JPH07238915A - Pierce nt - Google Patents

Abstract

PURPOSE:To form a desired uplift part in a pierce nut work process, fix the pierce nut on a metal plate surely, have sufficient pulling out resistance and rotational resistance, maintain a screw hole correctly, and extend the life of a die button. CONSTITUTION:In a circular pierce nut, an inner side wall 4 is erected in nut axial line (L) direction, and also an outer side wall 6 is inclined so as to form the cross section shape of an annular groove 5 in a tapered shape, and an uplift part 11 extending from a center range 10 to the inner side wall in circumferential direction is provided on the surface of a bottom wall 7. When the pierce nut is fixed on a metal plate 12, a metal plate material on the peripheral part of a hole flows from the uplift part to the bottom wall of an outer wall side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises an annular shearing edge and an annular groove adjacent to said shearing edge, said annular groove being defined by opposing inner and outer walls and a bottom wall, said shearing edge forming a metal. The present invention relates to a circular pierce nut adapted to be fixed to the metal plate by punching the plate and introducing the material of the metal plate around the hole into the annular groove while being plastically worked. .

[0002]

2. Description of the Related Art Conventionally, an annular shearing edge and an annular groove adjacent to the shearing edge are provided. The annular groove is defined by inner and outer side walls and a bottom wall which face each other, and a metal plate is punched by the shearing edge. In a circular pierce nut that is fixed to the metal plate by introducing the material of the metal plate in the peripheral portion of the hole into the annular groove while being plastically worked, The groove is inclined so that its cross-sectional shape is tapered, a ridge extending in the circumferential direction is provided in the central region of the surface of the bottom wall, and the periphery of the hole is fixed when the pierce nut is fixed to the metal plate. A pierce nut in which the material of the metal plate of the portion is made to flow toward both sides of the raised portion is known (for example, JP-A-5-21511).
(See Japanese Patent Publication No. 5).

[0003]

By the way, in the above-mentioned prior art, in order to form the raised portion in the central region of the bottom wall surface of the annular groove of the pierce nut, the pierce nut is machined from a material to form the annular groove. A forming punch having a cross-sectional shape corresponding to the shape of the raised portion and having a tip of a concave portion is used for forming. However, when oil or the like adheres to the concave portion of the forming punch, the oil cannot escape when forming the raised portion by the punch, and the oil accumulates in the concave portion, which becomes a resistance at the time of forming the raised portion, The ridge of the pierce nut is not formed into the desired shape. Therefore, when the pierce nut is fixed to the metal plate, the pierce nut and the metal plate may not be sufficiently brought into close contact with each other, and there is a possibility that sufficient pulling resistance and rotation resistance of the pierce nut may not be obtained.

Further, in the above-mentioned prior art, the inner wall is formed such that the cross-sectional shape of the annular groove is tapered, and when the pierce nut is fixed to the metal plate, the metal plate in the peripheral portion of the hole also extends to the inner wall side. Since there is a narrow gap between the screw hole of the nut and the annular groove, the excessive flow of force on the screw hole of the nut acts due to the flow of the material of the metal plate to the inner wall side. Therefore, the screw hole may be deformed and the screw engagement may become hard.

Further, in order to allow the material of the metal plate around the hole to flow to both sides of the raised portion, a fillet is formed on the inner peripheral side near the tip of the die button and on the outer peripheral side. Since the tip portion is made thinner by that amount (see Japanese Patent Application Laid-Open No. 5-212469), the tip of the die button cannot be made thick and the tip of the die button is weakened. There is a possibility that the die button may be damaged by long-term use and the life of the die button may be shortened.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to form a desired raised portion in a piercing nut working process so that the piercing nut can be formed. An object of the present invention is to provide a pierce nut that is securely fixed to a metal plate, has sufficient pull-out resistance and rotation resistance, maintains a screw hole accurately, and can prolong the life of a die button.

[0007]

In order to achieve the above object, in the pierce nut of the present invention, the inner wall is erected in the nut axial direction and the outer wall is inclined so that the cross-sectional shape of the annular groove is tapered. A ridge extending from the central region to the inner wall and extending in the circumferential direction is provided on the surface of the bottom wall, and when the pierce nut is fixed to the metal plate, the material of the metal plate in the peripheral portion of the hole is added to the ridge. Is directed to the bottom wall on the outer wall side.

