JP2003305530A - Method and apparatus for riveting and bond structure by riveting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the generation of cracks on a sheet material by applying adhesives. <P>SOLUTION: An outer peripheral wall 10 of a die groove 8 is an opened shape by a groove 9 retreated in the radius direction outside at a plurality of places and at the time of riveting, the sheet material W2 of the portion opened to the groove 9 of the outer peripheral wall 10 is partially diameter- expanded by the tip end of the shank 3 of the rivet to partly enlarge the space in which adhesives W3 are applied and adhesives W3 in the rest space not diameter-expanded are made to flow to the expanded space. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rivet driving of a self-piercing rivet which is inserted into a sheet material without being completely penetrated so that a deformed front end portion is covered with a raised portion of the sheet material. More particularly, the present invention relates to a rivet driving method, a rivet driving device, and a rivet coupling structure suitable for fastening a sheet material with an adhesive interposed.

[0002]

2. Description of the Related Art Conventionally, a rivet driving method, a rivet driving device, and a rivet coupling structure of this type have been known. For example, Japanese Patent Laid-Open No. 8-505087.
Some are disclosed in Japanese Patent Publication.

In this method, a rivet shaft portion having a cylindrical shaft portion and a head portion is pushed into two sheet materials that are stacked and clamped on a die, and the sheet material with the shaft portion in front is placed on the die side. The sheet material is penetrated while being deformed, and the diameter of the shaft portion is expanded from the tip end on the die side so that both sheet materials are fastened without completely penetrating. The tip of the deformed shaft of the rivet is in a state of being wrapped by the ridge on the die side of the sheet material.

[0004]

By the way, when joining sheet materials made of different materials such as steel and aluminum,
In order to prevent electrolytic corrosion of the sheet material due to infiltration of water or the like into the boundary surface of the joint portion, an adhesive agent is interposed between both sheet materials or a coating film is formed by resin coating.

However, in the above conventional example, FIG.
As shown in (A), the annular setter 111 and the clamping surfaces 106, 1 of the die 105 are set prior to the rivet setting.
At 13, the sheet materials W1 and W2 are clamped and brought into contact with each other. During this clamping, the annular clamping surfaces 106, 1
Since the sheet materials W1 and W2 are clamped at 13, the adhesive W3 between the sheet materials W1 and W2 is an annular clamp surface W.
1, W2 is confined in the inner peripheral portion, and the adhesive reservoir W30
Is in the state of making.

The adhesive reservoir W30 is a sheet material W.
When the plate thicknesses of 1 and W2 are relatively thin, or in order to prevent sagging after coating, they are relatively high in viscosity and are likely to occur in a vehicle body adhesive which is cured by heating in a coating oven in a coating process.

Thus, when the rivet 101 is pushed in while the adhesive W3 is confined, the pressure increase of the accumulated adhesive W3 causes the die side sheet material W2 to extend excessively, resulting in cracking. I have something to do. In particular, when the sheet material W2 on the die 105 side is a light metal material such as aluminum having a small elongation, the occurrence of cracks becomes remarkable.

The cracks could not prevent the infiltration of moisture, so that they caused the electrolytic corrosion of the sheet materials W1 and W2, the fatigue strength (durability) was lowered, and the appearance was not good.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a rivet driving method, a rivet driving device, and a rivet coupling structure which can suppress the occurrence of cracks even though an adhesive is interposed. .

[0010]

SUMMARY OF THE INVENTION A first invention is a self-piercing rivet driving method for a pair of sheet materials with an adhesive interposed, and a bulging portion formed by driving is not formed in the sheet material surface direction. The feature is that the diameter is expanded uniformly.

A second aspect of the invention is characterized in that, in the first aspect of the invention, the non-uniform diameter expansion of the bulging portion in the sheet material surface direction is performed at equal angular intervals in the circumferential direction.

According to a third aspect of the invention, in a self-piercing rivet driving device for a pair of sheet materials in which an adhesive is interposed, the outer peripheral wall of the die groove is opened at a plurality of locations by grooves that recede radially outward. It is characterized by having a different shape.

The groove may be a partial groove whose inner end is opened only on the outer peripheral wall of the die groove or a continuous groove whose inner and outer ends are opened.

In a fourth aspect based on the third aspect, the grooves are arranged at equal angular intervals in the circumferential direction.

A fifth aspect of the invention is characterized in that, in the third aspect of the invention, the groove is a continuous groove having open inner and outer ends.

