JP2007260740A - Manufacturing method for cylindrical product and die used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a cylindrical product which can reduce noise and vibration in press-forming compared with conventional ones, and can respond to a request of downsizing the product, and a die used therefor. <P>SOLUTION: In the manufacturing method, the cylindrical product 92 is formed by an additional press process for pressing an intermediate product 80 two or more times. At a relatively early stage of the additional press process, the bottom wall 81 of the intermediate product 80 is engraved with a recess part 83 to make a part of the bottom wall 81 a predetermined wall thickness easily, so that the cylindrical product 92 at the final shape is made into a predetermined wall thickness easily, to thereby reduce noise and vibration when forming. Furthermore, a large force is not applied to a punch 21, to thereby make the punch 21 small, and size reduction of the cylindrical product 92 can also be performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cylinder-formed product manufacturing method and a mold for forming a tube-formed product by drawing or ironing an intermediate-formed product having a bottom end and a plurality of times.

As a conventional method of manufacturing a cylinder-formed product, a method is known in which a molding material is inserted into a cavity of a die, and an impact extrusion molding is performed in which this material is pushed backward along the punch through a gap between the cavity and the punch. ing. And the convex part was provided in the front end surface of the punch used for the impact extrusion molding, and the thickness deviation of the cylinder formation type | mold goods was aimed at. In addition, when this manufacturing method is performed, a recessed part remains as a trace on the bottom surface of the completed cylinder-shaped product (see, for example, Patent Document 1). As another conventional method of manufacturing a cylinder-formed product, there is known a method of forming a cylinder-formed product through a plurality of drawing or ironing processes and performing impact extrusion molding at the final stage (for example, Patent Documents). 2).
JP 2000-107831 A (paragraphs [0009] to [0012], FIG. 1, FIG. 4, FIG. 5) Japanese Patent Laid-Open No. 10-5906 (paragraphs [0013] to [0018], FIG. 1)

  By the way, impact extrusion molding extrudes a member that forms the bottom wall of a cylinder-formed product from the gap between the die and the punch in the direction opposite to the pressing direction of the punch. Large press force. In particular, when impact extrusion molding is performed on a cylinder-shaped article as in the conventional manufacturing method described above, the corners of the bottom wall and the side wall of the cylinder-shaped article are in a so-called pin angle state. The members constituting the bottom wall of the cylinder-shaped product are difficult to flow and a great pressing force is required. For this reason, noise and vibration problems occur, and the punch is enlarged to ensure strength, and the request for downsizing the cylinder-formed product cannot be met.

  The present invention has been made in view of the above circumstances, and a method for manufacturing a cylinder-formed product that can reduce noise and vibration during press molding and can meet the demand for downsizing of a cylinder-formed product. And to provide molds.

  In order to achieve the above object, a method for manufacturing a cylinder-formed product according to the invention of claim 1 includes: an initial pressing step of pressing a blank material to form an intermediate molded product having a bottomed cylindrical shape; In a method for manufacturing a cylinder-shaped product, in which a product is pressed a plurality of times and the intermediate molded product is squeezed or subjected to a squeeze additional pressing process to form a cylinder-shaped product with a bottom. A concave portion is engraved in a part of the bottom wall of the molded product, and the concave portion or the periphery of the concave portion is characterized by being squeezed or ironed during the additional pressing process.

  According to a second aspect of the present invention, in the method for manufacturing a cylinder-shaped article according to the first aspect, the bottom wall of the cylinder-shaped article is formed at the central portion of the bottom wall of the intermediate molded article, and the bottom wall of the intermediate molded article The outer edge portion of Fig. 1 constitutes the lower portion of the side wall of the cylinder-shaped product, and the concave portion is marked on the central portion of the bottom wall of the intermediate molded product.

  According to a third aspect of the present invention, in the method for manufacturing a cylinder-shaped article according to the first aspect, the bottom wall of the cylinder-shaped article is constituted by the central portion of the bottom wall of the intermediate molded article, and the bottom wall of the intermediate molded article The outer edge portion in FIG. 3 constitutes the lower portion of the side wall of the cylinder-shaped product, and the concave portion is marked on the outer edge portion of the bottom wall of the intermediate molded product.

  According to a fourth aspect of the present invention, there is provided a method for manufacturing a cylinder-shaped product according to the third aspect, wherein a recess is engraved on the outer edge portion of the bottom wall of the intermediate molded product at a relatively initial stage of the additional press step, and then the bottom wall It is characterized in that the central part of the is pressed.

  According to a fifth aspect of the present invention, in the method for manufacturing a cylinder-shaped product according to any one of the first to fourth aspects, the intermediate molded product immediately after the initial pressing step is formed into a substantially elliptic cylindrical shape, and is subjected to an additional pressing step to be intermediate. It is characterized in that the molded product is formed into a flat cylindrical shape to form a cylinder-formed product.

  The mold according to the invention of claim 6 is composed of a plurality of pairs of punches and dies arranged in one direction, and is formed from a blank material with a bottom end with a punch and a die on one end side, In a mold that forms an end-bottomed cylinder-shaped product by sequentially pressing an intermediate molded product with multiple punches and dies, the punch is intermediately placed on the tip surface of the punch that is pressed at a relatively early stage. A stamped portion for marking a recess is formed on the bottom wall of the molded product, and at the stamped portion, a recess is stamped on a part of the bottom wall of the intermediate molded product. And the die is characterized in that it is configured to squeeze or squeeze around the recess or the recess.

