JP7224955B2 - pierce nut - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pierce nut that is secured to a metal plate by means of an impact crimp connection.

Pierce nuts have long been used in large quantities in the automobile industry and in the assembly of home appliances. A pierce nut is required to have rotational resistance and pull-out resistance when it is fixed to a metal plate. As a conventionally used pierce nut of this type, for example, the configuration disclosed in Patent Document 1 below can be cited. That is, in the conventional configuration, a protuberant portion formed of an inclined surface is provided around the base of the pilot portion that protrudes from the central portion of the nut body. When this conventional pierce nut is affixed to a metal plate, the metal plate is punched by the pilot portion. Also, the periphery of the opening formed by punching the pilot portion is pressed by the raised portion. As a result, the peripheral portion of the opening is press-fitted and deformed so as to come into close contact with the outer peripheral surface of the pilot portion, thereby improving the rotational resistance and the withdrawal resistance.

JP 2013-122283 A

In the conventional pierce nut as described above, the rim portion of the opening is pressed by the protuberance formed by the inclined surface, thereby improving the rotational resistance and the pull-out resistance. However, there is a demand for further improvements in rotational resistance and pull-out resistance.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a pierce nut capable of improving rotational resistance and pull-out resistance.

A pierce nut according to the present invention comprises a nut body having a threaded hole in the center, a fastening bearing surface provided at one end in the thickness direction of the nut body, and a fastening bearing surface protruding from the fastening bearing surface at the center of the nut body. and a raised portion protruding from the fastening bearing surface around the base of the pilot portion, and the fastening bearing surface is a flat surface extending from the outer peripheral edge of the raised portion to the outer peripheral edge of the nut body. The protuberance includes a protuberant outer peripheral surface protruding from the fastening seat surface, and a protrusion extending between the tip of the protuberance outer peripheral surface and the outer peripheral surface of the pilot portion and positioned away from the fastening seat surface due to the height of the protuberance outer peripheral surface. The height (H2) of the raised outer peripheral surface is 0.20 mm or more, and the ratio of the height (H2) of the raised outer peripheral surface to the height (H1) of the pilot portion (H2/H1) is greater than or equal to 0.05 and less than or equal to 0.23, and the thread nominal in the nut body is from M8 to M20 .

According to the pierce nut of the present invention, the protruding end surface of the protruding portion is positioned away from the fastening seat surface due to the height of the protruding outer peripheral surface. A greater amount of material positioned at the peripheral edge of the opening formed in the metal plate can be press-fitted and deformed so as to be in close contact with the outer peripheral surface of the pilot portion, thereby improving rotational resistance and pull-out resistance.

1 is a partial cross-sectional front view showing a pierce nut according to an embodiment of the present invention; FIG. FIG. 2 is a plan view showing the pierce nut of FIG. 1; 1. It is explanatory drawing which shows the manufacturing method of the pierce nut fixing structure using the pierce nut of FIG. FIG. 2 is an explanatory diagram for explaining the action of the raised portion in FIG. 1;

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated with reference to drawings. The present invention is not limited to each embodiment, and can be embodied by modifying the constituent elements without departing from the scope of the invention. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in each embodiment. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components of different embodiments may be combined as appropriate.

FIG. 1 is a partially cross-sectional front view showing a pierce nut 1 according to an embodiment of the present invention, and FIG. 2 is a plan view showing the pierce nut 1 of FIG. A pierce nut 1 shown in FIGS. 1 and 2 is a member that is fixed to a metal plate by driving and caulking. The side facing the metal plate is sometimes called the back side of the pierce nut 1, and the opposite side is sometimes called the front side of the pierce nut 1. The pierce nut 1 can be manufactured by forming a material such as ordinary steel by a forming method such as cold heading.

As shown in FIGS. 1 and 2, the pierce nut 1 has a nut body 2 , a fastening bearing surface 3 , a pilot portion 4 and a raised portion 5 . The nut body 2, the fastening bearing surface 3, the pilot portion 4, and the raised portion 5 are provided integrally with each other.

