CN114603075A - Method for connecting ultrahigh-strength steel and aluminum alloy by using self-piercing riveting technology - Google Patents

Abstract

The invention relates to a method for connecting ultra-high-strength steel and aluminum alloy using self-piercing riveting technology, comprising: 1) drilling a through hole in the to-be-riveted part of the ultra-high-strength steel plate, and the diameter of the through hole is the same as the outer diameter of the rivet; 2) drilling the hole The ultra-high-strength steel plate and the aluminum alloy plate are stacked together, and the ultra-high-strength steel plate is located above the aluminum alloy plate, and then clamped with a clamp; 3) Align the rivet with the through hole on the ultra-high-strength steel plate, and use a nail gun to punch riveting , After the rivet passes through the through hole on the ultra-high-strength steel plate, the tail structure expands and penetrates or passes through the lower aluminum alloy plate, and forms a firm riveting point. The invention adopts the method of drilling holes on the ultra-high-strength steel plate to solve the problem that the rivet is difficult to pierce the ultra-high-strength steel plate in the SPR technology, and can cooperate with welding or gluing to improve the joint strength, and finally obtain a steel-aluminum mixed material with excellent mechanical properties; the method is simple; Easy to implement and low cost to implement.

Description

A method of using self-piercing riveting technology to connect ultra-high strength steel and aluminum alloy

technical field

The invention relates to the technical field of connection of dissimilar materials, in particular to a method for connecting ultra-high-strength steel and aluminum alloy using self-piercing riveting technology.

Background technique

With the increasing emphasis on automobile safety in today's society, the comprehensive performance requirements for body materials are also constantly improving, and it is difficult for a single-material body to meet the market demand. The body made of pure steel has high strength, low manufacturing cost, and mature processing technology, but it has a heavy weight and low rigidity. The body made of pure aluminum has light weight and high rigidity, but the body strength is not high, and the processing cost and maintenance cost are high.

In order to meet the requirements of excellent comprehensive performance and moderate cost of the car body, multi-material hybrid car bodies have emerged. A multi-material hybrid body is a combination of aluminium, high-strength or ultra-high-strength steel, magnesium, plastics, and composite materials where applicable, in the sense of using the best materials for the proper function on the one hand. (eg drivability, safety or fuel efficiency), on the other hand refers to the overall cost-effectiveness of lightweight design.

Common dissimilar material connection methods include SPR (self-piercing riveting technology), RESW (resistance spot welding technology), FDS (flow drill screw technology), etc. Among these methods, SPR technology has been widely used in automotive material connection processes, including It has applications in various structures including body-in-white, four doors and two covers, and has a series of advantages such as high joint strength, small stress concentration, and excellent fatigue performance, and can be connected to steel, aluminum, titanium, magnesium, copper, carbon fiber, etc. Various structural materials.

The current SPR self-piercing riveting process is mainly used to connect mild steel such as deep-drawing steel and aluminum alloys, but in the steel-aluminum hybrid body, the application of high-strength cold-rolled steel and hot-formed steel with higher strength and hardness is more popular. Therefore, the connection between ultra-high-strength steel plates and aluminum materials has attracted people's attention. The rivets used in the existing SPR technology are difficult to penetrate the ultra-high-strength steel plates, and have high limitations in practical applications.

SUMMARY OF THE INVENTION

The invention provides a method for connecting ultra-high-strength steel and aluminum alloy by using self-piercing riveting technology. The method of drilling holes on ultra-high-strength steel plates solves the problem that rivets are difficult to pierce ultra-high-strength steel plates in SPR technology. Bonding improves the strength of the joint, and finally obtains a steel-aluminum hybrid material with excellent mechanical properties; the method is simple and easy to implement, and the implementation cost is low.

