JP2010007132A - Compacting method and compacting die device for component with thickness deviation shape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To compact a component with a thickness deviation shape whose compression direction thickness gradually increases in such a manner that it has a tilted surface with a relatively shape angle at a uniform green density. <P>SOLUTION: The inside of the die hole 1 of a die 20 is set with a lower punch 32 having a lower punch tilted surface 33 forming the tilted surface 5 of a component 1. The upper part of the lower punch 32 is provided with a slider 50 whose compression direction thickness is same as that of a component 1 and having a slider tilted surface 51 parallel to the lower punch tilted surface 33. In such a state that the slider 50 is retreated from the die hole 51, powder P is filled into the die hole 51, then, the slider 50 is progressed into the die hole 51, and in a state where the slider tilted surface 51 and the lower punch tilted surface 33 are superimposed to the upper and lower directions, the powder P is filled into the die hole 51. From this state, the upper punch 41 is inserted into the die hole 21, and further, while the slider 50 is gradually retreated from the slider synchronously with the operation of the inserting operation of the upper punch 41, the powder P is compressed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique of forming a powder compression molded body (a green compact) when manufacturing a part by powder metallurgy, and in particular, as the thickness in the compression direction gradually increases in one direction orthogonal to the compression direction. The present invention relates to a method and a mold apparatus for molding a green compact of an unevenly shaped part having an enlarged shape part.

  FIG. 17 shows an example of an unevenly shaped part targeted by the present invention. This part 1 has a cubic outer shape, but is not solid as a whole, and is open to the outside, leaving a pair of continuous two-sided portions, U-shaped, equal-width edge surfaces 2, 3. An internal space 4 is formed. Here, one edge surface 2 is a side edge surface 2a, 2a on both sides and a middle edge surface 2b connecting these side edge surfaces 2a, and the other edge surface 3 is a side edge surface 3a, 3a on both sides, It is set as the middle edge surface 3b which connects the side edge surface 3a. The bottom surface 5 of the internal space 4 is a rectangular plane. From the inner edge 2 c of the middle edge surface 2 b of one U-shaped edge surface 2 to the middle edge surface 3 b of the other U-shaped edge surface 3. It is formed in a state where it is inclined at an angle of about 45 ° with respect to each of the edge surfaces 2 and 3 over a position slightly inside from the inner edge 3c. The internal space 4 includes two bottom surfaces (hereinafter referred to as inclined surfaces) 5, an inner surface 6 a of a short short wall portion 6 from the other edge surface 3 to the inclined surface 5, and two triangular shapes on both sides of the inclined surface 5. The triangular wall portions 7 and 7 are surrounded by the inner surface 7a.

  In other words, the shape of the component 1 can be said to be a shape in which the triangular block 9 shown in FIG. 19 is fitted and integrated into the U-shaped body 8 having a constant thickness as shown in FIG. The triangular block 9 has an isosceles triangular shape, but one of two acute angle portions having substantially the same angle has a shape in which the corner portion is cut, and the middle edge surface 2b of the one edge surface 2 is It can be said that the surface is formed by cutting.

  In forming the green compact having a shape similar to the part 1, it is conceivable that each triangular wall portion 7 is compressed and formed in a plane direction orthogonal to the thickness direction. 20 (a) and 20 (b) show before and after compression in such a form. In this case, the vertical and horizontal directions of the two surfaces including the triangular wall portions 7 are the vertical and horizontal directions, and the short wall A cavity is formed by the die 10 and the lower punch 12 in a state where the portion 6 is arranged on the lower side and the internal space 4 is opened downward and laterally, and the powder P filled in the cavity is used as the upper punch 11. And the lower punch 12 are pressed and compressed in the axial direction.

  When the upper and lower punches 11 and 12 have a simple one-stage configuration as in this embodiment, each triangular wall portion 7 and short wall portion 6 and each triangular wall portion 7 and short wall portion 6 are located upward. The portion of the outer shape combined with the projected portion, that is, the portion of the U-shaped body 8 shown in FIG. 18, has the same compression amount and the same amount of compression. Compressed to powder density.

  However, the portion other than this, that is, the portion of the triangular block 9 in FIG. 19 has a wedge shape in which the thickness in the compression direction gradually increases from the left to the right in FIG. The compression ratio is extremely different between the left end with the largest thickness in the compression direction and the right end with the lowest thickness (left end <right end). The lower punch 11 shown in FIG. 20 is configured by a combination of an outer lower punch 12A corresponding to the U-shaped body 8 and an inner lower punch 12B corresponding to the triangular block 9. The compression direction thickness of the powder P before compression at the portion corresponding to the U-shaped body 8 is A1, and the compression direction thickness before compression of the powder P at the portion corresponding to the right end and the left end of the triangular block 9 is a1. , E1, and the compression direction thicknesses of these portions after compression are A2, a2, and e2, and the compression ratios are (A1 / A2) <(e1 / e2) <(a1 / a2).