The nut body 2 is a polygonal prism-shaped portion provided on the front side of the pierce nut 1 . The nut body 2 of this embodiment has an octagonal prism shape. However, the nut body 2 may be in the shape of another polygonal prism such as a quadrangular prism or in the shape of a cylinder. A threaded hole 20 is provided in the central portion of the nut body 2 . The threaded hole 20 penetrates the nut body 2 from one end to the other end in the thickness direction 2a of the nut body 2 . The thickness direction 2 a of the nut body 2 is the direction from the front side to the back side of the pierce nut 1 (or the direction from the back side to the front side), and is parallel to the extending direction of the screw hole 20 .

The fastening bearing surface 3 is an end face of the nut body 2 provided at one end (the back side of the pierce nut 1) in the thickness direction 2a of the nut body 2. As shown in FIG. When the pierce nut 1 is fixed to the metal plate, the fastening bearing surface 3 is brought into close contact with the surface of the metal plate. The fastening seat surface 3 of the present embodiment is a flat surface extending from the outer peripheral edge 50 (see FIG. 2) of the raised portion 5 to the outer peripheral edge 21 of the nut body 2 (see FIG. 2). In other words, the region from the outer peripheral edge 50 of the raised portion 5 to the outer peripheral edge 21 of the nut body 2 is not provided with a concave portion or a convex portion.

The fastening bearing surface 3 of the present embodiment extends along a plane perpendicular to the thickness direction 2a of the nut body 2 . However, the fastening seat surface 3 is perpendicular to the thickness direction 2a of the nut body 2 so that the outer peripheral edge 50 of the raised portion 5 protrudes toward the back side of the pierce nut 1 compared to the outer peripheral edge 21 of the nut body 2. It may extend obliquely with respect to the plane. When the fastening bearing surface 3 extends obliquely with respect to the plane perpendicular to the thickness direction 2a of the nut body 2, the inclination angle of the fastening bearing surface 3 with respect to the plane perpendicular to the thickness direction 2a of the nut body 2 is 0. It is preferably greater than 0° and 10° or less, more preferably greater than 0° and 5° or less.

The pilot portion 4 is a columnar portion protruding from the fastening bearing surface 3 toward the back side of the pierce nut 1 at the central portion of the nut body 2 . However, the external shape of the pilot portion 4 may be other shapes such as a polygonal prism shape. The threaded hole 20 of the nut body 2 passes through the inside of the pilot portion 4 to the tip of the pilot portion 4 . When the pierce nut 1 is fixed to the metal plate, the pilot part 4 punches the metal plate. When the pilot part 4 punches out a metal plate, the tip outer peripheral edge 40 of the pilot part 4 functions as a shearing blade.

It is preferable that the height H1 of the pilot portion 4 is approximately the same as the thickness of the metal plate (work) to which the pierce nut 1 is fixed. More specifically, the height H1 of the pilot portion 4 is preferably 80% or more and less than 100% of the thickness of the metal plate to which the pierce nut 1 is fixed. This is because if it is less than 80%, the punching is not performed completely, resulting in poor scrap removal. On the other hand, if it exceeds 100%, the tip of the pilot portion 4 of the pierce nut 1 will protrude outward from the back surface of the metal plate. The height H<b>1 of the pilot portion 4 is the distance from the proximal end to the distal end of the pilot portion 4 in the thickness direction 2 a of the nut body 2 . The position of the proximal end of the pilot portion 4 in the thickness direction 2 a of the nut body 2 can be the position of the fastening bearing surface 3 adjacent to the outer peripheral edge 50 of the raised portion 5 .

