Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B35/00—Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws
  • F16B35/04—Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws with specially-shaped head or shaft in order to fix the bolt on or in an object
  • F16B35/041—Specially-shaped shafts
  • F16B35/048—Specially-shaped necks

Definitions

• the present invention relates to a screw with a recess between thread and head and a method for producing such a screw.
• this undercut is produced by machining processes, usually by turning.
• the diameter of this undercut is usually below the core diameter of the screw thread.
• the machined undercut causes a weakening of the dynamic durability of the screw in this area. This is primarily due to the fact that the grain that is created during the non-cutting shaping is destroyed during the machining in this area. In addition, material hardening, which have resulted from the non-cutting shaping during manufacture of the S chraube, destroyed. In addition, the corresponding machining step for producing the undercut leads to additional costs, since this manufacturing step must be carried out on a separate machine.
• the undercut is produced by rolling or rolling.
• this object is also achieved by a method for producing a screw with an undercut between the thread and the head, in which the undercut is produced by rolling or rolling.
• the rolling or rolling of the undercut is carried out simultaneously with the rolling or rolling of the thread or on the same machine as the rolling or rolling of the thread.
• the undercut is even rolled to further strengthen the rolled area, which surprisingly further improves the fatigue strength of the screw between head and thread. This also improves the static strength.
• screws according to the invention break during a load test within the thread and not at the undercut.
• the present invention can be used particularly advantageously if the rolling of the undercut is carried out together with the rolling of the thread. In this way, the production of corresponding screws can be significantly accelerated and cheaper, since both work steps can be carried out simultaneously on the same machine. inventions Accordingly, the strength of the screw is improved and at the same time the manufacturing costs are reduced.
• FIGURE 1 a screw according to the invention from the side;
• FIGURE 2 shows a detailed representation of the undercut of the screw according to the invention from FIG. 1;
• FIGURE 3 another screw according to the invention.
• FIGURE 4 shows a detail of a screw according to the invention according to FIG. 3.
• FIGS. 1 to 4 each show a screw 10 with an undercut 12 between a thread 14 and a head 16.
• the undercut 12 is not produced here by machining processes, but rather by rolling.
• the undercut is preferably rolled simultaneously and on the same Machine like thread rolling 14.

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=29558051

Family Applications (1)

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Cited By (2)

Families Citing this family (2)

Citations (7)

• 2003
  • 2003-07-25 DE DE20311466U patent/DE20311466U1/de not_active Expired - Lifetime
• 2004
  • 2004-05-31 TW TW093115580A patent/TW200504294A/zh unknown
  • 2004-07-08 WO PCT/DE2004/001470 patent/WO2005011892A1/de active Application Filing
  • 2004-07-08 DE DE112004001884T patent/DE112004001884D2/de not_active Expired - Fee Related

Patent Citations (7)

Non-Patent Citations (2)

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