JP5986889B2 - Piercing nut - Google Patents

Description

The present invention relates to a pierce nut .

  Conventionally, a technique for coupling a pierce nut to a metal plate material is known (see, for example, Patent Document 1). The pierce nut described in Patent Document 1 has an annular inner wall portion and an outer wall portion on the back side that is a side to be joined to a metal plate material, and the inner wall portion protrudes along the nut axial direction. The outer wall portion is formed so as to protrude in the nut axial direction while being inclined toward the inner wall portion side. The inner wall portion and the outer wall portion define an annular groove portion along the circumferential direction, and the corner portion of the inner wall portion is formed into a sharp annular shear edge.

  Therefore, when the pierce nut is pushed into the metal plate material, the shear edge perforates the metal plate material to form a hole. The material of the metal plate at the peripheral edge of the hole is introduced into the annular groove while being plastically processed, so that the pierce nut is fixed to the metal plate.

JP-A-7-238915

  However, such conventional pierce nuts are often used for automobile parts and the like, and further improvement of the pull-through strength is desired.

Therefore, the present invention provides a pierce nut with further improved pull-through strength.

A pierce nut according to the present invention is a pierce nut whose back side is fixed to a metal plate material, a nut main body part having a screw hole extending along a nut axial direction in a central part in the radial direction, and a rear face of the nut main body part The outer wall portion is arranged annularly along the circumferential direction on the radially outer side of the outer wall portion, and is arranged annularly along the circumferential direction on the radially inner side of the outer wall portion with the outer wall portion standing along the nut axial direction. And an inner wall portion standing along the nut axial direction, a bottom surface portion disposed between the outer wall portion and the inner wall portion of the back surface of the nut main body portion, the inner wall portion, and the outer side An annular groove portion that is annularly defined along the circumferential direction on the back side of the nut body portion by the wall portion and the bottom surface portion, and the outer peripheral surface is radially inward as it goes to the front side in the side view The inner wall portion is formed in a cylindrical shape inclined to The height is set to be higher than the outer wall portion, and the tip end corner portion of the inner wall portion is formed in a shearing edge for drilling a metal plate, and the difference in height between the outer wall portion and the inner wall portion is determined as described above. The thickness is set to be equal to the thickness of the metal plate, and the bottom surface portion is adjacent to the first bottom surface portion extending from the inner wall portion to the outer wall portion in the circumferential direction of the first bottom surface portion, and radially outward. A third bottom surface portion disposed adjacent to a circumferential direction of the first bottom surface portion and radially inward of the second bottom surface portion, and the third bottom surface portion. A first step portion is formed between the first bottom surface portion and the second bottom surface portion, and the first bottom surface portion is formed. A second step portion is formed between the portion and the third bottom surface portion .

  According to the pierce nut and the pierce nut assembly according to the present invention, the inner wall portion is formed in a cylindrical shape whose outer peripheral surface is inclined radially inward as it goes to the front side in a side view. For this reason, when the pierce nut is pressed in the axial direction in a state in which the pierce nut is coupled to the metal plate member, the peripheral portion of the hole of the metal plate member is caught by the outer peripheral surface of the inner wall portion of the pierce nut. Furthermore, since the difference in height between the outer wall portion and the inner wall portion is set to be equal to the thickness of the metal plate material, the top surface of the inner wall portion is made of metal when the pierce nut is fixed to the metal plate material. The height of the inner wall portion can be increased and the outer diameter of the top surface of the inner wall portion can be increased within a range that does not protrude from the back surface of the plate material, and when the pierce nut is pressed in the axial direction, the state of the catch is kept long. be able to. Accordingly, the inner wall portion of the pierce nut is unlikely to be detached from the hole of the metal plate material, so that the pull-through strength is improved.

