JP5646249B2 - Exterior beam for vehicles - Google Patents

Description

  The present invention relates to an exterior beam for a vehicle such as a bumper disposed in a vehicle.

  In general vehicles such as trucks having a high vehicle height, a bumper is provided below the vehicle in order to prevent a car from falling when a low vehicle height collides. This bumper is generally formed in a square tube shape from steel, aluminum alloy, or the like, and is used by fastening with a bolt or the like when attached to a vehicle.

For example, Patent Literature 1 proposes a fastening method in which a pierce nut is driven into a plate-shaped wall of an aluminum alloy extruded profile from the inside of the hollow and fixed to the plate-shaped wall.
The pierce nut is a nut that is driven into a metal plate that supports the back surface with a caulking die with a driving punch, and the metal plate is punched out with the nut itself, and at the same time, the periphery of the punched hole is caulked and fixed to the metal plate. In this pierce nut, if the caulking force is small, it may fall off from the plate-like wall, and the bolt tightening operation may not be performed well. Therefore, in order to install the pierce nut, it is necessary to configure a plate-like wall having a thickness that can be punched by the nut itself and can withstand the caulking force.
Then, although the cross-sectional shape and plate | board thickness are set according to the impact load assumed for a plate-shaped wall, in the pierce nut of patent document 1, other part of the plate-like wall in which a pierce nut is driven is another A thick part having a thickness greater than that of the part is formed to increase the caulking force.

  Further, as a method of joining a bumper formed of an aluminum alloy or the like and a frame member, a fastening method using a caulking nut as proposed in Patent Document 2 is known. In this case, after the caulking nut is caulked and fixed around the through hole of the bumper, the bolt can be screwed into the caulking nut through the through hole of the frame member and fastened.

JP 2010-18061 A JP 2008-175380 A

Incidentally, in recent years, in order to reduce the weight of the bumper, the peripheral wall of an extruded material such as an aluminum alloy has been formed to be relatively thin.
Therefore, when the pierce nut shown in Patent Document 1 is used for fastening the bumper, the caulking force is secured by forming the peripheral portion including the driving portion thick, and the driving portion itself is punched through. Need to be formed.
In addition, since the limit torque of the pierce nut is low and the pierce nut and the bolt are likely to rotate together, it is difficult to fasten with the high torque.

  Even when the caulking nut shown in Patent Document 2 is used for fastening the bumper, it is easy to cause co-rotation at the caulking portion. To prevent co-rotation, the caulking nut is knurled or the diameter of the prepared hole is strictly set. Measures such as management are necessary.

  The present invention has been made in view of such circumstances, and provides an exterior beam for a vehicle that can prevent the fastening member from rotating together with a simple configuration and can be reliably fixed.

The exterior beam for a vehicle according to the present invention includes a caulking nut inserted into the mounting hole of the beam body to buckle a peripheral wall portion of the caulking nut to form a diameter-expanded portion that bulges outward in the radial direction, thereby causing the caulking nut to move toward the beam. A vehicular exterior beam fixed to a main body, wherein a projection portion into which a part of a diameter-enlarged portion of the caulking nut bites in a position near a mounting hole of the beam main body is provided. To do.

  In the vehicle exterior beam formed in this way, when the peripheral wall portion of the caulking nut is bulged and fixed, a part of the enlarged diameter portion bites into the protruding portion and deforms and is caulked. Since the biting portion between the enlarged diameter portion and the protrusion functions as a detent, it is possible to reliably prevent the caulking nut and the fastening bolt from co-rotating when mounting the exterior beam to the vehicle, and strengthen the exterior beam. Can be fixed to.

Moreover, the vehicle exterior beam of this invention WHEREIN: The said projection part is good in it being a protruding item | line along the longitudinal direction of the said beam main body.
When the protrusion is formed along the longitudinal direction of the beam body, the protrusion can be formed simultaneously with the formation of the beam body by extrusion molding or the like, and can be easily manufactured.

Furthermore, in the vehicle exterior beam of the present invention, it is preferable that the ridge is provided in a tangential direction of the mounting hole.
When the beam body protrusion is provided in the tangential direction of the mounting hole, it can be securely in contact with the enlarged diameter portion of the caulking nut, so that it can be bitten in a wide range even if there is a slight variation in the height of the protrusion. The co-rotation prevention function can be exhibited.

  ADVANTAGE OF THE INVENTION According to this invention, although it is the simple structure which forms a projection part in a beam main body, the joint rotation of a fastening member can be prevented and the exterior beam for vehicles which can be fixed reliably can be provided.

