JP5824291B2 - Manufacturing method of polygonal shaped parts with hooks - Google Patents

Description

  The present invention relates to a method for manufacturing a polygonal part with a flange provided with a collar part provided continuously with the polygonal part.

Conventionally, a polygonal part of a polygonal part is manufactured by a trimming method disclosed in Patent Document 1 or Patent Document 2. In this trimming method, a desired polygonal portion is obtained by trimming the outer periphery of a blank preformed in a cylindrical shape having a diameter equal to or larger than the circumscribed circle of the polygonal portion with a trimming punch. By using such a trimming method, it is possible to finish the corner portion of the polygonal portion into an accurate shape that is not rounded. However, when forming a polygonal part with a hook in which a collar part projecting outward is integrally formed at one end of the polygon part, the blank part cannot be cut off due to the collar part. This trimming method cannot be used. Therefore, such a polygonal part with a flange is usually formed by forging by upsetting. That is, first, as shown in FIG. 6 (a), it has a volume obtained by combining the polygon part and the collar part at a predetermined position on the shaft, and has a diameter substantially equal to the inscribed circle of the polygon part. The blank 10a which preformed the cylindrical part 11 to be formed is upset-molded. Next, as shown in FIG. 6 (b), the cylindrical portion 11 is placed in a die (not shown) having a concave portion corresponding to the polygonal portion and the flange portion, and the cylindrical portion 11 is polygonal. Molded into a part 12 and a collar part 13.

Japanese Patent Publication No. 3-37812 Japanese Patent No. 3656180

However, in the conventional method for manufacturing a polygonal part with a flange, since the cylindrical part 11 having the diameter of the inscribed circle of the polygonal part 12 is mounted on the die, the flow of the blank 10a in the die becomes insufficient. As shown in FIG. 6 (b), the flow of meat to the corners of the polygonal portion 12 was particularly insufficient, and the polygonal portion 12 could not be accurately formed.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a manufacturing method of a polygonal part with a hook that can accurately mold the corners of the polygonal part. In order to achieve this object, the present invention provides a polygonal shape with a hook formed by integrally molding a polygonal part and a collar part connected to the polygonal part and projecting outward from the polygonal part on the axis. A method of manufacturing a part, comprising an axial blank, having a volume in which a polygonal part and a flange part are combined at a predetermined position of the blank, and having a diameter substantially equal to the circumscribed circle of the polygonal part to a substantially total length. Preliminarily forming a cylindrical portion having crossing , firstly, the cylindrical portion is narrowed into a polygonal concave portion having a shape corresponding to the polygonal portion provided in the die, and then the polygonal portion is formed. It is characterized in that the flange portion is formed by setting up the remaining portion of the cylindrical portion including the surplus that is generated when the portion is drawn.

  According to the present invention, a cylindrical part having a diameter substantially equal to the circumscribed circle of the polygonal part is preformed on the blank, and the polygonal part is formed by placing the cylindrical part while squeezing. The flow of the blank becomes sufficient, and in particular, the corners of the polygonal part can be formed by forging into an accurate shape in which the meat is firmly turned. In addition, by drawing the polygonal part, the surface of the polygonal part can be formed more smoothly than in the trimming process, and the aesthetics of the polygonal part with ridges can be improved, and the surface polishing process There is also an advantage that the manufacturing of the polygonal shaped part with a flange can be made efficient by eliminating the post-process. Furthermore, since the surplus generated by the drawing is used for forming the flange portion, there is an advantage that it is possible to realize forging forming of a polygonal part with a flange without material loss.

It is a figure which shows an example of a polygonal-shaped component with a hook, Comprising: (a) is a left view, (b) is a front view, (c) is a right view, (d) is a perspective view. It is explanatory drawing which shows the form change of the blank in the manufacturing method of the polygonal-shaped component with a flange concerning this invention. It is process explanatory drawing of the manufacturing method of the polygonal-shaped components with a flange which concerns on this invention. It is process explanatory drawing of the manufacturing method of the polygonal-shaped components with a flange which concerns on this invention. It is process explanatory drawing of the manufacturing method of the polygonal-shaped components with a flange which concerns on this invention. It is explanatory drawing of the manufacturing method of the conventional polygonal-shaped components with a collar.

  In FIG. 1, 1 is an example of a polygonal part with a flange (hereinafter simply referred to as a part) manufactured by the manufacturing method according to the present invention. The component 1 is formed by forming a polygonal portion 3 having a hexagonal cross-sectional shape perpendicular to the axis in the middle of the solid shaft 2 and integrally forming a flange portion 4 at one end of the polygonal portion 3. The The eaves part 4 protrudes outward from the polygonal part 3, and is configured such that a cross-sectional shape perpendicular to the axis forms a circle. In addition, the shaft portion 2a connected to the flange portion 4 of the solid shaft 2 is configured to have a thicker diameter than the shaft portion 2b connected to the polygonal portion 3, and both the shaft portions 2a and 2b include The thread is rolled and formed in a later process.

  To manufacture the component 1, first, as shown in FIG. 2A, a blank 1 a is obtained in which shaft portions 2 a and 2 b and a columnar portion 5 sandwiched between the shaft portions 2 a and 2 b are integrally preformed. Specifically, as shown in FIG. 3A, the shaft-shaped blank 1 a is set on the split dies 20 and 21, and one end of the blank 1 a is regulated by the knockout pin 22. In this state, as shown in FIG. The columnar part 5 of the blank 1a thus obtained has a combined volume of the polygonal part 3 and the collar part 4, and the diameter thereof is substantially equal to the circumscribed circle of the polygonal part 3, preferably the same. It is formed to have a diameter slightly smaller than the circumscribed circle. Further, the end of the cylindrical portion 5 on the side of the shaft portion 2b is formed into a taper with a gradually decreasing diameter, and the press-fitting into the polygonal concave portion 32 of the die 30 is smoothly performed in the drawing step described later. It is configured as follows.