  According to a seventh aspect of the present invention, there is provided a metal mold according to the sixth aspect, wherein a taper surface is formed at a tip outer edge portion of a punch provided with a stamped portion, and the punch is in the vicinity of bottom dead center. This is characterized in that a space is formed between the inner surface of the die hole into which the is inserted and the tapered surface.

  The invention according to claim 8 is the mold according to claim 6 or 7, wherein the stamped portion is disposed at a position facing the central portion of the bottom wall of the intermediate molded product that becomes the bottom wall of the cylinder-shaped product, It is characterized in that the outer edge portion of the bottom wall of the intermediate molded product is squeezed by a plurality of punches and dies after the punch provided with the marking portion.

  The invention according to claim 9 is the mold according to claim 6 or 7, wherein the stamped portion is disposed at a position facing the outer edge portion which becomes the lower portion of the side wall of the cylinder-shaped product among the bottom wall of the intermediate molded product. It has the characteristics.

  A tenth aspect of the present invention is the mold according to the ninth aspect, wherein the partial pressurizing portion for pressurizing the central portion of the bottom wall of the intermediate molded product to the front end surface of the punch after the punch having the marking portion. It is characterized by the formation of

  The invention of claim 11 is the mold according to any one of claims 6 to 10, wherein both the punch for forming the intermediate molded product from the blank material and the cross section of the punch provided with the stamped portion are substantially elliptical. On the other hand, it is characterized in that the cross section of the punch that presses the intermediate molded product is formed into an elongated rectangular shape or an oval shape, and the cylindrical formed product is formed into a flat cylindrical shape.

[Invention of Claim 1]
According to the method for manufacturing a cylinder-formed product according to claim 1, a blank material is pressed in an initial pressing process to form an intermediate molded product having a bottomed end, and the intermediate molded product is pressed a plurality of times in an additional pressing process. To do. In the present invention, a concave portion is engraved on a part of the bottom wall of the intermediate molded product at a relatively initial stage of the additional pressing step, and the concave portion or the periphery of the concave portion is squeezed by subsequent pressing in the additional pressing step. Finally, a cylinder-formed product having a bottom area smaller than that of the intermediate molded product immediately after the initial pressing process is completed. Depending on the way of drawing or ironing at this time, the member corresponding to the concave portion of the intermediate molded product becomes the bottom wall or the lower portion of the side wall of the cylindrical formed product.

  Here, in the relatively initial stage of the additional press process, the corners of the bottom wall and the side wall of the intermediate molded product are bent relatively gently, so that the recesses are imprinted on the members constituting the bottom wall of the intermediate molded product. In this case, the member easily spreads to the side, and the recess can be imprinted without requiring a great pressing force as in the conventional impact extrusion molding. Then, by engraving the concave portion, a part of the bottom wall of the intermediate molded product can be set to a predetermined thickness, and the bottom wall or the lower portion of the side wall in the final cylinder-formed product can be set to a desired thickness.

  As described above, according to the manufacturing method of the cylinder-formed product of the present invention, the thickness of the bottom wall or the lower portion of the side wall in the final-formed cylinder-shaped product can be easily adjusted with a smaller pressing force than the conventional manufacturing method. be able to. As a result, noise and vibration can be reduced and the punch can be made small, and it becomes possible to meet the demand for downsizing of the cylinder-formed product. In the present invention, the “relative initial stage of the additional press process” refers to the first to the last half of the total number of presses among the multiple presses performed in the additional press process.

[Invention of claim 2]
According to the method for manufacturing a cylinder-shaped article of claim 2, the bottom wall of the cylinder-shaped article is constituted by the central portion of the bottom wall of the intermediate molded article. Then, at a relatively early stage of the additional press process, a concave portion is engraved in the central portion of the bottom wall of the intermediate molded product and the thickness of the central portion is set to a predetermined size, so that the final cylindrical formed product The wall thickness of the bottom wall can be easily adjusted.

[Invention of claim 3]
According to the method for manufacturing a cylinder-shaped article of claim 3, the lower part of the side wall of the cylinder-shaped article is constituted by the outer edge portion of the bottom wall of the intermediate molded article. Then, at a relatively initial stage of the additional press process, a concave portion is engraved on the outer edge portion of the bottom wall of the intermediate molded product, and the wall thickness of the outer edge portion is set to a predetermined size, so that the final cylindrical formed product It is possible to easily adjust the thickness of the lower portion of the side wall.

[Invention of claim 4]
According to the method for manufacturing a cylinder-shaped article of claim 4, the bottom wall of the cylinder-shaped article is formed at the center portion of the bottom wall of the intermediate molded article, and the cylinder is formed at the outer edge portion of the bottom wall of the intermediate molded article. The lower part of the side wall of the product is constructed. Then, in a relatively early stage of the additional pressing process, the concave portion is engraved on the outer edge portion of the bottom wall of the intermediate molded product, and after the thickness of the outer edge portion is set to a predetermined size, the center of the bottom wall of the intermediate molded product is Since the portion is pressurized and the thickness of the central portion is also set to a predetermined size, the thickness of both the bottom wall and the lower portion of the side wall in the final cylindrical formed product can be easily adjusted.