  Therefore, as shown in FIG. 21, the powder P is filled in a vertically symmetrical state with the cavity corresponding to the triangular block 9 and above the cavity, and the filling height of the powder P is proportional to the thickness in the compression direction. In this case, the compression ratio of the triangular block 9 can be made uniform. However, it is extremely difficult to pressurize the powder P with the upper punch 11 while filling the triangular block 9 in a vertically symmetrical state and holding the powder without collapsing it.

  If the inclined surface formed on the part has a relatively gentle wedge shape, the upper surface of the die 10 can be inclined as shown in FIG. When the surface inclination angle is large, even if the upper surface of the die is inclined, if the upper punch 11 comes into contact with the uppermost end (portion indicated by P1 in FIG. 22) of the filled powder, the powder may be collapsed. Is not realistic. In FIG. 22, reference numeral 13 denotes a lower punch.

  From the above situation, it is speculated that compact molding of the part 1 is impossible, and if it is manufactured by the powder metallurgy method, after obtaining a simple cubic sintered body, the sintered body is cut or the like. It was considered that the component 1 was obtained by removing the meat in the hollow portion 4 to form the inclined surface 5 and the inner surface 6a. However, if there are many parts to be removed, the production efficiency is reduced and the material is wasted. Depending on the shape, the cutting blade may not reach and cutting may not be possible. Further, machining made of a magnetic material cannot be applied. Therefore, a technique that enables green compact molding is desired.

  Therefore, as a result of further examination of the technology that enables green compacting of the component 1, as shown in FIG. 23, the inner lower punch that is inserted into the die 10 from the lower side to form the inclined surface 5 is divided in the inclination direction. And the metal mold | die comprised by the some division | segmentation lower punch (12a-12e) which raises / lowers independently was considered. According to this, as shown to Fig.23 (a), the inclination angle of the lower punch surface which is a continuous surface of the upper end surface of each division | segmentation lower punch 12a-12e is a steeper angle than the inclined surface 5 which should be formed, Further, the cavity of the triangular block 9 is formed in the die hole 10a of the die 10 by adjusting the compression ratio of the powder P to be uniform, and the powder P is filled in the cavity.

  Next, as shown in FIG. 23 (b), the upper punch 11 is inserted into the die hole 10 a and the divided lower punches 12 a to 12 e are raised so that the lower punch surface matches the angle of the inclined surface 5. The ascending amounts of the lower divided punches 12a to 12e are different. The larger the thickness in the compression direction, the larger the increasing amount, so that the compression ratio is constant for each portion compressed by the divided lower punches 12a to 12e. In FIG. 23, the compression direction thicknesses of the powder P before compression of the parts corresponding to the divided lower punches 12a and 12e are a1 and e1, and the compression direction thickness of the powder P before compression of the parts corresponding to the outer lower punch 12A. , A1 and A2, and the compression direction thickness after compression of these parts are illustrated as a2, e2, and A2, and the compression ratios (a1 / a2), (e1 / e2), and (A1 / A2) are substantially the same value. .

  However, the plurality of divided lower punches 12a to 12e forming the inclined surfaces are not suitable as shapes that receive a large load because their upper ends are sharply formed and are easily chipped. Moreover, it is extremely difficult to design a mechanism for raising and lowering each of the divided lower punches 12a to 12e independently because a small and precise operation is required. If the number of punches under division is reduced, the degree of miniaturization may be relaxed and design may be possible, but this time, the distribution to make the compression ratio uniform becomes coarse, and the purpose of making the compression ratio uniform Can't be done. Further, it is presumed that traces of the lower punch remain on the inclined surface formed by the plurality of lower punches such that the boundary portion of the lower punch is transferred or becomes an uneven surface. That is, it is still difficult to mold the green compact of the component 1, and the present situation is that a technology that enables molding is expected.

  The technology for forming a green compact having a surface inclined with respect to the compression direction is disclosed in Patent Documents 1 and 2, etc., and the compression ratio is determined by forming the inclined surface with a plurality of molds. The technique of making it uniform is known from Patent Document 3 and the like.

JP 2007-113074 A JP 2000-144211 A JP 2000-326100 A

  Therefore, the present invention provides a molding method and a mold capable of realizing compression molding of an unevenly shaped part having a relatively steep inclined surface and the like in which the thickness in the compression direction gradually increases to a uniform powder density. The object is to provide a device.

  The green compact forming method of the present invention has an inclined surface that is inclined with respect to the compression direction, so that the thickness approximates to an uneven-shaped part that increases in thickness in the compression direction toward one direction orthogonal to the compression direction. A lower punch having a lower punch inclined surface that forms the inclined surface of the part is set in a die hole of a die, and a compression direction is set above the lower punch. A slider having a slider inclined surface that has the same thickness as the part and is parallel to the lower punch inclined surface is disposed so as to be movable back and forth in a direction perpendicular to the compression direction with respect to the die hole. The die hole is filled with powder while retracted from the die hole, and then the slider is advanced into the die hole so that the slider inclined surface is superimposed on the lower punch inclined surface in the vertical direction. The powder is filled in, and then the upper punch is inserted into the die hole, and the powder in the die hole is compressed while the slider is gradually withdrawn from the die hole in synchronization with the insertion operation of the upper punch. It is characterized by that.

