JP2652927B2 - Powder molding die, powder molding apparatus and molding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for powder molding, a molding apparatus comprising the mold, and a method for producing a molded body using the same.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conventional powder molding method is an automatic molding method represented by a floating type system comprising an upper punch 1, a lower punch 2, a die set 3 and a support for supporting them. Machine is being used. In this case, as shown in FIG. 5 (A), the die set 3 is raised in advance, the powder material 5 is supplied to the concave portion 4 formed by this and the lower punch 2, and the upper punch 1 is lowered. Forming is performed by applying a predetermined pressure between the upper punch 1 and the lower punch 2 for a certain time as shown in FIG. FIG. 5 (C)
As shown in (1), after the molding is completed, immediately after the die set 3 is lowered, the upper punch 1 is raised at a speed of 3 to 5 cm / sec, and the molded body 6 is obtained on the lower punch 2.

[0003]

However, the molding method using such a conventional molding apparatus has the following problems to be improved. 1) The releasability of the molded body 6 from the mold is not sufficient. Therefore, the release agent is included in the powder material. However, even the molded body 6 including the release agent sometimes adheres to the upper punch 1 depending on the type of the powder agent, the molding conditions, and the like. There is a case where the compact 6 does not exist on the lower punch 2 which is a predetermined position.
For this reason, inconvenience due to the adhesion to the upper punch 1, that is, problems such as the inability to collect the molded body 6 and the molded body 6 falling and being damaged may occur. 2) Also, depending on the type of powder and the use of the molded article, the use of a release agent must be avoided, and the desired release properties cannot be achieved. For example, so-called high-value-added powders such as pharmaceuticals and superconductivity-related powders cannot contain a release agent, and the molded articles have a high rate of mold release failure, unrecoverability, breakage, etc., and a large loss. For this reason, it has been difficult to automate a series of processes including the automatic handling of the compact, which is a post-process. In addition, in the case of so-called high-value-added powders such as pharmaceuticals and superconductivity-related powders, they are primarily attached to the upper punch 1 and then fall, and the molded body is displaced due to expansion of the molded body 6, that is,
In many cases, the lower punch 2 is deviated from a predetermined position, and it is difficult to perform a series of automation including automatic handling of a formed body, which is a subsequent process. 3) Further, the molded body 6 obtained from so-called high value-added powders such as pharmaceuticals and superconductivity-related powders often needs to be divided in order to evaluate physical properties thereafter. However, since the size of the generally obtained molded body 6 is small, there is a problem that it is difficult to divide the molded body after molding. Therefore, the object of the present invention is to solve the above problems, when producing a molded body by powder molding, mold release failure from the mold,
An object of the present invention is to provide a powder molding die and a molding apparatus that prevent loss due to unrecoverability, breakage and the like. It is another object of the present invention to provide a molding apparatus capable of performing a series of automation of a powder molding process by performing a mold release of a compact in a powder molding without any inconvenience. It is a further object of the present invention to provide a molding die, a molding apparatus, and a molding method, which make it possible to satisfactorily release a molded body by powder molding and facilitate division after molding.

[0004]

The object of the present invention has been achieved by the following molding apparatus and molding method. (1) A powder molding die including an upper punch, a lower punch, and a die set, wherein the upper punch has a smooth surface, and the lower punch has a convex portion whose height is higher than the surface of the lower punch.
Consists recess is a surface portion other than the convex portion, the powder molding die and having a shape in which peaks and valleys and the upper punch on the lower punch to satisfy the following relationship. D ≦ ax + by, a> b, xy = 1 c + 1 ≦ H ≦ D / 4 (where a and b are the width of the concave portion and the width of the convex portion on the lower punch , respectively, and C is the convex portion with respect to the concave portion. , X and y are integers indicating the numbers of the concave and convex portions, D is the width of the upper punch, and H is the thickness of the molded body.
The units of c, D and H are all mm. (Clear from above )
As described above, in the present invention, the surface of the concave portion is
Is equivalent to ) (2) the height c of the width a and the convex portion of the concave portion of the lower punch 1/10
≤ c / a ≤ 1/6 (1)
The mold for powder molding according to the above item. (3) A claw for pinching the compact having two claw portions at the tip is provided so as to clamp the upper punch of the mold for powder molding with the claw portion at the tip, and the claw for clamping the compact and the die set are provided. and adjustable vertical distance, further at least one of the claw portion of the tip, so as to the upper punch, is pressed against the lower to narrow the width of the lower than the upper portion of the claw portion, and, gold powder for molding A powder molding apparatus, wherein the mold is the mold described in (1) or (2). (4) A powder molding method characterized in that a powder material is supplied to the concave portion of the lower punch of the powder molding device according to (3) to obtain a compact. (5) A claw for pinching the compact having two claw portions at the tip is provided so as to clamp the upper punch of the mold for powder molding with the claw at the tip, and the claw for clamping the compact and the die set are provided. and adjustable vertical distance, further at least one of the claw portion of the tip, so as to the upper punch, is pressed against the lower to narrow the width of the lower than the upper portion of the claw portion, and, gold powder for molding A powder molding apparatus, wherein the mold is a powder molding die including an upper punch, a lower punch, and a die set.