[Invention of claim 5]
According to the method for manufacturing a cylinder-shaped article of claim 5, the intermediate molded article immediately after the initial pressing step is formed into a substantially elliptic cylinder, and the bottom of the cylinder-shaped article is formed at the center portion along the long axis of the bottom wall. In addition to constituting the wall, the lower part of the side wall of the cylinder-shaped article can be constituted by the outer edge portion of the bottom wall of the intermediate molded article, thereby forming a flat cylindrical cylinder-shaped article.

[Invention of claim 6]
The mold according to claim 6 includes a plurality of pairs of punches and dies arranged in one direction, and forms one end-bottomed intermediate molded product from the blank material with the punches and dies on one end thereof, and the other plurality The intermediate molded product is sequentially pressed with a punch and a die. A punch that performs pressing at a relatively early stage among a plurality of punches is provided with a stamped portion, and a punch having the stamped portion is used to stamp a recess in a part of the bottom wall of the intermediate molded product. The cylindrical formed product is completed by squeezing or ironing the concave portion or the periphery of the concave portion with the plurality of punches and dies. Depending on the way of drawing or ironing at this time, the member corresponding to the concave portion of the intermediate molded product becomes the bottom wall or the lower portion of the side wall of the cylindrical formed product.

  Here, in a relatively initial stage among the multiple presses, the corners of the bottom wall and the side wall in the intermediate molded product are gently bent, so the bottom wall of the intermediate molded product is When a concave portion is imprinted on a component member, the member easily spreads to the side, and the concave portion can be imprinted without requiring a great pressing force as in conventional impact extrusion molding. Then, by engraving the concave portion, a part of the bottom wall of the intermediate molded product can be set to a predetermined thickness, and the bottom wall or the lower portion of the side wall in the final cylinder-formed product can be set to a desired thickness.

  As described above, according to the mold of the present invention, the wall thickness of the bottom wall or the lower part of the side wall in the final cylinder-formed product can be easily adjusted with a smaller pressing force than the conventional mold. As a result, noise and vibration can be reduced, and the punch can be made smaller, thereby meeting the demand for downsizing of the cylinder-formed product.

  In the present invention, “a punch that performs pressing at a relatively initial stage” refers to a punch on one side of the center among a plurality of arranged punches.

[Invention of Claim 7]
According to the mold of the seventh aspect, when the punch having the marking portion is inserted into the die hole of the die, a space is formed between the inner surface of the die hole and the tapered surface. When the concave portion is engraved on the member constituting the bottom wall, the member easily spreads in the space, and the concave portion is easily formed.

[Invention of Claim 8]
According to the metal mold of the eighth aspect, the bottom wall of the cylinder-shaped product is formed at the center portion of the bottom wall of the intermediate molded product. And a recessed part is formed in the center part in the bottom wall of an intermediate molded product by the stamping part of a punch at a comparatively initial stage among a plurality of presses. Thereby, the center part in the bottom wall of the intermediate molded product can be set to a predetermined thickness, and the thickness of the bottom wall in the final cylinder-formed product can be easily adjusted.

[Invention of claim 9]
According to the metal mold of the ninth aspect, the lower part of the side wall of the cylinder-shaped product is constituted by the outer edge portion of the bottom wall of the intermediate molded product. And a recessed part is formed in the outer edge part in the bottom wall of an intermediate molded product by the stamping part of a punch in the comparatively initial stage among several times of presses. Thereby, the outer edge part in the bottom wall of an intermediate molded product can be made into predetermined thickness, and the thickness of the lower part of the side wall in the cylinder-formed product of the final form can be adjusted easily.

[Invention of Claim 10]
According to the mold of the tenth aspect, the bottom wall of the cylinder-shaped product is constituted by the central portion of the bottom wall of the intermediate molded product, and the lower portion of the side wall of the cylinder-formed product is formed by the outer edge portion of the bottom wall of the intermediate molded product. Is configured. Then, in the relatively initial stage of multiple presses, the stamped portion of the punch presses the outer edge portion of the bottom wall of the intermediate molded product to obtain a predetermined thickness, and then the partial pressurization provided for the punch after the punch By the portion, the central portion of the bottom wall of the intermediate molded product can be pressurized and the thickness of the central portion can be easily set to a predetermined size. Thereby, the wall thickness of the bottom wall and the side wall lower part in the cylinder-formed product of the final form can be easily adjusted.

[Invention of Claim 11]
According to the mold of the eleventh aspect, the bottom shape of the intermediate molded product is initially formed into a substantially elliptical shape, and this is gradually drawn or squeezed to complete a flat cylindrical shaped product.

[First Embodiment]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 shows a transfer press 10 having a mold 20 (see FIG. 2) according to the present invention. The transfer press 10 includes an upper base 12 and a lower base 13 that are vertically opposed to each other between a pair of left and right side frames 11 and 11, and the upper base 12 reciprocates up and down.

  A plurality of punches 21 are fixed to the lower surface of the upper base 12 in a line in the left-right direction (opposite direction of the side frames 11, 11) in FIG. 1. Further, facing the punches 21, a plurality of dies 31 are held in a die holder 32 and fixed in a row on the lower base 13. The plurality of pairs of punches 21 and dies 31 constitute the mold 20 according to the present invention.