  Next, as shown in FIG.2 (b), the polygonal part 3 is draw-formed in the blank 1a. As shown in FIG. 4 (a), the die 30 used here has a columnar shape in which the columnar portion 5 can be fitted with a diameter substantially equal to the circumscribed circle of the polygonal portion 3 in order from the opening side. The concave portion 31, the polygonal concave portion 32 having a shape similar to the polygonal portion 3, and the hole portion 33 into which the shaft portion 2b is fitted are connected. Further, a punch 40 for pressing the blank 1a against the die 30 is provided at a position facing the die 30. The punch 40 is provided with a hole 41 into which the shaft portion 2a is fitted. The knockout pins 34 and 42 are always inserted and positioned in the hole 33 and the hole 41, respectively, and the shafts 2a and 2b of the blank 1a do not extend in the axial direction by the knockout pins 34 and 42 during forging. It is comprised so that it can regulate.

  In order to draw-form the polygonal portion 3 on the blank 1a, the cylindrical portion 5 of the blank 1a is placed on the open end of the polygonal recess 32 as shown in FIG. As shown in c), the shaft ends of the shaft portions 2 a and 2 b are regulated by the knockout pins 34 and 42, and the punch 40 is lowered to press the cylindrical portion 5 against the die 30. Thereby, the cylindrical part 5 having a diameter substantially equal to the circumscribed circle of the polygonal part 3 is narrowed down to the polygonal recessed part 32, thereby forming the polygonal part 3. At this time, the columnar portion 5 is squeezed into the polygonal concave portion 32 from the tapered end portion, so that the squeezing by the polygonal concave portion 32 is performed smoothly. In addition, by narrowing the cylindrical portion 5 having a diameter substantially equal to the circumscribed circle of the polygonal portion 3 with the polygonal concave portion 32, the polygonal portion 3 having an accurate shape without rounded corners can be formed. Along with the drawing of the polygonal part 3, a surplus is generated in the cylindrical part 5, but this surplus is brought close to the remaining part of the cylindrical part 5, that is, the part on the punch side. Since this is regulated by the cylindrical recess 31, the surplus thickness is integrally formed with the remaining portion of the cylindrical portion 5 along the recess 31 to be formed into a cylindrical shape.

  Finally, as shown in FIG. 2 (c), the flange portion 4 is upset and the part 1 is obtained. As shown in FIG. 5A, the die 50 used here includes, in order from the opening side, an annular recess 51 having a shape corresponding to the flange portion 4, and a polygonal recess 52 having a shape corresponding to the polygonal portion 3. The hole portion 53 into which the shaft portion 2b is fitted is continuously provided. A punch 60 for pressing the blank 1a against the die 50 is provided at a position facing the die 50. The punch 60 is provided with a hole 61 into which the shaft portion 2a is fitted. Knockout pins 54 and 62 are always inserted and positioned in the hole portion 53 and the hole portion 61, respectively, and the shaft portions 2a and 2b of the blank 1a do not extend in the axial direction by the knockout pins 54 and 62 during forging. It is comprised so that it can regulate.

  In order to form the collar part 4 in the blank 1a in which the polygonal part 3 is drawn, the polygonal part 3 of the blank 1a is fitted into the polygonal recess 52 as shown in FIG. 5C, the shaft ends of the shaft portions 2a and 2b are regulated by the knockout pins 54 and 62, and the punch 60 is lowered to press the cylindrical portion 5 against the die 50. As a result, the cylindrical portion 5 remaining after the above-described drawing of the polygonal portion 3 is deformed along the annular concave portion 51, thereby forming the flange portion 4. Thus, since the surplus produced at the time of drawing the polygonal part 3 is used for the upsetting of the collar part 4, the forging of the part 1 without material loss can be realized. Moreover, in this process, the polygonal part 3 can be pressed and finished to the polygonal recessed part 52, and the precision of the polygonal part 3 can further be improved.

  In the embodiment of the present invention, the polygonal part 3 has been described as a hexagonal part. However, the same effect is obtained even if the polygonal part is a polygonal part such as a pentagon or octagon. It is.

1 part 1a blank 2 solid shaft 2a shaft portion 2b shaft portion 3 polygonal portion 4 flange portion 5 cylindrical portion 20, 21 split die 23 punch 30 die 40 punch 50 die 60 punch

Claims (1)

A method of manufacturing a polygonal part with a hook formed by integrally forming a polygonal part and a collar part continuously provided on the polygonal part and projecting outward from the polygonal part on an axis,
An axial blank is installed, and a cylindrical portion having a volume in which the polygonal portion and the flange portion are combined at a predetermined position of the blank and having a diameter substantially equal to the circumscribed circle of the polygonal portion over the entire length. Preformed and
First, the polygonal portion is formed by narrowing the cylindrical portion into a polygonal concave portion having a shape corresponding to the polygonal portion provided on the die,
Next, a method for manufacturing a polygonal part with a flange, comprising forming a collar part by placing a remaining part of the cylindrical part including a surplus produced by drawing the polygonal part.

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