The outer peripheral surface 41 of the pilot portion 4 of the present embodiment extends obliquely with respect to the thickness direction 2a of the nut body 2 so that the distal end side of the pilot portion 4 is wider than the proximal end side. The inclination angle of the outer peripheral surface 41 of the pilot portion 4 with respect to the thickness direction 2a of the nut body 2 is preferably greater than 0° and 5° or less. This is because when the tilt angle is set to the negative side, that is, when the tip end side of the pilot portion 4 is narrower than the base end side, a gap is generated between the pilot portion 4 and the punching surface, resulting in clinch force. This is because the On the other hand, this is because the metal plate warps greatly due to the driving of the pierce nut at an angle exceeding 5°.

A plurality of recesses 42 are provided on the outer peripheral surface 41 of the pilot portion 4 of the present embodiment. When the pierce nut 1 is fixed to the metal plate, the metal of the metal plate bites into the recess 42 . A metal that constitutes a metal plate is sometimes called a material. The material bites into the recess 42 so that the recess 42 functions as a detent for the pierce nut 1 . The recessed portion 42 of the present embodiment extends from the tip side of the pilot portion 4 to the vicinity of the raised portion 5 .

The raised portion 5 is a portion that protrudes from the fastening bearing surface 3 toward the back side of the pierce nut 1 around the base of the pilot portion 4 . The raised portion 5 of the present embodiment has a raised outer peripheral surface 51 and a raised end surface 52 .

The raised outer peripheral surface 51 is the peripheral surface of the raised portion 5 protruding from the fastening seat surface 3 . The raised outer peripheral surface 51 of the embodiment extends along the thickness direction 2 a of the nut body 2 . However, the raised outer peripheral surface 51 may be inclined with respect to the thickness direction 2 a of the nut body 2 .

The raised outer peripheral surface 51 has a predetermined height H2 in the thickness direction 2a of the nut body 2 . The height H<b>2 of the raised outer peripheral surface 51 is the distance from the base end to the leading end of the raised outer peripheral surface 51 in the thickness direction 2 a of the nut body 2 . The height H2 of the raised outer peripheral surface 51 is preferably 0.20 mm or more. Moreover, the ratio H2/H1 of the height H2 of the raised outer peripheral surface 51 to the height H1 of the pilot portion 4 is preferably 0.05 or more and 0.23 or less. This is because deformation of the metal plate (work) to which the pierce nut 1 is fixed can be suppressed while ensuring sufficient clinch strength and torque strength, as will be described in detail later. As described above, the height H1 of the pilot portion 4 is determined by the thickness of the metal plate (work) to which the pierce nut 1 is fixed. The ratio H2/H1 represents the relationship between the thickness of the target metal plate (work) and the height H2 of the raised outer peripheral surface 51 .

The raised end surface 52 is an end surface of the raised portion 5 extending between the tip of the raised outer peripheral surface 51 and the outer peripheral surface 41 of the pilot portion 4, and is separated from the fastening seat surface 3 by the height H2 of the raised outer peripheral surface 51. is located. The raised end surface 52 of the present embodiment extends perpendicularly to the thickness direction 2 a of the nut body 2 . However, the protruded end surface 52 is formed with respect to the surface perpendicular to the thickness direction 2a of the nut body 2 so that the outer peripheral surface 41 side of the pilot portion 4 is retracted toward the front side of the pierce nut 1 compared to the protruded outer peripheral surface 51 side. may extend obliquely.

A distance D2 from the outer peripheral surface 41 of the pilot portion 4 to the outer peripheral edge 21 of the nut body 2 is preferably 2.0 mm or more and 3.5 mm or less. If the distance D2 is less than 2.0 mm, the fastening bearing surface 3 may become too small. If the distance D2 is greater than 3.5 mm, the size of the pierce nut 1 may become too large. A distance D1 from the outer peripheral surface 41 of the pilot portion 4 to the outer peripheral edge 50 of the raised portion 5 is preferably 1.00 mm or more and 1.5 mm or less. If the distance D1 is less than 1.00 mm, it may be difficult to form the raised portion 5 by forging. If the distance D1 is larger than 1.5 mm, there is a possibility that the effect of the raised portion 5 described later (the effect of press-fitting and deforming the material of the peripheral portion of the opening 80 formed in the metal plate 8) will be reduced. These distances D1 and D2 can be measured with the tip of the outer peripheral surface 41 of the pilot portion 4 as a reference. Further, the distance D1 can be measured using the outer peripheral edge of the raised end surface 52 of the raised portion 5 as a reference. Furthermore, the distance D2 can be measured using the outer peripheral edge of the fastening bearing surface 3 of the nut body 2 as a reference.

