JP2008246567A - Apparatus and method for powder molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for powder molding capable of manufacturing a green compact which does not damage a wire. <P>SOLUTION: In the powder molding apparatus 1, the green compact is manufactured by molding an outer peripheral face 50c of a powder molded body 50 with an inner peripheral face 2c of a frame die 2; molding a first face 50a of the powder molded body 50 with an end face 4a of a bottom die 4; and molding a second face 50b of the powder molded body 50 with the end face 14a of the top die 14; further molding an open edge on the first face 50a side of the powder molded body 50 with a slanted peripheral face 10a of a first inside die 6, and molding an open edge on the second face 50b side of the powder molded body 50 with a slanted peripheral face 20a of a second inside die 16. The peripheral faces 10a and 20a are slanted tapering toward a through hole of the frame die 2. Thus, formation of a tapered face 50e in the open edge of the through hole 52 can be performed in advance, where chamfering by a barrel polishing method is very difficult to apply. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a powder molding apparatus and a powder molding method.

Conventionally, as a powder molding apparatus for producing a powder molded body, for example, as described in Patent Document 1, a cylindrical die (frame type), and a cylindrical core rod disposed coaxially with the die in the die, And a lower punch (lower die) that can be fitted to the die from below and slidable with respect to the core rod, and an upper punch (upper die) that can be fitted to the die from above and slidable with respect to the core rod. Things are known. The lower punch and the upper punch have a cylindrical shape, and the end surfaces are flat surfaces. In this powder forming apparatus, a lower punch is fitted to a die to form a cavity, and after filling the formed cavity with raw material powder, the upper punch is fitted to pressurize the raw material powder. Thereby, a ring-shaped powder compact is produced. Wire winding or wire insertion is performed on the produced powder compact.
JP 2006-281274 A

  As for the compacting body obtained with the powder shaping | molding apparatus of patent document 1, an outer peripheral surface and an end surface and an inner peripheral surface and an end surface are orthogonal. For this reason, the wire is caught on the ridge line portion (corner portion), and there is a possibility that the wire breakage or the coating peeling occurs. Therefore, it is conceivable to chamfer the ridge portion by barrel polishing for the purpose of suppressing damage to the wire.

  About the ridgeline part which consists of an outer peripheral surface and an end surface, it can chamfer efficiently by barrel polishing. However, since it is difficult to contact the media in the barrel and the inner peripheral surface of the ridge line portion including the inner peripheral surface and the end surface, that is, the opening edge, chamfering cannot be sufficiently performed. For this reason, in the green compact obtained by the powder molding apparatus described in Patent Document 1, even when barrel polishing is performed, the wire may be damaged at the opening edge.

  Then, this invention makes it a subject to provide the powder shaping | molding apparatus and powder shaping | molding method which can manufacture the compacting body which does not produce the damage of a wire easily.

  The powder molding apparatus according to the present invention includes a first surface, a second surface opposite to the first surface, an outer peripheral surface continuous to the first and second surfaces, and a first surface opened to the first surface. A powder molding apparatus for producing a powder molded body having a concave portion and a second concave portion opened in the second surface, the powder molded body having a through hole and an inner peripheral surface forming the through hole A frame mold for molding the outer peripheral surface of the powder mold, and one end portion can be fitted into the through hole from one side of the through hole of the frame mold, and the first surface of the powder molded body is molded by the end surface of the one end portion. A mold, one end of which can be fitted into the through-hole from one side of the through-hole of the frame mold, and the first middle mold for forming the first concave portion of the powder molded body by the one end; An upper mold that can be fitted into the through hole from the other side of the through hole of the mold, and that forms the second surface of the powder molded body by the end surface of the one end, and one end A second middle mold that can be fitted into the through-hole from the other side of the through-hole of the mold and that forms the second concave portion of the powder molded body by the one end, and one end of the lower mold is cylindrical The first middle mold is slidably fitted inside the one end, the one end of the upper mold is cylindrical, and the second middle mold is slidably fitted inside the one end. The peripheral surface of the one end portion of the first medium mold includes an inclined surface that is tapered in a direction from one of the through holes of the frame mold toward the other, and the peripheral surface of the one end section of the second medium mold is , Including an inclined surface that is tapered in a direction from one of the other through holes of the frame mold to the other, and at least the first intermediate inclined surface forms the opening edge of the first recess of the powder molded body. The at least second medium-shaped inclined surface forms the opening edge of the second recess of the powder compact.

  In the powder molding apparatus according to the present invention, the lower mold and the first middle mold are inserted from one side into the through hole of the frame portion, and the upper mold and the second middle mold are inserted from the other side. The inner peripheral surface of the through hole in the frame portion forms the outer peripheral surface of the powder molded body, the end surface of the lower mold forms the first surface of the powder molded body, and the end surface of the upper mold is the second surface of the powder molded body. Is molded. Further, one end of the first medium mold forms the first recess of the powder compact, and one end of the second medium mold forms the second recess of the powder compact. In particular, the opening edge of the first recess is formed by at least a first medium-shaped inclined surface, and the opening edge of the second recess is formed by at least a second medium-shaped inclined surface. Since the inclined surfaces of the first and second medium sized taper toward the through hole, the opening edge has a tapered shape inclined toward the inside of the powder compact. As a result, it is possible to reduce the possibility of wire damage in the vicinity of the opening edges of the first recess and the second recess.

