Aluminum steel dissimilar metal resistance rivet welding system

Abstract

The utility model relates to the technical field of resistance welding equipment, in particular to an aluminum steel dissimilar metal resistance rivet welding system. Comprising a robot, a servo electrode holder and a staple bolt device, the robot comprises a robot body and a mechanical arm, the mechanical arm is connected to the robot body through a spherical hinge, the other end of the mechanical arm is connected with the servo electrode holder through a flange, a motor is fixedly installed on a holder body frame of the servo electrode holder, and the staple bolt device is fixedly installed at the bottom of a transmission rod of the motor; the aluminum-steel dissimilar metal connecting piece is high in welding spot bonding strength, good in corrosion resistance and low in requirement for performance of welding equipment, and the aluminum-steel dissimilar metal connecting cost can be reduced to a great extent.

Description

Technical Field

[0001] The utility model belongs to the technical field of resistance welding equipment, in particular to an aluminum-steel dissimilar metal resistance riveting welding system. Background Art

[0002] With the continued rapid development of the global automotive industry, the number of vehicles on the road has increased significantly both domestically and internationally. As a typical energy consumer and emissions carrier, automobiles have become a major source of oil consumption and pollutant emissions worldwide. To alleviate growing energy and environmental pressures, the most direct approach is to implement a lightweight vehicle strategy. Numerous studies both domestically and internationally have demonstrated that lightweighting is one of the most effective measures to reduce energy consumption and emissions.

[0003] There are currently four main methods for achieving lightweight automobiles: 1. Extensive use of low-alloy steel, advanced high-strength steel, and ultra-high-strength steel in vehicle body design instead of ordinary steel; 2. Use of light metals such as aluminum alloys and magnesium alloys instead of steel to manufacture components; 3. Introducing composite materials to manufacture vehicle body frames; and 4. Multi-material hybrid vehicle body structures. For multi-material hybrid vehicle body structures, the most widely used method is the joining of dissimilar metals of aluminum and steel. Considering the time efficiency, reliability, and cost-effectiveness of the process, the automotive industry tends to use existing mature technologies, such as resistance spot welding (RSW). However, when using RSW technology to join aluminum alloys and steel, it is easy to form Fe-Al intermetallic compounds (IMCs) at the joints, thereby reducing the mechanical properties of the joints. This severely limits the application of resistance spot welding in the joining of dissimilar metals of aluminum and steel.

[0004] Currently, the main methods used to join aluminum / steel dissimilar metals in vehicle bodies include flow drill screws (FDS) and self-piercing riveting (SPR). FDS, however, requires drilling through the lower sheet, which reduces the corrosion resistance of the joint. Furthermore, the longer screws increase the vehicle's weight, and the exposed screw tips interfere with subsequent assembly, requiring design considerations for avoidance. Furthermore, the FDS process operates from one side, resulting in significant impact forces on the workpiece and robot during operation, necessitating a robot with high load capacity and stability. During tightening, the screws must be perpendicular to the workpiece, requiring adequate support during fixture design. SPR is a cold-forming process for rapidly joining two or more sheets. After piercing the upper sheet, a rivet is inserted under certain die pressure, allowing the rivet legs to extend around the lower sheet without punching through the lower sheet, ultimately forming a mechanically interlocking structure. This type of structure generally has lower sheet-to-sheet bond strength than welded joints. Furthermore, the riveted joints are prone to cracking, resulting in significant impact on the workpiece, complex equipment, and extremely high costs.

[0005] Therefore, there is an urgent need for an aluminum-steel dissimilar metal resistance riveting welding system with high weld joint strength, good corrosion resistance, and the ability to greatly reduce the cost of connecting aluminum-steel dissimilar metals. Utility Model Content

[0006] The purpose of the utility model is to overcome the shortcomings of the prior art and provide an aluminum-steel dissimilar metal resistance riveting welding system that can realize dissimilar metal resistance riveting welding and has high weld joint strength and good corrosion resistance.

[0007] The utility model solves the technical problem by adopting the following technical solutions:

[0008] A resistance riveting welding system for dissimilar metals of aluminum and steel includes a robot, a servo welding clamp and a clamping device. The robot includes a body and a mechanical arm. The mechanical arm is connected to the body by a ball joint. The other end of the mechanical arm is connected to the servo welding clamp by a flange. A motor is fixedly mounted on the clamp body frame of the servo welding clamp, and a clamping device is fixedly mounted on the bottom of the transmission rod of the motor.