 Further, since the difference in height between the outer wall portion and the inner wall portion is set to be equal to the thickness of the metal plate material, when the pierce nut is fixed to the metal plate material, the back surface and the inner wall portion of the metal plate material The top surface of the same. Therefore, when the coupled plate material in which the bolt holes are formed is brought into contact with the metal plate material, the gap between the top surface of the inner side wall portion of these pierce nuts and the coupled plate material is reduced so that they are in close contact with each other. Therefore, when the pierce nut is pressed in the nut axial direction, the top surface of the inner wall portion of the pierce nut is supported by the coupled plate material, and the pierce nut is unlikely to be detached from the metal plate material, and the pull-through strength is further improved.

Drawing 1 is a perspective view which looked at the back side of the pierce nut concerning the embodiment of the present invention from the slanting direction. FIG. 2 is a back view of the back side of the pierce nut according to the embodiment of the present invention as viewed from above. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a cross-sectional view of the pierce nut assembly according to the embodiment of the present invention. FIG. 5 is an enlarged cross-sectional view of a main part of FIG. FIG. 6 is a back view of the back side of the pierce nut according to the comparative example as viewed from above. 7 is a cross-sectional view taken along line BB in FIG. FIG. 8 is a cross-sectional view of a pierce nut assembly according to a comparative example. FIG. 9 is an enlarged cross-sectional view of a main part of FIG. FIG. 10 is a plan view showing a procedure for performing free torque measurement. FIG. 11 is a cross-sectional view showing a procedure for performing the pull-through measurement. FIG. 12 is a table showing measurement results of free torque strength and pull-through strength in the examples.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1-3, the pierce nut 1 which concerns on embodiment of this invention is the nut main-body part 3, the outer side wall part 5, the inner side wall part 7, the bottom face part 9, the annular groove part 11, It has.

  The said nut main-body part 3 has the screw hole 13 penetrated along the nut axial direction L in the radial direction center part, and is formed in the cylindrical shape. The nut axial direction L is the same direction as the thickness direction of the pierce nut 1.

  The outer wall portion 5 is annularly arranged along the circumferential direction on the radially outer side of the back surface of the nut main body portion 3 and is erected along the nut axial direction L. The outer peripheral surface of the outer wall portion 5 is formed flush with the outer peripheral surface of the nut main body portion 3. The outer wall portion 5 is formed in a cylindrical shape as a whole.

  The inner wall portion 7 is annularly arranged along the circumferential direction on the radially inner side of the outer wall portion 5, and is erected along the nut axial direction L. The inner wall portion 7 is formed in a cylindrical shape with the outer peripheral surface 7b inclined as a whole. Specifically, the outer peripheral surface 7b of the inner wall portion 7 is formed to be inclined inward in the radial direction so that the radial length gradually decreases toward the front side in a side view. Here, the tip corner on the outer peripheral side of the inner wall portion 7 is formed in a shear edge 15 that perforates the metal plate 17.

 Further, as shown in FIG. 3, the difference in height H0 between the outer wall portion 5 and the inner wall portion 7 is equal to the thickness T of the metal plate material 17 (see FIGS. 4 and 5) to which the pierce nut 1 is fixed. Is set. That is, the top surfaces 5a and 7a of the outer wall portion 5 and the inner wall portion 7 are flat surfaces, and the top surface 7a of the inner wall portion 7 is formed higher. Here, the height difference H0 between the top surface 7a of the inner wall portion 7 and the top surface 5a of the outer wall portion 5 is set to be equal to the thickness T of the metal plate material 17 to which the pierce nut 1 is fixed. Yes.

 The bottom surface portion 9 is a portion of the back surface of the nut body portion 3 that is disposed between the outer wall portion 5 and the inner wall portion 7.

  The annular groove 11 is defined annularly along the circumferential direction on the back side of the nut body 3 by the inner wall 7, the outer wall 5, and the bottom 9.

 The bottom surface portion 9 includes a first bottom surface portion 21, a second bottom surface portion 23, and a third bottom surface portion 25. Specifically, a first bottom surface portion 21 having a rectangular shape in plan view is formed from the outer peripheral surface of the inner wall portion 7 to the inner peripheral surface of the outer wall portion 5. A second bottom surface portion 23 and a third bottom surface portion 25 are formed adjacent to the circumferential direction of the first bottom surface portion 21. That is, the second bottom surface portion 23 is adjacent to the circumferential direction of the first bottom surface portion 21 and is disposed radially outside. The third bottom surface portion 25 is adjacent to the circumferential direction of the first bottom surface portion 21 and is disposed on the radially inner side of the second bottom surface portion 23.