  Further, in the powder molding apparatus according to the present invention, burrs are generated in the powder molded body due to the boundary (partition line) between the lower mold and the first middle mold and the boundary between the upper mold and the second middle mold. For example, when the lower mold and the first middle mold cooperate to form the first recess, the boundary between the lower mold and the first middle mold is located inside the first recess, so that the burr also It will occur inside the first recess. It is very difficult to remove the burrs generated inside the first recess. On the other hand, in the present invention, the opening edge of the first recess is formed by at least the first medium-shaped inclined surface. In other words, in the present invention, of the opening edge of the first recess, the inner edge positioned inside the first recess is surely formed by the inclined surface of the first middle mold, and the outer edge positioned outside the first recess. Is formed by the other surface of the first medium mold or the lower mold. Therefore, the boundary between the lower mold and the first middle mold is necessarily located outside the first recess. Thereby, since the generation | occurrence | production position of a burr | flash also becomes the outer side of a 1st recessed part, it can remove easily by barrel grinding | polishing etc. Similarly, since the boundary between the upper mold and the second middle mold is also located outside the second recess, burrs generated at the boundary can be easily removed.

  The powder molding apparatus according to the present invention includes a first surface, a second surface facing the first surface, an outer peripheral surface continuous to the first and second surfaces, and the first and second surfaces, respectively. A powder molding apparatus for producing a powder molded body provided with a first through hole opened in the inner surface of the powder molded body, the second through hole having a second through hole. A frame mold for forming the outer peripheral surface, and one end portion of the frame mold can be fitted into the second through hole from one side of the second through hole of the frame mold, and the end surface of the one end portion is the first of the powder molded body A lower mold for molding the surface, and one end portion can be fitted into the second through hole from one side of the second through hole of the frame mold, and the one end portion of the first through hole of the powder molded body Of these, a first middle mold for molding a portion on the first surface side, and one end portion can be fitted into the second through hole from the other side of the second through hole of the frame mold, and the end surface of the one end portion Is powdered An upper mold for forming the second surface of the body, and one end portion can be fitted into the second through hole from the other side of the second through hole of the frame mold. A second middle mold that molds a portion on the second surface side of one through-hole, and one end of the lower mold has a cylindrical shape, and the first middle mold can slide inside the one end One end of the upper mold is cylindrical, and a second middle mold is slidably fitted inside the one end, and the first middle mold is inserted into the second through hole of the frame mold. The end surface of the one end is in contact with the end surface of the one end of the second medium mold, and the peripheral surface of the one end of the first medium mold is an inclined surface that tapers in a direction from one side of the second through hole to the other. And the peripheral surface of one end portion of the second medium mold includes an inclined surface that is tapered in a direction from the other of the second through holes toward the other, and at least the first medium mold is inclined. Forming the opening edge of the first through hole located on the first surface side of the powder compact, and at least the second medium-shaped inclined surface is located on the second face side of the powder compact. The opening edge of one through hole is formed.

  In the powder molding apparatus according to the present invention, the inner circumferential surface of the second through hole in the frame portion molds the outer circumferential surface of the powder molded body, the end surface of the lower mold molds the first surface of the powder molded body, The end surface of the mold forms the second surface of the powder compact. Further, the first end portions of the first and second medium molds form the first through-hole of the powder molded body by bringing the end faces into contact with each other. The opening edge of the first through hole in the first surface is formed by at least the first medium-shaped inclined surface, and the opening edge of the first through hole in the second surface is at least the second medium-shaped inclined surface. Is molded by. The first and second medium-sized inclined surfaces are inclined in a tapered manner toward the through hole. The opening edge of the 1st through-hole shape | molded by such an inclined surface becomes the taper shape which inclined in the taper shape toward the inside of a powder molded object. As a result, it is possible to reduce the possibility of wire damage near the opening edge of the first through hole.

  In the powder molding apparatus according to the present invention, the opening edge of the first through hole located on the first surface side is formed by at least the first and second medium dies. In other words, in the present invention, among the opening edges located on the first surface side, the inner edge is surely formed by the inclined surface of the first medium mold, and the outer edge is formed by the other surface of the first medium mold or the lower mold. Will be formed. Therefore, the boundary between the lower mold and the first middle mold is necessarily located outside the first through hole. Thereby, since the generation | occurrence | production position of a burr | flash also becomes the outer side of a 1st through-hole, it can remove easily by barrel grinding | polishing etc. Similarly, since the boundary between the upper mold and the second middle mold is also located outside the first through hole, burrs generated at the boundary can be easily removed. That is, the first through hole is closed by the first and second medium molds. Therefore, the boundary between the lower mold and the first middle mold is necessarily located outside the first through hole. As a result, the position where the burrs are generated is also outside the first through hole, so that it can be easily removed by barrel polishing or the like.