According to a sixth aspect of the present invention, in a joining structure of a pair of sheet materials with an adhesive layer interposed therebetween by a self-piercing rivet, the outer diameter of the bulging portion formed by driving is unevenly expanded. It is characterized by

[0017]

Therefore, according to the first aspect of the invention, in the self-piercing rivet driving method for a pair of sheet materials with an adhesive interposed, the bulging portions formed by the driving are uneven in the sheet material surface direction. Since the diameter of the sheet material is increased, the adhesive agent interposed between the sheet materials flows to the enlarged diameter portion, the adhesive agent in the gap between the remaining sheet materials can be made thin and uniform, and cracking of the sheet material can be prevented.

In the second invention, in addition to the effect of the first invention, the uneven expansion of the bulging portion in the sheet material surface direction is made at equal angular intervals in the circumferential direction. The adhesive layer can be thinly and uniformly formed in the circumferential direction of the rivet, and the quality of the joint can be stabilized.

According to the third aspect of the invention, in a self-piercing rivet driving device for a pair of sheet materials with an adhesive interposed, since the outer peripheral wall of the die groove is opened at a plurality of points, the rivet driving is performed. The sheet material that abuts on the open portion of the outer peripheral wall can be further outwardly expanded and deformed, and is partially expanded in diameter by the tip of the shaft portion of the rivet. Due to this partial diameter expansion, the space where the adhesive between the sheet materials exists is partially expanded, and the flow of the adhesive to the diameter expanded portion of the residual space that is not expanded is allowed, and the space between the sheet materials The adhesive in the gap can be made thin and uniform, and cracks in the sheet material can be prevented.

In the fourth invention, in addition to the effect of the third invention, since the grooves are arranged at equal angular intervals in the circumferential direction, the adhesive flows to the radially expanded portion where the adhesive is evenly arranged. snow,
The adhesive layer can be thinly and uniformly formed in the circumferential direction of the rivet, and the quality of the joint can be stabilized.

In the fifth invention, in addition to the effect of the third invention, the groove is formed by a continuous groove whose inner and outer ends are open.
At the time of clamping, the adhesive between the sheet materials at the portion corresponding to the die groove is caused to flow to the outer peripheral side of the portion abutting the die through the portion corresponding to the groove, and the adhesive is applied between the sheet materials at the portion corresponding to the die groove. It does not form a pool. Therefore, the adhesive in the gap between the sheet materials obtained by the third invention can be made thin and uniform, and the effect of preventing cracks in the sheet material can be further improved.

According to the sixth aspect of the invention, the outer diameter of the bulging portion formed by driving is unevenly expanded in the joining structure of the pair of sheet materials with the adhesive layer interposed therebetween by the self-piercing rivet. The adhesive agent interposed between the sheet materials flows to the enlarged diameter portion, the adhesive agent in the gaps between the remaining sheet materials can be made thin and uniform, and the sheet material can be prevented from cracking.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION A rivet setting device according to an embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the rivet 1 of this embodiment has a head portion 2 and a hollow shaft portion 3 extending from the lower surface of the head portion 2.
It is a self-piercing hollow rivet (also called self-piercing rivet). The head 2 and the shaft 3 of the rivet 1 are circular in shape. The tip of the shaft portion 3 is formed into a tapered taper 4, and the diameter of the shaft portion 3 is expanded from the tip as it is driven.

As shown in FIG. 2, the die 5 of the rivet driving device of the present embodiment has an annular clamp surface 6 that comes into contact with the sheet material to be fastened from the time of clamping, and a radial inner surface of the clamp surface 6. And a central portion thereof serves as a protrusion 7 and a die groove 8 is formed between the clamp surface 6 and the die surface.

The annular portion forming the clamp surface 6 is
As shown in FIG. 3, a plurality of grooves 9 are formed so as to traverse the annular portion in the radial direction at equal angular intervals, every 90 degrees in the illustrated example, and the inner peripheral end of each groove 9 is open to the die groove 8. . Therefore, in FIG. 4 showing a cross section taken along the line AA of the die 1 not including the groove 9, the outer periphery of the die groove 8 is closed by the outer peripheral wall 10 formed by the annular portion forming the clamp surface 6. On the other hand, in FIG. 5 showing a cross section of the die 1 including the groove 9 taken along the line BB, the outer peripheral side of the die groove 8 is the groove 9
It is open to the public.

Next, the operation of this embodiment will be described.