  As shown in FIG. 3, the third bottom surface portion 25, the second bottom surface portion 23, and the first bottom surface portion 21 are formed in the order of decreasing height. That is, the third bottom surface portion 25 is the highest, the second bottom surface portion 23 is the next highest, and the first bottom surface portion 21 is the lowest. Specifically, the second bottom surface portion 23 is formed higher than the first bottom surface portion 21 by a height H1 and the third bottom surface portion 25 is formed higher than the second bottom surface portion 23 by a height H2. ing.

 A first step portion 27 is formed along the circumferential direction between the first bottom surface portion 21 and the second bottom surface portion 23, and between the first bottom surface portion 21 and the third bottom surface portion 25. A second step portion 29 is formed along the circumferential direction.

  Further, the first stepped portion 27 is provided with a thin plate-like connecting wall surface portion 19 formed in a triangular shape in a side view. Specifically, the radially inner end 19a of the connection wall surface portion 19 is integrally coupled to the outer peripheral surface 25a (see FIG. 1) of the third bottom surface portion 25, and the top of the connection wall surface portion 19 increases toward the radially outer side. The surface is inclined and the height is gradually lowered to become a radially outer end 19 b having a height of zero on the second bottom surface portion 23. A plurality (16 in this embodiment) of the connecting wall surface portions 19 are arranged at predetermined intervals along the circumferential direction inside the annular groove portion 11.

  As shown in FIGS. 4 and 5, the back surface of the pierce nut 1 is fixed to the front surface side of the metal plate member 17, thereby forming a pierce nut combined body 31. That is, the pierce nut combined body 31 includes the pierce nut 1 and the metal plate material 17 to which the pierce nut 1 is connected.

  Specifically, when the pierce nut 1 is pressed against the metal plate member 17, the metal plate member 17 is perforated into a disk shape with a shear edge 15 and a die (not shown) provided on the inner wall portion 7, and this hole The metal material of the peripheral edge portion 17 a flows into the annular groove portion 11. As a result, the pierce nut 1 is coupled to the metal plate member 17 to form the pierce nut combined body 31.

 Here, as described above, the inner wall portion 7 is formed in a cylindrical shape in which the outer peripheral surface 7b is inclined in a side view. Further, the height difference H0 between the outer wall portion 5 and the inner wall portion 7 is set to be equal to the thickness T of the metal plate material 17 to which the pierce nut 1 is fixed. That is, the height difference H0 between the top surface 7a of the inner wall 7 and the top surface 5a of the outer wall 5 is set to be equal to the thickness T of the metal plate 17 to which the pierce nut 1 is fixed. .

 Next, the pierce nut 101 and the pierce nut assembly 131 according to the comparative example will be described with reference to FIGS.

 As shown in FIGS. 6 and 7, the pierce nut 101 according to the comparative example has an inner wall portion 107 formed in a cylindrical shape, and a difference h between the top surface 105 a of the outer wall portion 105 and the top surface 107 a of the inner wall portion 107. However, it is significantly smaller than the thickness T of the metal plate member 17 to be joined. Therefore, as shown in FIGS. 8 and 9, the inner wall portion 107 has a cylindrical shape along the nut axial direction L without the outer peripheral surface 107 b being inclined in a side view. Further, after the pierce nut 101 is coupled to the metal plate member 17, when the coupled plate member 35 in which the bolt hole 33 is formed is brought into contact with the metal plate member 17, the inner wall portions 107 of these pierce nuts 101 are formed. A large gap G is formed between the top surface 107 a and the coupled plate material 35.

 Below, the effect which concerns on this embodiment is demonstrated.

