JP5366320B2 - Molded body molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method, when molding a molded body having a projecting part reaching a top part via an inclined face rising from one end face, and having a plurality of groove parts extending almost in parallel with the end face opposite to the above one end face over one side face to the opposite side face, for forming dimensions of the groove parts and the top part of the projecting part with high precision. <P>SOLUTION: The raw material powder is subjected to compression molding by the upper and lower first punches, by using a molding die device constituted of: a fixed die 210 in which a plurality of groove parts 212, corresponding to the above groove parts of the molded body, extending almost in parallel with one another and having a die hole; a movable die 220 in which recessed parts 222 corresponding to the projecting parts of the molded body are formed at the side faces opposite to the fixed die, and which is freely slidably fitted into the die hole of the fixed die; and upper and lower first punches 310, 410 on the groove part side in the fixed die and upper and lower second punches 320, 420 on the fixed die side freely slidably suitable for a space formed between the fixed die and the movable die. Thereafter, compression molding is performed by the upper and lower second punches. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method for manufacturing a sintered machine part by a powder metallurgy method that sinters a molded body mainly made of metal powder. In order to form the molded body, a raw material powder mainly made of metal powder is filled in a die mold hole. The present invention also relates to a method for forming a molded body by a so-called pressing method, in which compression molding is performed with upper and lower punches.

  The powder metallurgy method, especially the manufacturing method of sintered machine parts by the die method, can be (1) shaped into a near net shape, and (2) suitable for mass production, and (3) obtained with melted materials. Due to the fact that special materials that cannot be produced can be produced, it has been applied to machine parts for automobiles and machine parts for various industries. In addition, the product shape is not only a simple gear shape, but is also applied to products with various complicated shapes, such as a shape having a convex part or a concave part on the end face (Patent Document 1 or the like).

JP-A-10-118797

  By the way, as shown in FIG. 8, the slide cam has an inclined surface 112b protruding from the end surface 111 on the 101 side end surface (upper end surface in the drawing) and a convex portion 112 reaching the top portion 112a via the inclined surface 112c. The 102 side end surface (the lower end surface in the figure) facing the 101 side end surface has a shape in which a plurality of substantially parallel groove portions 122 are formed on the end surface 121. The groove 122 is open to the side surface 131 on the side surface of the 103 side. The slide cam having such a shape is guided by the groove 122, moves forward and backward on a rail (not shown), and a contact position of a rod (not shown) that slides in contact with the end surface on the 101 side by the forward and backward movement of the slide cam. However, the rod is driven upward by displacing from the end surface 111 through the inclined surface 112b to the top portion 112a, and the rod is driven downward by displacing from the top portion 112a through the inclined surface 112b to the end surface 111 to move the rod up and down. To drive. That is, in the slide cam, the convex portion 112 functions as a cam. For this reason, in order to accurately drive the rod up and down, it is necessary to increase the accuracy of the dimension a of the groove 122 and the top 112a of the convex 112 as the slide cam.

  When such a slide cam is manufactured by a powder metallurgy method, the molding is generally performed as shown in FIG. In this case, the side surface is formed by the mold hole wall surface of the die 20, the 101 side end surface is formed by the upper punch 30, and the 102 side end surface is formed by the lower punch group 40. At this time, the end surface 111 of the slide cam is formed by the end surface 31 of the upper punch 30, and the convex portion 112 composed of the inclined surface 112 b and the top portion 112 a of the slide cam is formed on the top portion 32 a via the inclined surface 32 b of the upper punch 30. It is formed by the convex part 32 which reaches. Further, the end surface on the 102 side is formed by a plurality of lower punches 41 that form a plurality of end surfaces 121 and a plurality of lower punches 42 that form a plurality of groove portions 122.

  However, the upper punch 30 is attached to the upper ram of the molding press device, and the lower punch group 40 is attached to the platen of the molding press device, and each of them is compression-molded by a separate drive system. It is difficult to completely control the position and the tip position of the lower punch 42, and therefore, a variation occurs in the dimension a of the groove portion 122 and the top portion 112 a of the convex portion 112. Further, when adjusting the variation of the dimension a by machining, the profile of the cam is changed when the top portion 112a of the convex portion 112 is processed. Therefore, it is necessary to machine the groove portion 122 to adjust the variation. It is troublesome and costly to machine the plurality of grooves 122 with high accuracy and alignment.

  As described above, the present invention has, on one end surface, a convex portion that reaches the top via a raised inclined surface, and extends substantially parallel to the end surface facing the one end surface from one side surface to the opposite side surface. An object of the present invention is to provide a method for molding a molded body that can be molded with high accuracy by suppressing variation in the dimensions of the groove and the top of the convex portion when molding a molded body having a plurality of grooves.