In this embodiment, the rivet 1 is pushed in through the steps shown in FIGS. 6A, 6B and 7A, 7B. FIG. 6 (A) shows a set state of sheet materials, in which two sheet materials W1 and W2 with an adhesive W3 (or an adhesive layer W3) interposed are brought into contact with the clamping surface 6 of the die 5, An annular setter 11 and a punch 12 having the rivet 1 held at the tip thereof are arranged inside the setter 11 so as to face the die 5.

The adhesive W3 is, for example, a rubber-based or epoxy-based adhesive generally used as an anticorrosion-use vehicle adhesive and has a viscosity of about 2000 to 3000 poise at 20 ° C.

Next, as shown in FIG. 6B, the setter 11 is advanced to the die 5 side, and its tip clamping surface 13 is moved.
The sheet materials W1 and W2 are sandwiched and clamped by and the clamping surface 6 of the die 5. In this state, the sheet materials W1 and W
2 is sandwiched in an annular shape between the setter 11 and the clamping surfaces 6 and 13 of the die 5, and the adhesive W3 interposed between the sheet materials W1 and W2 is not clamped by the annular clamping surfaces 6 and 13 on the inner and outer peripheral sides. The ejected sheet materials W1 and W2 contact each other in an annular shape. The adhesive W3 on the inner peripheral side is the clamping surface V
The pressure increases with the pressing force of I and 13. Here, in the die 5 of this embodiment, radial grooves 9 are provided on the clamp surface 6 at equal angular intervals. For this reason, the adhesive W1 on the inner peripheral side where the pressure rises causes the adhesive W3 to flow from the portion where the contact between the sheet materials W1 and W2 in which the groove 9 is arranged is weak to the outer peripheral side of the clamp surfaces 6 and 13. Allow it and let it flow out as shown by the arrow in the figure. Therefore, the clamp surface 6,
Adhesive W between the sheet materials W1 and W2 surrounded by 13
The confinement amount of 3 can be reduced.

Next, as shown in FIG. 7 (A), the punch 12 is moved forward to push the shaft portion 3 of the rivet 1 held therein into the sheet materials W1 and W2 sequentially from the tip. The sheet materials W1 and W2 are pushed to the die 5 side by the shaft portion 3 and are deformed while being restrained by the die groove 8 on the die 5 side to form the bulging portion W4.

Next, as shown in FIG. 7B, the shaft portion 3 of the rivet 1 penetrates the sheet material W1 on the punch 12 side,
The head 2 of the rivet 1 is pushed into the sheet material W1 by the punch 12 and enters the sheet material W2 on the side of the die 5, and the bulging portion W4 follows the die groove 8 to complete the driving of the rivet 1.

FIGS. 8A to 8C show details of the state of the rivet 1 entering the sheet materials W1 and W2 in the section including the groove 9 of the die 5 in the initial (A), middle (B) and It is shown separately for the final stage (C). In the initial state (FIG. 8A), the shaft portion 3 of the rivet 1 presses the sheet materials W1 and W2 against the projections 7 of the die groove 8, and the tip of the shaft portion 3 enters the sheet material W1 on one side. Is shown. In this state, the adhesive layer W3 between the sheet materials W1 and W2 is still continuous.

In the middle period (FIG. 8B), the shaft portion 3 of the rivet 1 penetrates the sheet material W1 on one side, and the adhesive layer W
3 shows a state of penetrating 3 and entering the other sheet material W2. The back surface of the other sheet material W2 is pressed against the die surface 8, and the shaft portion 3 has a diameter-expanded tip. As the diameter of the shaft portion 3 increases, the portion of the sheet material W2 on the die 5 side where the shaft portion 3 enters is also pushed outward in the radial direction. By this expansion, the thickness of the gap on the outer peripheral side of the shaft portion 3 where the adhesive W3 exists between the sheet materials W1 and W2 gradually increases.

At the end (FIG. 8C), the die 5
The outer diameter of the side sheet material W2 is pressed against the outer peripheral wall 10 of the die groove 8 to prevent its diameter expansion, and the tip of the shaft portion 3 of the rivet 1 to be pressed in one side expands along the die groove 8. Since the diameter of the shaft portion 3 also expands the corresponding portion of the punch side sheet material W2 through which the shaft portion 3 penetrates, the adhesive W3 between the sheet materials W1 and W2 on the outer peripheral side of the shaft portion 3 exists. The thickness of the gap is reduced.