  The powder molding method according to the present invention is a powder molding method for producing a powder molded body, and a frame mold having a through-hole and one end portion can be fitted into the through-hole from one side of the through-hole of the frame mold. At the same time, the one end part is slidably fitted inside the lower mold and one end part of the lower mold, and one end part is fitted into the through hole from one side of the frame type through hole. And a first middle mold including an inclined surface in which the peripheral surface of the one end portion is tapered in a direction from one of the through holes toward the other, and one end portion of the one end portion in the through hole from the other side of the through hole. And is fitted to the inside of one end of the upper mold so that the one end is slidable, and the one end is inserted into the through hole from the other side of the through hole. A second intermediate mold including an inclined surface that can be fitted and has a circumferential surface of the one end portion that is tapered in a direction from the other through hole to the other; A preparation step of preparing a powder forming apparatus comprising: a cavity forming step of forming a cavity by fitting one end of the lower mold and one end of the first middle mold into the through hole of the frame mold; and a raw material in the cavity Filling step for filling powder, and pressure forming step for press-molding the raw material powder filled in the cavity by fitting one end of the upper die and one end of the second middle die into the through hole of the frame die And in the pressure forming step, the inclined surface of the first middle mold protrudes from the end surface of one end of the lower mold and the inclined surface of the second medium mold protrudes from the end surface of one end of the upper mold And forming an opening edge on one surface side of the powder molded body at least by the inclined surface of the first medium mold, and on the other surface side of the powder molded body by at least the inclined surface of the second medium mold. An opening edge is formed.

  In the powder molding method according to the present invention, the lower mold and the first middle mold are inserted from one side into the through hole of the frame portion, and the upper mold and the second middle mold are inserted from the other side, and the raw material powder is obtained. Press molding. At the time of pressure molding, the inclined surface of the first medium mold projects from the lower mold, and at least the inclined surface forms an opening edge on one surface of the powder molded body. The inclined surface of the second middle mold protrudes from the upper mold, and at least the inclined surface forms an opening edge on the other surface of the powder compact. The first and second medium-sized inclined surfaces are inclined in a tapered manner. Therefore, the opening edge formed by these inclined surfaces has a taper shape that is tapered toward the inside of the powder compact. As a result, it is possible to produce a powder compact that is less susceptible to wire damage near the opening edge.

  In the present invention, the opening edge located on the first surface side is formed by at least the first and second medium dies. In other words, in the present invention, among the opening edges located on the first surface side, the inner edge is surely formed by the inclined surface of the first medium mold, and the outer edge is formed by the other surface of the first medium mold or the lower mold. Will be formed. Therefore, the boundary between the lower mold and the first middle mold is necessarily located outside the opening. Thereby, since the generation | occurrence | production position of a burr | flash also becomes an outer side of an opening, it can remove easily by barrel grinding | polishing etc. Similarly, since the boundary between the upper mold and the second middle mold is also located outside the opening, burrs generated at the boundary can be easily removed.

  In the powder molding method according to the present invention, in the pressure molding step, it is preferable to perform pressure molding after the end surface of one end of the first medium mold and the end surface of one end of the second medium mold are abutted. In this case, a powder molded body having through holes can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the powder shaping | molding apparatus and powder shaping | molding method which can manufacture the compacting body which does not easily damage a wire can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  FIG. 1 is a cross-sectional view showing a powder molding apparatus according to this embodiment. 2-4 is sectional drawing which shows the manufacturing process of the powder compact using the powder shaping | molding apparatus which concerns on this embodiment. FIG. 5 is a perspective view of a powder molded body obtained using the powder molding apparatus according to the present embodiment.

  The powder molding apparatus 1 is for producing a substantially ring-shaped powder compact 50 as shown in FIG. The powder molding apparatus 1 includes a frame mold 2, a lower mold 4, a first middle mold 6, an upper mold 14, a second middle mold 16, and a feeder box 22. The frame mold 2, the lower mold 4, the first middle mold 6, the upper mold 14, the second middle mold 16, and the feeder box 22 are driven by a control unit (not shown).

  The frame mold 2, the lower mold 4, the first middle mold 6, the upper mold 14, and the second middle mold 16 are molds. The frame mold 2 has a through hole 3 (second through hole) at a substantially central portion. In the present embodiment, the through hole 3 has a circular cross section. From the lower side (one side) of the through-hole 3, more specifically, from the opening of the through-hole 3 formed in the first surface 2 a of the frame mold 2, one end of the lower mold 4 and the first middle mold 6 is It is inserted into the through hole 3.

