JP2003202012A - Nut fixing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nut fixing structure which reduces a manufacturing cost. <P>SOLUTION: An aluminium side surface AL of a base plate 10 is welded and fixed by polymerizing it on a panel member 100 by calking and fixing a nut 1 on an iron side surface S of the base plate 10 in the nut fixing structure to fix the iron made nut 1 on the aluminium made panel member 100 by interposing the base plate 10 made of a clad material made by polymerizing an aluminium plate and an iron plate by rolling. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nut fixing structure, and more particularly to a nut fixing structure for fixing an iron nut to a panel member made of aluminum.

[0002]

2. Description of the Related Art For example, in a panel member such as a vehicle frame constituting a vehicle body of a vehicle, a nut is previously fixed to the panel member in order to efficiently attach various parts to the panel member when assembling the vehicle body. Is being done. The fixing of the nut is generally performed by welding the nut to the panel member.

On the other hand, recently, lightweight aluminum panel members are often used for body frames and other panel members. Since a nut attached to the panel member is required to have fastening strength by screwing a bolt, an iron nut is generally used even for an aluminum panel member. However, it is difficult to join the iron member and the aluminum member by welding, and it is not possible to directly weld the iron nut to the aluminum panel member.

Therefore, as shown in a sectional view of FIG. 6, for example, an iron nut 112 is attached to an iron base plate 111.
Are welded in advance, and the base plate 111 to which the nut 112 is coupled is fixed to the panel member 100 made of aluminum in which the bolt insertion hole 101 is formed by the rivet 113.

Further, as disclosed in Japanese Patent Laid-Open No. 7-77213 and as shown in FIG. 7, an iron side of a base plate 125 made of a clad material obtained by polymerizing aluminum and iron by rolling and having a bolt insertion hole formed therein. Iron nut 1 on the surface
12 is welded, and an aluminum panel member 1 in which a bolt insertion hole is formed on the surface of the base plate 125 on the aluminum side
No. 00, and the base plate 125 is welded to the panel member 100.

[0006]

However, in the case of the structure shown in FIG. 6, the rivet insertion hole 1 for the rivet 113 formed in the panel member 100 and the base plate 111.
Two operations of drilling 00a and 111a and crimping the rivet 113 are required, and the connecting work is troublesome, the number of parts is large, the manufacturing cost is increased, and the rivet insertion holes 100a and 111a are drilled. Therefore, there is a concern that the corrosion resistance may decrease depending on the part used.

Further, in the case of the structure shown in FIG. 7, since the iron nut 112 is fixed to the iron side surface of the base plate 125 by welding, in addition to the work of forming the bolt insertion hole in the base plate 125, the base plate 1
It is necessary to weld the nut 112 to 25. Therefore, the work process of forming the base plate 125 into a shape attachable to the panel member 100, the base plate 12
5, a work step of welding and fixing the iron nut 112 to the No. 5 and a work step of welding and fixing the base plate 125 to which the nut 112 is attached to the panel member 100 are separately required, resulting in poor productivity and increase in manufacturing cost due to increase in man-hours. Is concerned.

The present invention has been made in view of the above points, and an object of the present invention is to provide a nut fixing structure which can reduce the manufacturing cost.

[0009]

According to the invention of a nut fixing structure as set forth in claim 1 for solving the above problems, an iron nut is made of aluminum by interposing a base plate made of a clad material obtained by polymerizing an aluminum plate and an iron plate by rolling. In the nut fixing structure for fixing to a panel member made of steel, the nut is caulked and fixed to the iron side surface of the base plate, and the aluminum side surface of the base plate is overlapped and fixed to the panel member by welding.

According to the present invention, the nut can be fixed to the base plate together with the press molding of the base plate. Therefore, it is possible to attach the iron nut to the aluminum panel member by the two work steps of press-forming the base plate and fixing the nut to the base plate and welding the base plate to the panel member by welding. it can.

