JP2012179651A - Method of manufacturing flange nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a flange nut by which thickness of a flange part of the flange nut can be set to be thin, and nonetheless a blank is accurately conveyed, and by which oblique punching is eliminated, punched chips are reduced and heating cost of a heater is suppressed.SOLUTION: First, by heading a solid bar-shaped blank X heated to high temperature, a first blank X1 is formed which is composed of a thick large-diameter disk part a and a thick small-diameter disk part c continuous with the disk part a through a tapered step part b and in which a tapered recessed part d and a small-diameter hole part e continuous with the recessed part d are formed in the center part of the large-diameter disk part a. Next, a second blank X2 in which a small-diameter communicating hole communicated with the center part of the tapered recessed part is formed, is formed by punching the hole bottom of the hole part e of the first blank X1. After that, the hexagonal columnar body of a nut having a through-hole for forming an inside screw, which is a nearly twice diameter of the communicating hole, is formed in the center part and simultaneously the flange nut is formed by successively and integrally providing thin large-diameter flange part12 at one end of the body of the nut and a projecting cylinder 13 at the other end.

Description

  The present invention relates to a method for manufacturing a flange nut that is integrally provided with a flange portion on a seating surface.

  Conventionally, as a method of manufacturing this type of flange nut, as shown in FIG. 6, first, in the first stage forging station S1, a solid bar shape heated to a high temperature and cut to a predetermined length. The blank X is upset by a die and a punch (both not shown), and unnecessary scale on the outer periphery is dropped, and at the same time, a disk-shaped first blank X1 having an outward bulge is formed by forging. Next, in the second forging station S2, the first blank X1 is forged with a punch and a die (both not shown), and a hexagonal columnar nut body a having a concave hole b 'at the center. At the same time as forming ', a large-diameter flange portion c' serving as a seating surface is integrally connected to one end of the nut main body a ', and a cylindrical portion d' protruding from the central portion of the nut main body a 'is integrally connected to the other end. The formed concave second blank X2 is formed, and then the through hole e 'for forming the inner screw is formed by punching the hole bottom of the hole b' of the second blank X2 at the final forging station S3. The flange nut 20 as the final molded product is manufactured.

  JP 11-114653 A

By the way, in the conventional flange nut manufacturing method described above, the bottomed second blank X2 in which the contour shape of the flange nut is completely formed is forged in the second stage forging station S2 which is the front side of the final stage. The flange nut 20 as a final molded product having a through hole e ′ for forming an internal thread is formed by punching only the hole bottom portion of the hole b ′ of the second blank X2 in the final forming station S3. Since the second blank X2 is conveyed from the second forging station S2 to the final forging station S3 by the material transferring chuck (not shown), the material transferring chuck is a flange portion. Only c ′ is sandwiched. However, since the flange portion c ′ is thin, the second blank X2 cannot be accurately clamped by the material transfer chuck, and the clamping posture of the second blank X2 may be tilted. There has been a problem that troubles such as oblique punching occur in the process of removing the bottom of the hole. In addition, in order to solve the problem of the conveyance trouble, the thickness of the flange portion c ′ has to be set to be thicker than necessary.

  Further, when punching the hole bottom of the hole b ′ of the second blank X2 at the final forging station S3, the punching hole e ′ for forming the inner screw is directly punched and formed using a large diameter punching pin. The residue f ′ has a large diameter and a large weight. As a result, there is a problem that a large amount of material loss is generated, and a heating amount of the rod-shaped blank X by the heater is large, and the heating cost of the heater is high.

  Therefore, the present invention can carry out the blank accurately and easily, eliminates the troubles such as the above-mentioned oblique punching, can set the thickness of the flange portion thin, and reduces the punching debris and heats the heater. It is an object of the present invention to provide a method for manufacturing a flange nut capable of keeping costs low.

