can get.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a molding apparatus according to an embodiment of the present invention.
FIG. 2 is an enlarged sectional view showing a main part of the molding apparatus of FIG.
FIG. 3 is a cross-sectional view showing a molded product formed by a die and a punch of the molding device, corresponding to a line AA of FIG. 2;
FIG. 4 is an enlarged view showing the surface structure of a conventional die and punch.
[Explanation of symbols]
10 Forming device 11 Sintered die (die)
11a Forming hole 12 of sintered die Lower punch (punch)
12a Tip surface 13 of lower punch 13 Upper punch (punch)
13a Tip surface 19 of upper punch 19 Raw material powder 20 of molded product Gear 21 as small module product (molded product) Gear portion of gear

Claims (8)

A sintered die that forms a desired molded product by compressing a molded product raw material powder filled in a molding hole by a punch,
A die formed of a base material powder having an average particle size of 0.2 to 0.5 μm. A sintered punch that is inserted into the molding hole of the die and compresses the raw material powder filled in the molding hole of the die to form a desired molded product,
A punch formed of a base material powder having an average particle size of 0.2 to 0.5 μm. A molding apparatus comprising the die according to claim 1 and the punch according to claim 2. The molding apparatus according to claim 3,
The molding apparatus, wherein the die and the punch are configured for molding a molded product having an outer diameter of φ2 to φ6 mm. The molding device according to claim 3 or 4,
The molding device, wherein the sintering die and the sintering punch are configured for gear molding. The base material powder is compressed to form a die compact, and then the die compact is sintered to form a die intermediate, and then the die intermediate is straightened to produce a die. In a method of manufacturing a die,
A method for manufacturing a die, comprising forming the molded body for a die with a base material powder having an average particle diameter of 0.2 to 0.5 μm. The base material powder is compressed to form a molded body for punch, and then the molded body for punch is sintered to form an intermediate for punch, and then the intermediate for punch is straightened to produce a punch. In the method of manufacturing a punch,
A method for manufacturing a punch, wherein the molded body for a punch is formed from a base material powder having an average particle size of 0.2 to 0.5 μm. A molding step of compressing the base material powder to form a molded body for a die and a molded body for a punch, and sintering the molded body for a die and the molded body for a punch to form an intermediate for a die and an intermediate for a punch A sintering step, and a method of manufacturing a die and a punch through a straightening step of straightening and finishing a die intermediate and a punch intermediate in order,
The method of manufacturing a molding apparatus, wherein the molding step comprises compressing a base material powder having an average particle size of 0.2 to 0.5 μm to form a molded body for a die and a molded body for a punch.

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