The pierce nut 1 of this embodiment may be fixed to a relatively thick metal plate. A relatively thick metal plate may be a metal plate with a thickness of 3.0 mm or more and 10.0 mm or less, more specifically a metal plate with a thickness of 4.5 mm or more and 6.0 mm or less. Moreover, the pierce nut 1 of this embodiment can be a relatively large-diameter nut. As a relatively large-diameter nut, a nut having a nominal thread within the nut body 2 of M8 to M20 (JIS B 0205:2001), more specifically, a nut having a nominal thread within the nut body 2 of M12 to M16 is used. A nut is considered.

Next, FIG. 3 is an explanatory view showing a method of manufacturing a pierce nut fixing structure using the pierce nut 1 of FIG. As shown in FIGS. 3(a) to 3(e), the pierce nut 1 is secured to the metal plate 8 using a punch 6 and a die 7. As shown in FIG. A structure in which the pierce nut 1 is fixed to the metal plate 8 can be called a pierce nut fixing structure 9 (see FIG. 3(e)).

The die 7 is a member having a hole 70 and the metal plate 8 is placed on the die 7 . The inner diameter of the hole portion 70 is set to a size obtained by adding a predetermined clearance to the outer diameter of the pilot portion 4 . The punch 6 is configured to be vertically movable and has a claw portion 60 for supporting the pierce nut 1 .

When the pierce nut 1 is fixed to the metal plate 8, as shown in FIG. 3A, the pierce nut 1 is supported by the punch 6 above the metal plate 8 with the pilot portion 4 directed downward. . As shown in (b) of FIG. 3 , when the punch 6 and the pierce nut 1 are further lowered from the state where the tip of the pilot portion 4 is in contact with the metal plate 8 , the outer peripheral edge 40 of the tip of the pilot portion 4 touches the metal plate. 8 shear begins. By further lowering the punch 6 and the pierce nut 1 from the state of (b) of FIG. 3, the metal plate 8 is punched out as shown in (c) of FIG. be.

As shown in FIG. 3(d), the punch 6 and the pierce nut 1 are lowered until the fastening bearing surface 3 is brought into close contact with the surface of the metal plate. When the punch 6 and the pierce nut 1 are lowered to this position, the protuberance 5 is pressed against the peripheral edge of the opening 80, and the peripheral edge of the opening 80 is press-fitted and deformed so as to be in close contact with the outer peripheral surface of the pilot portion 4. be. As a result, the rotational resistance and pull-out resistance of the pierce nut 1 are improved. As shown in FIG. 3E, the punch 6 is lifted leaving the pierce nut 1 fixed to the metal plate 8, thereby completing the manufacture of the pierce nut fixing structure 9. As shown in FIG.

Next, FIG. 4 is an explanatory diagram for explaining the action of the raised portion 5 of FIG. FIG. 4(a) is a cross-sectional view of a pierce nut fixing structure 9 using the pierce nut 1 having the raised portion 5 of the present embodiment shown in FIG. 1, and FIG. 4(b) is a comparative example. FIG. 10 is a cross-sectional view of a conventional pierce nut fixing structure 900 using a pierce nut 100 having a protuberance 500 consisting of an inclined surface.

