JP6041208B2 - Metal powder molded product manufacturing method and press apparatus used therefor - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a method for producing a metal powder molded product and a press device used therefor, and in particular, a method for producing a metal powder molded product by compressing metal powder in a through hole penetrating a main body mold in the vertical direction. The present invention relates to a method and a press apparatus used therefor.

  There is a method of loading a metal powder into a mold and compressing the metal powder to obtain a metal powder molded product. For example, by loading metal powder inside a mold having a long columnar space and compressing it uniaxially along the longitudinal direction, the metal powder is compressed while being restrained on the side wall by the columnar space inner wall and deformed plastically. Is fixed. Specifically, a lower mold and an upper mold having a shape that can be fitted to the inner hole cross section of a main body mold (die) having an inner hole formed of a columnar space are prepared, and the lower side of the main body mold The lower mold is inserted into the inner hole. Metal powder is loaded thereon, and the upper mold is inserted into the inner hole from the upper side of the main mold. When the lower mold and the upper mold are moved relatively close to each other, the metal powder is confined and compressed in a space defined by the main body mold, the lower mold, and the upper mold, and processed into the space shape. The After depressurizing the compression load, the metal powder molded product compressed together with the lower mold and / or the upper mold can be moved along the inner hole and taken out from the upper part or the lower part of the main body mold.

  By the way, during the metal powder compression processing, if the fixing occurs between each mold and the metal powder molded product, or between the main body mold and the lower mold or the upper mold, the metal powder molding from the main body mold. This may cause malfunctions such as being unable to take out the product or causing the lower mold and / or the upper mold to move relative to the main mold. In addition, even if the metal powder molded product can be removed from the main body mold, the mold is damaged by the operation of repeatedly removing the metal powder molded product, and the mold is strongly exchanged due to the defect that the scratch is transferred to the metal powder molded product. It is also possible that

  For example, Patent Document 1 describes seizure between a main body mold and a metal powder molded product when a flange-shaped step is provided on the outer peripheral surface of the inner hole end of the main body mold having a cylindrical inner hole. Yes. In the flange-shaped stepped portion, the thickness of the main body mold is reduced, the rigidity is lowered, and it is easily deformed so as to expand outward during compression processing. Therefore, when the metal powder molded product is repeatedly taken out in the longitudinal direction of the inner hole, that is, in the vertical direction, a vertical sliding line is generated in the main body mold, and finally the mold operation such as seizure occurs. Defects are supposed to occur. Therefore, it is disclosed that the thickness of the flange-shaped step portion of the main body mold is compensated to prevent deformation of the main body mold during compression processing and prevent seizure. Furthermore, in order to eliminate the non-uniformity of the compression pressure in the flange-shaped step portion during compression processing, the metal powder is moved by performing the compression processing by moving the lower die together with the upper die close to the flange-shaped step portion. It also describes the ability to correct variations in compression density in molded products.

  Moreover, in patent document 2, the metal mold | die by the adhering between the lower metal mold | die and / or an upper metal mold | die and a metal powder molded product when metal powder is compression-processed inside the internal hole of a main body metal mold | die which has a cylindrical internal hole. Describes malfunctions. Here, the metal powder is heated at the time of compression processing and is simultaneously sintered. However, since the reaction is likely to occur between the metal powder and the mold, the upper mold and / or the lower mold It discloses that a spacer made of, for example, carbon or the like is inserted between the metal powder molded product.

Japanese Patent Laid-Open No. 9-94699 JP 2004-323923 A

  As described in Patent Document 1, when a mold is damaged, a malfunction of the mold tends to occur eventually. In particular, in a manufacturing method for obtaining a metal powder molded product by inserting an upper mold and a lower mold from above and below the through hole of the main body mold as described above, the metal powder is compressed while being constrained on the inner wall of the through hole. Therefore, in the process of moving the upper mold and / or the lower mold along the through hole and taking out the metal powder molded product from the main body mold, it is easy to damage the mold along the through hole. The malfunction of the mold is a problem.

  The present invention has been made in view of such a situation, and the object of the present invention is to insert an upper mold and a lower mold from both sides of the through hole of the main body mold and move them close to each other. In the manufacturing method for compressing the metal powder given to the inside of the through hole to obtain a metal powder molded product, providing a manufacturing method capable of preventing malfunction of the mold and giving excellent productivity, An object of the present invention is to provide a press apparatus suitable for such a manufacturing method.