(1) The pierce nut 1 according to the present embodiment is a pierce nut 1 whose back side is fixed to the metal plate material 17. In particular,
A nut main body 3 having a screw hole extending along the nut axial direction L in the radial center;
An outer wall portion 5 that is annularly arranged along the circumferential direction on the radially outer side of the back surface of the nut body portion 3 and that stands up along the nut axial direction L;
An inner wall portion 7 that is arranged annularly along the circumferential direction on the radially inner side of the outer wall portion 5 and that stands up along the nut axial direction L;
Of the back surface of the nut body 3, a bottom surface portion 9 disposed between the outer wall portion 5 and the inner wall portion 7,
An annular groove portion 11 that is annularly defined along the circumferential direction is provided on the back surface side of the nut main body portion 3 by the inner wall portion 7, the outer wall portion 5, and the bottom surface portion 9.

 And the said inner wall part 7 is formed in the cylinder shape which the outer peripheral surface 7b inclines in radial direction as it goes to the front side in a side view, and the height of the said inner wall part 7 is set higher than the outer wall part 5. At the same time, the tip corner of the inner wall 7 is formed in a shear edge 15 that perforates the metal plate 17, and the height difference H 0 between the outer wall 5 and the inner wall 7 is set to the height of the metal plate 17. It is set equal to the thickness T.

 In this manner, the inner wall 7 is formed in a cylindrical shape that is inclined inward in the radial direction as the outer peripheral surface 7b moves to the front side in a side view. Therefore, when the pierce nut 1 is pressed in the axial direction in a state where the pierce nut 1 is coupled to the metal plate member 17, the peripheral edge portion 17 a of the hole of the metal plate member 17 becomes the outer periphery of the inner wall portion 7 of the pierce nut 1. It catches on the surface 7b. Further, since the difference in height between the outer wall portion 5 and the inner wall portion 7 is set to be equal to the thickness of the metal plate member 17, when the pierce nut 1 is fixed to the metal plate member 17, the inner wall portion 7. As long as the top surface 7a does not protrude from the back surface of the metal plate member 17, the height of the inner wall 7 can be increased and the outer diameter of the top surface 7a of the inner wall 7 can be increased. When pressed, the hooked state can be maintained for a long time. Accordingly, the inner side wall portion 7 of the pierce nut 1 is not easily detached from the hole of the metal plate member 17, so that the pull-through strength is improved.

 Further, since the difference H0 between the height of the outer wall portion 5 and the height of the inner wall portion 7 is set to be equal to the thickness T of the metal plate member 17, the pierce nut 1 is fixed to the metal plate member 17. The back surface of the metal plate 17 and the top surface 7a of the inner wall 7 are flush with each other. Therefore, when the plate member 35 to which the bolt hole 33 is formed is brought into contact with the metal plate member 17, the gap between the top surface 7a of the inner wall 7 of the pierce nut 1 and the plate member 35 is reduced. And stick to each other. Therefore, when the pierce nut 1 is pressed in the nut axial direction L, the top surface 7a of the inner wall 7 of the pierce nut 1 is supported by the coupled plate member 35, and the pierce nut 1 is less likely to come off from the metal plate member 17, Pru-through strength is further improved.

(2) The bottom surface portion 9 is adjacent to the first bottom surface portion 21 extending from the inner wall portion 7 to the outer wall portion 5, and the circumferential direction of the first bottom surface portion 21, and is disposed radially outward. The second bottom surface portion 23 and the third bottom surface portion 25 adjacent to the circumferential direction of the first bottom surface portion 21 and disposed radially inside the second bottom surface portion 23.
By forming the third bottom surface portion 25, the second bottom surface portion 23, and the first bottom surface portion 21 in order of decreasing height, a first step is formed between the first bottom surface portion 21 and the second bottom surface portion 23. A portion 27 is formed, and a second step portion 29 is formed between the first bottom surface portion 21 and the third bottom surface portion 25.

 As described above, the third bottom surface portion 25, the second bottom surface portion 23, and the first bottom surface portion 21 are formed in the order of decreasing height. For this reason, the material of the metal plate member 17 introduced into the annular groove portion 11 flows into the third bottom surface portion 25, the second bottom surface portion 23, and the first bottom surface portion 21 and is intertwined in a complicated manner. Accordingly, when a pressing load is applied to the pierce nut 1, the pierce nut 1 is unlikely to be detached from the metal plate member 17, so that the pull-through strength of the pierce nut 1 is improved.