  In the molding method of the molded body of the present invention, one end surface has a convex portion that reaches the top via a protruding inclined surface, and the end surface facing the one end surface is substantially parallel to the side surface facing from one side surface. A method for forming a molded body having a plurality of grooves extending in a fixed die having a mold hole, a movable die slidably fitted in the mold hole, the fixed die, and the movable die The upper punch and the lower punch, which are slidably fitted in the space formed by the above, correspond to the groove portion of the molded body on the side surface facing the movable die of the mold hole of the fixed die with a space therebetween A plurality of grooves extending substantially in parallel from one end surface to the other end surface are formed, and a concave portion corresponding to the convex portion of the molded body is formed on a side surface of the movable die facing the fixed die, The upper punch is slidably fitted into the groove portion of the fixed die. The upper punch includes an upper second punch that is slidably fitted to the upper first punch and the movable die, and the lower punch is slidably fitted to the groove portion of the fixed die. The fixed die, the movable die, and the lower punch are formed using a molding die device that includes a lower first punch, and a lower second punch that is slidably fitted to the lower first punch and the movable die. After the raw material powder is filled into the space formed, the raw material powder is first compression-molded by the upper first punch and the lower first punch, and then the raw material powder is formed by the upper second punch and the lower second punch. The molding is performed by compression molding, and the obtained molded body is extracted from the fixed die by raising the movable die and the lower punch relative to the fixed die.

  According to the present invention, the one end surface has a convex portion that reaches the top portion via the protruding inclined surface, and extends substantially in parallel from one side surface to the opposite side surface to the end surface facing the one end surface. In molding a molded body having a plurality of groove portions, variation in the dimensions of the groove portions and the top portions of the convex portions can be suppressed, and molding can be performed with high accuracy.

It is the schematic which shows the shaping die apparatus used in the shaping | molding method of the molded object of this invention, (a) is a top view of die | dye which consists of a fixed die and a movable die, (b) is sectional drawing of a shaping die apparatus, c) is a perspective view of a die composed of a fixed die and a movable die. It is sectional drawing of the shaping die apparatus which shows the filling state of the raw material powder in the shaping | molding method of the molded object of this invention. It is sectional drawing of the shaping die apparatus which shows the shaping | molding state of the raw material powder by the up-and-down 1st punch in the shaping | molding method of the molded object of this invention. It is sectional drawing of the shaping die apparatus which shows the shaping | molding state of the raw material powder by the up-and-down 2nd punch in the shaping | molding method of the molded object of this invention. It is sectional drawing of the shaping die apparatus which shows the state which shaping | molding of the raw material powder in the shaping | molding method of the molded object of this invention was completed. It is sectional drawing of the shaping die apparatus which shows the extraction state of a molded object in the shaping | molding method of the molded object of this invention. It is sectional drawing of the shaping die apparatus which shows the molded object state in the shaping | molding method of a comparative molded object. It is a figure which shows the shape of a slide cam, (a) is a side view, (b) is a front view, (c) is a top view, (d) is a bottom view, (e) is a perspective view. It is sectional drawing of the shaping die apparatus which shows the conventional shaping | molding method.

  The molding die apparatus in the molding method of the molded body of the present invention is shown in FIG.

  The die includes a fixed die 210 and a movable die 220.

  Formed on one side surface of the mold hole of the fixed die 210 are a plurality of convex strips 211 that form a plurality of groove portions 122 that extend substantially parallel to the molded body, and a groove portion 122 of the molded body. A recess 212 for forming the end surface 121 is formed. The ridges 211 and the ridges 212 are formed to penetrate from the upper end surface of the fixed die 210 to the lower end surface.

  The movable die 220 is opposed to the side surface of the mold hole in which the convex stripes 211 and the concave stripe 212 of the fixed die 210 are formed with a distance a2, and is slidably fitted to the side surfaces 213 and 214 of the mold hole. As shown in FIG. 1C, the movable die 220 is slidable in the vertical direction relative to the fixed die 210. Further, the movable die 220 has a concave portion 222 having a depth a1 for forming the convex portion 112 of the molded body on the side surface 221 facing the side surface of the mold hole in which the convex strip 211 and the concave strip 212 of the fixed die 210 are formed. Is formed. The concave portion 222 of the movable die 220 includes a bottom portion 222a, an inclined surface 222b, and an inclined surface 222c. The bottom portion 222a inclines the top portion 112a of the molded body convex portion 112, and the inclined surface 222b inclines the inclined surface 112b of the molded body convex portion 112. The surface 222 c forms the inclined surface 112 c of the molded body convex portion 112.

  The upper punch 300 and the lower punch 400 are a space formed by the fixed die 210 and the movable die 220, that is, a plurality of convex stripes 211 and 212, a mold hole side surface 214, and a movable die side surface 221. Fits slidably. Further, the upper punch 300 and the lower punch 400 include a first upper punch 310 and a second lower punch 410 that are slidably fitted to the plurality of ridges 211 and ridges 212 of the fixed die 210, the movable die 220, and the first dies. The second upper punch 320 is slidably fitted to the first upper punch 310, and the second lower punch 420 is slidably fitted to the movable die 220 and the first lower punch 410.