It is a perspective view of the exterior beam of this embodiment. It is a principal part enlarged view of the beam main body shown in FIG. 1, (a) is a front view, (b) is a side view. It is a side sectional view explaining attachment of a caulking nut, (a) shows before fixation and (b) shows after fixation. It is a principal part enlarged view of the exterior beam shown in FIG. 1, (a) is a perspective view, (b) is a side view. It is a schematic block diagram of the limit torque evaluation apparatus of a caulking nut. It is a figure explaining the beam main body of other embodiment.

Hereinafter, an embodiment of a vehicle exterior beam according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the vehicle exterior beam 100 according to the present embodiment is configured by fixing a caulking nut 20, which is a fastening member, in an attachment hole 11 of a beam body 10 formed in a rectangular tube shape.

As shown in FIG. 1, the beam body 10 is formed in a rectangular tube shape by extrusion molding of an aluminum alloy, and is formed to have a length comparable to the width dimension of the vehicle to be attached.
A mounting hole 11 for inserting and fixing a caulking nut 20 is provided in the peripheral wall of the beam main body 10, and the position near the mounting hole 11 on the inner wall of the beam main body 10 is along the longitudinal direction of the beam main body 10. Protruding protrusions 12 are formed.
As shown in FIG. 2, the protrusion 12 is provided on one side of the mounting hole 11 (on the left side in FIG. 2) to form an end surface 13 along the axis of the mounting hole 11 and has a trapezoidal cross section. 11 is partially cut out, and the cut out portion is formed in a substantially triangular longitudinal section.

  As shown in FIG. 3A, the caulking nut 20 is formed of a cylindrical cylindrical body 21, and has a flange portion 22 at one end thereof. The front end of the cylindrical body 21 is formed thick, and a female screw portion 23 is formed inside thereof. And between the internal thread part 23 and the flange part 22 of the cylindrical body 21, it is the surrounding wall part 24 formed by making the opening diameter larger than the front-end | tip of the cylindrical body 21, and thinly.

The caulking nut 20 configured as described above is fixed to the beam body 10 as follows.
First, as shown in FIG. 3A, the caulking nut 20 is inserted into the mounting hole 11 of the beam body 10, and the flange portion 22 is brought into contact with the outer wall of the beam body 10. In this state, the fastening bolt 30 is inserted from the flange portion 22 side and screwed into the female screw portion 23, and the flange portion 22 is fixed with a caulking tool (not shown) and tightened to tighten the cylindrical body 21. The distal end is drawn toward the inner wall side of the beam main body 10, and the peripheral wall portion 24 formed thinly bulges outward in the radial direction and buckles, so that as shown in FIGS. 25 is formed. When the fastening bolt 30 is further tightened, the wall of the beam main body 10 is clamped between the flange portion 22 and the enlarged diameter portion 25 of the caulking nut 20 and caulked. At this time, a part of the enlarged diameter portion 25 of the swollen caulking nut 20 bites into the protruding portion 12 formed on the inner wall of the beam body 10 and is fixed by being deformed.

  When the exterior beam 100 configured as described above is attached to the vehicle, the biting portion 25a between the enlarged diameter portion 25 of the caulking nut 20 and the projection portion 12 of the beam body 10 functions as a detent, so that the caulking nut 20 is fastened. Co-rotation with the bolt 30 can be reliably prevented, and the exterior beam 100 can be firmly fixed.

Next, an embodiment according to the vehicle exterior beam of the present invention will be described.
As shown in FIG. 5, the step height (step height) of the protrusion 12 is h, the distance from the inner peripheral end of the mounting hole 11 to the end face 13 of the protrusion 12 is w, and Table 1 is used instead of the beam body. Sample pieces 15 having protrusions 12 formed thereon were manufactured under the conditions shown in FIG. 6 and the caulking nuts 20 were fixed to the respective sample pieces 15 to confirm the mounting strength of the caulking nuts 20 fixed to the respective sample pieces 15.
An aluminum alloy plate having a plate thickness of 10 mm and a diameter of the mounting hole 11 of 11.9 mm is used as the sample piece 15, and the steel plate 40 is inserted in a state where the steel plate 40 is overlapped and fixed to each sample piece 15 to which the caulking nut 20 is attached. The fastening bolt 30 inserted from the hole 41 is screwed into the caulking nut 20, and torque is applied to the fastening bolt 30 with a torque wrench 50, so that the caulking nut 20 and the fastening bolt 30 rotate together, or the screw is broken or the fastening bolt 30 is broken. Torque was continued to be applied to the fastening bolt 30 until. The results are shown in Table 1.