  As shown in FIG. 1, the punch 21 is fixed to the upper base 12 by a punch holder 22. Further, as shown in FIG. 2, the die 31 is formed by stacking the upper block 33 and the lower block 34 vertically and is fixed to the lower base 13 (see FIG. 1) while being accommodated in the through hole of the die holder 32. The upper surface of the upper block 33 faces the punch 21. Further, the die hole 35 into which the punch 21 enters the die 31 extends over the upper block 33 and the lower block 34, and a back-up punch 36 is provided at the back of the die hole 35 so as to be movable up and down. A processing stage is configured for each punch 21 and die 31 that are opposed to each other in the mold 20, and the punch 21 enters the die hole 35 in each processing stage, whereby an elliptical plate 91 or an intermediate molded product 80 described later is formed into the die hole. It is pushed into 35 and squeezed or squeezed. When the punch 21 is retracted from the die hole 35, the backup punch 36 pushes up the intermediate molded product 80 and removes it from the die hole 35. Other than the above configuration, the configuration of the punch 21 and the die 31 will be described in detail later.

  In general, “squeezing” means moving a member constituting the bottom wall of the molded product to the side wall side and reducing the bottom surface (diameter in the case of a cylinder), and “squeezing” means the side wall of the molded product. This means reducing the wall thickness.

  The transfer device 14 provided in the transfer press 10 sequentially moves the intermediate molded product 80 between the adjacent processing stages each time the upper base 12 moves up and down. For this purpose, the transfer device 14 includes a pair of transfer slides 15 and 15 (see FIG. 2) extending in the arrangement direction of the plurality of dies 31, and a plurality of transfer slides 15 and 15 along the longitudinal direction of the opposing surfaces. Fingers 16, 16 (see FIG. 2, in which only a pair of fingers 16, 16 is shown). The transfer slides 15, 15 reciprocate in the longitudinal direction each time the upper base 12 reciprocates up and down once. First, each intermediate molded product 80 in a plurality of processing stages is held between the opposing fingers 16 and 16, and in this state, the transfer slides 15 and 15 slide in one direction and move to the adjacent processing stage. Next, after the thimble 23 spreads the fingers 16 and 16 with the lowering of the upper base 12 and releases the grip by the fingers 16 and 16, the punch 21 inserts each intermediate molded product 80 into the die hole 35 of the die 31. The transfer slides 15, 15 slide in the opposite direction and return to their original positions. Thus, each time the upper base 12 moves up and down, the intermediate molded product 80 is sequentially fed to the processing stages of the punches 21 and the dies 31.

  Hereinafter, when the processing stages are distinguished, the first processing stage, the second processing stage,... Are called from the upstream side in the feeding direction of the intermediate molded product 80, and finally the intermediate molded product 80 is processed. The stage is called the final processing stage.

  A blank material 90 (for example, a thickness) is provided between the punch 21 of the first processing stage located on the left side in FIG. 1 and the die 31 in the die holder 32 (corresponding to the “one end side punch and die” according to the present invention). 0.6 mm high strength aluminum plate) is supplied. As shown in FIG. 3A, the punch 21 and the die 31 of the first processing stage punch the elliptic plate 91 from the blank 90, and at the same time, the elliptic plate 91 is squeezed into FIG. 3B. The intermediate molded product 80 shown is molded. The intermediate molded product 80 formed in this way is sequentially sent to the remaining processing stages by the transfer device 14 as described above and pressed a plurality of times. At this time, the intermediate molded product 80 is squeezed or squeezed so that the intermediate molded product 80 has one end. A bottom cylinder-formed product 92 (see FIG. 3D) is formed.

  Specifically, the punch 21 of the first machining stage has a substantially elliptical cross section (not shown) orthogonal to the axial direction, and the punch 21 of the final machining stage has a substantially rectangular shape with a long and narrow cross section. Yes. The punches 21 of the remaining plural (for example, 2 to 10) machining stages have a shape in which the cross section approaches a substantially rectangular shape from a substantially elliptical shape toward the post-process side. The cross section of the die hole 35 of each die 31 has a shape corresponding to each punch 21. As a result, the intermediate molded product 80 (see FIG. 3B) immediately after being molded from the elliptical plate 91 has a substantially elliptical cylindrical shape, which is gradually squeezed or squeezed and finally has a flat rectangular cylindrical shape. It is formed into a cylinder forming product 92 (see FIG. 3D).

4 and 5 show the punch 21 and the die 31 of the second processing stage. The cross section perpendicular to the axial direction in the die hole 35 of the punch 21 and the die 31 is a substantially elliptical shape that approximates the cross-sectional shape of the punch 21 and the die 31 of the first processing stage. A stamped portion 21A according to the present invention is formed on the front end surface of the punch 21. The engraved portion 21 </ b> A has an oval shape and is disposed at the center portion of the front end surface of the punch 21, and extends in the major axis direction of the substantially elliptical cross section of the punch 21. A tapered surface 21B is formed on the entire outer edge of the tip of the punch 21.
The protruding amount of the stamped portion 21A with respect to the tip surface of the punch 21 is about 0.2 [mm]. Further, the taper surface 21 </ b> B has an inclination angle of approximately 30 degrees with respect to the axial direction of the punch 21.