  According to the present invention, in the compression molding process, the powder filling height of the portions having different thicknesses in the compression direction can be reduced by moving the slider backward in synchronization with the powder compression operation by the lowering of the upper punch. It is possible to realize the principle that the amount is proportional to the directional thickness and the powder is compressed while maintaining the state. For this reason, the compression ratio can be made uniform, so that the whole green compact can be compression molded to a uniform green density.

  Next, the green compact molding apparatus of the present invention is an apparatus that can suitably realize the molding method of the present invention, and is set by inserting a die having a die hole and the die hole from below. A lower punch having a lower punch inclined surface that forms the inclined surface of the component, an upper punch inserted into the die hole from above and compressing powder in cooperation with the lower punch, and the die hole Can move forward and backward along the direction orthogonal to the compression direction, and has a slider inclined surface parallel to the lower punch inclined surface having the same compression direction thickness as that of the component, A slider disposed above the lower punch so that the slider inclined surface overlaps the lower punch inclined surface in the vertical direction; and the slider in synchronism with the compression operation of the upper punch being inserted into the die hole. The die from the hole It is characterized in that it comprises a slider retracting mechanism for retracting the.

  The slider retracting mechanism in the green compact mold apparatus according to the present invention is configured to be integrated with the cam receiving member provided on the slider and the upper punch as a form that realizes an accurate operation with a simple configuration. It is preferable to include a cam that moves up and down, acts on the cam receiving member when lowered, and retracts the slider via the cam receiving member.

  According to the present invention, there is an effect that it is possible to realize compression molding of an unevenly shaped part having a relatively steep inclined surface and the like in which the thickness in the compression direction is gradually increased to a uniform powder density. .

Embodiments of the present invention will be described below with reference to the drawings.
[1] First Embodiment (1) Configuration of Mold Device FIGS. 1 and 2 are similar to a part 1 by compression molding raw material powder when the part 1 shown in FIG. 1 shows a mold apparatus for obtaining a green compact having a shape to be formed. Reference numeral 20 in these drawings denotes a die whose upper surface is set horizontally. A die hole 21 is formed in the die 20 so as to penetrate the die 20 in the vertical direction. The die hole 21 is formed in a rectangular shape having a cross-sectional shape and size substantially the same as the upper surface 1a of the component 1 in FIG. The die 20 can be moved up and down along the axial direction (vertical direction) of the die hole 21 by a lifting mechanism (not shown).

  In the die hole 21, a cavity filled with powder is formed together with the die hole 21, and two types of lower punches 31 and 32 that compress the raw material powder filled in the cavity together with an upper punch 41 described later in the axial direction. It is inserted from the lower side so as to be movable up and down. One lower punch: The outer lower punch 31 has the same U-shape as the upper surface 8a of the U-shaped body 8 shown in FIG. In FIG. 2, the die hole 21 is inserted into the die hole 21 from below while facing right (X2 direction) and having the outer surface sliding on the inner surface of the die hole 21.

  Another lower punch: The inner lower punch 32 has a rectangular parallelepiped shape whose main portion has a rectangular cross section corresponding to the cross section of the rectangular space surrounded by the outer lower punch 31 and the inner surface of the die hole 21. It is a block. It can be said that the shape and size of the cross section of the inner lower punch 32 are substantially the same shape and size as the upper surface 9a of the triangular block 9 shown in FIG. The upper end surface of the outer lower punch 31 is formed as an inclined surface having an upward slope from one end in the width direction to the other end (left end to right end in FIG. 1). This inclined surface (hereinafter referred to as a lower punch inclined surface) 33 is a form in which the inclined surface 5 of the component 1 is inverted, and the inclination angle θ1 is 45 °. The outer lower punch 31 has a lower punch inclined surface 33 facing upward and to the left (X1 direction) in FIG. 1, and the side surfaces of the outer lower punch 31 and the die hole 21. It is inserted into the die hole 21 from below while sliding on the inner surface.

  An upper punch 41 is slidably inserted into the die hole 21 from above. An upper punch surface 42 which is a lower end surface of the upper punch 41 is horizontal and flat. The upper punch 41 is fixed to the lower surface of the upper ram 43 that moves in the vertical direction. The upper punch 41 is inserted into the die hole 21 from the upper side in accordance with the operation of the upper ram 43, and is lifted and pulled upward from the die hole 21. Is issued.

  A guide groove 22 having a rectangular cross section extending in the left-right direction (X1 and X2 directions) and communicating with the die hole 21 is formed on the upper surface of the die 20 on the right side in FIG. 1 and FIG. . A slider 50 is slidably accommodated in the guide groove 22 along the guide groove 22. The main part of the slider 50 is a rectangular parallelepiped block having a rectangular cross section having substantially the same shape and dimensions as the upper surface of the triangular block 9, and is accommodated in the guide groove 22 in a horizontally placed state.