  In order to solve the above problem, the invention described in claim 1 of the present application is a solid bar blank X which is first heated to a high temperature and cut to a predetermined length in the first stage forging station S1. Is formed with a thick large-diameter disk part and a thick small-diameter disk part that is continuously connected to this through a taper step part, and the center of the large-diameter disk part. A concave first blank X1 having a large-diameter tapered recess and a small-diameter hole continuous in the center of the tapered recess is formed, and then the second blank is formed in the second forging station S2. The bottom of the hole in X1 is punched to form a second blank X2 in which a large-diameter tapered recess and a small-diameter communication hole communicating with the center of the tapered recess are formed in the center of the first blank X1. Then, the final forging station S The second blank X2 is forged with a punch and a die to form a hexagonal column-shaped nut body having a through hole for forming an internal screw having a diameter approximately double the diameter of the communication hole at the center, and at the same time, the nut body A flange nut as the final molded product, which has a thin-walled large-diameter flange projecting radially outward at one end and a cylindrical section projecting axially outward from around the through-hole at the other end. It is characterized by being molded.

  According to the flange nut manufacturing method of the present invention, as described above, in the forging station S2 on the front stage side of the final stage, a small diameter communication hole is formed by punching the bottom of the small diameter hole portion in the concave first blank X1. After that, in the final forging station S3, the small diameter communication hole portion is almost doubled to form a through hole for forming an internal thread, and at the same time, the final molded product in which the contour shape of the flange nut is completely formed. Therefore, the thickness of the large-diameter disk portion in the first blank X1 and the second blank X2 can be set to be thick regardless of the thickness of the flange portion in the final molded product. Accordingly, when the second blank X2 in which the communication hole is formed by punching is transported from the second forging station S2 to the final forging station S3 by the material transporting chuck, the second blank X2 is transported by the material transporting chuck. X2 can be reliably held and conveyed accurately without tilting its posture. As a result, there is no trouble such as oblique punching in the process of punching the bottom of the hole due to the inclination of the blank supply posture to the final stage as in the prior art, and the small diameter communication in the forging station S3 in the final stage. It is possible to accurately and reliably form a flange nut having a through hole almost twice as large as the hole portion and in which the required contour shape is completely formed.

  Further, when forming the communication hole by punching out the hole bottom of the first blank X1 in the second forging station S2, the diameter of the communication hole is set to be smaller than the diameter of the through hole of the final molded product. As a result, the punched debris from the punching pin can be reduced in diameter and weight. As a result, the material loss can be reduced, the amount of heating of the bar-shaped blank X by the heater can be reduced, and the heating cost of the heater can be reduced.

It is a partially cutaway front view of the flange nut manufactured with the manufacturing method concerning the present invention. It is the same top view. It is explanatory drawing which shows the shape change in each process of the flange nut manufactured with the manufacturing method which concerns on this invention. It is a longitudinal cross-sectional view which shows the state just before the forging process in the last process. It is a longitudinal cross-sectional view which shows the state at the time of completion | finish of the forging process in the last process. It is conventional explanatory drawing.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG.1 and FIG.2 shows the flange nut 1 manufactured with the manufacturing method of the flange nut based on this invention. The flange nut 1 is formed with a hexagonal columnar nut body 11 having a through hole 11a for forming an inner screw at the center, and a thin-walled large-diameter flange portion 12 serving as a seating surface at one end of the nut body 11. A cylindrical portion 13 that protrudes outward in the axial direction from around the through hole 11a of the nut body 11 is integrally formed at the other end.

  FIG. 3 shows a change in shape in the molding process when the flange nut 1 described above is manufactured consistently from a rod-shaped material by a multistage forging machine. The manufacturing method will be described below.

  First, in the first stage forging station S1, a solid bar blank X heated to a high temperature and cut to a predetermined length is forged with a punch and a die to obtain a thick large-diameter disk portion. a and a thick small-diameter disk part c continuously connected to this through a taper step part b. A large-diameter taper recess d at the center of the large-diameter disk part a and the center of the taper recess d A concave first blank X1 in which a small-diameter hole e continuous with the portion is formed is formed. At this time, the diameter e of the small-diameter hole e is formed to be about half the diameter of the above-described through-hole for forming an internal screw.