  In the manufacturing method according to the present invention, an upper die and a lower die are inserted from above and below a through-hole penetrating the main body mold in the vertical direction, respectively, and the metal powder provided therebetween is moved between them. In which a metal powder molded product is obtained by compressing the metal powder on the top surface of the lower mold provided with a stress adjustment step along the peripheral edge of the top surface. After the upper mold is moved close to the lower mold and the metal powder is compressed, the lower mold is moved upward in the through hole to move the metal powder molded product. It is extracted from the through hole.

  According to this invention, it is possible to prevent the metal powder from sticking around the peripheral edge of the top surface of the lower mold and the main body mold during compression processing, and in particular to damage the inner surface of the through hole of the main body mold. Therefore, it is possible to prevent the metal powder from being caught between the lower mold and the mold, thereby suppressing the malfunction of the mold and giving excellent productivity.

  The above-described invention may include a step of disposing a spacer that gives the stress adjustment stepped portion to the lower mold on the main body of the lower mold. According to this invention, the stress adjustment stepped portion can be easily formed at the peripheral edge portion of the top surface of the lower mold, the metal powder can be prevented from sticking, the metal powder can be prevented from biting, and the spacer can be removed. This makes it possible to replace the molds, simplify the cleaning of the molds, suppress malfunctions between the molds and / or the mold and the powder molded product, and provide excellent productivity.

  In the above-described invention, the main body mold may be heated, and the spacer may be heated and then disposed on the main body of the lower mold. According to this invention, it is possible to increase the molding density by warm molding while suppressing malfunction of the mold and giving excellent productivity.

  Further, the press device according to the present invention inserts the upper mold and the lower mold from above and below the through hole penetrating the main body mold in the vertical direction and moves the metal mold close to each other so that the metal powder provided between them can be obtained. A pressing device for obtaining a metal powder molded product by compression processing inside a through hole, the metal powder being provided on a top surface of the lower die, and the upper die being directed toward the lower die In the press apparatus for moving the lower mold upward in the through hole and extracting the metal powder molded product from the through hole after compressing the metal powder by moving close to the lower mold, Is characterized by being provided with a stress adjustment step along the peripheral edge of the top surface.

  According to this invention, it is possible to prevent the metal powder from sticking around the peripheral edge of the top surface of the lower mold and the main body mold during compression processing, and in particular to damage the inner surface of the through hole of the main body mold. Therefore, it is possible to prevent the metal powder from being caught between the lower mold and the mold, thereby suppressing the malfunction of the mold and giving excellent productivity.

It is a sectional side view of the metal mold | die of the press apparatus by this invention. It is a sectional side view of the other metal mold | die of the press apparatus by this invention. It is a flowchart which shows the manufacturing process of a metal powder molded product. It is a side view of a metal mold | die and a metal powder molded product. It is a sectional side view of the metal mold | die of the press apparatus as a comparative example.

  One embodiment of a mold of a press apparatus for obtaining a metal powder molded product according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1A, a mold 1 incorporated in a press apparatus includes a die 3 which is a main body mold having a through-hole 31 having a circular cross section whose axis is directed in the vertical direction, and a through-hole 31. It includes a die pin 4 that is a lower die inserted from the lower opening and a punch 2 that is a substantially cylindrical upper die inserted from the upper opening of the through hole 31.

  Referring also to FIG. 1 (b), the die pin 4 has a slight gap R 1 between its outer peripheral surface and the inner surface of the through hole 31, and its inner wall with respect to the through hole 31 of the die 3. It can be moved up and down while sliding. Further, the die pin 4 has a stepped portion 44 that gives a notch to the peripheral portion of the top surface 43 and has a gap R <b> 2 with respect to the through hole 31 of the die 3.

  Here, as another embodiment, FIG. 2 shows a mold 1 ′ in which the above-described stepped portion 44 is provided by a substantially disc-shaped spacer 42. As shown in FIG. 2A, the mold 1 ′ incorporated in the press apparatus includes a die 3, a die pin 4 ′, and a punch 2, similar to the mold 1.

  Referring also to FIG. 2B, the die pin 4 'includes a substantially cylindrical body 41 and a spacer 42 placed on the upper surface thereof. Again, the die pin 4 ′ has a slight gap R 1 around the body portion 41 with respect to the through hole 31, and can move up and down while sliding on the inner wall with respect to the through hole 31 of the die 3. is there. The spacer 42 is a substantially disc body having a smaller diameter than the main body portion 41. As a result, a stepped portion 44 is provided around the peripheral portion of the top surface 43 of the die pin 4 ′, that is, around the spacer 42 so as to have a gap R <b> 2 with respect to the through hole 31 of the die 3. The spacer 42 has a guide hole (not shown) on its lower surface, and a center guide (not shown) protruding above the main body 41 can be inserted into the spacer 42 so that the axes can be easily aligned.