Therefore, the number of working steps can be reduced as compared with the conventional one, the work can be simplified, the productivity can be improved, and the manufacturing cost can be reduced by reducing the man-hours. Further, it is possible to avoid direct contact between the iron pierce nut and the aluminum-side surface of the base plate, prevent occurrence of electrolytic corrosion due to contact between different materials of iron and aluminum, and improve corrosion resistance.

According to a second aspect of the present invention, in the nut fixing structure according to the first aspect, the nut is pressed against the iron side surface of the base plate with a predetermined pressing force to communicate with the threaded hole portion of the nut. Is a pierce nut that is pierced into the base plate and fixed by caulking. According to the present invention, it is possible to form the opening hole in the base plate and fix the nut at the same time during press working. Therefore, the number of man-hours at the time of press working can be reduced, and the work can be simplified and the manufacturing period can be shortened.

According to a third aspect of the present invention, in the nut fixing structure according to the second aspect, the panel member includes a pair of vertical wall portions and a bottom wall portion connecting the opposite end portions of the vertical wall portions. In the case of a V-shaped bracket, the base plate to which the nut is fixed has the aluminum side surface of the base plate overlapped with the inner surface of the bottom wall, and the bolt insertion hole that is predrilled in the bottom wall has an opening hole and a nut. It is characterized in that the screw holes are welded and fixed at a communicating position.

According to a fourth aspect of the present invention, in the nut fixing structure according to the second aspect, the panel member has a pair of vertical wall portions and a bottom wall portion connecting between opposite end portions of the vertical wall portions. In the case of a bracket with a U-shaped cross section, the base plate to which the nut is fixed is placed between the vertical wall parts so as to face the bottom wall part, and the aluminum side surface of the flange-bent end is overlapped with the inner surface of the vertical wall part. Then, the screw hole portion and the opening hole of the nut are welded and fixed so as to be arranged coaxially with the bolt insertion hole of the bottom wall portion.

According to the inventions of claims 3 and 4, the base plate functions as a reinforcing member for the bracket, and the rigidity of the bracket can be improved. Therefore, for example, when a vehicle body underbody component such as a suspension is fixed to the bracket, steering stability can be improved.

According to a fifth aspect of the present invention, in the nut fixing structure according to the fourth aspect, an iron spacer having an insertion hole into which a bolt screwed into the nut is inserted and supported is formed by rolling an aluminum plate and an iron plate. The iron side surface of the phosphorus hose made of the polymerized clad material is pressed with a predetermined pressing force and an opening hole communicating with the fitting hole is formed in the phosphorus hose and fixed by caulking.
The aluminum side surface of the phosphorus hose with the spacer fixed to the iron side surface is overlapped with the inner side surface of the bottom wall by welding and fixed, and the bolt whose tip is screwed into the nut through the bolt insertion hole is supported by the spacer. Is characterized by.

According to the present invention, the bracket is reinforced by the base plate and the phosphorus hose, and its rigidity is further improved. Therefore, the rigidity thereof can be further enhanced as compared with the fourth aspect.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a nut fixing structure according to the present invention will be described with reference to the drawings. Figure 1
2 is a diagram schematically showing the present embodiment, FIG. 2 is a diagram for explaining a method of caulking and fixing the pierce nut 1 to the base plate 10, and FIG. 3 is a process for pressing the base plate 10 into a desired shape. FIG.

The pierce nut 1 has a so-called hexagonal nut shape made of an iron material, and is an opening hole communicating with the screw hole portion 2 when pressed against the surface of the base plate 10 with a predetermined pressing force. 11 has a structure in which 11 is punched in the base plate 10 and fixed by caulking.

In the case of this embodiment, as shown in FIG.
On the fixed end surface 3 of the pierce nut 1, the base plate 10
A cylindrical portion 4 for punching out a circular opening 11 is punched out, and an annular groove 5 for caulking and fixing the pierce nut 1 to the base plate 10 is recessed.

The cylindrical portion 4 projects from the fixed end surface 3 along the axis of the screw hole portion 2, and the wall thickness is gradually increased as it moves to the tip, and the base plate 10 is punched out in cooperation with the die button P2. A shearing edge that pierces the circular opening 11 is provided on the outer peripheral edge of the tip.