  The front end surface of the slider 50 (the end surface on the left side in FIGS. 1 and 2) is formed as an inclined surface that is inclined downward toward the front end. This inclined surface (hereinafter referred to as “slider inclined surface”) 51 is a form in which the inclined surface 5 of the component 1 is inverted, and the inclination angle θ 2 is 45 °, which is the same as the lower punch inclined surface 33 of the inner lower punch 32. That is, the slider 50 has the same outer shape and dimensions as the inner lower punch 32. As shown in FIGS. 1 and 2, when the slider 50 moves to the left (X1 direction) along the guide groove 22 and the tip of the portion where the slider inclined surface 51 is formed enters the die hole 21, The slider inclined surface 51 is overlapped with the lower punch inclined surface 33 of the inner lower punch 32 in the vertical direction. Note that the position where this state is reached is the compression start position of the slider 50 when the powder is actually compressed.

  The slider 50 moves forward in the tip direction (X1 direction) where the slider inclined surface 51 is formed, and moves backward in the opposite direction (X2 direction). As shown in FIG. 2, a slit 52 having a rectangular shape in plan view penetrating in the vertical direction is formed in a portion close to the rear end portion from the vicinity of the center portion of the slider 50. A cam roller 54 is rotatably supported at a rear end portion in the slit 52 via a shaft 53 that extends in a direction perpendicular to the moving direction of the slider 50.

  An air cylinder device 60 is disposed behind the slider 50 in the guide groove 22. The air cylinder device 60 includes a sealed cylinder 61 whose axial direction extends along the advancing / retreating direction of the slider 50, and a piston rod 62 inserted in an airtight manner at the end of the cylinder 61 on the die hole 21 side. It has. The cylinder 61 is a rectangular tube having a rectangular cross-section whose outer cross-sectional area is substantially the same as that of the slider 50, and is fixed in the guide groove 22 with a predetermined interval between the cylinder 61.

  The piston rod 62 extends from the cylinder 61 toward the slider 50, and the tip is connected to the rear end surface of the slider 50. According to this air cylinder device 60, air is supplied into or exhausted from the cylinder 61, and the piston rod 62 is changed according to the pressure in the cylinder 61 that fluctuates accordingly. In 2, it stretches to the left or shrinks to the right. As the piston rod 62 expands and contracts, the slider 50 moves forward and backward with respect to the die hole 21.

  As shown in FIG. 1, a cam 66 for retracting the slider 50 is disposed above the cam roller 54. The cam 66 protrudes toward the lower cam roller 54 and is fixed to the lower surface of the upper ram 43. The cam 66 moves up and down integrally with the upper punch 41 by the lifting and lowering operation of the upper ram 43. The cam 66 is a plate having a thickness capable of entering the slit 52 of the slider 50 from above. The lower end portion of the cam 66 has a shape that is cut from the upper right to the lower left in FIG. 1, and the lower surface is formed on a cam surface 67 that is inclined in the backward direction (X2 direction) of the slider 50. The angle θ3 of the cam surface 67 is 45 °, which is the same as the inclination angle of the lower punch inclined surface 33 and the slider inclined surface 51.

  When the upper ram 43 is lowered while the slider 50 is in the compression start position, the cam surface 67 of the cam 66 comes into contact with the cam roller 54, and when further lowered, the cam surface 67 rotates the cam roller 54 in the arrow direction. Press in the X2 direction. As a result, the slider 50 moves backward in the X2 direction. As the cam 66 descends, the slider 50 is retracted to a position where the tip end enters the guide groove 22 from the die hole 21. A clearance hole 23 that allows the tip of the cam 66 to enter and allow the cam 66 to descend is formed at a position in the guide groove 22 that is below the lower end of the cam 66.

  The lower end of the cam 66 is located below the lower end of the upper punch 41. The vertical positional relationship between them is that the cam surface 67 is in contact with the cam roller 54 and the upper punch surface 42 of the upper punch 41 is in the die hole 21. It is set so that it may occur at the same time that it contacts the ground surface (upper surface) of the powder filled in (see FIG. 5). This means that the slider 50 starts to retract at the same time as the powder compression starts.

(2) Molding of green compact A procedure for molding a green compact having a shape approximating the shape of the part 1 using the mold apparatus having the above-described configuration will be described.

(2-1) Filling of raw material powder As shown in FIG. 3, the pressure in the cylinder 61 of the air cylinder device 60 is adjusted, and the position where the tip of the slider 50 is retracted from the die hole 21 and enters the guide groove 22. Retreat until. Further, the outer lower punch 31 and the inner lower punch 32 inserted into the die hole 21 are stopped and held at the cavity forming position. The cavity forming position of the inner lower punch 32 is a position where the upper end is lower than the guide groove 22 by a predetermined distance, and the cavity forming position of the outer lower punch 31 is lower than the lower punch inclined surface 33 of the inner lower punch 32. And, it is a position where the short wall portion 6 of the component 1 can be formed.