  Next, a method for obtaining a molded product by compression using the mold 1 ′ including the spacer 42 described above will be described with reference to FIGS. 2 and 4 as appropriate along FIG. 3.

  As shown in FIG. 4A, each part of the mold 1 ′ heated to a predetermined temperature is arranged at the initial position, that is, the upper surface of the main body 41 is located near the lower opening of the through hole 31 of the die 3. Arrange as follows. Further, the spacer 42 is placed on the main body 41. Here, the spacer 42 may be placed on the main body 41 after being heated to a predetermined temperature if desired. Next, as shown in FIG. 4B, the metal powder for one shot is weighed (S1), the lubricant is applied to the inner surface of the mold 1 (S2), and then the measured metal powder 10 is penetrated. The die 31 is loaded on the top surface 43 of the die pin 4 'in the hole 31 (S3).

  Subsequently, as shown in FIG. 4 (c), the punch 2 is caused to enter from the upper opening of the through hole 31 of the die 3 into the inside thereof, and is moved close to the die pin 4 '(S4). Thereby, inside the through-hole 31, the metal powder 10 is compression-processed and given a shape, and becomes a molded product 10 '. Here, in the present embodiment, the die 3 and the die pin 4 ′ are fixed, and the punch 2 is inserted from the upper part of the through hole 31 and moved to perform compression processing.

  Thereafter, as shown in FIG. 4 (d), the load of the punch 2 is unloaded, the die pin 4 ′ is moved upward, and the punch 2 and the molded product 10 ′ are moved above the through hole 31 of the die 3. Let Then, as shown in FIG. 4E, the molded product 10 'is extracted from the upper opening of the die 3 (S5), and the die pin 4' is returned to the initial position (S6). The above steps S1 to S6 are repeated to repeatedly manufacture the molded product 10 '.

  Here, the spacer 42 is placed without being fixed on the main body 41 of the die pin 4 ′, and is temporarily attached to the molded product 10 ′ extracted from the die 3, but this is easy. Can be disengaged. In returning the die pin 4 ′ to the initial position, the spacer 42 is placed on the main body 41. However, a plurality of spacers 42 may be prepared in advance, and the spacer may be replaced for each shot. In such a case, cleaning of the stepped portion 44 and the main body portion 41 can be simplified, which is preferable.

  Subsequently, the molded product 10 ′ taken out from the die 3 is appropriately subjected to machining or heat treatment for obtaining a predetermined product shape to be a final product. For example, when a wrinkled target used for thin film formation is used as a final product, a molded product 10 ′ is manufactured by the above-described process using a metal powder having a component composition used as a target, and then heat treatment and machining are performed. Thus, a product having a flange on the outer periphery is obtained.

  In addition, even if it is the integrated die 1 which does not contain a spacer as shown in FIG. 1, it does not include the step of placing a spacer among the steps S1 to S6, and is molded in substantially the same step. Product 10 'can be manufactured.

  According to the method of manufacturing the molded product 10 ′ using the mold 1 (or the mold 1 ′), it is possible to suppress the metal powder 10 from sticking around the die pin 4 (or 4 ′), and for each shot. Cleaning that removes the adhered metal powder can be simplified or omitted, and even if the molded product is continuously manufactured, the relative movement between the die 3 and the die pin 4 (or 4 ′) is hindered. Such a malfunction of the mold 1 does not occur. Therefore, it can give excellent productivity.

  Here, the reason why the obstacle of relative movement between the die 3 and the die pin 4 can be suppressed by using the mold 1 (or the mold 1 ′) having the stepped portion 44 described above will be considered.

  First, as shown in FIG. 5, in the mold 101 including the die pin 104 having no stepped portion, stress is applied to the vicinity of the corner (A portion) between the die 3 and the top surface 143 of the die pin 104 when the metal powder is compressed. Easy to concentrate.

  On the other hand, as shown in FIG. 1, even in the mold 1 including the die pin 4 having the stepped portion 44, similarly, stress concentration is likely to occur in the vicinity of the corner portion of the top surface 43 of the die pin 4 when the metal powder is compressed. Further, the metal powder is prevented from sticking at the lower end portion of the step portion 44. Therefore, even if the die pin 4 is moved with respect to the die 3, the metal powder is not caught, and the movement of the die pin 4 with respect to the die 3 is not hindered. That is, the malfunction of the mold 1 is difficult to occur. As such a stepped portion 44, it is preferable that the clearance R2 / the height H of the stepped portion be 0.02 to 0.1.