  The upper block 33 of the die 31 of the second processing stage is formed with a guide portion 31A in which the upper end opening of the die hole 35 is gradually narrowed toward the back side. Further, an inlet squeezing and squeezing part 31B having the narrowest die hole 35 is provided at a position near the lower end of the upper block 33. It is gently sloping and spreads out. On the other hand, in the lower block 34, the die hole 35 has a substantially uniform cross-sectional shape and extends from the upper end portion of the lower block 34 to the middle portion. The lower end portion of the die hole 35 communicates with an accommodation hole 34A formed in the lower block 34, and a pressure receiving stand 37 is accommodated in the accommodation hole 34A.

  The backup punch 36 of the second machining stage includes a head portion 36B having a substantially elliptical cross section at the upper end of a linear motion shaft 36A having a circular cross section, and the linear motion shaft 36A is passed through the through hole 37A of the pressure receiving base 37. The lower surface of the head part 36 </ b> B can be brought into contact with the upper surface of the pressure receiving table 37. Further, as shown in FIGS. 5A and 5B, when the punch 21 reaches the vicinity of the bottom dead center, a space K1 is formed between the inner side surface 35S of the die hole 35 and the tapered surface 21B of the punch 21. Is formed.

  FIG. 6 shows the punch 21 and the die 31 provided in the nth processing stage near the final processing stage among the plurality of processing stages. The punch 21 is rounded on the entire outer edge of the tip, and the tip is flat. In the upper block 33, the die hole 35 of the die 31 extends below the inlet squeezing and squeezing part 31B toward the back side with substantially the same inclination as the guiding part 31A. Further, in the lower block 34, the die hole 35 is sufficiently wider than the inlet throttle ironing portion 31 </ b> B of the upper block 33. Further, the backup punch 36 has a uniform cross-sectional shape in the vertical direction.

  Further, although not shown, in the punch 21 and the die 31 of the final processing stage, the entire outer edge at the tip of the punch 21 has a smaller radius of curvature (larger curvature) than the R chamfer of the punch 21 provided in the nth processing stage. R chamfering is applied. Further, in the die 31, the lower side of the entrance throttle ironing part 31 </ b> B spreads toward the back side with a steeper slope than the guiding part 31 </ b> A. Final punching is performed by the punch 21 and the die 31.

  This completes the description of the configuration of the mold 20 of the present embodiment. Next, a manufacturing method of the cylinder forming product 92 using the mold 20 will be described.

  When the transfer press 10 of the present embodiment is operated, the punch 21 and the die 31 of the first processing stage in the mold 20 punch the elliptical plate 91 from the blank 90 shown in FIG. The intermediate molded product 80 shown in FIG. 3B is formed by narrowing the elliptical plate 91. Then, the intermediate molded product 80 is pushed down to the positions of the fingers 16 and 16 of the transfer device 14. The pressing by the punch 21 and the die 31 in the first processing stage corresponds to the “initial pressing step” according to the present invention. Here, since the cross-sectional shape of the punch 21 of the first processing stage is substantially elliptical, the intermediate molded product 80 immediately after the initial pressing step has a substantially elliptical cylindrical shape with one end.

  When the punch 21 is retracted from the die 31, the transfer device 14 (see FIG. 2) grips the intermediate molded product 80 and moves from the first processing stage to the second processing stage. This operation is repeated each time the upper base 12 moves up and down, and the intermediate molded product 80 is sequentially sent to the next processing stage and pressed a plurality of times. The step of pressing a plurality of times corresponds to the “additional press step” according to the present invention.

  In the punch 21 and the die 31 of the second processing stage, the intermediate molded product 80 is molded as follows. That is, in the process in which the intermediate molded product 80 is pushed into the die hole 35 by the punch 21, the side wall 82 of the intermediate molded product 80 is squeezed or squeezed between the inlet squeezing and ironing portion 31 </ b> B of the die 31 and the punch 21. At this time, the bottom wall 81 of the intermediate molded product 80 is axially pressed against the tip of the punch 21, and a taper wall is formed on the outer edge of the lower end of the intermediate molded product 80 corresponding to the tapered surface 21 </ b> B provided at the tip of the punch 21. 88 is formed.

  When the punch 21 further enters the back side, the bottom wall 81 of the intermediate molded product 80 comes into contact with the upper surface of the backup punch 36 (see FIG. 5A). Then, the bottom wall 81 of the intermediate molded product 80 comes into contact with the punch 21 and the backup punch 36, and the punch 21 further moves downward to crush the bottom wall 81 of the intermediate molded product 80. The dead point is reached (see FIG. 5B). At this time, a recess 83 is stamped on the bottom wall 81 of the intermediate molded product 80 corresponding to the stamped portion 21A provided on the punch 21 (see FIG. 7).

  Here, at a relatively initial stage in the additional pressing process, the corners of the bottom wall 81 and the side wall 82 in the intermediate molded product 80 are gently bent, so that the recess 83 is stamped on the bottom wall 81 by the stamped portion 21A. In this case, the member constituting the bottom wall 81 easily spreads to the side, and the recess 83 can be stamped without requiring a great pressing force as in the conventional impact extrusion molding.