  Next, the powder feeder F sliding on the upper surface of the die 20 is advanced onto the die hole 21, and the raw material powder P is dropped into the die hole 21. The powder feeder F is moved to a position that covers the tip of the guide groove 22 so that the powder P also falls on the slider inclined surface 51 of the slider 50. The amount of the powder P that sufficiently fills the space in the die hole 21 and the guide groove 22 falls from the powder feeder F. Next, as shown in FIG. 4, the piston rod 62 of the cylinder 61 is extended to advance the slider 50 in the X1 direction, and the slider 50 is stopped at the compression start position where the slider inclined surface 51 enters the die hole 21. . Thereafter, the powder feeder F is moved backward to cut off the powder P.

(2-2) Compression Molding The powder filling is completed as described above, and then the upper ram 43 is lowered and the upper punch 41 is inserted into the die hole 21 as shown in FIGS. To form a green compact 1A. FIG. 5 shows a stage in which the upper punch surface 42 of the upper punch 41 is in contact with the upper surface (ground surface) of the powder P. At this time, the cam surface 67 of the cam 66 contacts the cam roller 54. When the upper ram 43 continues to descend from this state, the slider 50 is retracted in the X2 direction by the cam 66. That is, in synchronization with the powder compression operation by the lowering of the upper ram 43, the slider 50 moves backward and is gradually extracted from the powder P. And finally, as shown in FIG. 7, it withdraws from the die hole 21 and is extracted. In this case, since the inclination angle θ3 of the cam surface 67 is 45 °, the lowering speed of the upper punch 41 and the retreating speed of the slider 50 are the same. In the final stage of the compression molding shown in FIG. 7, the lower punches 31 and 32 are appropriately raised to complete the powder compression.

  At the time of interlocking such as the retreat of the slider 50 accompanying the lowering of the upper punch 41, the inclination direction and the inclination angle of the slider inclined surface 51 and the cam surface 67 are the same. The positional relationship with the slider 50 that retreats as it descends is always maintained such that the end of the upper punch surface 42 on the X2 side is closest to the slider inclined surface 51. When the slider 50 is retracted, the slider 50 is always urged in the X1 direction by the air cylinder device 60, and the cam roller 54 is always held in contact with the cam surface 67. The cam 66 is kept in contact with the air cylinder device 60. The slider 50 is retracted against the urging force.

  In this compression operation, the powder P is compressed and molded between the lower punches 31 and 32 and the upper punch 41. The part of the U-shaped body 8 of the part 1 corresponding to the outer lower punch 31 is formed. From the initial stage of compression to the final stage in which the slider 50 retreats from the die hole 21, it is always shaped by receiving an axial compression force uniformly. On the other hand, in the upper part of the inner lower punch 32 corresponding to the triangular block 9 on the inner side of the U-shaped body 8, the compression force from the upper punch 41 is blocked by the slider 50, so that it is not compressed all over. The part immediately after the front end of the slider 50 is retreated gradually spreads as a part compressed as the slider 50 retreats, and the triangular block 9 part is compression-molded.

  The thickness in the compression direction at the compression portion that gradually increases in this way is determined from the distance between the upper punch surface 42 and the lower punch inclined surface 33, and further the thickness (high height) of the slider 50 at each compression portion. This is the amount after subtracting For example, the thickness in the compression direction at the compression site g shown in FIG. 6 is (g1 + g2 + g3) in FIG. As shown in FIG. 21, the powder is compressed while the slider 50 is retracted. As shown in FIG. 21, the powder filling height increases as the thickness in the compression direction increases, and the powder fills as the thickness in the compression direction decreases. It can be said that the principle of reducing the height and obtaining the necessary and sufficient filling height proportional to the thickness in the compression direction has been put into practical use.

(2-3) Demolding When the green compact 1A is compression molded as described above, the upper ram 43 is raised to the standby position and the upper punch 41 is extracted from the die hole 21 as shown in FIG. The cam 66 is extracted from the slit 52 of the slider 50. Next, the die 20 is lowered until the green compact 1A comes out upward, and the inner lower punch 32 is further lowered and removed from the green compact 1A. The green compact 1A is placed on the outer lower punch 31 and can be taken out. When the compression molding is completed and the mold is removed, the urging of the slider 50 by the air cylinder device 60 in the advancing direction (X1 direction) is released, and the slider 50 is moved from the die hole 21 by the air cylinder device 60. Hold the evacuated state. When the next compression molding is performed, the slider 50 is advanced to the compression start position by the air cylinder device 60.

  The green compact 1A is compression-molded in a shape similar to that of the part 1. The part corresponding to the U-shaped body 8 of the part 1 has three side surfaces formed by the inner surface of the die hole 21, and the upper surface 1a by the upper punch 41. The lower end surface (edge surface 3) is formed by the outer lower punch 31. The portion corresponding to the inner surface 6 a of the short wall portion 6 of the U-shaped body 8 is formed by the upper end portion of the side surface of the inner lower punch 32 that continues downward from the lower punch inclined surface 33. In the portion corresponding to the triangular block 9, the upper surface 9 a (a part of the upper surface 1 a) is formed by the upper punch 41, and the inclined surface 5 is formed by the inner lower punch 32. A portion corresponding to the middle edge surface 2 b of the triangular block 9 is formed by the inner surface of the die hole 21.