[0009] Moreover, the servo welding clamp includes a clamp body frame, a movable arm, a static arm and a connecting piece. A connecting piece is fixedly installed on one side of the clamp body frame, and the connecting piece is connected to one end of the robotic arm through a flange. The movable arm is fixedly installed on the side opposite to the connecting piece, and the static arm is fixedly installed on the vertical side of the connecting piece.

[0010] Moreover, a slide rail is fixedly installed on the inner side of the movable arm, a motor is fixedly installed between the clamp body frames, a guide block is sleeved on the transmission rod of the motor, and one side of the guide block is slidably installed on the slide rail of the movable arm.

[0011] Moreover, the staple device includes a cylinder, a telescopic sleeve, an upper electrode support seat and an upper electrode. The upper electrode support seat is fixedly installed at the bottom of the transmission rod of the motor, and the upper electrode is fixedly installed at the bottom of the upper electrode support seat. The telescopic sleeve is sleeved between the bottom of the transmission rod and the upper electrode, and the cylinder is sleeved outside the telescopic sleeve. The top of the cylinder is fixedly installed with an air circuit joint.

[0012] Moreover, a lower electrode support seat is fixedly mounted at the port of the stationary arm, and a lower electrode is fixedly mounted on the lower electrode support seat. The lower electrode is arranged opposite to the upper electrode.

[0013] Moreover, the robot further comprises a moving device, which is arranged at the bottom of the body, wherein the moving device is wheeled or tracked.

[0014] Moreover, it also includes a pressure sensor and a control unit. A pressure sensor is provided on the inner side of the static arm, and the pressure sensor is connected to the control unit.

[0015] The advantages and positive effects of the utility model are:

[0016] 1. The utility model realizes resistance riveting welding of dissimilar metals of aluminum and steel by arranging a clamping device on the boom. The weld joint has high bonding strength and good corrosion resistance. It does not require high performance of welding equipment and can greatly reduce the cost of connecting dissimilar metals of aluminum and steel.

[0017] 2. The utility model provides a slide rail on the inner side of the movable arm to adjust the accuracy of the up and down displacement of the motor drive rod, and provides a telescopic sleeve in the clamping device to accurately adjust the welding pressure, thereby further improving the bonding strength of the weld point.

[0018] 3. The utility model is equipped with a control unit and a pressure sensor to collect the resistance welding pressure in real time. By adjusting the welding pressure, the dynamic resistance is ensured to be highly consistent with the sample resistance, thereby avoiding the occurrence of welding cost reduction and cold welding of solder joints, and further ensuring the consistency of riveted solder joints. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a diagram of the usage state of the utility model.

[0020] Figure 2 This is a diagram of the servo welding clamp from the first perspective of the present invention.

[0021] Figure 3 This is a diagram of the servo welding clamp from the second viewing angle of the present invention.

[0022] Figure 4 This is a diagram of the state where the telescopic sleeve of the staple device of the utility model is extended.

[0023] Figure 5 This is a diagram of the state in which the telescopic sleeve of the staple device of the utility model is retracted.

[0024] Reference numerals

[0025] 1-stitching device, 2-servo welding clamp, 3-robotic arm, 4-body, 5-moving device, 6-connecting part, 7-clamp body frame, 8-pressure sensor, 9-static arm, 10-transmission rod, 11-moving arm, 12-motor, 13-guide block, 14-slide rail, 15-cylinder, 16-telescopic sleeve, 17-gas line connector, 18-upper electrode support seat 19-upper electrode, 20-lower motor support seat, 21-lower electrode. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and through specific embodiments. The following embodiments are merely illustrative and non-restrictive, and should not be used to limit the scope of protection of the present invention.

[0027] A resistance riveting system for dissimilar aluminum and steel metals includes: a robot, a servo welding clamp 2, and a stapling device 1. The robot includes a body 4 and a robotic arm 3. The robotic arm 3 is connected to the body 4 by a ball joint. The other end of the robotic arm 3 is connected to the servo welding clamp 2 via a flange. A motor 12 is fixedly mounted on the clamp body frame 7 of the servo welding clamp 2. A stapling device 1 is fixedly mounted at the bottom of the transmission rod 10 of the motor 12.