Next, the present invention will be described with reference to one embodiment shown in the drawings. FIG. 1 is an enlarged view showing a shape of a lower punch 10 of a powder molding die as one embodiment of the present invention. In contrast, an enlarged view of a conventional lower punch 2 is shown in FIG. . FIG. 3 is a schematic diagram showing a manufacturing process of a compact using a powder compacting apparatus as one embodiment of the present invention. FIG. 4 is a perspective view of the powder molding apparatus of FIG. In FIG. 1, 11
Indicates a concave portion, and 12 indicates a convex portion. Unlike the surface of the lower punch 2 shown in FIG. 2 which is flat, the present invention is characterized in that the surface is formed with irregularities as shown in FIG. In FIG. 1, a and b are the width of the concave portion and the width of the convex portion on the lower punch , respectively, where a> b. If the width of the projection is not uniform, b is the width of the widest part. The numbers x and y of the concave and convex portions are not particularly limited, but x is 2 or more, and the upper limit is preferably 5 or less. y is one less than x. Although the number of x varies depending on the powder material to be subjected to powder molding, it is preferably 2 to 4 for superconducting-related powders and 2 to 5 for pharmaceuticals. D is the width (mm) of the upper punch 13, preferably 5 ≦ D ≦ 33, and there is a relation of D ≦ ax + by = E between this and the width E (mm) of the lower punch 10. The width of the obtained molded body is equal to the lower punch width E. Also, the width D of the upper punch 13 and the height c of the convex portion
It is necessary that the following relationship be established between the molded product and the thickness H of the molded product. c + 1 ≦ H ≦ D / 4 If the thickness H of the molded body 6 is less than c + 1, it is difficult to mold, and at the same time, cracks occur during molding, and a molded body having a desired shape cannot be obtained. When the thickness H of the molded body exceeds D / 4,
The molded body cannot be divided uniformly.

In FIG. 1, the projection on the lower punch 10 is shown in a side view of a rectangular parallelepiped. However, the projection is not limited to this shape. Any shape can be adopted as long as the shape is not larger than the bottom surface of the convex portion and is easily removed from the molded body. The material may be a conventionally used material such as stainless steel, and there is no particular limitation. The range of c / a is 1/10 ≦ c / a, depending on the type of powder and the size E and thickness H of the compact.
≤ 1/6, more preferably 1/9 ≤ c / a ≤ 1
7 If c / a is more than 1/6, it may be difficult to divide the molded body uniformly. One embodiment of the powder molding apparatus using the mold of FIG. 1 will be described with reference to FIGS. As shown in FIG. 3A, the powder material is supplied to the concave portion 4 of the powder molding die. As shown in FIG. 3B, a predetermined pressure is applied for a certain time by the upper punch 13 and the lower punch 10 to form the molded body 6. At this time, as shown in FIG. 3 (B), the claws 14 and 15 for sandwiching the molded body are extended and sandwich both sides of the upper punch 13. Of the claws 14, 15 for sandwiching the molded body, 15 is a claw portion lower portion 15 a is an upper portion 15.
It is formed narrower than b. The molded body 6 formed as shown in FIG. 3 (C) sometimes adheres to the upper punch 13 and rises with the rise of the upper punch 13 even when the claw 1 for sandwiching the molded body is raised.
Since it falls immediately upon contact with 4 and 15, it is placed on the lower punch 10 without being damaged. If it does not adhere to the upper punch 13, it is placed at a predetermined position on the lower punch 10 as it is.