On the other hand, in the portion where the outer peripheral wall 10 of the die groove 8 is removed due to the existence of the groove 9, as shown in the drawing,
The outer deformation of the sheet material W2 on the die 5 side is allowed,
The thickness of the gap where the adhesive W3 exists between the sheet materials W1 and W2 is increased.

Therefore, the adhesive W3 in the gap in the portion without the groove 9 flows into the gap in which the thickness of the groove 9 is increased,
The rise of the internal pressure of the adhesive W3 is moderated and suppressed, and a thin and uniform adhesive layer W3 is formed as a whole. In the figure, W4 indicates the bulging portion.

FIG. 9 shows the sheet materials W1 and W in the portion having the groove 9.
2 is a cross-sectional view of FIG. 2, and FIG.
1 and W2 are cross-sectional views, respectively. In FIG. 9, on the outer peripheral side of the shaft portion 3 of the rivet 1, the outer peripheral side of the sheet material W2 on the die 5 side is changed from the state shown by the dotted line to the solid line shown in FIG.
The diameter is increased at the portion where the groove 9 is present, and this diameter increase increases the thickness of the adhesive layer W3. This increase in the thickness of the adhesive layer W3 suppresses an increase in the internal pressure of the adhesive W3, and the adhesive layer W3 in the portion without the groove 9 becomes a thin and uniform adhesive layer W3 as shown in FIG. Therefore, the occurrence of cracks in the sheet material W2 on the die 5 side is suppressed.

By the way, in the conventional example where the clamp surface 6 does not have the groove 9, the adhesive W3 has ring-shaped clamp surfaces 106 and 113 in the clamped state shown in FIG. 13 (A).
The rivet 101 is struck by pushing the rivet 101 in the state where the adhesive reservoir W30 is present in the state where the adhesive reservoir W30 is formed in the rivet driving state shown in FIG. 13B. Due to the edge of the shaft portion 103 of the
It is divided into 1 and W32. Then, as shown in FIG. 14, when the rivet 1 is completely driven in, the outer peripheral side of the sheet material W3 on the die 105 side is prevented from being deformed outward by the outer peripheral wall 110 of the die groove 108. For this reason, the internal pressure of the adhesive in the adhesive reservoir W30 is extremely increased while being restrained in the die groove 108, and a crack S is generated on the thinned surface side of the sheet material W2.

FIG. 11 shows a modified example of this embodiment. In the die of FIGS. 2 to 5, four grooves 9 are arranged on the clamp surface 6 every 90 degrees. In this example, four grooves 9 are further added, and eight grooves 9 are arranged at equal angular intervals. Therefore, the adhesive of the thin adhesive layer W3 is effectively flowed to the thicker adhesive layer W3 arranged closer to the adhesive layer W3, so that the pressure increase of the adhesive W3 is further suppressed and the thin and uniform adhesive layer is formed. W3
It is possible to prevent cracks from occurring and stabilize the quality of the joint.

FIG. 12 shows another modification of the present embodiment, in which the groove 9 provided in the clamp surface 6 is provided with a groove 9.
Is not provided across the inner and outer circumferences, but only on the inner circumference side.
A is provided and can be operated in the same manner as in each of the above-described embodiments, and since the clamp surface 6 can be formed in a ring shape, the strength of the die 5 can be improved.

In this embodiment, the following effects can be obtained. That is, in the punching rivet driving method for the pair of sheet materials W1 and W2 with the adhesive W3 interposed, the bulging portion W formed by driving.
In order to make the spread of the sheet materials W1 and W2 of No. 4 in the surface direction non-uniform by expanding the diameter of the portion having the groove 9 with respect to the portion having no groove 9.
The adhesive W3 interposed between the sheet materials W1 and W2 flows to the enlarged portion, and the adhesive W3 in the gap between the remaining sheet materials W1 and W2 can be made thin and uniform, and the cracks in the sheet materials W1 and W2. Can be prevented.

Since the expansion of the bulging portion W4 is expanded at equal angular intervals in the circumferential direction, the layer of the adhesive W3 can be thinly and uniformly formed in the adhesive W4 in the circumferential direction of the rivet 1K, and the quality of the joint is stable. Can be realized.

In the rivet driving device, since the outer peripheral wall 10 of the die groove 8 has a shape opened at a plurality of points, the sheet material W2 that abuts on the opened part of the outer peripheral wall 10 at the time of rivet driving is outward. Further deformation is possible, and the diameter of the rivet 1 is partially expanded by the tip of the shaft portion 3. Due to this partial diameter expansion, the gap in which the adhesive W3 exists between the sheet materials W1 and W2 is partially expanded, and the flow of the adhesive W3 in the remaining space that is not expanded is permitted to the expanded diameter portion, and The adhesive W3 in the gap between the partial sheet materials W1 and W2 can be made thin and uniform, and cracking of the sheet material W2 can be prevented.