The cross section perpendicular to the circumferential direction of the raised portion is
It is characterized in that a flat top surface is formed following the arc shape from the central area, or an arc shape with the inner wall side as the apex from the central area.

Further, the present invention is characterized in that a plurality of discontinuous portions are formed on the raised portion.

[0010]

[Operation] The pierce nut configured as described above,
Since the shape of the ridge on the bottom wall surface of the piercing nut is a ridge extending from the central region to the inner wall and extending in the circumferential direction, it can be used as a forming punch when processing the piercing nut from a material to form the annular groove. Therefore, a punch having a tip of a substantially L-shaped cross-section corresponding to the shape of the raised portion is used, and therefore oil or the like is not accumulated at the tip of the punch, and oil or the like is temporarily stored in the punch. Even when the ridges are attached, the oil flows along the surface of the ridge toward the inner wall and is discharged to the outside along the inner wall. Can be made into an accurate shape. Moreover, since the raised portion is located closer to the inner wall so as to extend from the central region to the inner wall, the outer wall and the raised portion can be relatively wide.

Then, when the outer wall is inclined so that the cross-sectional shape of the annular groove is tapered, and when the pierce nut is fixed to the metal plate, the material of the metal plate in the periphery of the hole is moved from the raised portion to the outer wall side. Since it was made to flow sufficiently toward the bottom wall of
Sufficient pulling resistance and rotation resistance can be obtained for the pierce nut. Moreover, since the inner wall is erected in the axial direction of the nut and the material of the metal plate around the hole does not flow to the inner wall when the pierce nut is fixed to the metal plate, the nut screw The distance between the hole and the annular groove can be made relatively wide, and the component force of the material flow of the metal plate into the screw hole of the nut is very small.

Further, a cross section perpendicular to the circumferential direction of the raised portion is
When a flat top surface is formed following the circular arc shape from the central region, or when the circular arc shape is formed with the inner wall side as the apex from the central region, it adheres to the forming punch during the forming process of the pierce nut. The oil, etc. that had been released is released more smoothly.

Further, when a plurality of discontinuous portions are formed on the raised portion, when the pierce nut is fixed to the metal plate, the material of the metal plate around the hole also flows to the discontinuous portions. The rotational resistance of the pierce nut can be increased.

[0014]

Embodiments of the present invention will be described with reference to the accompanying drawings. 1 is a plan view of a piercing nut according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. In the figure, reference numeral 1 is a so-called circular pierce nut having a circular outer shape, and an inner side wall 4 having an annular shearing edge 3 is formed in a central portion including a screw hole 2. The annular groove 5 adjacent to the shear edge 3 is defined by the inner wall 4, the outer wall 6 and the bottom wall 7 which face each other.

An annular surface 8 parallel to the axis L of the nut 1 is formed on the inner wall 4 following the shearing edge 3 in the direction of the axis L of the nut 1. Further, the outer wall 6 is formed with an annular surface 9 that is inclined so that the cross-sectional shape of the annular groove 5 is tapered (thin downward in FIG. 2). Further, a ridge 11 extending in the circumferential direction is provided on the surface of the bottom wall 7 between the central region 10 and the annular surface 8 of the inner wall 4.

As described above, the pierce nut 1 has the bottom wall 7 thereof.
Since the shape of the ridge portion 11 on the surface is a ridge extending from the central region 10 to the annular surface 8 of the inner wall 4 and extending in the circumferential direction,
As a forming punch for forming the annular groove 5 by processing the pierce nut 1 from a material, a forming punch having a tip of an L-shaped cross section corresponding to the shape of the raised portion is used. Therefore, oil or the like does not accumulate at the tip of the forming punch, and even if oil or the like is attached to the forming punch, the oil flows toward the annular surface 8 of the inner side wall 4 on the surface of the raised portion 11, Since it is released to the outside along the annular surface 8 of the inner wall 4, there is no resistance due to oil when forming the raised portion 11,
The raised portion 11 can be shaped accurately.

Then, the pierce nut 1 as described above is driven into the metal plate 12 by a plunger (not shown) or the like as shown by an imaginary line. At the time of this driving, the die button 13 as shown by a virtual line in cooperation with the pierce nut 1
Is used. Then, when the pierce nut 1 is driven into the metal plate 12, the metal plate 12 is perforated by the die button 13 and the shearing edge 3 of the pierce nut 1, and the material of the metal plate around the hole is the die button 13 and the pierce nut. 1 is introduced into the annular groove 5 while being plastically processed.