  Further, by using the mold 1 (or the mold 1 ′) having the stepped portion 44, cleaning inside the mold for each shot can be simplified.

  That is, when the mold 101 is used, the metal powder pushed into the gap R1 is subjected to a large stress during compression molding as described above, and tends to remain as a fixed substance at the corner of the die pin 104. This fixed object is considered to make it easier for metal powder to bite in the next production of a molded product. Therefore, when the mold 101 is used, such a fixed object is removed for each shot. Needed mold cleaning. On the other hand, when the mold 1 (or 1 ') is used, the metal powder dropped into the gap R2 is loaded with a small stress at the time of compression molding and is easily taken out as a burr together with the molded product 10'. Even in the case where it remains as a fixed object to the corners around the top surface 43 without being taken out as burrs, the gap R2 does not contribute to biting and can be removed relatively easily. Therefore, when the mold 1 is used, cleaning of the mold 1 for each shot is unnecessary, and even when necessary, the number of times of cleaning can be reduced and the time can be shortened.

  The mold 1 ′ having the spacer 42 indicates how much the malfunction of the mold can be suppressed when the molded product 10 ′ is continuously manufactured without cleaning the mold by the manufacturing process described above. It confirmed using. The mold 1 ′ is configured to be disposed on the main body 41 of the die pin 4 ′ after the spacer 42 is heated.

  Specifically, compression processing was performed by a 600-ton hydraulic press apparatus at a temperature of 170 ° C. using metal powder in which Ti or Cr powder and Al powder were mixed at a predetermined ratio. That is, the die 3 was heated to 170 ° C., and the pre-heated metal powder 10 was used to produce a molded product 10 ′ in the same manner as described above. Such production was performed for each of three types of metal powders of Ti-50Al, Ti-60Al, and Cr-70Al. Then, in all three types of metal powder, even if the molded product 10 ′ is manufactured continuously for 100 shots or more without cleaning the inside of the mold, it can be confirmed that the malfunction of the mold 1 ′ does not occur. It was.

  In addition, when the spacer 42 is detached from the molded product 10 ′, a fixed substance may remain in the vicinity of the upper surface around the spacer 42. As described above, a plurality of spacers 42 are prepared and pre-shot for each shot. If the heated spacer 42 is replaced, it is possible to remove the sticking matter of the spacer 42 used for the previous shot while performing the compression process, simplify the cleaning of the mold 1 ', and maintain excellent productivity. .

  The manufacturing method described above can also be used for cold compression processing. Also. In the above description, so-called binary metal powders such as Ti—Al have been described. However, multi-component metal powders based on Ti—Al or Cr—Al and added with Si, B, V, W, Nb, etc. Can also be used.

  So far, representative examples and modifications thereof according to the present invention have been described, but the present invention is not necessarily limited thereto. Those skilled in the art will recognize a variety of alternative embodiments and modifications without departing from the scope of the appended claims.

1, 1 'Die 2 Punch 3 Die 4, 4' Die pin 31 Through-hole 41 Main body part 42 Spacer 43 Top surface 44 Step part R1, R2 Gap

Claims (3)

The upper mold and the lower mold are inserted from the upper and lower sides of the through hole penetrating the main body mold in the vertical direction, respectively, and the metal powder provided therebetween is compressed inside the through hole. A manufacturing method for obtaining a metal powder molded product,
On said lower die body, in a state of being arranged a spacer providing a step portion on the lower mold, the top surface of the peripheral edge the stepped portion and the lower die of the top surface on which given along The metal powder is applied to the metal mold, and the upper mold is moved toward the lower mold to compress the metal powder, and then the lower mold is moved upward in the through hole. A method for producing a metal powder molded product, wherein the metal powder molded product is extracted from the through hole.   The method for producing a metal powder molded product according to claim 1, wherein the main body mold is heated and the spacer is heated and then disposed on the main body of the lower mold. The upper mold and the lower mold are inserted from the upper and lower sides of the through hole penetrating the main body mold in the vertical direction, respectively, and the metal powder provided therebetween is compressed inside the through hole. A pressing device for obtaining a metal powder molded product,
After the metal powder is provided on the top surface of the lower mold and the upper mold is moved close to the lower mold to compress the metal powder, the lower mold is placed inside the through hole. In the press device for moving the metal powder upward and extracting the metal powder molded product from the through-hole , a spacer is disposed on the main body of the lower mold, and the spacer is arranged on the peripheral portion of the top surface. pressing device, characterized in that given a stepped difference portion along.

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