The lower claw portion of the claw 15 for sandwiching the molded body is tapered so that the width of the lower portion 15a is shorter than the width of the upper portion 15b.
mm, preferably 3 mm, 3-7 mm at the top, preferably 5 mm. An elastic body 16 such as a spring or a leaf spring is provided for bringing the lower portion into contact with the upper punch 13. When using springs, the number is not particularly limited.
2 can be selected. 15 when using one spring
Can be pivotally connected at 15c, and the upper part 15b can be pressed against the upper punch by pulling the upper part 15b with a spring and rotating the lower part 15a. The spring may be provided between the two claws 14 and 15 so as to be pulled toward each other. Fig. 3 (D) after molding
As shown in (2), the claw for holding the molded body is retracted and removed. FIG. 4 is an overall perspective view of the molding apparatus shown in FIG. 17 in the figure
Is a mechanism for moving the claw for holding the compact, and 18 is an upper plate. The same reference numerals as those in FIG. 3 indicate the same components. As shown in FIG. 4, the claw 15 for holding the formed body is installed horizontally on the die set 3, but the lowermost part of the claw 15 for holding the formed body is not necessarily perpendicular to the upper surface of the die set 3. No need,
It must be determined in consideration of the shapes of the molded body sandwiching claws 14 and 15 described below, the thickness H of the molded body, the diameter of the punch, and the like. Therefore, 0 to 0 in the vertical direction of the die set 3.
Allow 50 mm movement. Finally, it is preferable that the vertical distance of the claw 15 for sandwiching the molded body of the die set 3 is not more than the thickness H of the molded body. The other claw portion 14 has the same size at both the uppermost portion and the lowermost portion and is 3 to 7 mm, preferably 5 mm, and the vertical distance between the lowermost portion and the uppermost portion is 10 mm.
There is no particular problem if it is up to 20 mm. Claw for sandwiching molded body 1
The total length of 5 is not particularly limited, but may be selected from 50 to 200 mm. In the present invention, at least one of the claws 14 and 15 has a narrow lower portion as described above, and comes into contact with the molded body by a spring or the like. When using metal, it is necessary that the material of the claws 14, 15 for sandwiching the molded body should be different from the element of the powder to be handled. Usually, a stainless steel rope is used, but a high polymer substance such as polypropylene, polyethylene, polytetrafluoroethylene or A metal material coated with these may be used. In this case, the metal material is not particularly limited. Further, it is preferable that the material of the spring be a commercially available material and that the spring can be replaced. FIG. 4 is an example of these conceptual diagrams, and the claw moving mechanism itself is not particularly limited, and it is sufficient to use a conventional technique.
Instead of the mold according to the present invention, a conventional mold shown in FIG. 5 can be used in the molding apparatus of the present invention.

[0008] The molding apparatus of the present invention, as a powder, M = Y,
For the production of compacts from powders of metal elements such as Ba, Bi, Fe, Sr, Cu, etc., A = oxygen or CO ₃ , α, β is an oxide or carbonate consisting of MαAβ represented by an integer and mixtures thereof. Applicable. In the present invention, an automatic molding system is preferably used. It is feasible to incorporate the mold of the present invention into an automatic molding machine in place of a conventional mold without any difficulty. Except for using this mold and providing the claws 14 and 15 for sandwiching the molded body, the molding method itself can be carried out in the same manner as a normal method.

[0009]

In the powder molding die of the present invention, the lower punch 1
0, and the contact area between the compact 6 and the compact 6 is larger than the contact area between the compact 6 and the upper punch 13 so that the powder does not adhere to the upper punch 13 and a desired division from the powder material is performed. A molded body is formed. According to the molding device of the present invention,
When the compact 6 adheres to the upper punch 13, the compact 6 always comes into contact with the claw 15 for sandwiching the compact, so that the compact 6 comes off the upper punch 13, falls, and can settle at a predetermined position of the lower punch 10.