The material around the hole of the metal plate introduced into the annular groove 5 is pressed by the die button 13 and the pierce nut 1 and extended by the annular groove 5 to define the annular groove 5. The annular surface 8 of the inner side wall 4, the annular surface 9 of the outer side wall 6 and the bottom wall 7 are in close contact with each other, but the shape of the raised portion 11 on the surface of the bottom wall 7 of the pierce nut 1 is changed from the central region 10 to the inner side wall. Four
Since it is a ridge extending to the annular surface 8 and extending in the circumferential direction, since the ridge 11 is located close to the annular surface 8 of the inner wall 4, the distance between the annular surface 9 of the outer wall 6 and the ridge 11 is increased. Can be relatively wide.

Further, the annular surface 9 of the outer wall 6 is inclined so that the transverse shape of the annular groove 5 is tapered, and the pierce nut 1
When fixing the metal plate 12 to the metal plate 12, the metal plate 12 around the hole
Since the material of (3) is made to flow from the raised portion 11 to the relatively wide portion of the bottom wall 7 on the annular surface 9 side of the outer wall 6, the amount of bite of the metal plate into the pierce nut 1 increases and it is sufficient. Since pull-out drag force and rotation drag force are obtained,
For the metal plate 12 from a thin plate (for example, 0.6 mm) to a thick plate (for example, 2.0 mm), one type of nut can be used with the same size nut, and the nut can be shared.

Further, the tip shape of the die button 13 used when fixing the pierce nut 1 to the metal plate 12 is such that the material of the metal plate 12 around the hole is made to flow only to one side of the raised portion 11. For this reason, since the fillet 18 is only formed on the outer peripheral side near the tip of the die button 13, the tip of the die button 13 becomes relatively thick and the tip of the die button 13 The die button 13 is not weakened, and the tip of the die button 13 is not easily damaged and the life of the forming punch is shortened.

Moreover, the annular surface 8 of the inner wall 4 is formed in the direction of the axis L of the nut 1, and when the pierce nut 1 is fixed to the metal plate 12, the annular surface 8 side of the inner wall 4 is surrounded by a hole. Since the material of the metal plate 12 of the portion does not flow, the distance between the screw hole 2 of the nut 1 and the annular groove 5 can be made relatively wide, and the screw of the nut 1 due to the flow of material of the metal plate 12 The component force to 2 is also very small.

In the case of this embodiment, the ridge 11 has a flat top surface 15 in the circumferential direction perpendicular cross section of the ridge, followed by an arcuate shape 14 from the central region 10. With such a raised portion 11, the die button 1
When the material of the metal plate 12 at the periphery of the hole is pressed by 3, the material of the metal plate 12 at the periphery of the hole is relatively wide between the annular surface 9 of the outer wall 6 and the ridge 11. It can easily flow into the part 7.

Further, in the case of this embodiment in which the discontinuous portions 16, 16 ... Are formed on the raised portion 11, the metal plate 12 is used.
When fixing the pierce nut 1 to the
Since the material of the metal plate 12 in the peripheral portion of the hole also flows to 6, the rotational resistance of the pierce nut can be increased. The rotational resistance can be further enhanced by increasing the number of divisions of the discontinuous portions 16, 16 ... And the height of the raised portion 11. The number of discontinuous portions 16, 16 ... Is not limited to 6 and may be a plurality of locations, and normally 4 to 10 locations are suitable.

FIG. 3 is a cross-sectional view of a pierce nut according to another embodiment of the present invention, which is different from the above embodiment only in the shape of the raised portion 11, and the remaining structure is the same as that of the above embodiment. Are substantially the same as those in FIG. In this embodiment, the vertical cross section of the ridge 11 in the circumferential direction is composed of an arcuate projection 17 having the apex of the annular surface 8 of the inner wall 4 from the central region 10. The material of the metal plate 12 in the peripheral portion of the hole can easily flow into the relatively wide bottom wall portion 7 between the annular surface 9 of the outer wall 6 and the ridge portion 11 when the ridge portion is pressed. Is.