  In particular, in the mold 20 of the present embodiment, a tapered surface 21B is provided on the punch 21 provided with the marking portion 21A, so that a space K1 is formed between the tapered surface 21B and the inner surface 35S of the die hole 35. In addition, the tapered wall 88 is formed in the intermediate molded product 80 as described above. As a result, when the member constituting the bottom wall 81 spreads sideways, the taper wall 88 of the intermediate molded product 80 can be easily moved outward with its upper end as a fulcrum as shown by the arrow in FIG. And the machining resistance is reduced. Then, as shown in FIG. 7 (A), the recessed portion 83 stamped as described above has an oval shape corresponding to the stamped portion 21A, and is disposed at the center portion of the bottom wall 81 of the intermediate molded product 80. It will be in the state extended in the major axis direction of the substantially ellipse which is 81 shape. Thus, by marking the recess 83 at a relatively initial stage of the additional pressing process, a part of the bottom wall 81 of the intermediate molded product 80 can be easily made to have a predetermined thickness. Specifically, as shown in FIG. 7B, for example, the thickness t2 of the central portion of the bottom wall 81 having the recess 83 is set to 0.4 [mm], and the thickness t1 of the other outer edge portion is set to be 0.4 mm. It can be set to 0.6 [mm] which is substantially the same as the blank material 90. Note that the wall thickness t3 of the side wall 82 is 0.4 [mm] due to the squeezing at the inlet throttle ironing portion 31B.

  Next, when this intermediate formed product 80 is sent to each processing stage after the third and pressed, intermediate forming immediately after the end of pressing the second processing stage is performed, as shown in the change from FIG. 7 to FIG. The outer edge portion of the bottom wall 81 of the product 80 is squeezed and squeezed to become the lower side wall portion 82A of the intermediate molded product 80 (including a part of the lower corner portion of the intermediate molded product 80). Becomes smaller. Further, the side wall 82 of the intermediate molded product 80 is squeezed so that the thickness t3 is, for example, 0.4 [mm] to 0.3 [mm], and the outer edge portion of the bottom wall 81 is squeezed and squeezed. The thickness gradually decreases from 0.6 [mm] toward the wall thickness 0.3 [mm] of the side wall 82.

  Then, when the pressing at the final processing stage is completed, the intermediate molded product 80 becomes the cylinder-formed product 92 shown in FIG. The entire bottom wall 93 of the cylinder-formed product 92 is constituted by the central portion where the recess 83 is formed in the bottom wall 81 of the intermediate molded product 80. The wall thickness t5 (= 0.4 [mm]) of the bottom wall 93 of the cylinder-formed product 92 is the wall thickness t2 (= 0.4 [= [[0.4] [mm]) formed at a relatively initial stage in the additional press process. mm]). Further, the wall thickness t6 of the side wall 94 of the cylinder-shaped product 92 is finally squeezed to 0.2 [mm], for example. As a result, a cylindrical member 92 having a flat rectangular tube shape with a side wall of 0.2 [mm] and a bottom wall of 0.4 [mm] is formed from the blank material 90 having a thickness of 0.6 [mm].

As described above, according to the mold 20 and the manufacturing method of the present embodiment, the bottom wall 93 of the cylinder-formed product 92 is formed at the center portion of the bottom wall 81 of the intermediate molded product 80, and the relatively early stage of the additional press process. At the stage, the thickness of the bottom wall 93 in the cylinder-shaped shaped article 92 in the final form can be easily adjusted by imprinting the concave portion 83 in the central portion of the bottom wall 81 to make the thickness a predetermined size. Can do. Further, since the thickness of the final cylinder-formed product 92 can be easily adjusted with a small pressing force compared to the conventional mold and manufacturing method, noise and vibration are reduced and the punch 21 is made small. Therefore, it is possible to meet the demand for downsizing of the cylindrical formed article 92. More specifically, for example, the above-described flat rectangular tube-shaped shaped article 92 can be formed from high-strength aluminum having a tensile strength of 200 [N / mm ² ] or more, which is generally difficult to form.

  Although the tapered surface 21B is formed on the punch 21 of the second machining stage described above, a curved surface 21C may be formed instead of the tapered surface 21B as shown in FIG. Even in this configuration, since the corner portion of the bottom wall 81 and the side wall 82 of the intermediate molded product 80 is gently bent, when the concave portion 83 is stamped on the bottom wall 81 by the stamped portion 21A, the bottom wall The member constituting 81 spreads easily to the side, and the recess 83 can be stamped without requiring a great pressing force.

[Second Embodiment]
This embodiment is shown in FIGS. 11 to 14, and the structure of the punch 21 of the second processing stage is different from that of the first embodiment. A pair of stamped portions 21D and 21D are provided on the front end surface of the punch 21 of the second processing stage. Each marking portion 21D has a rectangular shape extending in the major axis direction of the ellipse, which is the shape of the tip surface of the punch 21, and these marking portions 21D form a pair in the minor axis direction of the ellipse and deviate from the center of the minor axis. It is placed at the target position. Further, the engraved portions 21D and 21D have their side surfaces facing each other standing upright from the front end surface of the punch 21, and the other side surfaces are inclined with respect to the front end surface of the punch 21 at the same angle as the tapered surface 21B. Since it is the same as the metal mold | die 20 of 1st Embodiment except the said structure, the same code | symbol is attached | subjected to the same site | part and the duplicate description is abbreviate | omitted.

  When the transfer press 10 of the present embodiment is operated, a pair of recesses 84 and 84 are stamped on the bottom wall 81 of the intermediate molded product 80 by the punch 21 of the second processing stage. As shown in FIG. 12A, the concave portions 84 and 84 have a rectangular shape corresponding to the marking portion 21 </ b> D, and are disposed at the outer edge portion of the bottom wall 81 of the intermediate molded product 80. Moreover, three inner side surfaces 84S (refer FIG. 12 (A)) close | similar to the side wall 82 of the intermediate molded product 80 among each recessed parts 84 and 84 become an inclined shape.

