JP2011094758A - Stainless steel welding nut with minute diameter, method for producing the same, and punching punch for use in production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stainless steel welding nut with a minute diameter to be easily produced by punching a stainless steel plate, a method for producing the same, and a punching punch for use in the production method. <P>SOLUTION: The stainless steel welding nut with a minute diameter has a screw diameter of M1.2 to M1.6, wherein welding projections 23 is molded at the bottom subtense portions of a nut body 21 with a hexagonal outline by punching a material 20 of a stainless steel plate having a thickness equal to height of the nut. The production method is characterized by a process in which the material 20 is punched to form the nut body 21, and at the same time the welding projections 23 are molded at the bottom subtense portions of the nut body 21. A punching punch 2 used in the production method has a hexagonal column shape corresponding to the outline of the nut body 21, and is provided with cutouts 5 for molding the welding projections 23 at the subtense portions of the circumference of the lower end surface of the punching punch 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a stainless steel weld nut having a small diameter of M1.2 to 1.6 manufactured by punching a stainless steel plate, a manufacturing method thereof, and a punching punch used in the manufacturing method. is there.

  For assembling cellular phones and other various small electronic devices, for example, a clinch having a small stainless steel screw diameter (nominal diameter of about M1.6) on a mounting board made of a thin stainless steel plate having a thickness of about 0.4 mm. A nut is caulked and various parts or members are screwed to the mounting board using the clinch nut. However, in the clinch nut, it is inevitable that the cylindrical portion for caulking and coupling slightly protrudes to the back side of the mounting substrate. On the other hand, with the recent thinning of mobile phones and other small electronic devices, there has been an increasing demand for such a slight protruding portion not allowed. In order to reduce the protruding cylindrical portion of such a clinch nut, it is conceivable to employ a weld nut.

  Hex nuts, squares, and T-shaped weld nuts are defined by JIS B1196 established in 1982, but small dimensions with a nominal thread diameter of M4 or less and stainless steel are excluded. This is due to manufacturing difficulties. Among the welding nuts established in the above JIS standards, T-types that can be obtained by drawing a thin steel sheet that does not use cold heading, and screw pilot hole processing by shear punching from a coil material with a short cross-section The “ID type” in the JIS Attached Table 2 square weld nut, in which only four corners of the square nut obtained by cutting of a predetermined length are drawn by an open die to obtain weld projections, is JIS It has a history of being produced and used before the establishment of the standard.

  However, in the method for manufacturing a weld nut established in the JIS standard as described above, the above-described screw diameter of the present invention is M1.2 to 1.6 (commonly referred to as a micro screw), It has been difficult to produce a stainless steel weld nut with a small diameter and a thin diameter (low height).

  The present invention has been made in view of the above circumstances, and easily manufactures the above-described thin, small-diameter stainless steel welding nut having a screw diameter of M1.2 to 1.6 by punching a stainless steel plate. It is an object of the present invention to provide a stainless steel weld nut that can be manufactured, a manufacturing method thereof, and a punching punch used in the manufacturing method.

  In order to achieve the above object, the present invention has the following configuration.

  The invention according to claim 1 is a stainless steel weld nut having a small diameter of a screw diameter of M1.2 to M1.6, and stamping and forming a material of a stainless steel plate having a thickness equal to the height of the nut, A nut body having an outer shape of a hexagon or a quadrangle, and a welding projection is formed on the opposite side of the bottom of the nut body, and a female screw is provided on the inner periphery of a screw hole having a small diameter punched into the nut body It is characterized by that.

  The invention according to claim 2 is a manufacturing method of a stainless steel welding nut having a micro diameter with a screw diameter of M1.2 to M1.6, wherein the outer shape is made of a stainless steel plate having a thickness equal to the height of the nut. Simultaneously punching a square or square nut body, forming a welding projection on the opposite side of the bottom of the nut body, punching a screw hole in the nut body, and the screw hole in the nut body And a step of machining an internal thread on the inner peripheral portion of the.

  According to a third aspect of the present invention, in the method for manufacturing a small-diameter stainless steel weld nut according to the second aspect, the nut main body and the weld projection are simultaneously punched from the material of the stainless steel plate, and then the nut is formed. The screw pilot hole is punched into the main body.