 A first step portion 27 is formed between the first bottom surface portion 21 and the second bottom surface portion 23, and a second step portion 29 is formed between the first bottom surface portion 21 and the third bottom surface portion 25. Is done. For this reason, when the torque along the circumferential direction is applied to the pierce nut, the first stepped portion 27 and the second stepped portion 29 hit the material of the metal plate material 17 introduced into the annular groove portion 11 and are difficult to rotate. Further, the free torque strength of the pierce nut is improved.

(3) A plurality of thin plate-like connecting wall surface portions 19 provided in the first step portion 27 and extending along the radial direction are arranged at predetermined intervals in the circumferential direction.

 As described above, since a plurality of the connecting wall surface portions 19 are arranged at a predetermined interval in the circumferential direction, when a torque along the circumferential direction is applied to the pierce nut 1, the proof strength against this torque is improved. Therefore, the free torque strength of the pierce nut 1 is improved.

(4) The pierce nut assembly 31 according to the present embodiment includes the metal plate member 17 and the pierce nut 1 whose back side is fixed to the metal plate member 17.

The pierce nut 1 is
A nut main body 3 having a screw hole extending along the nut axial direction L in the radial center;
An outer wall portion 5 that is annularly arranged along the circumferential direction on the radially outer side of the back surface of the nut body portion 3 and that stands up along the nut axial direction L;
An inner wall portion 7 that is arranged annularly along the circumferential direction on the radially inner side of the outer wall portion 5 and that stands up along the nut axial direction L;
Of the back surface of the nut body 3, a bottom surface portion 9 disposed between the outer wall portion 5 and the inner wall portion 7,
An annular groove portion 11 that is annularly defined along the circumferential direction is provided on the back surface side of the nut main body portion 3 by the inner wall portion 7, the outer wall portion 5, and the bottom surface portion 9.

 And the said inner wall part 7 is formed in the cylinder shape which inclines in radial direction as the outer peripheral surface 7b goes to the front side in a side view, and the height of the said inner wall part 7 is set higher than the outer wall part 5. At the same time, the tip corner of the inner wall 7 is formed in a shear edge 15 that perforates the metal plate 17, and the height difference H 0 between the outer wall 5 and the inner wall 7 is set to the height of the metal plate 17. It is set equal to the thickness T.

 As described above, the inner wall 7 is formed in a cylindrical shape in which the outer peripheral surface 7b is inclined inward in the radial direction toward the front side in a side view. Therefore, when the pierce nut 1 is pressed in the axial direction in a state where the pierce nut 1 is coupled to the metal plate member 17, the peripheral edge portion 17 a of the hole of the metal plate member 17 becomes the outer periphery of the inner wall portion 7 of the pierce nut 1. It catches on the surface 7b. Further, since the difference in height between the outer wall portion 5 and the inner wall portion 7 is set to be equal to the thickness of the metal plate member 17, when the pierce nut 1 is fixed to the metal plate member 17, the inner wall portion 7. As long as the top surface 7a does not protrude from the back surface of the metal plate member 17, the height of the inner wall 7 can be increased and the outer diameter of the top surface 7a of the inner wall 7 can be increased. When pressed, the hooked state can be maintained for a long time. Accordingly, the inner side wall portion 7 of the pierce nut 1 is not easily detached from the hole of the metal plate member 17, so that the pull-through strength is improved.

 Further, since the difference H0 between the height of the outer wall portion 5 and the height of the inner wall portion 7 is set to be equal to the thickness T of the metal plate member 17, the pierce nut 1 is fixed to the metal plate member 17. The back surface of the metal plate 17 and the top surface 7a of the inner wall 7 are flush with each other. Therefore, when the plate member 35 to which the bolt hole 33 is formed is brought into contact with the metal plate member 17, the gap between the top surface 7a of the inner wall 7 of the pierce nut 1 and the plate member 35 is reduced. And stick to each other. Therefore, when the pierce nut 1 is pressed in the nut axial direction L, the top surface 7a of the inner wall 7 of the pierce nut 1 is supported by the coupled plate member 35, and the pierce nut 1 is less likely to come off from the metal plate member 17, Pru-through strength is further improved.