[0010]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. The units of a, b, c, D, E, and H in the examples are all mm. Example 1 As a sample, Y ₂ O ₃ having a metal element ratio of 1: 2: ₃ ,
A mixed powder of BaCO ₃ and CuO was prepared. In FIG. 1, H = 8.25, c = 1, D = ax + by, xy =
The molding was performed by an automatic molding machine shown in FIGS. 3 and 4 incorporating the present mold under the conditions of D = 33, y = 2, a = 10, and b = 1.5. The convex portion of the lower punch 10 used was a rectangular parallelepiped. On the other hand, the shape of the molded product sandwiching claws 14 and 15 has a total length of 100, an uppermost width of 5, a lowermost width of 3, and a vertical distance of 8 between the lowermost portion and the uppermost portion. The vertical distance between the lowermost part and the die set was set to be the same as the molded product thickness H = 8.25. Table 1 shows the results of the state of adhesion to the upper punch 13, the positional deviation of the lower punch 10, and the state of division of the obtained molded body.

Example 2 The procedure of Example 1 was repeated, except that the molding conditions of Example 1 were changed to a = 6 and b = 7.5. Table 1 shows the results. Example 3 Example 3 was carried out in the same manner as in Example 1 except that the molding conditions were changed to a = 6 and D = 21. Table 1 shows the results. Example 4 The same operation as in Example 1 was carried out except that the mixture of Example 1 was changed to only Y ₂ O ₃ . Table 1 shows the results. Examples 5 to 9 In place of the mixture of Example 1, Ba, Bi, Fe, Sr or C
The same operation as in Example 1 was performed except that the oxide of u was used. Table 1 shows the results.

Example 10 The same procedure as in Example 1 was carried out except that the claws 14 and 15 for sandwiching the compact were omitted. Table 1 shows the results. Example 11 The same operation as in Example 2 was performed except that the claws 14 and 15 for sandwiching the molded body of Example 2 were omitted. Table 1 shows the results. Example 12 Example 12 was carried out in the same manner as in Example 3, except that the claws 14 and 15 for sandwiching the compact were removed. Table 1 shows the results. Example 13 The same procedure as in Example 4 was carried out except that the claws 14 and 15 for sandwiching the compact were removed. Table 1 shows the results. Examples 14 to 18 The same procedure as in Examples 5 to 9 was carried out except that the claws 14 and 15 for sandwiching the molded body of Examples 5 to 9 were omitted. Table 1 shows the results.

Comparative Example 1 The molding conditions a = 10 and b = 1.5 of Example 10 were changed to a = 5.
The same operation as in Example 10 was performed except that b was changed to 9. Table 1 shows the results. Comparative Example 2 The molding conditions a = 10 and b = 1.5 of Example 10 were changed to a = 3.
The same operation as in Example 10 was performed except that 0 and b = 0 were changed.
Table 1 shows the results. Comparative Example 3 The same procedure was performed as in Example 10 except that the molding conditions y = 2, a = 10, b = 1.5 of Example 10 were changed to y = 1, a = 1, b = 1. Table 1 shows the results. Comparative Example 4 The molding conditions a = 10 and b = 1.5 of Example 10 were changed to a = 1.
5, The procedure was the same as in Example 10, except that b was changed to 1.
Table 1 shows the results. Comparative Example 5 Molding conditions of Example 10 H = 8.25, a = 10, b =
The same operation as in Example 10 was performed except that 1.5 was changed to H = 15, a = 15, and b = 1. Table 1 shows the results. Comparative Example 6 The same procedure as in Example 10 was performed except that the molding condition H = 8.25 in Example 10 was changed to H = 1.5. Table 1 shows the results.

Example 19 Example 1 was repeated except that the mold of Example 1 was replaced with a conventional mold.
The same was done. Table 2 shows the results. Example 20 Example 3 was performed except that the mold of Example 3 was replaced with a conventional mold.
The same was done. Table 2 shows the results. Example 21 Example 4 was repeated except that the mold of Example 4 was replaced with a conventional mold.
The same was done. Table 2 shows the results. Examples 22 to 26 The same procedures were performed as in Examples 5 to 9 except that the molds of Examples 5 to 9 were replaced with conventional molds. Table 2 shows the results.

Comparative Example 7 The same procedure as in Example 1 was carried out except that the claws 14 and 15 for sandwiching the compact in Example 1 were used, and the mold was replaced with a conventional mold. Table 2 shows the results. Comparative Example 8 The same procedure as in Example 3 was carried out except that the claws 14 and 15 for sandwiching the molded body of Example 3 were used, and the mold was changed to a conventional mold. Table 2 shows the results. Comparative Example 9 The same operation as in Example 4 was performed except that the claws 14 and 15 for sandwiching the molded body of Example 4 were omitted and the mold was changed to a conventional mold. Table 2 shows the results. Comparative Examples 10 to 14 Comparative Examples 10 to 14 were carried out in the same manner as in Examples 5 to 9 except that the claws 14 and 15 for sandwiching the compacts of Examples 5 to 9 were used and the mold was changed to a conventional mold. Table 2 shows the results.