The annular groove 5 is the fixed end surface 3 of the pierce nut 1.
Has a dovetail-shaped cross-sectional shape that expands as it moves from the side to the pressing end surface 6 side. As shown in FIG.
The edge portion 11a of the opening hole 11 which is press-fitted and raised by 2 is engaged and fixed by caulking.

The base plate 10 is made of a clad material obtained by polymerizing an aluminum plate and an iron plate by rolling, and is subjected to progressive processing as shown in FIG. In particular,
It is rolled and placed on the roll field R so that it can be pulled out, and is pressed from the roll field R with the aluminum-side surface AL on the lower side and the iron-side surface S on the upper side by a transport device (not shown). It is pulled out to the field P. Then, it is sequentially pressed by a progressive die (not shown) in the press field P, press-molded into a desired shape, and then carried out from the press field P.

In the press field P, the pierce nut 1 is attached simultaneously with the pressing. As shown in FIG. 2, a punch P1 for pressing the pierce nut 1 against the lower press die against the base plate 10 with a predetermined pressing force is provided in the press upper die of the press working machine (not shown). A die button P2 is provided on the lower press die at a position facing the punch P1.

When the base plate 10 is placed at the predetermined press working position, the press upper die is lowered to punch P1.
The pierce nut 1 above the base plate 10,
That is, the iron side surface S is pressed with a predetermined pressing force.

When the pierce nut 1 is pressed against the base plate 10 by the punch P1, the cylindrical portion 4 of the pierce nut 1 and the die button P2 cooperate with each other to punch the base plate 10 to form the opening hole 11. And
The edge portion 11a of the opening hole 11 is press-fitted into the annular groove 5 by the die button P2 and is raised and engaged. Therefore, the pierce nut 1 is caulked and fixed to the base plate 10. Further, in the annular groove 5, the aluminum side surface AL of the end edge portion 11a and the pierce nut 1 are arranged so as to be separated from each other, and the aluminum side surface AL and the pierce nut 1 are not in direct contact with each other.

When the base plate 10 is press-formed into a desired shape in the press field P and the pierce nut 1 is attached, the base plate 10 is carried out from the press field P, and the base plate 10 shown in FIG.
As shown in FIG. The attachment of the base plate 10 to the panel member 100 is performed by spot welding the overlapping portion of the base plate 10 and the panel member 100 in a state where the aluminum side surface AL of the base plate 10 is overlapped with the panel member 100. In this way, the pierce nut 1 which is a fastener made of iron is fixed to the panel member 100 made of aluminum. It should be noted that the bolt insertion hole 101 preliminarily formed in the panel member 100 has an inner diameter into which the cylindrical portion 4 can be inserted.

According to the nut mounting structure of this embodiment,
The pierce nut 1 can be fixed to the base plate 10 at the same time when the base plate 10 is press-molded. Therefore, by the two work processes of the work process of press-molding the base plate 10 and fixing the pierce nut 1, and the work process of welding and fixing the base plate 10 on which the press-molding and fixing the pierce nut 1 is performed to the panel member 100. The pierce nut 1 made of iron can be attached to the panel member 100 made of aluminum. Therefore, it is possible to reduce the number of working steps as compared with the related art, the work can be simplified, the productivity can be improved, and the manufacturing cost can be reduced by reducing the number of steps. In addition, the surface A of the pierce nut 1 made of iron and the aluminum side of the base plate 10
Since L does not directly abut, it is possible to prevent the occurrence of electrolytic corrosion due to the contact between different materials of iron and aluminum, and to improve the corrosion resistance.

4 and 5 show a concrete example of the nut mounting structure in the above embodiment.
FIG. 4 shows a structure in which an iron nut for mounting a member such as a bumper beam is fixed to the front end of a main beam 12 which constitutes a body frame made of aluminum. As shown in FIG. 4 (A), the main beam 12 has a U-shaped cross section and a shape extending in the front-rear direction of the vehicle body. At its front end, a mirror surface portion 13 made of an aluminum plate is provided. It is provided. Then, as shown in FIG. 4B which is a cross section taken along line XX of FIG. 4A, the end portion of the mirror surface portion 13 is flange-bent and spot welded in a state of being overlapped with the inner surface of the main beam 12. It is fixed by.