(3) Effects of First Embodiment According to the first embodiment, in the compression molding step, the slider 50 is retracted in synchronization with the powder compression operation by the lowering of the upper punch 41, thereby As shown in FIG. 21, the portion corresponding to the triangular block 9 is set to an amount proportional to the thickness in the compression direction as shown in FIG. 21, and the powder is compressed while maintaining the state. Can be realized by substantially the same principle although the forms are different. For this reason, the compression ratio of the powder corresponding to the triangular block 9 can be made uniform, and the whole green compact can be compression-molded to a uniform green density.

  In the first embodiment, when the cam 66 moves down together with the upper punch 41, the cam roller 54 provided on the slider 50 is pressed by the cam surface 67 of the cam 66 to convert the slider 50 into a backward movement. The slider 50 is retracted in synchronization with the compression operation by the upper punch 41. Such a mechanism can appropriately perform an operation such that the slider 50 moves backward together with the upper punch 41 with a simple configuration.

  For example, if the retracting operation of the slider 50 synchronized with the upper punch 41 is performed by the air cylinder device 60, it is necessary to precisely control the air pressure such as supply of air to the cylinder 61 and discharge of air from the cylinder 61. Even if a drive mechanism using a motor is used instead of the air cylinder device 60, precise control is required to move the slider 50 back at an appropriate speed in synchronization with the lowering of the upper punch 41. In this respect, in the present embodiment, the slider 50 can be retracted in synchronization with the lowering of the upper punch 41 without requiring precise control. As a result, an increase in the number of parts and an increase in cost can be suppressed. .

  From the viewpoint of reliably preventing the upper punch 41 from coming into contact with the slider inclined surface 51 of the slider 50 during compression molding, the inclination angle θ2 of the slider inclined surface 51 is slightly larger than the tip angle θ3 of the cam 66, It is a preferable mode that the slider inclined surface 51 is always retracted quickly from the descending upper punch 41.

(4) Modification of First Embodiment FIG. 9 shows a modification of the mold apparatus of the first embodiment. This modification is a mold apparatus that molds an inclined surface 5 of the component 1 that is not flat but a cylindrical concave surface. Therefore, the lower punch inclined surface 31 of the inner lower punch 32 forming the concave inclined surface is formed as a cylindrical convex surface having a shape in which the concave inclined surface is transferred. Correspondingly, the slider inclined surface 51 is also formed in a cylindrical convex surface of the same shape, while the cam surface 67 of the cam 66 is formed in a cylindrical concave surface in a shape to which the slider inclined surface 51 is transferred. Has been. The slider inclined surface 51 has substantially the same shape as the inclined surface of the component.

[2] Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. In these drawings, the same components as those in the first embodiment are denoted by the same reference numerals, and description of these components will be simplified.

  FIG. 10 shows a component 71 to be molded in the second embodiment. The component 71 has a shape in which the inclined surfaces on both sides are formed in a convex shape by forming grooves 72 on the inclined surfaces on both sides of the trapezoidal block. In other words, the component 71 is integrally formed with a trapezoidal block portion 74 having a shorter upper surface and lower surface than the trapezoidal plate portion 73 at a central portion between a pair of trapezoidal plate portions 73 arranged in parallel at intervals. It can be said that it was done. The thickness of the side wall portions 75 on both sides of the groove 72 is the same, the depth of the groove 72 is constant, and the bottom surface 72a of the groove 72 and the inclined surface 75a of the side wall portion 75 are parallel.

(1) Configuration of Mold Device FIGS. 11 and 12 show a mold device that compresses raw material powder to form a green compact that approximates the part 71. In these drawings, reference numeral 80 denotes a die having a die hole 81 having a rectangular cross section. On both sides of the die hole 81 on the upper surface of the die 80, a guide groove 82 having a rectangular cross section extending in the left-right direction and communicating with the die hole 81 is formed. In the guide grooves 82, a slider 90 that moves forward and backward with respect to the die hole 81 by the air cylinder device 60 is accommodated slidably along the guide grooves 82.

  The slider 90 is similar to the slider 50 of the first embodiment, and is different from the slider 50 in that the shape of the tip portion is a shape in which the slope of the component 71 is transferred. That is, as shown in FIG. 13, the tip of the slider 90 is inclined downwardly toward the tip as a whole, but a convex portion that forms the groove 72 of the component 71 at the center in the width direction of the inclined surface. 91 is formed, and on both sides of the convex portion 91, a stepped slope 92 that forms a slope 75 a of the trapezoidal plate portion 75 is formed. The width of the convex portion 91 corresponds to the width of the groove 72, and the width of the stepped slope 92 corresponds to the width of the trapezoidal plate portion 75. The angle θ4 of the tip end slope of the slider 90 is the same as the angle θ5 of the slope of the component 71 (the bottom face 72a and the slope of the slope 75a shown in FIG. 10B).

