JP4191196B2 - Method of manufacturing apparatus for preventing scattering of frictional waste generated by screw tightening - Google Patents

Description

The present invention relates to a method of manufacturing an apparatus for preventing frictional waste such as metal powder generated when two members are fixed by tightening screws from being scattered around. Examples of applications include fixing two members above a printed wiring board and fixing two members inside a housing in which an optical component or the like is housed.

  As a conventional technique, a case where an upper member is fixed to a lower member with a screw will be described (for example, see Patent Document 1).

  FIG. 6A is a cross-sectional view of a main part of the casing 21 in a state where the cover member 28 is not provided. When the upper member 23 is fixed to the protrusions 24 of the lower member 22 (formed at the four corners of the rectangular housing), if a screw 25 having a diameter of 3 mm and a total length of 5 mm is used, the screw 25 is loosened. In order to prevent this, the screw 25 is usually tightened while applying a force of about 5.4 kgf / cm. Then, friction occurs between the inner peripheral portion of the hole 23 a of the upper member 23 and the inner peripheral portion of the screw hole 24 a of the protruding portion 24 of the lower member 22 and the screw thread of the screw 25. Fine metal powder of about several tens of μm is generated.

  In the state shown in FIG. 6A, the metal powder 26 generated from the fixing portions of the four screws 25 falls below the housing 21 and is arranged on the surface of the lower member 22 as it is. And so on. As a result, the metal powder 26 adheres to the optical component 27 or the optical fiber, which may cause deterioration of characteristics or scratches, or the metal powder 26 adheres to the periphery of the electric circuit, which may cause a short circuit or noise. Become.

  On the other hand, FIG. 6B shows a state in which the cover member 28 is provided on the lower surface of the protruding portion 24. When the screw 25 is tightened, the metal powder 26 generated as described above accumulates in the recess 28 a of the cover member 28. Since the recess 28a is hermetically sealed, the metal powder 26 does not reach the periphery of the optical component 27 or the like even when the housing 21 vibrates.

  An apparatus for accommodating metal powder generated by this type of screw tightening is also described in a publication distributed before the present application (see, for example, Patent Document 2).

JP 2004-79562 A (page 5, line 14 to line 43, FIG. 5) JP 2001-102777 A (page 2, column 2, lines 31 to 50, FIG. 1)

  In the case 21 where the upper member 23 of the prior art is fixed to the lower member 22 with the screw 25, the operation of providing the cover member 28 on the protruding portion 24 of the lower member 22 is complicated and the structure is It is complicated.

Therefore, the present invention improves the drawbacks of the prior art, has a simple structure, and is easy to manufacture. Friction debris such as metal powder generated when two members are fixed by tightening screws is It is an object of the present invention to provide a method for manufacturing an apparatus that prevents splashing.

  The present invention employs the following means in order to solve the above problems.

A first member having a female screw, a second member having a screw insertion hole, a screw having a male screw, and a cap having a female screw inside, and the first member and the The screw is arranged on one side of the two members, the cap is arranged on the other side, the screw penetrates the screw insertion hole of the second member and is screwed into the female screw of the first member, and the cap The female screw is a device for preventing the scattering of frictional waste generated by screwing that engages with an engaging portion formed by bending the tip of the protruding portion formed on the first member substantially at a right angle. In this manufacturing method, the protruding portion is formed on the first member by burring, a first mold divided into two is applied from both the left and right outer sides of the protruding portion, and a second metal having a shaft in the center. Insert the mold upward from below the protrusion The lower end of the protruding portion is bent outward at a substantially right angle to form the engaging portion, the second die is removed from the first member, and the first die is moved to the left and right. A method for manufacturing a device that prevents the scattering of frictional waste generated by screwing to the outside.

  As is apparent from the description of the specification, the present invention has the following effects.

  1. Friction scraps such as metal powder generated when the two members are fixed by tightening screws are accommodated in the cap and do not scatter around.

  2. Since the cap having the female screw on the inside is disposed on one member, the structure is simple.

  3. Since the female screw of the cap engages with an engaging portion formed by bending the tip of the protruding portion of one member at a substantially right angle, attachment is easy.

  4). Manufactures one member of a device that prevents the scattering of frictional waste generated by screw tightening by adopting burring, a split first mold and a second mold with a shaft in the center. Manufacturing operations are simple.

The manufacturing method of the apparatus which prevents the scattering of the friction waste generated by the screw tightening of one Example of this invention is demonstrated.

  A first embodiment of the present invention will be described with reference to FIGS.

  1A and 1B are a front view and a perspective view, respectively, of the apparatus according to the first embodiment. Since the sheet metal member 1 and the member 2 are provided on a metal screw 3 and a burring portion (described later) of the sheet metal member 1, the sheet metal member 1 and the member 2 are fixed by a screw portion 1 b (see FIG. 5D). A washer 5 is disposed between the screw 3 and the member 2.

  2A and 2B are various views of the apparatus of Example 1. FIG. 2A is a plan view, FIG. 2B is a cross-sectional view taken along the line AA in FIG. The expanded sectional view in the circle of a two-dot chain line in B) is shown, respectively.