  According to a fourth aspect of the present invention, in the method for manufacturing a small-diameter stainless steel weld nut according to the second aspect, the screw pilot hole is punched into a material of the stainless steel plate, and then the screw pilot hole is used as a center. At the same time that the nut body is punched, the weld protrusion is formed on the opposite side portion of the bottom of the nut body.

  The invention according to claim 5 is a punching punch used in the method for manufacturing a small diameter stainless steel weld nut according to claims 2 to 4, wherein the punching punch is a hexagon corresponding to the outer shape of the nut body. Alternatively, it has a quadrangular cross-sectional shape, and a notch for forming the welding projection is provided on the opposite side portion of the outer peripheral portion of the lower end surface of the punching punch.

  According to the present invention, the nut body is punched into a material of a stainless steel plate having a thickness equal to the height of the nut, and at the same time a plurality of welding protrusions are formed on the bottom opposite side portion of the nut body. A small diameter stainless steel weld nut having a screw diameter of M1.2 to 1.6 can be easily manufactured by a simple punching process. Therefore, a small-sized stainless steel nut can be fixed to a mobile phone made of a thin stainless steel plate or a mounting substrate for various small electronic devices without generating a protrusion.

  Moreover, if the punch according to claim 5 is used, the method for manufacturing a weld nut according to the present invention can be easily implemented.

It is explanatory drawing which shows the manufacturing process of the nut main body by the press processing apparatus of Example 1 which implements the manufacturing method of this invention, (a) is the punching start of the external shape of a nut main body, (b) is the middle of the punching, ( c) shows the completion of punching and the forming state of the welding projection. . It is an enlarged front view of the punching punch principal part of a press processing apparatus same as the above. It is an enlarged end elevation of the punching punch same as the above. The main part of the press processing apparatus which punches a screw pilot hole in the punching-molded nut main body is shown, (a) shows the state by which the nut main body was set with the welding protrusion upward, (b ) Shows a state in which the nut body is set with its welding projection in a downward posture. It is a longitudinal cross-sectional view of the nut blank which punched the screw pilot hole in the nut main body. It is the top view seen from the side which provided the welding protrusion of the nut blank same as the above. The main part of the well-known automatic tapping machine which processes a female screw in the screw pilot hole of a nut blank same as the above is shown, (a) is a principal part cross-sectional plan view, (b) is along the bb line of (a). It is sectional drawing. The completed hexagonal welding nut is shown, (a) is a top view, (b) is a front view, (c) is a bottom view. It is explanatory drawing which shows the use condition of the hexagonal welding nut which concerns on this invention. The usage state of the hexagonal welding nut which provided the welding protrusion is shown. It is explanatory drawing which shows the punching process of the screw pilot hole by the press processing apparatus of Example 2 which enforces the manufacturing method of this invention. It is explanatory drawing which shows the manufacturing process of the nut main body by the press work apparatus of Example 2 same as the above, (a) is the time of the punching start of the external shape of a nut main body, (b) has shown the completion of punching and the formation state of a welding protrusion. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the illustrated embodiment, the hexagonal weld nut is illustrated and described. However, with respect to the square weld nut, only the outer shape of the nut body is different, and thus the illustration and description are omitted.

  1 to 8 show a manufacturing process according to a welding nut and a manufacturing method thereof according to Embodiment 1 of the present invention.

  FIG. 1 shows a process of processing a nut main body by a press working apparatus for carrying out a manufacturing method according to a first embodiment of the present invention. A punching punch 2 arranged opposite to a punching die 1 is manufactured by hexagonal welding. It has a hexagonal column shape corresponding to the ring shape of the nut.

  As shown in FIGS. 2 and 3, the punching punch 2 is provided with notches 5 for forming welding protrusions 23 described later at three locations on the opposite side portion 4 of the outer peripheral portion of the lower end surface 3. The notch 5 has a predetermined width A on the lower end surface 3, is formed in a semiconical recess having a predetermined height B along the side wall 4 a of the opposite side portion 4, and has a height B In order to accurately regulate, a small shoulder 6 is formed at the upper end portion of the concave portion that converges on the side wall 4a, and a welding projection having a predetermined weld nugget area and welding strength is formed.

  The above-described hexagonal weld nut blank 20 is made of a stainless steel plate having a thickness (about 1.3 mm) equal to the height of the nut to be manufactured. As shown in FIGS. The outer shape of the square nut body 21 is punched by shearing, and at the same time, the notched portion 5 is ironed at three locations on the opposite side portion 22 of the nut body 21 to have a semiconical shape having a predetermined width A and height B. The welding projections 23 of the nut main body 21 are formed so as to protrude at three locations on the opposite side portion 22 on the outer periphery of the seat surface (see FIG. 6).

