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KR-20260065437-A - Mold having variable wheel structure replacing swaging process to prevent nut loosening, and method for manufacturing nut element using the same

KR20260065437AKR 20260065437 AKR20260065437 AKR 20260065437AKR-20260065437-A

Abstract

The variable wheel structure mold according to the present invention is intended for manufacturing a nut element of a floating nut. The end portion of the nut element, which is made by a press mold, is formed into an elliptical shape. Since the gap between opposing forming wheels can be adjusted, it is possible to work on nut elements of various specifications. Furthermore, since the forming wheels are rotatable, the occurrence of product surface scratches that could adversely affect the fatigue life of the product (nut element) can be prevented. Additionally, since the threaded portion of the nut element is inserted into the upper through hole of the upper die, the vertical and horizontal alignment of the product can be easily ensured, productivity is high, and production costs can be lowered. In addition, the present invention also provides a method for manufacturing a nut element using this mold.

Inventors

  • 정기호
  • 임성식

Assignees

  • 한국생산기술연구원

Dates

Publication Date
20260508
Application Date
20241101

Claims (9)

  1. An upper die (110) installed below the press and having an upper surface (111) on which a nut element is seated and an upper through hole (112); A lower die (120) installed below an upper die (110) and having a lower through hole (122); An elastic member (130) installed between the upper and lower dies (110) (120) to provide an upward restoring force to the upper die (110); and, It includes a set of molding wheels rotatably installed on a lower die (120), and The nut element includes a threaded portion (210) and a support portion (220) extending horizontally from the threaded portion (210), the threaded portion (210) is inserted into an upper through hole (112) and the support portion (220) is seated on an upper surface (111). The upper and lower through holes (112)(122) are formed at corresponding positions, and The molding wheel set includes a first set, and the first set includes two molding wheels (140) arranged parallel to each other with a first gap (D1) in the left and right directions. The press descends to press the nut element and the upper die (110), and as the upper die (110) and the nut element move downward together, the end portion (211) of the screw portion (210) is inserted between the two molding wheels (140) and deformed to be molded into an elliptical shape. A mold that replaces a swaging process, characterized in that when the press rises, the upper die (110) rises upward by the upward restoring force of the elastic member (130).
  2. In paragraph 1, The molding wheel set further includes a second set, A mold that replaces a swaging process, characterized in that the second set includes two forming wheels (140) arranged parallel to each other with a second gap (D2) in the front-rear direction, and the first gap (D1) and the second gap (D2) are different.
  3. In paragraph 2, A mold that replaces a swaging process, characterized in that the molding wheel (140) includes a rotation axis (141) installed along its length, and the molding wheel (140) is installed on a lower die (120) so as to be rotatable around the rotation axis (141).
  4. In paragraph 3, A mold that replaces a swaging process, characterized by being able to adjust the first gap (D1) and the second gap (D2) by adjusting the position of the rotation axis (141).
  5. (a) A step of manufacturing a nut element having a threaded portion (210) and a support portion (220) by processing a sheet metal strip (1) with a press mold; (b) a step of installing the nut element on the upper die (210) such that the support portion (220) is positioned on the upper surface (111) of the upper die (110) and the screw portion (210) is inserted into the upper through hole (112); and, (c) After step (b) above, a step of forming the end portion (211) of the screw portion (210) into an elliptical shape by pressing the nut element and the upper die (110) downwards with a press so that the end portion (211) of the screw portion (210) is inserted between the molding wheels (140) facing each other; characterized by a method for manufacturing a nut element.
  6. In paragraph 5, A method for manufacturing a nut element characterized by adjusting the spacing between the molding wheels (140) facing each other according to the outer diameter of the screw portion (210) and the lengths of the major and minor axes of the ellipse prior to step (c) above.
  7. In paragraph 6, Several upper and lower dies (110) (120) are arranged in the transverse direction, and the upper die (110) is moved up and down simultaneously by a single press, and A method for manufacturing a nut element characterized by forming the end portion (211) of the threaded portion (210) of several nut elements into an elliptical shape by one up-and-down reciprocating movement of a press.
  8. In paragraph 6, The upper die (110) descends toward the lower die (120) by the pressure of the press, and when the pressure is removed, the upper die (110) rises by the upward restoring force of the elastic member (130). A method for manufacturing a nut element, characterized in that the lower die (120) includes a lower through hole (122) corresponding to the upper through hole (112), and the molding wheel (140) is installed around the lower through hole (122), with a part of the molding wheel (140) protruding toward the center of the lower through hole (122).
  9. In paragraph 8, A method for manufacturing a nut element, characterized in that the molding wheel (140) is installed on the lower die (120) so as to be rotatable around a rotation axis (141) provided in the longitudinal direction.