  The sheet metal member 1 is formed with a protruding portion 1a by burring, and further, the engaging portion 1a1 is formed by bending the tip of the protruding portion 1a substantially at a right angle. Corresponding to the engaging portion 1a1 of the sheet metal member 1, a female screw 4a is formed on the cap 4 by molding. The cap 4 is made of resin and is preferably a flexible material such as rubber or silicone.

  FIG. 2C shows a state in which the sheet metal member 1 and the member 2 are fixed by the screw 3, and the female screw 4 a of the cap 4 is engaged with the engaging portion 1 a 1 of the sheet metal member 1. The cap 4 is configured as a bottomed cylinder having a substantially U-shaped cross section. The metal powder of the sheet metal member 1 generated when the screw 3 is screwed in, the metal powder of the screw 3 and the resin powder of the cap 4 fall to the inner bottom portion of the cap 4. Therefore, even if the signal pattern of the printed wiring board is arranged below the sheet metal member 1, no trouble occurs.

  FIG. 3 is a diagram of the sheet metal member 1 and the cap 4. (A) is a front view of the sheet metal member 1 in which the protrusion part 1a and the engaging part 1a1 are formed, (B) is a perspective view of the sheet metal member 1. FIG. (C) is a bottom view of the cap 4, and (D) is a perspective view of the cap 4. (E)-(G) are various figures of the state in which the cap 4 is attached to the sheet-metal member 1, (E) is a front view, (F) is a perspective view, (G) is the line B in (E). Cross-sectional views of the cut surface of −B viewed in the direction of the arrow are shown. (G) is a state where the upper part of the female screw 4 a of the cap 4 is engaged with the engaging portion 1 a 1 of the sheet metal member 1.

  FIG. 4 is an exploded perspective view of the sheet metal member 1, the member 2, the screw 3, the washer 5, and the cap 4 constituting the apparatus of the first embodiment.

  FIGS. 5A to 5D sequentially show cross-sectional views of the processing steps of the sheet metal member 1. (A) is a state before a process, (B) is the state by which the protrusion part 1a was formed in the sheet metal member 1 by the burring process. In the state of (B), the two first dies 6, 6 are applied from the left and right outer sides of the protruding portion 1a. Then, the 2nd metal mold | die 7 with which the axis | shaft 7a was provided in the center is inserted upwards from the lower side of the protrusion part 1a. Then, as shown in (C), the lower end of the projecting portion 1a is bent outward at a substantially right angle to form the engaging portion 1a1. Thereafter, when the second mold 7 is removed downward from the sheet metal member 1, the first molds 6 and 6 are removed to the left and right outer sides, and the female screw 1b is erected by tapping the protrusion 1a, (D To the state after processing shown in FIG.

It is an apparatus of Example 1 of this invention, (A) shows a front view, (B) shows a perspective view, respectively. BRIEF DESCRIPTION OF THE DRAWINGS It is various figures of the apparatus of Example 1, (A) is a top view, (B) is sectional drawing which looked at the cut surface by the line AA in (A) in the arrow direction, (C) is in (B). The expanded sectional view in the circle of a two-dot chain line is shown, respectively. FIG. 3 is a diagram of a sheet metal member and a cap in the apparatus of Example 1. (A) is a front view of the sheet metal member, (B) is a perspective view of the sheet metal member, (C) is a bottom view of the cap, (D) is a perspective view of the cap, and (E) is the same cap. The front view of the state attached to the sheet metal member, (F) is a perspective view of the same state, (G) is a cross-sectional view taken along the line BB in (E) in the direction of the arrow. 1 is an exploded perspective view of an apparatus according to Embodiment 1. FIG. It is sectional drawing of the manufacturing process of the sheet-metal member, and shows to (D) sequentially. It is sectional drawing of the housing | casing by which the upper member which is 1st prior art is fixed to a lower member with a screw, (A) is a state in which the cover member is not provided, (B) is provided with the cover member Each state is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheet metal member 1a Protrusion part 1a1 Engagement part 1b Female thread 2 Member 3 Screw 3a Male thread 4 Cap 4a Female thread 5 Washer 6 1st metal mold 7 2nd metal mold 7a Shaft

Claims (1)

A first member having a female screw, a second member having a screw insertion hole, a screw having a male screw, and a cap having a female screw inside;
The screw is disposed on one side of the first member and the second member being overlapped, and the cap is disposed on the other side;
The screw passes through the screw insertion hole of the second member and is screwed into the female screw of the first member;
The cap's female screw prevents scattering of frictional waste generated by screwing that engages an engaging portion formed by bending the tip of the protruding portion formed on the first member substantially at a right angle. In the manufacturing method of the device to
Forming the protrusion by burring on the first member;
Apply the first mold divided in two from the left and right outer sides of the protrusion,
By inserting a second mold having a shaft in the center upward from the lower side of the protruding portion, the lower end of the protruding portion is bent outward at a substantially right angle to form the engaging portion,
A method of manufacturing an apparatus for preventing scattering of frictional waste generated by screw tightening, wherein the second mold is removed downward from the first member, and the first mold is removed left and right.

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