  Next, in the second forging station S2, the bottom of the hole d in the first blank X1 is punched, and a large-diameter tapered recess is formed in the center of the first blank X1 and the center of the tapered recess d is formed. The 2nd blank X2 in which the small-diameter communication hole f which connects is formed. The punching waste g punched out by the punch is discharged to the outside.

  Thereafter, in the final stage forging station S3, as shown in FIGS. 4 and 5, the second blank X2 is forged by the die 2 and the punch 3 so that the inner screw has a diameter approximately double that of the communication hole f at the center. A hexagonal columnar nut body 11 having a through-hole 11a for forming is formed, a thin-walled large-diameter flange portion 12 serving as a seating surface is formed at one end of the nut body 11, and the other end is extended outward from the periphery of the through-hole 11a. The flange nut 1 is molded as a final molded product in which the protruding cylindrical portions 13 are integrally connected.

  The molded flange nut 1 is pushed out of the die by the push-out operation of the known knockout pin mechanism 4 after the punch is retracted.

  As described above, according to the flange nut manufacturing method of the present invention, the small-diameter communication hole is formed by punching the bottom of the small-diameter hole e in the concave first blank X1 in the forging station S2 on the front side of the final stage. f is formed, and then, in the final forging station S3, the small-diameter communication hole portion is enlarged approximately twice to form the through-hole 11a for forming the inner screw, and at the same time, the contour shape of the flange nut 1 is completely formed. Since the flange nut 1 as the final molded product is molded, the thickness of the large-diameter disk portion a in the first blank X1 and the second blank X2 is increased regardless of the thickness of the flange portion 12 in the final molded product. Can be set. Thus, when the second blank X2 in which the communication hole f is formed by punching is transported from the second forging station S2 to the final forging station S3 by the material transporting chuck, the second blank X2 is transported by the material transporting chuck to the second. The blank X2 can be reliably sandwiched and accurately conveyed without tilting its posture. As a result, there is no trouble such as oblique punching in the process of punching the bottom of the hole due to the inclination of the blank supply posture to the final stage as in the prior art, and the small diameter communication in the forging station S3 in the final stage. It is possible to accurately and reliably form the flange nut 1 having the through hole 11a almost double the hole f portion and in which the required contour shape is completely formed.

  Moreover, when punching the bottom of the hole e in the first blank X1 in the second stage forging station S2 to form the communication hole f, the diameter of the communication hole f is compared with the diameter of the through hole 11a of the final molded product. Since the diameter can be set to a small diameter, the punching residue g by the punching pin can be reduced in diameter and weight. As a result, the material loss can be reduced, the amount of heating of the bar-shaped blank X by the heater can be reduced, and the heating cost of the heater can be reduced.

DESCRIPTION OF SYMBOLS 1 Flange nut 11 Nut main body 11a Through-hole 12 Flange part 13 Cylindrical part a Large-diameter disk part b Taper step part c Small-diameter disk part d Taper recessed part e Hole part f Communication hole g

Claims (1)

  First, in the first stage forging station S1, a solid bar blank X heated to a high temperature and cut to a predetermined length is forged by a die and a punch, and a thick large-diameter disk portion And a thick-walled small-diameter disk part integrally connected to this through a taper step part. A large-diameter taper concave part at the center part of the large-diameter disk part and a small-diameter continuous part at the center part of the taper concave part. A concave first blank X1 formed with a hole is formed, and then the bottom of the hole in the second blank X1 is punched in the second stage forging station S2, and the center of the first blank X1 is formed. A second blank X2 having a large-diameter tapered recess and a small-diameter communication hole communicating with the central portion of the tapered recess is formed in the portion, and then the second blank X2 is punched in the forging station S3 at the final stage. Forging with die In addition, a hexagonal columnar nut body having a through hole for forming an inner screw having a diameter almost double that of the communication hole is formed at the center, and at the same time, a thin-walled large-diameter protruding radially outward at one end of the nut body. Manufacturing of a flange nut characterized by forming a flange nut as a final molded product in which a flange portion and a cylindrical portion projecting axially outward from the periphery of the through hole are integrally provided at the other end. Method.

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