As described above, the protruding end surface 52 of the protruding portion 5 of the present embodiment is positioned apart from the fastening seat surface 3 by the height H2 of the protruding outer peripheral surface 51 . Therefore, much of the material around the periphery of the opening 80 formed in the metal plate 8 can be press-fitted and deformed. On the other hand, as shown in FIG. 4(b), when the protuberant portion 500 is formed only by inclined surfaces, there is less material that can be press-fitted and deformed compared to the protuberant portion 5 of the present embodiment. That is, by adopting the raised portion 5 of the present embodiment, it is possible to improve the rotational resistance and the pull-out resistance.

FIG. 4(a) shows a mode in which the raised end surface 52 extends perpendicularly to the thickness direction 2a of the nut body 2. Compared to the raised outer peripheral surface 51 side, the outer peripheral surface 41 side of the pilot portion 4 is If the raised end surface 52 is inclined so as to be retracted toward the front side of the pierce nut 1, more material can be press-fitted and deformed. However, the pierce nut 1 having the raised end face 52 extending perpendicularly to the thickness direction 2a of the nut body 2 is easier to manufacture by forging than the pierce nut 1 having the inclined raised end face 52 as described above.

A sheared surface 80a and a fractured surface 80b are formed at the back of the opening 80. As shown in FIG. The sheared surface 80a is a surface formed by shearing by the distal end outer peripheral edge 40 of the pilot portion 4, and is formed following the opening 80. As shown in FIG. The fracture surface 80b is a surface where the material is fractured by the pushing of the pilot portion 4, and is formed at a position farther from the pierce nut 1 than the sheared surface 80a in the radial direction of the pierce nut 1. As shown in FIG. The sheared surface 80a is smoother than the fractured surface 80b. By bringing the wide sheared surface 80a into close contact with the outer peripheral surface of the pilot portion 4, the rotational resistance and the pull-out resistance can be improved.

In the comparative example of FIG. 4B, only a portion of the entry side of the opening 80 can be brought into close contact with the outer peripheral surface of the pilot portion 4, and only a portion of the sheared surface 80a can be effectively utilized. However, in the raised portion 5 of the present embodiment, the sheared surface 80a can be brought into close contact with the outer peripheral surface of the pilot portion 4 more widely, and the rotational resistance and the pull-out resistance can be improved.

Examples are given below. The present inventors prepared a plurality of pierce nuts 1 having different sizes of protuberances 5 and fixed the pierce nuts 1 to a metal plate to experimentally manufacture a plurality of pierce nut fixing structures 9 . The pierce nut 1 was fixed to the metal plate with the center of the axis of the pierce nut 1 coinciding with the center of the metal plate. As the metal plate, a 400 MPa class Zn-Al-Mg alloy plated steel plate having a nominal thickness of 4.5 mm and an outer shape of 50 mm square was used. In addition, a clinch strength test, a torque strength test, and an observation of workpiece (steel plate) deformation were performed on these pierce nut fixing structures 9 . Table 1 shows the results.

The thickness T of the metal plate in Table 1 indicates the measured value of the thickness of the workpiece. A pierce nut 1 having a height H1 of the pilot portion 4 of 4.30 mm is used when the measured plate thickness of the work is 4.40 mm. The pierce nut 1 has a size of M12.

The clinch strength test was performed in accordance with "Push peel strength and its test method" described in JIS B 0205:2001, Annex A (reference). When the clinch strength measured by the test was 5 kN or more, it was evaluated as preferable. That is, in Table 1, ◯ indicates the case where the clinch strength is 5 kN or more, and x indicates the case where the clinch strength is less than 5 kN.

The torque strength test was conducted in accordance with "Torque peel strength and its test method" described in Appendix B (reference) of JIS B 1196:2010. A case where the torque strength measured by the test was 50 N·m or more was evaluated as preferable. That is, in Table 1, ◯ indicates a case where the torque strength is 50 N·m or more, and x indicates a case where the torque strength is less than 50 N·m.