[0025]

In the piercing nut according to the present invention, since the shape of the ridge on the bottom wall surface of the pierce nut is a ridge extending from the central region to the inner wall and extending in the circumferential direction, the pierce nut is machined from a material. As a forming punch for forming the annular groove, a forming punch having a tip with a substantially L-shaped cross section corresponding to the shape of the raised portion is used. Even if oil or the like adheres to the forming punch, the oil flows along the surface of the ridge toward the inner wall and is discharged to the outside along the inner wall. There is no resistance due to oil at the time of forming the part, the protruding part can be formed into an accurate shape, the metal plate and the protruding part of the pierce nut can be in close contact with each other in the desired shape, and a sufficient pulling resistance and rotational resistance can be obtained. Becomes

Then, when the outer wall is inclined so that the cross-sectional shape of the annular groove is tapered, and when the pierce nut is fixed to the metal plate, the material of the metal plate around the hole is moved from the raised portion to the outer wall side. Since it is made to flow toward the bottom wall of the pierce nut, it becomes a pierce nut that can obtain more sufficient pulling-out drag force and rotation drag force. Moreover, since the inner wall is erected in the axial direction of the nut and the material of the metal plate around the hole does not flow to the inner wall when the pierce nut is fixed to the metal plate, the nut screw Since the distance between the hole and the annular groove can be made relatively wide and the component force to the screw hole of the nut due to the flow of the material of the metal plate is very small, the screw hole is accurately maintained without breaking, It is a pierce nut with a good screw engagement.

Moreover, since the raised portion is located closer to the inner side wall, the distance between the outer side wall and the raised portion can be made relatively wide, so that the pull-out drag force with which the metal plate bites a lot becomes a larger pierce nut. , The tip of the die button used when fixing the pierce nut to the metal plate can be made relatively thick, and the tip of the die button becomes strong, and the tip will be changed due to long-term use of the die button. The pierce nut is less likely to be damaged and shorten the life of the forming punch.

In addition, a cross section perpendicular to the circumferential direction of the raised portion is
If a flat top surface is formed following the arc shape from the central area, or if the shape is an arc shape with the inner wall side as the apex from the central area, it is attached to the forming punch during the forming process of the pierce nut. The oil, etc. is discharged more smoothly and the accurate ridge is formed, so that the metal plate and the ridge of the pierce nut can be brought into close contact with each other in the desired shape, and pullout resistance and rotation resistance can be obtained more sufficiently. It becomes a pierce nut that can be used.

Further, when a plurality of discontinuous portions are formed on the raised portion, when the pierce nut is fixed to the metal plate, the material of the metal plate around the hole also flows to the discontinuous portions. The pierce nut can further enhance the rotational resistance of the pierce nut.

[Brief description of drawings]

FIG. 1 is a plan view of a piercing nut according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view of a piercing nut according to another embodiment of the present invention.

[Explanation of symbols]

 1 Pierce Nut 2 Screw Hole 3 Shear Edge 4 Inner Side Wall 5 Annular Groove 6 Outer Side Wall 7 Bottom Wall 10 Central Region 11 Ridge 12 Metal Plate 14 Arcuate Ridge 15 Flat Top 16 Discontinuity 17 Arcuate R L Nut Axis

Claims (4)

[Claims] 1. An annular shearing edge and an annular groove adjacent to the shearing edge, wherein the annular groove is defined by inner and outer side walls and a bottom wall which face each other, and the shearing edge pierces a metal plate, In the circular pierce nut that is fixed to the metal plate by introducing the material of the metal plate in the peripheral portion of the hole into the annular groove while being plastically worked, the inner wall is formed in the nut axial direction. The pierce is erected, and the outer wall is inclined so that the cross-sectional shape of the annular groove is tapered, and a protrusion extending from the central region to the inner wall and extending in the circumferential direction is provided on the surface of the bottom wall. A pierce nut characterized in that, when the nut is fixed to the metal plate, the material of the metal plate in the peripheral portion of the hole is caused to flow from the raised portion toward the bottom wall on the outer wall side. 2. The pierce nut according to claim 1, wherein a vertical cross section in the circumferential direction of the raised portion has a flat top surface following an arc shape from the central region. 3. The pierce nut according to claim 1, wherein a vertical cross section in the circumferential direction of the raised portion is formed in an arc shape having an apex on the inner wall side from the central region. 4. The pierce nut according to claim 1, wherein a plurality of discontinuous portions are formed on the raised portion.