  One end portions of the lower mold 4 and the first middle mold 6 are movable in the arrow A direction, that is, the axial direction of the through hole 3. The lower die 4 has a cylindrical shape, and the outer shape of the lower die 4 is formed along the inner peripheral surface 2 c of the frame die 2. The end surface 4a on the one end side of the lower mold 4 is a flat surface. The first middle mold 6 is slidably fitted inside the lower mold 4. The first middle mold 6 has a body portion 8 and a tip portion 10. The body portion 8 has a columnar shape, and the outer shape of the body portion 8 is formed along the inner peripheral surface of the lower mold 4. The tip portion 10 is composed of a truncated cone portion having a truncated cone shape and a cylindrical column portion having a cylindrical shape. One end of the truncated cone portion is integrated with one end of the body portion 8, and one end of the cylindrical portion is a cone shape. It is integrated with the other end of the base part. The end surface on one end side of the truncated cone portion has substantially the same size as the end surface on one end side of the body portion 8. The end surface on one end side of the cylindrical portion has substantially the same size as the end surface on the other end side of the truncated cone portion. Further, the truncated cone portion is tapered in a direction from the lower side to the upper side (the other side) of the through-hole 3, more specifically in a direction from the first surface 2a of the frame mold 2 to the second surface 2b. is doing. Therefore, the first middle mold 6 includes an inclined tapered peripheral surface 10a, a cylindrical peripheral surface 10b continuous with the tapered peripheral surface 10a, and a flat end surface 10c continuous with the cylindrical peripheral surface 10b. It will have at one end.

  One end portions of the upper mold 14 and the second middle mold 16 are formed from the upper side of the through hole 3, more specifically from the opening of the through hole 3 formed in the second surface 2 b of the frame mold 2. It is inserted in. One end portions of the upper mold 14 and the second middle mold 16 are movable in the arrow A direction. The upper mold 14 has a cylindrical shape, and the outer shape of the upper mold 14 is formed along the inner peripheral surface 2 c of the frame mold 2. The end surface 14a on the one end side of the upper mold 14 is a flat surface. The upper mold 14 and the lower mold 4 are substantially the same, and therefore the end surface 14 a of the upper mold 14 has the same shape and size as the end surface 4 a of the lower mold 4.

  The second middle mold 16 is slidably fitted inside the upper mold 14. Similar to the first middle mold 6, the second middle mold 16 has a body portion 18 and a tip portion 20. The body portion 18 has a columnar shape, and the outer shape of the body portion 18 is formed along the inner peripheral surface of the upper mold 14. The tip portion 20 includes a truncated cone portion having a cone shape and a cylindrical portion provided on the end surface of the truncated cone portion and having a cylindrical shape. The trunk | drum 18, the truncated cone part, and the cylindrical part are integrated. The truncated cone portion is inclined in a tapered manner in a direction from the upper side to the lower side of the through hole 3, more specifically in a direction from the second surface 2 b of the frame mold 2 to the first surface 2 a. Therefore, the second middle mold 16 includes an inclined tapered peripheral surface 20a, a cylindrical peripheral surface 20b continuous with the tapered peripheral surface 20a, and a flat end surface 20c continuous with the cylindrical peripheral surface 20b. It will have at one end. The peripheral surfaces 20a and 20b and the end surface 20c of the second medium mold 16 have the same shape and size as the peripheral surfaces 10a and 10b and the end surface 10c of the first medium mold 6.

  A feeder box 22 is placed on the second surface 2 b of the frame mold 2. The feeder box 22 is filled with a raw material powder 24. The feeder box 22 is movable in the direction of arrow B, that is, in the direction of advancing / retreating with respect to the through hole 3.

  A powder molding method using the powder molding apparatus 1 having the above-described configuration will be described with reference to FIGS. The following operations are controlled by a control unit (not shown).

  First, as shown in FIG. 1, one end of the lower mold 4 and the first middle mold 6 is fitted into the through hole 3 of the frame mold 2 to form a cavity C1 (cavity forming step). More specifically, the lower mold 4 and the first middle mold 6 are moved toward the through hole 3, and one end portions of the lower mold 4 and the first middle mold 6 are inserted into the through hole 3 from below the through hole 3. Let After the insertion, only the first middle mold 6 is further moved, and a part of the body portion 8 and the front end 10 of the first middle mold 6 are projected from the lower mold 4. Then, the end surface 10 c of the first middle mold 6 is positioned on the same plane as the second surface 2 b of the frame mold 2. By doing in this way, the inner peripheral surface 2c of the frame mold 2, the end surface 4a of the lower mold 4, the peripheral surface of the body portion 8 of the first medium mold 6, and the peripheral surface 10a of the tip section 10 of the first medium mold 6 are achieved. The cavity C1 is defined by the peripheral surface 10b and the end surface 10c.

  Next, the raw material powder 24 is filled into the cavity C1 (filling step). More specifically, as shown in FIG. 2A, the feeder box 22 containing the raw material powder 24 is moved onto the cavity C1, and the raw material powder 24 is dropped into the cavity C1. After dropping the raw material powder 24, the feeder box 22 is moved to the original position as shown in FIG. At this time, the raw material powder 24 rising from the cavity C1 and the raw material powder 24 placed on the end face 10c of the middle mold 6 are scraped off by the end face of the moving feeder box 22.

  Next, one end of the upper die 14 and the second middle die 16 is fitted into the through hole 3 of the frame die 2 and the raw material powder filled in the cavity C1 is pressure-molded (pressure molding step). More specifically, as shown in FIG. 2C, first, only the second middle mold 16 is moved toward the through-hole 3, and a part of the body portion 18 and the front end 20 of the second middle mold 16 are moved. Project from the lower mold 4. The protruded end surface 20c of the second middle mold 16 is abutted against and brought into contact with the end surface 10c of the first middle mold 6. Then, as shown in FIG. 3A, the first and second middle molds 6 and 16 are moved while maintaining the state where the end face 10c and the end face 20c are in contact with each other, and the body portion 18 of the second middle mold 16 is moved. Are introduced into the cavity C <b> 1 filled with the raw material powder 24. When one end of the body portion 8 of the first middle mold 6, in other words, the root of the front end portion 10 of the first middle mold 6 reaches the same plane as the end surface 4 a of the lower mold 4, the first and second middle molds 6, 16. Stop moving.