The phosphorus hose 15 constituted by the base plate 10 is fixed to the inner side surface of the mirror surface portion 13 by spot welding in a state where the aluminum side surface AL is superposed on the inner side surface of the mirror surface portion 13. In addition, a phosphorus hose 15 is provided on the inner surface of the mirror surface portion 13 that is flange-bent.
Are fixed by welding in a state where the end portions of are overlapped. The pierce nut 1 is fixed to the iron-side surface S of the phosphorus hose 15. The pierce nut 1 is fixed so that the screw hole portion 2 of the pierce nut 1 and the opening hole 16 formed by the pierce nut 1 communicate with a through hole 14 that is predrilled in the mirror surface portion 13.

As a result, the aluminum main beam 12
On the other hand, the pierce nut 1 which is a fastener made of iron can be fixed. Therefore, a member such as a bumper beam can be securely fixed to the vehicle body frame. Moreover, the main beam 12 can be reinforced by the phosphorus hose 15, and the mounting rigidity can be improved.

FIG. 5 shows a nut fixing structure for attaching a member such as a suspension to the aluminum bracket 20.

The bracket 20 has a U-shaped cross section, and both ends thereof are fixed by welding to a body frame (not shown). The phosphorus hose 22 constituted by the base plate 10 is fixed to the inner surface of the bottom wall portion 21 of the bracket 20 by spot welding in a state where the aluminum-side surface AL is overlapped with the inner surface of the bottom wall portion 21. .

The end of the phosphorus hose 22 is flange-bent, and its aluminum side surface AL is fixed by spot welding in a state of being superposed on the inner side surface of the vertical wall portion 23 of the bracket 20. On the iron side surface S of the phosphorus hose 22,
An iron spacer 30 is fixed. Spacer 30
Has a disc shape having a fitting hole 31 into which a bolt 33 described later can be inserted and supported, and the fitting hole 31 is preliminarily drilled in the opening hole 24 formed in the phosphorus hose 22 and the bottom wall portion 21. It is fixed so as to communicate with the through hole 25.

Although not particularly shown in the drawings, the spacer 30 includes the cylindrical portion 14 and the annular groove 15 of the pierce nut 10 described above.
Has a cylindrical portion and an annular groove similar to the above in the fixed end surface 32,
It is fixed to the phosphorus hose 22 in the same manner as the pierce nut 1 during the progressive processing of the phosphorus hose 22.

A retainer 26 formed by the base plate 10 is provided inside the bracket 20.
The aluminum side surface AL of the flange-bent end of the retainer 26 is welded and fixed to the inner side surface of the vertical wall portion 23, which is disposed between the vertical wall portions 23 and faces the bottom wall portion 21 of the bracket 20. The pierce nut 1 is fixed to the iron-side surface S of the retainer 26. The pierce nut 1 has an opening hole 2 formed when the screw hole 2 and the retainer 26 are fixed.
7 is fixed so as to be arranged coaxially with the fitting hole 31 of the spacer 30.

The iron bolt 33 is fitted and supported from the bottom wall portion 21 side into the fitting hole 31 of the spacer 30 through the through hole 25, and the tip thereof is screwed into the pierce nut 1 fixed to the retainer 26. A member 34 such as a suspension is clamped and fixed to the bracket 20.

According to the structure shown in FIG. 5, the iron pierce nut 1 for mounting the iron bolt 33 on the aluminum bracket 20 is fixed, and the iron bolt 33 is fixed.
An iron spacer 30 for supporting the is fixed. Therefore, the member 34 such as the suspension can be securely fixed to the bracket 20, and the steering stability of the vehicle can be improved. Also, the phosphorus hose 22
Thus, the bracket 20 can be reinforced, and its mounting rigidity can be improved.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in the above embodiment, the pierce nut 1 is used to simultaneously form and attach the opening hole 11 to the base plate 10. However, for example, the opening hole 11 is formed in the previous pressing step in the press field. However, the nut may be caulked and fixed in the next pressing step.