The nut main body 21 provided with the welding projections 23 as described above is transferred to a press working apparatus for punching a screw pilot hole shown in FIGS.
In the press working apparatus, a pilot hole punching punch 12 is disposed opposite to the pilot hole punching die 11, and the upper end of the pilot hole punching die 11 has a diameter smaller than the inscribed circle of the three welding projections 23 of the nut body 21. The protrusion support part 13 which has is provided. A positioning holder 14 is attached and fixed to the upper end portion of the lower hole punching die 11. The positioning holder 14 has an opening 15 for fitting and positioning the nut main body 21, and when the welding projection 23 of the nut main body 21 fitted to the positioning opening 15 is in a downward posture, FIG. As shown in FIG. 6, the welding projection 23 is accommodated in an annular space portion 16 formed between the protruding support portion 13 at the upper end of the lower hole punching die 11 and the positioning opening 15. Therefore, the nut main body 21 can be correctly positioned and held by fitting into the positioning opening 15 even when the welding projection 23 is in the upward posture as shown in FIG. 4A or in the downward posture as shown in FIG. 4B. It is configured.

  As described above, with the nut main body 21 fitted into the positioning opening 15 of the positioning holder 14 and positioned and held, the pilot hole punching punch 12 punches the screw pilot hole 24 at the central portion of the nut main body 21, and FIG. And the nut blank 25 shown in FIG. 6 is manufactured.

  In the nut blank 25 punched and formed from the material 20 in this way, the internal thread 26 is processed in the inner peripheral portion of the screw pilot hole 24 in the tapping process shown in FIG. 7 to complete the hexagonal weld nut 27 shown in FIG. To do.

  FIG. 7 shows a main part of a known automatic tapping machine using a bend tap 40, and the bend tap 40 passes through a support shaft 43 fitted to a cylindrical rotating body 42 connected to a rotation drive shaft 41. The nut blank 25 supplied through the chute 44 is fed to the tap portion 40a of the bend tap 40 by the nut push rod 45, and the internal thread 26 is tapped in the screw pilot hole 24. The screwed hexagonal welding nut 27 is automatically fed out through the curved handle portion 40b of the bend tap 40 and discharged from a discharge port 46 provided in the cylindrical rotating body 42.

  As described above, the hexagonal welding nut 27 provided with the welding projections 23 on the opposite side portion 22 of the nut body 21 is advantageous when welding to a limited space of the mounting substrate. For example, as shown in FIG. 9, when a welding nut is attached to a corner portion of the embossed portion 31 of the mounting substrate 30, a hexagonal welding nut 28 provided with welding protrusions 23 at a diagonal portion is shown in FIG. As shown in FIG. 9, the welding projection 23 may be separated from the welding space, but the hexagonal welding nut 27 according to the present invention in which the welding projection 23 is provided on the opposite side portion 22 shown in FIG. 8 is shown in FIG. As described above, the welding projection 23 does not leave the welding space and can be welded satisfactorily.

  10 and 11 show a manufacturing process according to a method for manufacturing a weld nut according to Embodiment 2 of the present invention. In the second embodiment, after the screw hole 24 is punched into the material 20, the nut body 21 is punched around the screw hole 24, and at the same time, the welding protrusion 23 is formed on the opposite side portion of the nut body 21. Since the manufacturing process is only different from that of the first embodiment, and other manufacturing processes are the same as those of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

  FIG. 10 shows a process for punching a screw pilot hole by the press working apparatus according to the second embodiment. In the die holder 50, a pilot hole punching die 51 and a positioning pin 52 are spaced from each other at a predetermined interval in the feed direction of the material 20. A punch hole punch 54 is mounted on the punch holder 53 so as to face the lower hole punching die 51 and move up and down.

  The material 20 is made of a strip-shaped stainless steel plate having a thickness (about 1.3 mm) equal to the height of the nut to be manufactured. As shown in the drawing, the positioning pin 52 is provided in the screw pilot hole 24 punched in the previous process. In a state where the material 20 is placed and placed and held on the lower hole punching die 51, the lower hole punching punch 54 is lowered to punch the screw lower hole 24 into the material 20.