[0016]

[Table 1]

[0017]

[Table 2]

Note that the adhesion state indicates the number of adhesions to the upper punch in 100 molded bodies, and the predetermined position deviation state indicates the number of deviations from the predetermined position in the 100 moldings (with the adhesion to the upper punch. , Or those which have fallen on the way after the upper punch has adhered and have deviated from the predetermined position and those which have deviated from the predetermined position due to expansion). As for the division situation, the compact was divided manually and the weight of each was ± 1.
Those that subsided at 0% distribution were marked with a circle, and those that did not are marked with a cross.

[0019]

According to the powder molding die of the present invention, the molded article has excellent releasability from the die, and therefore it is not always necessary to include a release agent in the powder material. In addition, it is possible to efficiently manufacture the compacts of various powders without adhering to the upper punch and without causing displacement on the lower punch. Further, the obtained molded body can be uniformly divided according to the subsequent use and purpose of use. Further, according to the powder molding apparatus of the present invention, it is possible to prevent loss due to defective release of the molded body from the mold, unrecoverability, breakage, and the like. Further, according to the present invention, it is possible to release the molded body in the powder molding without any inconvenience and to automate a series of steps of the powder molding.

[Brief description of the drawings]

FIG. 1 is an explanatory view of one embodiment of a mold of the present invention.

FIG. 2 is an explanatory view of a conventional mold.

FIG. 3 is an explanatory view of a molding step using an embodiment of the molding apparatus of the present invention.

FIG. 4 is a perspective view of the molding apparatus of FIG. 3;

FIG. 5 is an explanatory view of a conventional molding production process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper punch 2 Lower punch 3 Die set 4 Concave part 5 Powder material 6 Molded body 10 Lower punch 11 Concave part 12 Convex part 13 Upper punch 14 Claw for pinching a compact 15 Claw for pinching a compact 15a Claw lower part 15b Claw upper part 16 Spring 17 Claw moving mechanism 18 Upper plate

Claims (5)

(57) [Claims] 1. A powder molding die comprising an upper punch, a lower punch, and a die set, wherein the upper punch has a smooth surface, and the height of the lower punch is higher than the surface of the lower punch. br /> consists recess is a surface portion other than the convex portion and the convex portion, gold for powder molding and having a shape in which peaks and valleys and the upper punch on the lower punch satisfies the following relationship Type. D ≦ ax + by, a> b, xy = 1 c + 1 ≦ H ≦ D / 4 (where a and b are the width of the concave portion and the width of the convex portion on the lower punch , respectively, and c is the convex portion relative to the concave portion. , X and y are integers indicating the numbers of the concave and convex portions, D is the width of the upper punch, and H is the thickness of the molded body.
The units of c, D and H are all mm. ) 2. The powder molding metal according to claim 1, wherein the width a of the concave portion and the height c of the convex portion of the lower punch have a relationship of 1/10 ≦ c / a ≦ 1/6. Type. 3. A claw for pinching a compact having two claw portions at its tip is provided such that the claw at the tip clamps an upper punch of a mold for powder molding, and the claw for clamping a compact and a die set are provided. the vertical distance is adjustable with further at least one of the claw portion of the tip, so as to the upper punch is lower, pressed against by narrowing the width of the lower than the upper portion of the claw portion, and the powder molding A powder molding apparatus, wherein the mold for use is the mold according to claim 1. 4. A powder molding method according to claim 3, wherein a powder material is supplied to a concave portion of the lower punch of the powder molding apparatus to obtain a compact. 5. A claw for pinching a compact having two claw portions at its tip is provided so that the claw at the tip clamps an upper punch of a mold for powder molding, and the claw for clamping a compact and a die set are provided. the vertical distance is adjustable with further at least one of the claw portion of the tip, so as to the upper punch is lower, pressed against by narrowing the width of the lower than the upper portion of the claw portion, and the powder molding A powder molding apparatus, wherein the molding die is a powder molding die comprising an upper punch, a lower punch, and a die set.