  After stopping the movement of the first and second middle molds 6, 16, the upper mold 14 is moved toward the through hole 3 as shown in FIG. 3 is inserted. At this time, the moving upper die 14 presses the raw material powder 24 in the cavity C1. When the end surface 14a of the upper mold 14 reaches one end of the body 18 of the second middle mold 16, in other words, the base of the tip 20 of the second middle mold 16, the movement of the upper mold 14 is stopped. Thereby, the pressure molding of the powder compact 50 is completed.

  After the movement of the upper mold 14 is stopped, the upper mold 14 and the second middle mold 16 are pulled out from the through hole 3 as shown in FIG. After the upper mold 14 and the second middle mold 16 are pulled out, the lower mold 4 and the first middle mold 6 are moved toward the second surface 2b as shown in FIG. 4a and the end surface 10c of the first middle mold 6 are positioned on the same plane as the second surface 2b of the frame mold 2. With such movement of the end face 10c of the first middle mold 6, the powder compact 50 is pushed out of the cavity C1.

  When the powder compact 50 is pushed out to the second surface 2b side of the frame mold 2, as shown in FIG. 4B, the feeder box 22 in which the raw material powder 24 is newly accommodated is directed toward the powder compact 50. Move. The powder compact 50 is moved by being pushed by the feeder box 22, and is placed on the second surface 2 b of the frame 2. When the powder compact 50 is placed on the second surface 2 b of the frame mold 2, the lower mold 4 is moved toward the first surface 2 a of the frame mold 2. Then, the cavity C1 is formed again, and the raw material powder 24 in the feeder box 22 falls into the cavity C1. Thereafter, the steps shown in FIGS. 2A to 4B are repeated.

  As shown in FIG. 5, the powder compact 50 obtained through such a process includes a first surface 50 a, a second surface 50 b facing the first surface 50 a, and first and second surfaces. It has a substantially ring shape having an outer peripheral surface 50c continuous with the surfaces 50a and 50b and an inner peripheral surface 50d continuous with the first and second surfaces 50a and 50b. The through hole 52 (first through hole) surrounded by the inner peripheral surface 50d is opened at the first surface 50a and the second surface 50b, and an inner edge located inside the through hole 52 among the opening edges. Has a tapered surface 50e.

  As described above, in the powder molding apparatus 1 of the present embodiment, the lower mold 4 and the first middle mold 6 are fitted into the through hole 3 of the frame mold 2 from the first surface 2a side, and the second mold 4 is inserted. The upper mold 14 and the second middle mold 16 are inserted from the surface 2b side. The inner peripheral surface 2c of the frame mold 2 forms the outer peripheral surface 50c of the powder molded body 50, the end surface 4a of the lower mold 4 molds the first surface 50a of the powder molded body 50, and the end surface 14a of the upper mold 14 is powder. The second surface 50b of the molded body 50 is molded. Furthermore, the end portion 10 of the first middle mold 6 and the end portion 20 of the second middle mold 16 are in contact with the end faces 10c, 20c to form the through hole 52 of the powder compact 50. Here, the opening edge on the first surface 50 a side of the through hole 52 is formed by the inclined peripheral surface 10 a of the first middle mold 6, and the opening edge on the second surface 50 b side is inclined of the second middle mold 16. It is molded by the peripheral surface 20a. The peripheral surfaces 10 a and 20 a of the first and second middle molds 6 and 16 are inclined in a tapered manner toward the through hole 3. The opening edge of the through hole 52 formed by the inclined peripheral surfaces 10 a and 20 a is inclined toward the inside of the powder compact 50 in a tapered manner. Thus, in the present embodiment, the tapered surface 50e can be formed in advance at the opening edge of the through hole 52, which is difficult to chamfer by barrel polishing. As a result, when a wire is wound around the powder compact 50, the possibility of damage to the wire near the opening edge of the through hole 52 can be reduced.

  In the step shown in FIG. 3B, burrs are generated at the boundary (partition line) between the lower mold 4 and the first middle mold 6 and at the boundary between the upper mold 14 and the second middle mold 16. When the boundary between the lower mold 4 and the first middle mold 6 and the boundary between the upper mold 14 and the second middle mold 16 are located inside the through hole 3, burrs are also generated inside the through hole 3. End up. It is very difficult to remove the burr generated inside the through hole 3. In the present embodiment, the inclined peripheral surfaces 10 a and 20 a of the first and second middle molds 6 and 16 are formed on the inner edge located inside the through hole 52 among the opening edges of the through hole 52, and the through holes 52 are formed. End surfaces 4a and 14a of the lower mold 4 and the upper mold 14 are formed on the outer edge located outside. Therefore, the boundary between the lower mold 4 and the first middle mold 6 is necessarily positioned outside the through hole 52. As a result, the generation position of the burr is also outside the through hole 52, and can be easily removed by barrel polishing or the like.