Since the grooves 9 are arranged at equal angular intervals in the circumferential direction, the adhesive W3 flows to the radially expanded portion where the adhesive W3 is evenly arranged, and the adhesive W3 is applied in the circumferential direction of the rivet 1.
Can be formed thinly and uniformly, and the quality of the joint can be stabilized.

In the case of the continuous groove 9 shown in FIGS. 2 and 3 in which the inner and outer ends of the groove 9 are open, the adhesive W3 between the sheet materials W1 and W2 at the portion corresponding to the die groove 8 is diced during clamping. 5 is made to flow to the outer peripheral side of the portion abutting 5 through the portion corresponding to the groove 9, and no pool of adhesive W3 is formed between the sheet materials W1 and W2 in the portion corresponding to the die groove 8. Therefore, the obtained sheet materials W1 and W
The adhesive W3 in the gap between the two can be made thin and uniform, and the sheet material W
The effect of preventing the crack of No. 2 can be further improved.

Moreover, in the joint structure by the rivet 1 of the present embodiment, the bulging portion W4 formed by driving in
Since the outer diameter of the sheet is expanded nonuniformly, the sheet materials W1 and W2
The adhesive W3 interposed therebetween flows to the expanded diameter portion,
The adhesive W3 in the gap between the remaining sheet materials W1 and W2 can be made thin and uniform, and cracking of the sheet material W2 can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective view showing a rivet according to an embodiment of the present invention.

FIG. 2 is a perspective view of a die of a rivet driving device according to an embodiment of the present invention.

FIG. 3 is a plan view of the die shown in FIG.

4 is a cross-sectional view taken along the line AA of the die in FIG.

5 is a cross-sectional view of the die of FIG. 3 taken along the line BB.

FIG. 6 shows the rivet setting step of the present embodiment (A),
Sectional drawing which divides and shows to (B).

FIG. 7 is a cross-sectional view showing the rivet driving step following FIG. 6 of the present embodiment, divided into (A) and (B).

FIG. 8 is a cross-sectional view showing the deformation process of the sheet material in the rivet driving step divided into (A) to (C).

FIG. 9 is a cross-sectional view showing a distribution state of the adhesive in a portion where a groove is present on the outer peripheral wall of the die groove at the end of rivet driving.

FIG. 10 is a cross-sectional view showing the distribution state of the adhesive in the portion where the groove does not exist on the outer peripheral wall of the die groove at the end of rivet driving.

FIG. 11 is a plan view showing a modified example of the die of the rivet setting device according to the first embodiment of the present invention.

FIG. 12 is a perspective view showing another modified example of the die of the rivet setting device according to the first embodiment of the present invention.

FIG. 13 is a sectional view showing a rivet driving step in a conventional example, which is divided into (A) and (B).

FIG. 14 is a cross-sectional view of a sheet material and rivets at the end of driving a rivet in a conventional example.

[Explanation of symbols]

W1, W2 sheet material W3 adhesive (adhesive layer) W4 bulge 1 rivet 2 heads 3 shafts 4 taper 5 dice 6,13 Clamping surface 7 Projection 8 die groove 9 grooves 10 Outer wall 11 setters 12 punches

Claims (6)

[Claims] 1. A method of driving a self-piercing rivet into a pair of sheet materials with an adhesive interposed, wherein a bulging portion formed by the driving is unevenly expanded in the sheet material surface direction. Rivet driving method. 2. The rivet driving method according to claim 1, wherein the non-uniform expansion of the bulging portion in the sheet material surface direction is performed at equal angular intervals in the circumferential direction. 3. A self-piercing rivet driving device for a pair of sheet materials with an adhesive interposed, wherein the outer peripheral wall of the die groove is opened at a plurality of locations by grooves that recede radially outward. A rivet setting device characterized in that 4. The rivet setting device according to claim 3, wherein the grooves are arranged at equal angular intervals in a circumferential direction. 5. The rivet setting device according to claim 3, wherein the groove is a continuous groove having open inner and outer ends. 6. A rivet characterized in that a bulging portion formed by driving is unevenly expanded in a joint structure by a self-piercing rivet of a pair of sheet materials with an adhesive layer interposed. Bond structure.