  When the intermediate molded product 80 is pressed a plurality of times by the punch 21 and the die 31 of each processing stage after the third, as shown in the change from FIG. 12 to FIG. 13, the bottom wall 81 of the intermediate molded product 80. The outer edge portion of is gradually drawn and squeezed to become the lower side wall portion 82A of the intermediate molded product 80 (including a part of the lower end corner portion of the intermediate molded product 80). Here, since the outer edge portion of the bottom wall 81 is thinned in advance by forming the recess 84, it can be easily drawn and ironed. Moreover, since the inner side surface 84S near the side wall 82 of the recesses 84 and 84 is inclined, the boundary portion between the recess 84 and the periphery thereof can be smoothed.

  When the press at the final processing stage is completed, the intermediate molded product 80 becomes the cylinder-formed product 92 shown in FIG. Here, initially, the outer edge portion of the bottom wall 81 of the intermediate molded product 80 finally becomes the side wall lower portion 94A of the cylinder-shaped product 92, and is left between the pair of recesses 84, 84 in the bottom wall 81. The entire bottom wall 93 of the cylinder forming product 92 is constituted by the central portion. As a result, in the cylinder-formed product 92 of the present embodiment, the thickness of the bottom wall 93 (t5 = 0.6 [mm]) is increased while the thickness of the side wall lower portion 94A (t6 = 0.2 [mm]). ) Can be made thinner. That is, according to the mold 20 and the manufacturing method of the present embodiment, the recesses 84 and 84 are imprinted on the outer edge portion of the bottom wall 81 of the intermediate molded product 80 at a relatively initial stage of the additional press step, and the outer edge portion By setting the wall thickness to a predetermined size, the wall thickness of the side wall lower portion 94A in the final cylinder-formed product 92 can be easily adjusted. In addition, if the lower end corner portion is still thick and squeezed, cracks (cracks) are likely to occur in the lower end corner portion. However, as in the present invention, by reducing the portion corresponding to the lower end corner portion in advance, Generation of cracks at the corners can be prevented.

[Third Embodiment]
This embodiment is shown in FIGS. 15 to 17, and is a modification of the second embodiment. The partial pressurizing portion (not shown) according to the present invention is provided on the tip surface of the punch 21 of the third processing stage. ) Is formed. The partial pressurizing portion is an oval having the same shape as the stamped portion 21A (see FIG. 5) provided in the punch 21 of the first embodiment, and protrudes from the front end surface of the punch 21. Since it is the same as the metal mold | die 20 of 2nd Embodiment except the said structure, the overlapping description is abbreviate | omitted.

  In the present embodiment, when the transfer press 10 operates, a pair of recesses 84 and 84 are imprinted on the bottom wall 81 of the intermediate molded product 80 in the second processing stage, and the outer edge portion of the bottom wall 81 has a predetermined thickness ( t = 0.4 [mm]). And in the 3rd processing stage, the center part in the bottom wall 81 of the intermediate molded product 80 is pressurized, and the wall thickness of the outer edge part and center part of the bottom wall 81 is made equivalent.

  When the intermediate molded product 80 is drawn or squeezed by the punch 21 and the die 31 of each of the fourth and subsequent processing stages, the outer edge portion of the bottom wall 81 of the intermediate molded product 80 as shown in the change from FIG. 15 to FIG. However, it is gradually drawn and squeezed to become the side wall lower portion 82A of the intermediate molded product 80. Then, when the press in the final processing stage is completed, the intermediate molded product 80 becomes the cylindrical formed product 92 shown in FIG. 17, and the central portion pressed by the partial pressurizing portion of the bottom wall 81 of the intermediate molded product 80. The entire bottom wall 93 of the cylinder-formed product 92 is formed.

  As described above, according to the present embodiment, in a relatively initial stage of the additional pressing process, the concave portion is marked on the outer edge portion of the bottom wall 81 of the intermediate molded product 80, and the thickness of the outer edge portion is set to a predetermined size. After that, the central portion of the bottom wall 81 is pressurized so that the thickness of the central portion is also a predetermined size, so that the thickness of the bottom wall 93 and the side wall lower portion 94A in the final cylindrical formed article 92 can be easily achieved. Can be adjusted to.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.

  (1) In the first and second embodiments, the punch 21 of the second processing stage is provided with the marking portions 21A and 21D, but the processing stage performs pressing at a relatively initial stage among the plurality of processing stages. The punch 21 may be provided on the punch 21 of a machining stage other than the second machining stage.

  (2) In the above-described embodiment, the mold 20 for forming the flat-tube-shaped tube-forming product 92 is exemplified. However, the present invention is a mold for forming a tube-forming product having a shape other than the flat-tube-shaped tube. And may be applied to a manufacturing method.