For observation of work (steel plate) deformation, the magnitude of warpage of the work between the center and the edge of the work was measured. As described above, the axial center of the pierce nut 1 is aligned with the center of the metal plate. Moreover, the workpiece has a size of 50 mm square. A displacement of less than 1 mm (less than 1 mm/25 mm) at the edge relative to the center of the work was evaluated as favorable. That is, ◯ indicates a case where the displacement of the end portion with respect to the center of the work is 1 mm, and x indicates a case where the displacement of the end portion with respect to the center of the work is 1 mm or more.

In the comprehensive judgment in Table 1, ○ indicates that all of the clinch strength, torque strength, and work deformation can be evaluated as preferable, and x indicates that any one of these clinch strength, torque strength, or work deformation is evaluated as unfavorable. showing. Note that even if any one of the clinch strength, torque strength, and work deformation is x, it may be allowed depending on the intended use of the pierce nut fixing structure 9 .

No. in Table 1. Samples 1 to 7 are samples in which only the height H2 of the raised outer peripheral surface 51 is changed. By changing the height H2 of the raised outer peripheral surface 51 while the height H1 of the pilot portion 4 is fixed, the ratio H2/H1 of the height H2 of the raised outer peripheral surface 51 to the height H1 of the pilot portion 4 also changes. ing. No. in Table 1. 1 to 7, by setting the height H2 of the protuberance outer peripheral surface 51 to 0.20 mm or more and the ratio H2/H1 to 0.05 or more and 0.23 or less, clinch strength, torque strength, and workpiece All deformations could be evaluated as favorable (comprehensive evaluation: ◯). When the height H2 of the raised outer peripheral surface 51 is less than 0.20 mm, the clinch strength and torque strength are evaluated as x. This is probably because the material of the peripheral portion of the opening 80 could not be sufficiently press-fitted and deformed due to the low height H2 of the raised outer peripheral surface 51 . On the other hand, when the ratio H2/H1 exceeds 0.23, the work deformation is evaluated as x. It is considered that this is because the raised portion 5 is too large with respect to the plate thickness of the work.

No. in Table 1. 8-14 and No. Samples No. 15 to 21 are No. 1 to 7, the distance D2 from the outer peripheral surface 41 of the pilot portion 4 to the outer peripheral edge 21 of the nut body 2 is changed by changing the height H2 of the protruding outer peripheral surface 51. It is a sample made larger than 1-7. By changing the distance D2 from the outer peripheral surface 41 of the pilot portion 4 to the outer peripheral edge 21 of the nut body 2 while fixing the distance D1 from the outer peripheral surface 41 of the pilot portion 4 to the outer peripheral edge 50 of the raised portion 5, the distance The ratio D2/D1 of the distance D1 to D2 is changed. Even if the ratio D2/D1 is changed, the usefulness of setting the ratio H2/H1 to 0.05 or more and 0.23 or less (favorable results in clinch strength, torque strength, and workpiece deformation) are It could be confirmed. Note that if the distance D2 is less than 2.0 mm, there is a risk that the fastening seat surface 3 will be too small. Also, if the distance D2 is larger than 3.5 mm, the size of the pierce nut 1 may become too large.

Further, the present inventors changed the work to a 400 MPa class Zn-Al-Mg alloy plated steel sheet having a nominal thickness of 6.0 mm and an outer shape of 50 mm square, and conducted the same test. When the measured plate thickness of the workpiece was 5.90 mm, the pierce nut 1 with the height H1 of the pilot portion 4 of 5.80 mm was used. Table 2 shows test conditions and evaluation results. Conditions not shown in the table are the same as the tests in Table 1.

No. in Table 2. Samples 1 to 7 are samples in which only the height H2 of the raised outer peripheral surface 51 is changed. By changing the height H2 of the raised outer peripheral surface 51 while the height H1 of the pilot portion 4 is fixed, the ratio H2/H1 of the height H2 of the raised outer peripheral surface 51 to the height H1 of the pilot portion 4 also changes. ing. It was confirmed that clinch strength, torque strength, and work deformation are all favorable by setting the ratio H2/H1 to 0.05 or more and 0.23 or less even for a work with a nominal plate thickness of 6.0 mm. .