  Thus, the raw material 20 in which the screw prepared holes 24 are punched at a predetermined interval is transferred to the press working device of the nut main body 21 shown in FIG.

In the press working apparatus, a punching die 56 and a positioning pin 57 are mounted on a die holder 55 at a predetermined interval in the feed direction of the material 20, and are disposed so as to face the punching die 56. The hexagonal shape corresponding to the contour shape of the hexagonal welding nut manufactured in the same manner as the punching punch 2 of Example 1 is provided. As shown in FIGS. 2 and 3, the punching punch 58 has a configuration in which the notch portions 5 for forming the welding projections 23 are provided at three locations on the opposite side portion 4 of the outer peripheral portion of the lower end surface 3. The same as Example 1, except that a pilot pin 59 is fitted on the lower end surface 3 so as to fit into a screw pilot hole 24 machined into the material 20.

  As shown in FIGS. 11 (a) and 11 (b), the material 20 on which the screw hole 24 is punched is placed on a punching die 56, and the positioning pin 57 is fitted to the screw hole 24 in the next process, With the material 20 positioned and held, the punching punch 58 descends, and the pilot pin 59 passes through the screw pilot hole 24. Then, the outer shape of the hexagonal nut body 21 is centered on the screw pilot hole 24 with the punching punch 58. At the same time as the punching process, the notch 5 is used to iron the opposite side 22 of the nut body 21 so that a semiconical welding projection 23 having a predetermined width A and height B is formed on the nut body 21. The nut blank 25 is manufactured by projecting into three portions of the opposite side portion 22 on the outer periphery of the seat surface side (see FIG. 6).

  In the nut blank 25 punched and formed from the material 20 in this manner, the internal thread 26 is processed in the inner peripheral portion of the screw lower hole 24 in the tapping process shown in FIG. The hexagonal welding nut 27 shown is completed.

  In the above-described embodiment, the welding projection 23 has a semiconical shape, but the welding projection 23 is not limited to the illustrated shape, and may have a triangular pyramid shape or other shapes.

DESCRIPTION OF SYMBOLS 1 Punching die 2 Punching punch 3 Lower end surface of Punching punch 2 4 Opposite side part of Punching punch 2 5 Notch part 6 Shoulder part 11 Lower hole punching die 12 Lower hole punching punch 13 Projection support part 14 Positioning holder 15 Positioning opening 20 Material 21 Nut body 22 Opposite side 23 Weld projection 24 Screw pilot hole 25 Nut blank 26 Female thread 27 Hex weld nut 40 Bend tap 51 Lower hole punching die 52 Positioning pin 54 Lower hole punching punch 56 Punching die 57 Positioning pin 58 Punching punch 59 Pilot pin

Claims (5)

It is a stainless steel welding nut with a small diameter of M1.2 to M1.6,
A stainless steel plate material having a thickness equal to the height of the nut is stamped and formed into a hexagonal or square nut body, and a welding protrusion is formed on the opposite side of the bottom of the nut body. A weld nut made of stainless steel with a small diameter, wherein a female thread is provided on the inner peripheral portion of the machined screw hole with a small diameter. A method of manufacturing a stainless steel welding nut having a small diameter of M1.2 to M1.6,
Simultaneously punching a hexagonal or quadrangular nut body from a stainless steel plate having a thickness equal to the height of the nut, and simultaneously forming a welding projection on the opposite side of the nut body;
A process of punching a screw pilot hole in the nut body;
And a step of machining a female screw on the inner peripheral portion of the screw pilot hole of the nut body.   3. The small diameter stainless steel according to claim 2, wherein the nut body and the welding projection are simultaneously punched from the material of the stainless steel plate, and then the screw hole is punched into the nut body. Manufacturing method of welding nut.   After punching the screw pilot hole in the stainless steel material, the nut main body is punched around the screw pilot hole, and at the same time, the welding protrusion is formed on the opposite side portion of the nut main body. The manufacturing method of the small diameter stainless steel welding nut of Claim 2 to do. A punch for use in a method for producing a small diameter stainless steel weld nut according to claims 2 to 4,
The punching punch has a hexagonal or square cross-sectional shape corresponding to the outer shape of the nut body, and a notch for forming the welding projection is provided on the opposite side portion of the outer peripheral portion of the lower end surface of the punching punch. Punching punch characterized by being.

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