1 is a front view of a transfer press machine according to an embodiment of the present invention. Cross section of transfer device and mold (A) Perspective view of a state in which an elliptical plate is punched from a blank material, (B) Perspective view of an intermediate molded product immediately after the initial pressing step, (C) Perspective view of an intermediate molded product in which a recess is engraved on the bottom wall Figure, (D) Perspective view of cylinder-formed product Side sectional view of the mold of the second machining stage (A) Side cross-sectional view of the mold immediately before imprinting the concave portion, (B) Side cross-sectional view of the mold immediately after imprinting the concave portion Side sectional view of the mold of the nth processing stage (A) Plan view of intermediate molded product, (B) Side sectional view (A) Plan view of intermediate molded product, (B) Partial side sectional view thereof (A) Plan view of cylinder-formed product, (B) Partial side sectional view (A) Side sectional view just before the mold of the modification of the first embodiment is imprinted with the recess, (B) Side sectional view of the mold just after imprinting the recess (A) Side sectional view immediately before the mold according to the second embodiment imprints the recess, (B) Side sectional view of the mold immediately after imprinting the recess. (A) Plan view of intermediate molded product, (B) Side sectional view (A) Plan view of intermediate molded product, (B) Partial side sectional view thereof (A) Plan view of cylinder-formed product, (B) Partial side sectional view (A) The top view of the intermediate molded product shape | molded by the metal mold | die of 3rd Embodiment, (B) The partial sectional side view (A) Plan view of intermediate molded product, (B) Partial side sectional view thereof (A) Plan view of cylinder-formed product, (B) Partial side sectional view

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Transfer press machine 20 Die 21 Punch 21A, 21D Stamping part 21B Tapered surface 31 Die 35 Die hole 80 Intermediate molded product 81 Bottom wall 82 Side wall 82A Side wall lower part 83, 84 Recessed part 90 Blank material 91 Elliptical plate 92 Cylinder-formed product 93 Bottom wall 94 Side wall 94A Lower side wall

Claims (11)

One end-bottomed through an initial press step of pressing a blank material to form a one-end-bottomed cylindrical intermediate molded product, and a step of pressing the intermediate molded product multiple times to squeeze or squeeze the intermediate molded product, or an additional pressing step In the manufacturing method of the cylinder-formed product for forming the cylinder-formed product of
A concave portion is engraved on a part of the bottom wall of the intermediate molded product at a relatively initial stage of the additional pressing step, and the concave portion or the periphery of the concave portion is squeezed or squeezed around the additional pressing step. A method for manufacturing a cylinder-shaped product. The bottom wall of the cylinder-shaped article is configured at the center portion of the bottom wall of the intermediate molded article, and the lower side wall of the cylinder-shaped article is configured at the outer edge portion of the bottom wall of the intermediate molded article,
The method for manufacturing a cylinder-formed product according to claim 1, wherein the concave portion is stamped on the central portion of the bottom wall of the intermediate molded product. The bottom wall of the cylinder-shaped article is configured at the center portion of the bottom wall of the intermediate molded article, and the lower side wall of the cylinder-shaped article is configured at the outer edge portion of the bottom wall of the intermediate molded article,
2. The method for manufacturing a cylinder-formed product according to claim 1, wherein the concave portion is stamped on the outer edge portion of the bottom wall of the intermediate molded product.   4. The center portion of the bottom wall is pressurized after the concave portion is engraved on the outer edge portion of the bottom wall of the intermediate molded product at a relatively initial stage of the additional pressing step. Manufacturing method for cylinder-shaped products. The intermediate molded product immediately after the initial pressing step is molded into a substantially elliptic cylinder,
5. The method for manufacturing a cylinder-formed product according to any one of claims 1 to 4, wherein the intermediate-formed product is formed into a flat cylindrical shape through the additional pressing step, and the tube-formed product is formed. It consists of a plurality of pairs of punches and dies arranged in one direction, and forms a bottomed intermediate molded product from a blank material with the punches and dies on one end side, and a plurality of other punches and dies on the other end. In a mold for sequentially pressing the intermediate molded product to form a cylindrical formed product with one end,
A stamped portion for marking a recess on the bottom wall of the intermediate molded product is formed on a tip surface of the punch that is pressed at a relatively initial stage among the plurality of punches, and the intermediate molded product is formed at the stamped portion. A concave portion is engraved on a part of the bottom wall, and the plurality of punches and dies after the punch having the engraved portion are configured to squeeze or squeeze around the concave portion or the concave portion. Mold to be used. Forming a tapered surface at the outer edge of the punch provided with the marking portion;
A space is formed between the inner surface of the die hole into which the punch is inserted in the die and the tapered surface in a state where the punch reaches near the bottom dead center. Item 7. The mold according to Item 6.   The stamped portion is disposed at a position opposed to a central portion of the bottom wall of the intermediate molded product that becomes the bottom wall of the cylindrical formed product, and a plurality of the punches after the punch including the stamped portion and The mold according to claim 6 or 7, wherein the die is configured so that an outer edge portion of the bottom wall of the intermediate molded product is narrowed.   The mold according to claim 6 or 7, wherein the stamped portion is disposed at a position facing an outer edge portion of the bottom wall of the intermediate molded product, which is a lower portion of the side wall of the cylinder-shaped product.   The partial pressurization part for pressurizing the center part in the bottom wall of the intermediate molded product was formed in the tip end face of the punch after the punch provided with the marking part. Mold. The cross section of the punch for forming the intermediate molded product from the blank material and the punch provided with the stamped portion are both substantially elliptical, and the cross section of the punch for finally pressing the intermediate molded product is an elongated rectangular shape. The mold according to any one of claims 6 to 10, wherein the mold is formed into an oblong shape and the cylinder-formed product is formed into a flat cylinder.

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