Description

Mold having variable wheel structure replacing swaging process to prevent nut loosening, and method for manufacturing nut element using the same The present invention relates to a variable wheel structure mold for forming the end portion of a nut element into an elliptical shape. More specifically, the invention relates to a variable wheel structure mold that allows for processing nut elements of various specifications by adjusting the gap between opposing forming wheels, prevents scratches on the product surface by allowing the forming wheels to rotate, easily ensures the vertical and horizontal alignment of the product, offers high productivity, and reduces production costs. In addition, the present invention also relates to a method for manufacturing a nut element using this variable wheel structure mold. Generally, floating nut plates are used in the assembly of aircraft fuselages, luxury cars, etc. As shown in FIG. 1, the floating nut plate (10) includes a base plate (11) fixed to an aircraft fuselage, etc., a nut element (200) fastened to a bolt (not shown in the drawing), and a clip (13) that fixes the nut element (200) to the base plate (11). The bolt passes through the base plate (11) and is fastened to the nut element (200). However, to prevent loosening due to vibration after bolt assembly, the end portion (211) of the nut element (200) is compressed to become elliptical. To achieve this, the nut element (200) undergoes a swaging process. As is known, swaging is a type of forging process that can reduce or deform the cross-section of pipes, round bars, etc. by applying a radial load. This swaging process can be carried out by rotary swaging equipment. However, if swaging is not automated, workers must manually push very small products (nut elements) into the exact center while aligning them horizontally and vertically, which is disadvantageous in terms of work efficiency and defect rate. Additionally, since only one product can be formed per swaging machine, there is a problem that additional equipment must be introduced to increase production volume. FIG. 1 is a perspective view showing an example of a floating nut plate. FIG. 2 is a perspective view showing the nut element of the floating nut plate of FIG. 1. FIG. 3a is a cross-sectional view showing a variable wheel structure mold according to a preferred embodiment of the present invention. FIG. 3b is a cross-sectional view showing when the press presses the upper die and the nut element in the mold of FIG. 3a. FIG. 4 is a plan view showing an example of the arrangement of molding wheels in the molds of FIG. 3a and 3b. FIG. 5 is a plan view showing that the mold is arranged horizontally so that multiple nut elements can be processed by one up-and-down reciprocating movement of the press. FIG. 6 is a flowchart showing a process for manufacturing a nut element according to a preferred embodiment of the present invention. FIG. 7 is a plan view schematically showing the S1 to S4 processes of FIG. 6 being performed on a steel plate strip. FIG. 8a is a cross-sectional view showing punching a sheet metal strip to form the threaded portion of a nut element. FIG. 8b is a perspective view showing a nut element made by punching FIG. 8a. Hereinafter, the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely embodiments of the present invention and do not represent all aspects of the technical spirit of the present invention; therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application. In this specification, 'vertical' and 'horizontal' include not only 'vertical' and 'horizontal' in the mathematical sense, but also those that are inclined in a manner close to it. Additionally, in the drawings below, the same components are denoted by the same reference numerals. Below, the variable wheel mold according to the present invention will be described first, followed by a description of the manufacturing process of a nut element using the variable wheel mold. FIG. 3a is a cross-sectional view showing a variable wheel structure mold according to a preferred embodiment of the present invention, and FIG. 3b is a cross-sectional view showing when a press presses the upper die and the nut element. FIG. 4 is a plan view showing an example of the arrangement of the forming wheel of the mold. The variable wheel structure mold (100) is a devic