In order to achieve the above object, the present invention adopts the following technical solutions to realize:

A method for connecting ultra-high-strength steel and aluminum alloy using self-piercing riveting technology, comprising the following steps:

1) Drill through holes in the parts to be riveted of the ultra-high-strength steel plate, and the diameter of the through holes is the same as the outer diameter of the rivet;

2) Stack the drilled ultra-high-strength steel plate and the aluminum alloy plate together, the ultra-high-strength steel plate is located above the aluminum alloy plate, and then clamp it with a clamp;

3) Align the rivet with the through hole on the ultra-high-strength steel plate, and use a nail gun to punch the rivet. After the rivet passes through the through-hole on the ultra-high-strength steel plate, the tail structure expands and penetrates or passes through the lower aluminum alloy plate, forming a solid riveting point.

The rivet is made of high-strength steel or high-alloy steel.

After riveting, the joint strength is strengthened by welding between the rivet head and the ultra-high-strength steel plate; the rivet is made of low-alloy steel, and the tail of the rivet passes through the lower aluminum alloy plate.

The welding includes laser welding, argon arc welding and brazing.

The head of the rivet and the ultra-high-strength steel plate are glued to strengthen the joint strength.

Compared with the prior art, the beneficial effects of the present invention are:

1) The method of drilling holes on the ultra-high-strength steel plate solves the problem that it is difficult for rivets to pierce the ultra-high-strength steel plate in the SPR technology;

2) On the basis of the drilling self-piercing riveting process, it can also cooperate with welding or gluing to improve the joint strength, and finally obtain a steel-aluminum mixed material with excellent mechanical properties;

3) Riveting can be achieved by using ordinary rivets, the method is simple and easy to implement, and the implementation cost is low;

4) The range of connectable materials is wide, and the mechanical properties of the joint are excellent, which is more in line with the requirements of multi-material connection in various mechanical structures, and is close to the actual needs of engineering applications.

Description of drawings

Figure 1 is a schematic diagram of a conventional self-piercing riveting method.

FIG. 2 is a schematic diagram of the method for connecting ultra-high strength steel and aluminum alloy by self-piercing riveting technology according to the present invention.

In the picture: 1. Ultra-high strength steel plate 2. Aluminum alloy plate 3. Rivet 4. Nail gun 5. Fixture 6. Through hole

Detailed ways

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings:

As shown in Figure 2, a method for connecting ultra-high strength steel and aluminum alloy using self-piercing riveting technology according to the present invention includes the following steps:

1) Drill a through hole 6 in the to-be-riveted part of the ultra-high-strength steel plate 1, and the diameter of the through hole 6 is the same as the outer diameter of the rivet 3;

2) stack the ultra-high-strength steel plate 1 and the aluminum alloy plate 2 after the drilling, and the ultra-high-strength steel plate 1 is located above the aluminum alloy plate 2, and then clamp with a clamp 5;

3) Align the rivet 3 with the through hole 6 on the ultra-high-strength steel plate 1, and use a nail gun 4 for punching riveting. After the rivet 3 passes through the through-hole 6 on the ultra-high-strength steel plate 1, the tail structure expands and penetrates or passes through the lower layer. Aluminum alloy plate 2, and form a firm riveting point.

The rivet 3 is made of high-strength steel or high-alloy steel.

After riveting, the joint strength is strengthened by welding between the head of the rivet 3 and the ultra-high-strength steel plate 1;

The welding includes laser welding, argon arc welding and brazing.

The head of the rivet 3 and the ultra-high-strength steel plate 1 are glued to strengthen the joint strength.

As shown in Figure 1, SPR self-piercing riveting technology is mainly used in the connection of dissimilar materials that are difficult to weld, and is mostly used for the connection between steel and aluminum, magnesium alloy, composite materials and other parts on the body. However, when ultra-high-strength steel is used as the steel in dissimilar materials, the rivets are severely deformed after penetrating the ultra-high-strength steel plate, and riveting cannot be achieved.

As shown in FIG. 2, the present invention fully considers the problem that the rivet is difficult to penetrate the high-strength steel plate, and drills the high-strength steel plate. In addition, considering that the self-piercing riveting of the present invention is essentially a single-layer plate punching riveting, the joint strength is slightly lower than that of the double-layer plate punching riveting. For the insufficient joint strength, welding or gluing are used to strengthen it. A steel-aluminum connection point with excellent mechanical properties of the joint is obtained.