  In addition to the powder compact 50 having a through hole as shown in FIG. 5, the powder compactor 1 can also produce a powder compact 60 having a recess as shown in FIG. 9. The manufacturing process of the powder compact 60 will be described with reference to FIGS.

  As shown in FIG. 6A, first, the lower mold 4 and the first middle mold 6 are moved toward the through hole 3, and one end portions of the lower mold 4 and the first middle mold 6 are moved from below the through hole 3. Fit into the through hole 3. After the insertion, only the first middle mold 6 is further moved toward the second surface 2 b of the frame mold 2, and a part of the body portion 8 and the front end 10 of the first middle mold 6 are protruded from the lower mold 4. At this time, the end surface 10 c of the first middle mold 6 is positioned below the second surface 2 b of the frame mold 2.

  Next, as shown in FIG. 6B, the feeder box 22 in which the raw material powder 24 is accommodated is moved over the opening of the through hole 3. And the inner peripheral surface 2c of the frame mold 2, the end surface 4a of the lower mold 4, the peripheral surface of the body portion 8 of the first middle mold 6, and the peripheral surfaces 10a, 10b of the front end portion 10 of the first middle mold 6; The raw material powder 24 is dropped into the cavity C2 defined by the end face 10c. After the raw material powder 24 falls, the feeder box 22 moves to the original position as shown in FIG. When the raw material powder 24 is filled into the cavity C2, the second middle die 16 is moved toward the through hole 3, and a part of the body portion 18 and the tip portion 20 of the second middle die 16 protrude from the upper die 14. Let Then, as shown in FIG. 7A, a part of the body portion 18 and the tip portion 20 of the second middle mold 16 are introduced into the cavity C1. When the end surface 20c of the second middle mold 16 reaches a predetermined position, the movement of the second middle mold 16 is stopped. At this time, the end surface 20c of the second medium mold 16 and the end surface 10c of the first medium mold 6 are not in contact with each other.

  After the movement of the second middle mold 16 is stopped, the upper mold 14 is moved toward the through hole 3, and one end of the upper mold 14 is fitted into the through hole 3. At this time, the moving upper die 14 presses the raw material powder 24 in the cavity C2. As shown in FIG. 7B, when the end surface 14a of the upper die 14 reaches the same plane as one end of the body portion 18 of the second middle die 16, in other words, the root of the tip portion 20 of the second middle die 16. The movement of the upper mold 14 is stopped. On the other hand, the lower mold 4 is moved toward the second surface 2 b of the through hole 3. When the end surface 4a of the lower die 4 reaches one end of the body portion 8 of the first middle die 6, in other words, the base of the tip portion 10 of the first middle die 6, the movement of the lower die 4 is stopped. By moving the upper mold 14 and the lower mold 4 in this way, the raw material powder 24 in the cavity C2 is pressurized, and the powder compact 60 is molded.

  Next, as shown in FIG. 7C, the upper mold 14, the second middle mold 16, the lower mold 4, and the first middle mold 6 are connected to the first mold 6 while maintaining the state where the powder compact 50 is sandwiched therebetween. The first surface 2a is moved in the direction toward the second surface 2b. As shown in FIG. 8A, when the end surface 4a of the lower mold 4 reaches the same plane as the second surface 2b of the frame mold 2, the movement of the lower mold 4 and the first middle mold 6 is stopped. Then, by moving the first middle mold 6 toward the first surface 2 a of the frame mold 2, the tip portion 10 of the first middle mold 6 is pulled out from the powder compact 60. The upper mold 14 and the second middle mold 16 are separated from the powder compact 60 by further moving in the direction from the first surface 2a toward the second surface 2b. Thereafter, as shown in FIG. 8B, the feeder box 22 in which the raw material powder 24 is newly accommodated is moved toward the powder compact 60. The powder compact 60 is moved by being pushed by the feeder box 22 and placed on the second surface 2 b of the frame 2.

  When the powder compact 60 is placed on the second surface 2 b of the frame mold 2, the lower mold 4 and the first middle mold 6 are moved toward the first surface 2 a of the frame mold 2. Then, the cavity C1 is formed again, and the raw material powder 24 in the feeder box 22 falls into the cavity C1. Thereafter, the steps shown in FIGS. 6B to 8B are repeated.

  As shown in FIG. 9, the powder molded body 60 obtained through such a process includes a first surface 60 a, a second surface 60 b that faces the first surface 60 a, and the first and second surfaces. The outer peripheral surface 60c is continuous with the surfaces 60a and 60b, the first recess 62 has an opening edge on the first surface 60a, and the second recess 63 has an opening edge on the second surface 60b. . The bottom of the first concave portion 62 and the bottom of the second concave portion 63 are not connected to each other, and at the opening edge of the first and second concave portions 62, 63, inside the first and second concave portions 62, 63. The inner edge located is a tapered surface 60d.