[0040]

As described above, according to the nut fixing structure of the present invention, the pierce nut can be fixed to the base plate together with the press forming of the base plate. Therefore, the work process of attaching the iron nut to the aluminum panel member, the work process of press-molding the base plate and fixing the pierce nut, and the base plate 10 after the press-molding and fixing of the pierce nut 1 are performed.
Can be two of the work steps of welding and fixing to the panel member 100. Therefore, it is possible to reduce the number of working steps as compared with the related art, the work can be simplified, the productivity can be improved, and the manufacturing cost can be reduced by reducing the number of steps. Further, it is possible to avoid direct contact between the iron pierce nut and the aluminum-side surface of the base plate, prevent occurrence of electrolytic corrosion due to contact between different materials of iron and aluminum, and improve corrosion resistance.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing the present embodiment.

FIG. 2 is a diagram illustrating a method of caulking and fixing a pierce nut to a base plate.

FIG. 3 is a diagram illustrating a processing step of pressing a base plate into a desired shape.

FIG. 4 shows a specific example of a nut fixing structure.

FIG. 5 shows a specific example of a nut fixing structure.

FIG. 6 is a diagram illustrating a conventional technique.

FIG. 7 is a diagram illustrating a conventional technique.

[Explanation of symbols]

1 piercing nut 2 screw holes 10 base plate 11 open holes 100 panel members P1 punch P2 processing die

Claims (5)

[Claims] 1. In a nut fixing structure for fixing an iron nut to an aluminum panel member with a base plate made of a clad material obtained by polymerizing an aluminum plate and an iron plate interposed, a nut fixing structure is provided on the iron side surface of the base plate. A nut fixing structure characterized in that the aluminum side surface of the base plate is superposed on the panel member and fixed by welding by caulking and fixing. 2. The pierce is fixed to the base plate by caulking and fixing an opening hole communicating with a threaded hole portion of the nut by pressing the iron side surface of the base plate with a predetermined pressing force. The nut fixing structure according to claim 1, wherein the nut fixing structure is a nut. 3. The base plate, to which the nut is fixed, when the panel member is a bracket having a U-shaped cross section, the bracket having a pair of vertical wall portions and a bottom wall portion connecting between opposed ends of the vertical wall portions. At the position where the aluminum side surface of the base plate is superposed on the inner side surface of the bottom wall portion, and the opening hole and the screw hole portion of the nut communicate with the bolt insertion hole pre-drilled in the bottom wall portion. The nut fixing structure according to claim 2, which is fixed by welding. 4. The base plate, to which the nut is fixed, when the panel member is a bracket having a U-shaped cross section, the bracket having a pair of vertical wall portions and a bottom wall portion connecting between opposed ends of the vertical wall portions. Is disposed facing the bottom wall portion between the vertical wall portions, the aluminum side surface of the flange-bent end portion is overlapped with the inner side surface of the vertical wall portion, and the screw hole portion and the opening hole of the nut are The nut fixing structure according to claim 2, wherein the nut fixing structure is welded and fixed so as to be arranged coaxially with the bolt insertion hole of the bottom wall portion. 5. An iron spacer having a fitting hole into which a bolt to be screwed into the nut is fitted and supported is pressed against an iron-side surface of a phosphorus hose made of an aluminum plate and a clad material obtained by polymerizing the iron plate by rolling. An opening hole communicating with the fitting hole is formed by punching in the phosphorus hose and fixed by caulking, and the aluminum side surface of the phosphorus hose having the spacer fixed to the iron side surface is an inner surface of the bottom wall portion. 5. The nut fixing structure according to claim 4, wherein the spacer is supported by a bolt whose tip is screwed to the nut through the bolt insertion hole and is welded and fixed to the nut.