  A molding die apparatus comprising the fixed die 210, the movable die 220, the upper punch 300 (upper first punch 310 and upper second punch 320) and the lower punch 400 (lower first punch 410 and lower second punch 420). The molding method of the molded body of the present invention to be used will be described below. First, as shown in FIG. 2, the raw material powder is filled in the space formed by the fixed die 210, the movable die 220 and the lower punch 400.

  Next, as shown in FIG. 3, the upper first punch 310 and the lower first punch 410 are driven in a relatively approaching direction to pressurize the raw material powder. At this time, the raw material powder at the portion sandwiched between the upper first punch 310 and the lower first punch 410 is compressed and densified. In addition, a part of the raw material powder flows to a portion sandwiched between the non-pressurized upper second punch 320 and the lower second punch 420 as indicated by an arrow in the drawing, and the raw material powder becomes dense at the central portion.

  Thereafter, as shown in FIG. 4, the upper second punch 320 and the lower second punch 420 are driven in a relatively approaching direction to pressurize the raw material powder. At this time, since the raw material powder at the portion sandwiched between the upper second punch 320 and the lower second punch 420 is first densified at the central portion, the upper second punch 320 and the lower second punch 420 are pressed. As a result, the raw material powder becomes dense while flowing into the concave portion 222 of the movable die 220 as indicated by the arrows in the figure.

  Thus, as shown in FIG. 5, the raw material powder is compressed until the end surfaces of the upper second punch 320 and the lower second punch 420 are flush with the end surfaces of the upper first punch 310 and the lower first punch 410. By doing so, the pressing force of the punch is also propagated to the raw material powder filled in the concave portion 222 of the movable die 220, and a sufficient molding density can be obtained.

In the molding method of the molded article of the present invention, the convex portion 112 of the shaped body (slide cam) is to be formed by the recess 222 formed in the movable die 220, the depth a ₁ is always constant. Further, the movable die 220 to be restrained by the die hole of the stationary die 210, the distance _{a 2} of the movable die 220 and the fixed die 210 is also always constant. Therefore, the dimension a of the convex part top 112a and the groove part 122 of a molded object (slide cam) can be shape | molded with very high precision.

  The molded body obtained by the above molding is easily extracted from the fixed die 210 by simultaneously raising the movable die 220 and the lower punch 400 relative to the fixed die 210, as shown in FIG. .

  When the upper punch 300 and the lower punch 400 are used as punches that are not divided as in the prior art, the pressing force of the raw material powder acts vertically and fills the concave portion 222 of the movable die 220 as shown in FIG. Pressurizing force is unlikely to act on the raw material powder, and the density of the molded body convex portion 112 becomes low, or the raw material powder does not harden.

  In the molding method of the molded body of the present invention, one end surface has a convex portion that reaches the top via a protruding inclined surface, and the end surface facing the one end surface is substantially parallel to the side surface facing from one side surface. In forming a molded body having a plurality of groove portions extending in the shape, variation in the dimensions of the groove portions and the top portions of the convex portions can be suppressed and molding can be performed with high accuracy, so that the slide cam can be used for manufacturing by powder metallurgy.

112 Convex part of slide cam (molded body) 122 Groove part of slide cam (molded body) 210 Fixed die 211 Convex line of fixed die 212 Concave line of fixed die 220 Movable die 222 Concave part of movable die 300 Upper punch 310 Upper first punch 320 Upper second punch 400 Lower punch 410 Lower first punch 420 Lower second punch

Claims (1)

On one end surface, it has a convex part that reaches the top part via a raised inclined surface,
A molding method of a molded body having a plurality of groove portions extending substantially in parallel from one side surface to a side surface facing the one end surface,
A fixed die having a mold hole, a movable die slidably fitted in the mold hole,
An upper punch and a lower punch that are slidably fitted in a space formed by the fixed die and the movable die,
A plurality of groove portions extending substantially in parallel from one end surface to the other end surface corresponding to the groove portion of the molded body are formed on a side surface of the fixed die that faces the movable die with a space therebetween,
A concave portion corresponding to the convex portion of the molded body is formed on a side surface of the movable die facing the fixed die,
The upper punch is composed of an upper first punch that is slidably fitted to the groove portion of the fixed die, and an upper second punch that is slidably fitted to the upper first punch and the movable die.
The lower punch includes a lower first punch that is slidably fitted to the groove portion of the fixed die, and a lower second punch that is slidably fitted to the lower first punch and the movable die. Using a molding tool
After filling the raw material powder into the space formed by the fixed die, the movable die and the lower punch, first, the raw material powder is compression-molded by the upper first punch and the lower first punch, and then the upper second The raw material powder is compression-molded by the punch and the lower second punch, and the resulting molded body is extracted from the fixed die by raising the movable die and the lower punch relative to the fixed die. A method for forming a molded body characterized by the above.

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