  As shown in FIG. 13, protrusions 83 extending in the vertical direction are formed on the left and right inner surfaces of the die hole 81, and grooves 84 are formed on both sides of these protrusions 83. The width of the ridge 83 corresponds to the width of the groove 72 of the component 71, and the width of the groove 84 corresponds to the thickness of the trapezoidal plate portion 75 of the component 71. Three types of lower punches 101, 102, and 103 are inserted and set in the die hole 81 from the lower side.

  One lower punch: The lower base punch 101 has an H-shaped cross section, and is slidably inserted into the center of the die hole 81 with each groove 101a facing in the left-right direction. The width of the groove 101a of the base lower punch 101 is the same as the width of the ridge 83, and the central lower punch 102 is slidable between the groove 101a and each ridge 83 facing the groove 101a. Inserted. The side lower punch 103 is slidably inserted into the grooves 84 on both sides of the ridge 83.

  The upper ends of the center lower punch 102 and the side lower punch 103 are formed in inclined surfaces that are inclined downward at the same angle toward the inside. The angles θ6 of these inclined surfaces (lower punch inclined surfaces) 102a and 103a are the same as each other and the same angle as the tip of the slider 90. A cavity for forming the groove 72 and the side wall 75 of the component 71 is formed by the center lower punch 102, the side lower punch 103, and a part of the protrusion 102.

  As shown in FIG. 11, the upper punch 111 fixed to the upper ram 43 is slidably inserted into the die hole 81 as the upper ram 43 descends. The upper punch 111 is mainly composed of a main body portion 112 having a rectangular cross section. On the left and right outer surfaces of the main body portion 112, convex pieces 113 extending in the vertical direction corresponding to the stepped slope 92 of the slider 90 are formed. ing.

  Two cams 121 acting on the cam roller 54 of each slider 90 are fixed to the upper ram 43 as in the first embodiment. The inclination angle θ7 of the cam surface 122 of these cams 121 is the same angle as the inclination surface θ4 of the slider 90 on the side where each is arranged.

(2) Molding of green compact A procedure for molding a green compact having a shape approximating the shape of the component 71 using the mold apparatus having the above configuration will be described.

(2-1) Filling of raw material powder The upper and lower positions of the lower punches 101, 102, and 103 are adjusted so that cavities for forming the grooves 72 and the side wall portions 75 of the component 71 are formed (see FIG. 11). Further, the left and right sliders 90 are retracted to a position where the tip is retracted from the die hole 81 and enters the guide groove 82. From this state, the powder is filled into the die hole 81, and then each slider 90 is advanced to a position where the upper end of the stepped slope 92 is on the edge of the die hole 81 as shown in FIG. Trimming is performed (see FIG. 14).

(2-2) Compression Molding As shown in FIGS. 14 to 15, the upper ram 43 is lowered and the upper punch 111 is inserted into the die hole 81 to compress the powder P, thereby molding the green compact 71 </ b> A. FIG. 14 shows a stage where the upper punch surface 114 of the upper punch 111 is in contact with the upper surface (ground surface) of the powder P. At this time, the cam surface 122 of the cam 121 contacts the cam roller 54. When the upper ram 43 continues to descend from this state, the slider 90 moves backward in synchronization with the operation, and is gradually pulled out from the powder P. Finally, as shown in FIG. 15, the slider 90 retreats until it is in a state where a portion on the tip side from the stepped slope 92 is left. At the time of powder compression, the upper punch 111 pressurizes the upper part of the convex part 91 of the slider 90 by the main body 112, and the convex piece 113 pressurizes the upper part of the stepped slope 92.

  As shown in FIG. 15, the punch surface 114 of the upper punch 111 reaches the bottom surface height of the guide groove 82, and the lower punches 101, 102, 103 are slightly raised to lower the center lower punch 102 and the side lower punch 103. When the upper end reaches the bottom surface height of the guide groove 82, the compression of the powder P is completed, and the powder P is formed into a green compact 71A having a shape similar to the part 71.

(2-3) Demolding When the green compact 71A is compression molded as described above, the upper ram 43 is raised to the standby position and the upper punch 111 is extracted from the die hole 81 as shown in FIG. The cam 121 is extracted from the slit 52 of the slider 90. Next, the die 80 is lowered until the green compact 71A comes out upward, and the center lower punch 102 and the side lower punch 103 are lowered. The green compact 71A is placed on the base lower punch 101 and can be taken out.

  As described above, the green compact 71A having a shape approximate to the component 71 is formed. Also in this embodiment, as in the first embodiment, the slider 90 is moved in synchronization with the powder compression operation by the lowering of the upper punch 111. By retreating, the powder filling height of the portion corresponding to the inclined surfaces (the bottom surface 72a of the groove 72 and the inclined surface 75a of the side wall 75) having different thicknesses in the compression direction is set to an amount proportional to the thickness in the compression direction. This allows the entire green compact to be compression molded to a uniform green density.