 Next, the present invention will be described more specifically through examples.

 In this example, the free torque strength and the pull-through strength were measured for the pierce nut assembly according to the invention example shown in FIG. 4 and the pierce nut assembly according to the comparative example shown in FIG.

 As shown in FIG. 10, the free torque strength is measured by applying a torque Tr for rotating the pierce nut 1 in the pierce nut combined body 31 in a clockwise direction (indicated by an arrow) in plan view so that the pierce nut 1 is made of metal. This is a method of measuring the torque Tr released from the plate material 17.

  As shown in FIG. 11, the method for measuring the prue-through strength is such that the both sides of the metal plate 17 in the pierce nut combined body 31 are gripped via a jig 41 and the bolt 42 is fastened to the pierce nut 1. In this method, a pressing load F is applied so as to press 42, and the pressing load F at which the pierce nut 1 is detached from the metal plate 17 is measured.

  The metal plate 17 was made of SPHC having a plate thickness of 2.0 mm. As the pierce nut, an M8 nut was used.

  Under the above conditions, free torque strength and pull-through strength were measured, and the results are shown in the table of FIG. About the free torque strength, the pierce nuts according to Examples 1 to 3 of the present invention were improved over the pierce nuts according to the comparative examples. In addition, the pierce nuts according to Examples 1 to 3 of the present invention were significantly improved in the pull-through strength as compared with the pierce nuts according to the comparative examples.

DESCRIPTION OF SYMBOLS 1 Pierce nut 3 Nut main-body part 5 Outer wall part 7 Inner wall part 7b Outer peripheral surface 9 Bottom face part 11 Annular groove part 13 Screw hole 15 Shear edge 17 Metal plate material 19 Connection wall part 21 1st bottom face part 23 2nd bottom face part 25 1st 3 bottom surface portion 27 first step portion 29 second step portion 31 pierce nut combined body

Claims (2)

A pierce nut whose back side is fixed to a metal plate,
A nut main body having a screw hole extending along the nut axial direction in the radial center;
An outer wall portion that is annularly arranged along the circumferential direction on the radially outer side of the back surface of the nut body portion, and that stands up along the nut axial direction;
An inner wall portion that is arranged annularly along the circumferential direction on the radially inner side of the outer wall portion, and that stands up along the nut axial direction;
Of the back surface of the nut body portion, a bottom surface portion disposed between the outer wall portion and the inner wall portion,
An annular groove portion that is annularly defined along the circumferential direction on the back surface side of the nut body portion by the inner wall portion, the outer wall portion, and the bottom surface portion;
The inner wall portion is formed in a cylindrical shape whose outer peripheral surface is inclined radially inwardly toward the front side in a side view, the height of the inner wall portion is set higher than the outer wall portion, and the inner wall portion The tip corner is formed in a shear edge that perforates a metal plate,
The difference in height between the outer wall portion and the inner wall portion is set equal to the thickness of the metal plate ,
The bottom surface portion includes a first bottom surface portion extending from the inner wall portion to the outer wall portion, a second bottom surface portion adjacent to the circumferential direction of the first bottom surface portion, and disposed radially outward, A third bottom surface portion that is adjacent to the circumferential direction of the first bottom surface portion and is arranged radially inside the second bottom surface portion;
By forming the third bottom surface portion, the second bottom surface portion, and the first bottom surface portion in order of decreasing height, a first step portion is formed between the first bottom surface portion and the second bottom surface portion, A pierce nut, wherein a second step portion is formed between the first bottom surface portion and the third bottom surface portion . 2. The pierce nut according to claim 1 , wherein a plurality of thin plate-like connecting wall surfaces provided in the first step portion and extending in the radial direction are arranged at predetermined intervals in the circumferential direction.

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