“◯” in Table 1 indicates a sample piece in which torque can be continuously applied until screw breakage occurs without occurrence of co-rotation or misalignment. Co-rotation indicates that the fastening bolt 30 and the caulking nut 20 rotate together, and misalignment means that the axial center of the mounting hole 11 of the sample piece 15 and the male screw portion of the caulking nut 20 is displaced, resulting in the fastening bolt. 30 indicates that only halfway can be inserted. In Table 1, a sample piece having a step height h of 0 mm is a flat plate on which no protrusion 12 is formed.
The “step position S” is the distance L from the inner peripheral end of the mounting hole 11 to the maximum bulging end of the enlarged diameter portion 25 of the caulking nut 20 and the distance from the inner peripheral end of the mounting hole 11 to the end surface 13 of the protrusion 12. It represents the ratio to the distance w, and is a value obtained by multiplying w / L by 100. It shows that the projection part 12 is formed away from the attachment hole 11 as the value of the step position S increases. For example, when the step position S is 100, the distance L and the distance w are the same distance, and the enlarged diameter portion 25 of the caulking nut 20 is attached so as not to bite into the protrusion 12. Indicates.

As shown in Table 1, in the case of a flat plate without the protrusion 12 having a step height h of 0 mm, co-rotation occurs. Further, when the step position S is large and the step height h is low, that is, when the amount of biting between the enlarged diameter portion 25 of the caulking nut 20 and the protruding portion 12 of the sample piece 15 is small, co-rotation occurs. It turns out that the function as a stop cannot be obtained. On the other hand, when the step height h is too high, misalignment occurred, and the fastening bolt could not be tightened any further.
When the step position S is 0, that is, when the protrusion 12 is provided in the tangential direction of the mounting hole 11, the protrusion 12 is securely brought into contact with the enlarged diameter portion 25 of the caulking nut 20 and bited. Therefore, it was found that the step height h can be applied in a wide range (0.5 to 3.6 mm), and co-rotation can be prevented in a wide range.
The sample pieces that could be tightened until screw breakage were evaluated as “◯” had a maximum torque of 45 N · m or more, and were firmly fixed.

In addition, this invention is not limited to the thing of the structure of the said embodiment, In a detailed structure, a various change can be added in the range which does not deviate from the meaning of this invention.
In the above-described embodiment, only one protruding protrusion is provided, but a plurality of protruding portions may be provided as shown in FIG. For example, like the beam main body 10A shown in FIG. 6A, a protruding portion 12A may be provided so as to cross the mounting hole 11, and the protruding portion 12A divided into two may be formed. As shown in the beam main body 10B shown in FIG. 5B, the protrusions 12B are formed in the tangential direction on both sides of the attachment hole 11 with the attachment hole 11 being sandwiched, and the protrusions 12B are arranged to face each other via the attachment hole 11. Good. Moreover, it is good also as a structure which provided both the protrusion part 12B extended in the tangential direction of the attachment hole 11, and the protrusion part 12A which crosses the attachment hole 11, like 10C of beam main bodies shown to (c).

In the above embodiment, the case where the vehicle exterior beam is attached to the vehicle has been described. However, the present invention is also used when peripheral components such as a lamp, a license plate, and a harness are attached to the vehicle exterior beam. .
Further, the present invention can be applied not only to a beam main body formed in a rectangular tube shape but also to a beam main body having a C-shaped cross section having no hollow portion, for example.

DESCRIPTION OF SYMBOLS 100 Exterior beam for vehicles 10, 10A, 10B, 10C Beam main body 11 Mounting hole 12, 12A, 12B Protrusion part 13 End surface 15 Sample piece 20 Caulking nut 21 Cylindrical body 22 Flange part 23 Female thread part 24 Peripheral wall part 25 Expanded part 25a Part 30 Fastening bolt 40 Steel plate 41 Insertion hole 50 Torque wrench

Claims (3)

A vehicular exterior formed by fixing the caulking nut to the beam body by buckling the peripheral wall portion of the caulking nut inserted into the mounting hole of the beam body to form a diameter-expanded portion bulging outward in the radial direction. A vehicular exterior beam, characterized in that a projecting portion into which a part of the diameter-enlarged portion of the caulking nut bites in is provided near a mounting hole of the beam body.   The vehicular exterior beam according to claim 1, wherein the protrusion is a ridge along the longitudinal direction of the beam body.   The vehicular exterior beam according to claim 2, wherein the ridge is provided in a tangential direction of the mounting hole.

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