No. in Table 2. 8-14 and No. Samples No. 15 to 21 are No. 1 to 7, the distance D2 from the outer peripheral surface 41 of the pilot portion 4 to the outer peripheral edge 21 of the nut body 2 is changed by changing the height H2 of the protruding outer peripheral surface 51. It is a sample made larger than 1-7. Even for a workpiece with a nominal plate thickness of 6.0 mm, the usefulness of setting the ratio H2/H1 to 0.05 or more and 0.23 or less regardless of the ratio D2/D1 (clinching strength, torque strength, and work deformation It was confirmed that favorable results were obtained in all cases).

In such a pierce nut, the raised end surface 52 of the raised portion 5 is positioned away from the fastening seat surface 3 due to the height H2 of the raised outer peripheral surface 51. Therefore, when the pierce nut 1 is fixed to the metal plate 8, By punching out the pilot part 4, more material located at the peripheral edge of the opening 80 formed in the metal plate 8 can be press-fitted and deformed so as to be in close contact with the outer peripheral surface of the pilot part, improving the rotational resistance and the pull-out resistance. can.

In addition, since the raised end surface 52 extends perpendicularly to the thickness direction 2a of the nut body 2, it is possible to press-fit and deform a large amount of material in the peripheral portion of the opening 80 formed in the metal plate 8, and to press and deform it. can be manufactured more easily.

Further, the height H2 of the raised outer peripheral surface 51 is 0.20 mm or more, and the ratio H2/H1 of the height H2 of the raised outer peripheral surface 51 to the height H1 of the pilot portion 4 is 0.05 or more and 0.23 or less. Therefore, clinch strength, torque strength and workpiece deformation can be favored.

Furthermore, the distance D2 from the outer peripheral surface 41 of the pilot portion 4 to the outer peripheral edge 21 of the nut body 2 is 2.0 mm or more and 3.5 mm or less. , the possibility that the size of the pierce nut 1 becomes excessively large can be avoided.

REFERENCE SIGNS LIST 1 pierce nut 2 nut body 20 screw hole 21 outer peripheral edge 3 fastening bearing surface 4 pilot portion 41 outer peripheral surface 5 raised portion 50 outer peripheral edge 51 raised outer peripheral surface 52 raised end surface

Claims (4)

a nut body having a threaded hole in the center;
a fastening bearing surface provided at one end in the thickness direction of the nut body;
a pilot portion projecting from the fastening seat surface at the central portion of the nut body;
a raised portion projecting from the fastening seat surface around the base of the pilot portion,
The fastening seat surface is a flat surface extending from the outer peripheral edge of the raised portion to the outer peripheral edge of the nut body,
The raised portion extends between a raised outer peripheral surface protruding from the fastening seat surface and a tip of the raised outer peripheral surface and an outer peripheral surface of the pilot portion, and the height of the raised outer peripheral surface increases the height of the raised outer peripheral surface. and a raised end face positioned away from the
The height (H2) of the raised outer peripheral surface is 0.20 mm or more,
A ratio (H2/H1) of the height (H2) of the protuberance outer peripheral surface to the height (H1) of the pilot portion is 0.05 or more and 0.23 or less,
the nominal diameter of the threads in the nut body is from M8 to M20;
pierce nut. For a metal plate with a plate thickness of 3.0 mm or more and 10.0 mm or less,
A pierce nut according to claim 1. The raised end face extends perpendicularly to the thickness direction of the nut body,
The pierce nut according to claim 1 or 2 . The distance (D2) from the outer peripheral surface of the pilot portion to the outer peripheral edge of the nut body is 2.0 mm or more and 3.5 mm or less.
Pierce nut according to any one of claims 1 to 3.

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