  As described above, in the powder molding apparatus 1 of the present embodiment, the tip portion 10 of the first middle mold 6 molds the first recess 62 of the powder compact 50 and the tip portion 20 of the second middle mold 16 The second recess 63 of the powder compact 50 is formed. The opening edge of the first recess 62 is formed by the inclined peripheral surface 10 a of the first intermediate mold 6, and the opening edge of the second recess 63 is formed by the inclined peripheral surface 20 a of the second intermediate mold 16. The peripheral surfaces 10 a and 20 a are inclined in a tapered manner toward the through hole 3. Therefore, the opening edges of the first and second recesses 62 and 63 are tapered toward the inside of the powder compact 50. Thus, in this embodiment, the tapered surface 60d can be formed in advance on the opening edges of the first and second recesses 62 and 63, which are difficult to chamfer by barrel polishing. As a result, when a wire is wound around the produced powder compact 60, the possibility of damage to the wire near the opening edges of the first and second recesses 62 and 63 can be reduced.

  Similarly to the production of the powder compact 50, burrs are generated at the boundary between the lower mold 4 and the first middle mold 6 and the boundary between the upper mold 14 and the second middle mold 16 when the powder molded body 60 is produced. . However, of the opening edge of the first recess 62, the inner edge is formed by the peripheral surface 10 a of the first middle mold 6, and the outer edge is formed by the end face 4 a of the lower mold 4. Of the opening edge of the second recess 63, the inner edge is formed by the peripheral surface 20a of the second middle mold 16, and the outer edge is formed by the end face 14a of the lower mold 14. Therefore, the boundary between the lower mold 4 and the first middle mold 6 and the boundary between the upper mold 14 and the second middle mold 16 are located outside the first and second recesses 62 and 63. As a result, the occurrence position of burrs is also outside the first and second recesses 62 and 63, and can be easily removed by barrel polishing or the like.

  The present invention is not limited to the above-described embodiment, and various modifications can be made.

  For example, in the present embodiment, the through hole 3 of the frame mold 2 has a circular cross section, but the cross sectional shape of the through hole 3 is not limited thereto. Further, the tip portions 10 and 20 of the first and second middle dies 6 and 16 are composed of a truncated cone portion and a cylindrical portion, but the tip portions 10 and 20 of the first and second middle dies 6 and 16 are truncated cones. It may consist of only parts.

  In addition, the end surface on one end side of the truncated cone portion has substantially the same size as the end surface on one end side of the body portions 8 and 18, but the end surface on one end side of the truncated cone portion has the body portion 8. , 18 may be smaller than the end face on one end side. In this case, the end surfaces on one end side of the trunk portions 8 and 18 are partially exposed. The exposed end surfaces of the body portions 8 and 18 cooperate with the end surfaces 4a and 14a of the lower mold 4 and the upper mold 14 when the powder molded body 50 is pressed to form the first and second surfaces 50a and 50b. Will form. Therefore, of the opening edge of the through hole 52, the inner edge located inside the through hole 52 is formed by the peripheral surfaces 10a and 20a of the tip portions 10 and 20, and the outer edge located outside the through hole 52 is defined as the body part 8, 18 end surfaces are formed, and the opening edge of the through hole 52 is formed only by the first and second middle molds 6 and 16.

  Moreover, the shape of the front-end | tip part 10 of the 1st middle mold 6 is not restricted to the thing of this embodiment. However, the peripheral surface must include an inclined surface inclined in a tapered shape. Further, the tapered peripheral surfaces 10a and 20a of the first and second middle dies 6 and 16 are curved so that part or the whole of the surfaces 50e and 60d of the powder compacts 50 and 60 have an R shape. It may be.

It is sectional drawing which shows the powder shaping | molding apparatus which concerns on this embodiment. It is sectional drawing which shows the manufacturing process of the powder compact using the powder molding apparatus which concerns on this embodiment. It is sectional drawing which shows the manufacturing process of the powder compact using the powder molding apparatus which concerns on this embodiment. It is sectional drawing which shows the manufacturing process of the powder compact using the powder molding apparatus which concerns on this embodiment. It is a perspective view of the powder compact obtained using the powder compactor concerning this embodiment. It is sectional drawing which shows the manufacturing process of the other powder compact using the powder molding apparatus which concerns on this embodiment. It is sectional drawing which shows the manufacturing process of the other powder compact using the powder molding apparatus which concerns on this embodiment. It is sectional drawing which shows the manufacturing process of the other powder compact using the powder molding apparatus which concerns on this embodiment. It is a perspective view of the other powder compact obtained using the powder compactor concerning this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Powder shaping | molding apparatus 10, 20 ... 1st main surface, 12, 22 ... 2nd main surface, 14 ... Recessed part, 14a, 24a, 24b, 40a, 40b ... Opening edge , 14c, 24c, 40c ... peripheral wall, 14b ... bottom, 16 ... crack, 24, 40 ... through hole, 32 ... electronic component, F1, F2, F3 ... ferrite sintered Connection board, S1 ... 1st protective layer, S2 ... 2nd protective layer.