It is a partial cross section side view showing the metallic mold device concerning a 1st embodiment of the present invention. It is a top view which shows a part of metal mold | die apparatus of 1st Embodiment. It is a partial cross section side view which shows the powder filling step of the compression molding process of 1st Embodiment. It is a partial cross section side view showing the slider advancement stage of the same process. It is a partial cross section side view which shows the powder compression initial stage of the process. It is a partial cross section side view which shows the powder compression middle stage of the process. It is a partial cross section side view which shows the powder compression final stage of the process. It is a partial cross section side view which shows the state after the demolding of the process. It is a partial cross section side view which shows the modification of the metal mold | die apparatus which concerns on 1st Embodiment. It is (a) top view, (b) side view, (c) bottom view, (d) perspective view of the uneven thickness shaped component which concerns on 2nd Embodiment of this invention. It is a partial cross section side view showing the metallic mold device concerning a 2nd embodiment of the present invention. It is a top view which shows a part of metal mold | die apparatus of 2nd Embodiment. It is a perspective view which shows a part of metal mold | die apparatus of 2nd Embodiment. It is a partial cross section side view which shows the powder compression initial stage of the compression molding process of 2nd Embodiment. It is a partial cross section side view which shows the powder compression final stage of the process. It is a partial cross section side view which shows the state after the demolding of the process. BRIEF DESCRIPTION OF THE DRAWINGS It is (a) side view, (b) front view, (c) bottom view, (d) perspective view of the uneven shape part which this invention makes object and shape | molds green compact in 1st Embodiment. It is the (a) perspective view and (b) side view of the U-shaped body which decomposed | disassembled the components shown in FIG. It is the (a) perspective view and (b) side view of the triangular block which decomposed | disassembled the components shown in FIG. FIG. 18 is a cross-sectional view illustrating a case where the green compact of the component illustrated in FIG. 17 is simply compressed in the axial direction, and is (a) before compression and (b) after compression. It is sectional drawing which shows the principle of the method of shape | molding the green compact of the components shown in FIG. 17 so that a compression ratio may become uniform. It is an example of the metal mold | die which compression-molds components with a comparatively small slope angle. It is sectional drawing which shows the method of shape | molding so that the compression ratio of a green compact may become uniform by disassembling a lower punch into plurality, (a) Before compression, (b) After compression.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,71 ... Uneven-shaped part 1A, 71A ... Green compact 5 ... Part inclined surface 20, 80 ... Die 21, 81 ... Die hole 31 ... Outer lower punch 32 ... Inner lower punch 33, 102a, 103a ... Lower punch Inclined surface 41, 111 ... Upper punch 50, 90 ... Slider 51 ... Slider inclined surface 54 ... Cam roller (cam receiving member)
66, 121 ... Cam 101 ... Base lower punch 102 ... Center lower punch 103 ... Side lower punch

Claims (3)

This is a method of forming a green compact with a shape approximating an unevenly shaped part that has an inclined surface that is inclined with respect to the compression direction, and whose thickness in the compression direction increases in one direction perpendicular to the compression direction. And
A lower punch having a lower punch inclined surface that forms the inclined surface of the part is set in the die hole of the die, and the thickness of the compression punch is the same as that of the part above the lower punch, and the lower punch inclined A slider having a slider inclined surface parallel to the surface is disposed so as to freely advance and retract along the direction perpendicular to the compression direction with respect to the die hole.
Filling the die hole with powder in a state where the slider is retracted from the die hole,
Next, the slider is advanced into the die hole, and the slider inclined surface is vertically superimposed on the lower punch inclined surface, and the die hole is filled with powder,
Next, the upper punch is inserted into the die hole, and the powder in the die hole is compressed while the slider is gradually retracted from the die hole in synchronization with the insertion operation of the upper punch. A compact molding method for shaped parts. A mold apparatus for forming a green compact having a shape approximating an uneven-thickness shaped part that has an inclined surface that is inclined with respect to the compression direction, and whose thickness in the compression direction increases in one direction orthogonal to the compression direction. Because
A die having a die hole;
A lower punch having a lower punch inclined surface that is inserted and set in the die hole from below and forms the inclined surface of the component;
An upper punch that is inserted into the die hole from above and compresses the powder in cooperation with the lower punch;
It can move forward and backward along the direction perpendicular to the compression direction with respect to the die hole, has a slider inclined surface that has the same thickness as the part and is parallel to the lower punch inclined surface, and advances into the die hole. When the slider is disposed above the lower punch, the slider inclined surface overlaps the lower punch inclined surface in the vertical direction;
A compact molding tool for unevenly shaped parts, comprising: a slider retracting mechanism for gradually retracting the slider from the die hole in synchronism with a compression operation in which the upper punch is inserted into the die hole. . The slider retracting mechanism is
A cam receiving member provided on the slider;
3. The uneven thickness shape according to claim 2, further comprising a cam that moves up and down integrally with the upper punch, acts on the cam receiving member when lowered, and retracts the slider via the cam receiving member. Compacting mold equipment for parts.

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