The material of the rivet of the present invention is the same as that of the common rivet, and the strength and hardness of the rivet need to reach the standard of self-piercing riveting.

According to the actual production situation, if the mechanical properties of the joint meet the requirements, the joint strengthening step may not be implemented to reduce the production cost. If the joint performance requirements are higher, it can be further strengthened by welding or applying structural adhesive.

The following examples are implemented on the premise of the technical solutions of the present invention, and provide detailed embodiments and specific operation processes, but the protection scope of the present invention is not limited to the following examples.

【Example】

In a steel-aluminum hybrid body, the primary role of steel is to maintain structural integrity. Therefore, in this embodiment, PHS2000 ultra-high-strength hot-formed steel and 6-series aluminum alloy are selected as the connected plates.

As shown in Figure 2, first of all, a through hole with the same diameter as the rivet is drilled on the PHS2000 ultra-high-strength hot-formed steel plate (hereinafter referred to as the steel plate), and it is stacked with the aluminum alloy plate one on top of the other.

Use the fixture of the nail gun to fix the stacked plates, and then use the nail gun to pierce the rivets into the aluminum alloy plate through the through holes on the steel plate.

After riveting, measure the interlock value, and test its mechanical properties such as strength and fatigue. If the mechanical properties do not meet the requirements, it is necessary to further increase the welding or gluing process.

Commonly used rivets are generally made of medium and high alloy steel, and the steel plate is low-alloy steel; if welding is required, the rivet is made of low-alloy steel with better welding performance, and the tail of the rivet passes through the aluminum alloy plate (easy to energize during welding), welding In addition to ordinary resistance spot welding, laser welding, and argon arc welding, brazing can also be used.

Structural adhesive can be used for bonding, and the structural adhesive is applied between the head of the rivet and the steel plate.

After the self-piercing riveting technique is used for connection in this embodiment, the connection between the steel plate and the aluminum alloy plate is intact, and the interlock value meets the requirements for use. In order to increase the strength of the rivet joint, the method of gluing is adopted. Under the joint action of rivets and structural adhesives, the mechanical properties of the joints are excellent.

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. The equivalent replacement or change of the inventive concept thereof shall be included within the protection scope of the present invention.

Claims (5)

1. a method utilizing self-piercing riveting technology to connect ultra-high strength steel and aluminum alloy, is characterized in that, comprises the steps: 1) Drill through holes in the parts to be riveted of the ultra-high-strength steel plate, and the diameter of the through holes is the same as the outer diameter of the rivet; 2) Stack the drilled ultra-high-strength steel plate and the aluminum alloy plate together, the ultra-high-strength steel plate is located above the aluminum alloy plate, and then clamp it with a clamp; 3) Align the rivet with the through hole on the ultra-high-strength steel plate, and use a nail gun to punch the rivet. After the rivet passes through the through-hole on the ultra-high-strength steel plate, the tail structure expands and penetrates or passes through the lower aluminum alloy plate, forming a solid riveting point. 2 . The method for connecting ultra-high-strength steel and aluminum alloy using self-piercing riveting technology according to claim 1 , wherein the rivet is made of high-strength steel or high-alloy steel. 3 . 3. A method of utilizing self-piercing riveting technology to connect ultra-high-strength steel and aluminum alloy according to claim 1, wherein after riveting, the joint strength is strengthened by welding between the rivet head and the ultra-high-strength steel plate; The rivet is made of low-alloy steel, and the tail of the rivet passes through the lower aluminum alloy plate. 4 . The method for connecting ultra-high strength steel and aluminum alloy by self-piercing riveting technology according to claim 3 , wherein the welding comprises laser welding, argon arc welding and brazing. 5 . 5. A method for connecting ultra-high-strength steel and aluminum alloy using self-piercing riveting technology according to claim 1, wherein the head of the rivet and the ultra-high-strength steel plate are glued to strengthen the joint strength .

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