Claims (4)

A first surface, a second surface facing the first surface, an outer peripheral surface continuous to the first and second surfaces, a first recess opened in the first surface, A powder molding apparatus for producing a powder molded body comprising a second concave portion opened in a second surface,
A frame mold having a through hole, and molding the outer peripheral surface of the powder molded body by an inner peripheral surface forming the through hole;
A lower mold in which one end portion can be fitted into the through hole from one side of the through hole of the frame mold, and the first surface of the powder molded body is formed by the end surface of the one end portion;
A first middle mold in which one end part can be fitted into the through hole from one side of the through hole of the frame mold, and the first concave part of the powder compact is formed by the one end part;
An upper mold that can be fitted into the through-hole from the other side of the through-hole of the frame mold, and that molds the second surface of the powder compact by the end surface of the one-end part;
A second intermediate mold in which one end part can be fitted into the through hole from the other side of the through hole of the frame mold, and the second concave part of the powder compact is formed by the one end part;
With
The one end of the lower mold has a cylindrical shape, and the first middle mold is slidably fitted inside the one end.
The one end of the upper mold has a cylindrical shape, and the second middle mold is slidably fitted inside the one end.
The peripheral surface of the one end portion of the first medium mold includes an inclined surface that is tapered in a direction from one of the through holes to the other of the frame mold,
The peripheral surface of the one end portion of the second middle mold includes an inclined surface that is tapered in a direction from one of the through holes of the frame mold toward the other,
At least the inclined surface of the first medium mold forms the opening edge of the first recess of the powder molded body, and at least the inclined surface of the second medium mold forms the second edge of the powder molded body. A powder forming apparatus for forming an opening edge of a recess. A first surface, a second surface facing the first surface, an outer peripheral surface continuous to the first and second surfaces, and a first opening opened in each of the first and second surfaces A powder molding apparatus for producing a powder molded body having a through hole,
A frame mold having a second through hole, and molding the outer peripheral surface of the powder compact by an inner peripheral surface forming the second through hole;
One end portion can be fitted into the second through hole from one side of the second through hole of the frame mold, and the first surface of the powder compact is formed by the end surface of the one end portion. Type,
One end portion can be fitted into the second through hole from one side of the second through hole of the frame mold, and the first end of the first through hole of the powder molded body by the one end portion. A first middle mold for molding the surface side portion of
One end portion can be fitted into the second through hole from the other side of the second through hole of the frame mold, and the second surface of the powder compact is formed by the end surface of the one end portion. Type,
One end portion can be fitted into the second through hole from the other side of the second through hole of the frame mold, and the second end of the first through hole of the powder molded body by the one end portion. A second middle mold for molding the surface side portion of
With
The one end of the lower mold has a cylindrical shape, and the first middle mold is slidably fitted inside the one end.
The one end of the upper mold has a cylindrical shape, and the second middle mold is slidably fitted inside the one end.
In the second through-hole of the frame mold, the end surface of the one end portion of the first medium mold contacts the end surface of the one end section of the second medium mold,
The peripheral surface of the one end portion of the first medium mold includes an inclined surface that is tapered in a direction from one of the second through holes toward the other,
The peripheral surface of the one end portion of the second medium mold includes an inclined surface inclined in a tapered manner in a direction from the other of the second through holes toward one side,
At least the inclined surface of the first medium mold forms an opening edge of the first through-hole located on the first surface side of the powder compact, and at least the inclined surface of the second medium mold is A powder molding apparatus for molding an opening edge of the first through hole located on the second surface side of the powder compact. A powder molding method for producing a powder molded body,
A frame mold having a through-hole, one end portion of which can be fitted into the through-hole from one side of the through-hole of the frame mold, the one end portion having a cylindrical shape, and the lower mold The one end portion is slidably fitted inside, and the one end portion can be fitted into the through hole from one side of the through hole of the frame mold, and the peripheral surface of the one end portion is formed on the through hole. A first middle mold including an inclined surface that is tapered in a direction from one side to the other, and one end portion can be fitted into the through hole from the other side of the through hole, and the one end portion is cylindrical. The upper mold is slidably fitted to the inside of the one end of the upper mold, and the one end can be fitted into the through hole from the other side of the through hole. A powder molding apparatus comprising: a second intermediate mold including an inclined surface whose surface is tapered in a direction from one of the through holes toward the other. And provides step of preparing,
A cavity forming step of forming a cavity by fitting the one end of the lower mold and the one end of the first middle mold into the through hole of the frame mold;
A filling step of filling the cavity with raw material powder;
A pressure forming step of pressure-molding the raw material powder filled in the cavity by fitting the one end of the upper mold and the one end of the second middle mold into the through hole of the frame mold; ,
Including
In the pressure molding step, the inclined surface of the first middle mold is projected from the end surface of the one end portion of the lower mold, and the inclined surface of the second middle mold is projected from the end surface of the one end portion of the upper mold. Press-molding in a protruding state, forming an opening edge on one surface side of the powder molded body by at least the inclined surface of the first medium mold, and at least by the inclined surface of the second medium mold, A powder molding method comprising molding an opening edge on the other surface side of the powder compact.   The pressure molding step is performed by pressure molding after the end surface of the one end portion of the first medium mold and the end surface of the one end portion of the second medium mold are brought into contact with each other. Powder molding method.

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