[0028] The servo welding clamp 2 includes a clamp body frame 7, a movable arm 11, a static arm 9 and a connecting piece 6. A connecting piece 6 is fixedly installed on one side of the clamp body frame 7. The connecting piece 6 is connected to one end of the robotic arm 3 through a flange. The free swing of the robotic arm 3 is driven by the robot to realize the free swing of the servo welding clamp 2; the movable arm 11 is fixedly installed on the side opposite to the connecting piece 6, and the static arm 9 is fixedly installed on the vertical side of the connecting piece 6.

[0029] A slide rail 14 is fixedly installed on the inner side of the movable arm 11, and a motor 12 is fixedly installed between the clamp body frames 7. A guide block 13 is mounted on the transmission rod 10 of the motor 12, and one side of the guide block 13 is slidably installed on the slide rail 14 of the movable arm 11; the motor 12 drives the transmission rod 10 to move up and down, and then drives the guide block 13 to move up and down along the slide rail 14 to prevent the transmission rod 10 from deflecting, swinging or twisting during movement, thereby improving the positioning accuracy.

[0030] The stapling device 1 includes a cylinder 15, a telescopic sleeve 16, an upper electrode support seat 18 and an upper electrode 19. The upper electrode support seat 18 is fixedly mounted at the bottom of the transmission rod 10 of the motor 12, and the upper electrode 19 is fixedly mounted at the bottom of the upper electrode support seat 18. The telescopic sleeve 16 is sleeved between the bottom of the transmission rod 10 and the upper electrode 19. The cylinder 15 is sleeved on the outer surface of the telescopic sleeve 16. The top of the cylinder 15 is fixedly mounted with a gas circuit connector 17 to realize the input and output of gas and control the telescopic movement of the telescopic sleeve 16 by the cylinder 15. When the cylinder 15 controls the telescopic sleeve 16 to extend, the telescopic sleeve 16 completely covers the upper electrode 19. When the cylinder 15 controls the telescopic sleeve 16 to retract, the upper electrode 19, the upper electrode support seat 18 and part of the transmission rod 10 leak out.

[0031] A lower electrode support seat 20 is fixedly mounted at the end of the stationary arm 9 , and a lower electrode 21 is fixedly mounted on the lower electrode support seat 20 . The lower electrode 21 is arranged opposite to the upper electrode 19 .

[0032] The robot further includes a moving device 5 , which is disposed at the bottom of the body 4 . The moving device 5 may be wheeled or tracked to enable the robot to move between different locations.

[0033] The system also includes a pressure sensor 8 and a control unit. A pressure sensor 8 is located inside the stationary arm 9 and is connected to the control unit. By collecting electrical signals, the actual resistance is closer to the sample resistance, resulting in higher-quality solder joints, effectively reducing solder spatter and ensuring solder consistency.

[0034] Working principle:

[0035] Steel plates and aluminum plates are placed on the fixture from bottom to top. The robot moves the servo welding clamp to the position of the aluminum plates and steel plates, and controls the servo welding clamp to align the upper electrode and the lower electrode with the test piece to be welded, so that the lower electrode contacts the bottom steel plate; at this time, the telescopic sleeve in the clamping device is in the extended state, and then a steel rivet is added to the telescopic sleeve, and the transmission rod of the drive motor moves downward until the steel rivet presses the aluminum plate and the steel plate, and the cylinder controls the telescopic sleeve to retract, and the welding clamp maintains a certain pressure to press the steel rivet to the aluminum plate and the steel plate, and then a preheating current is applied, and the steel rivet uses the heat generated by the preheating current to penetrate the upper aluminum plate, and then a welding current is applied to connect the steel rivet to the lower steel plate; after completing the welding process, the robot controls the static arm to leave the lower steel plate, and the transmission rod of the drive motor moves the movable arm away from the aluminum plate, and the clamping device extends to prepare for the next welding.

[0036] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will understand that various replacements, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. An aluminum-steel dissimilar metal resistance riveting welding system, characterized by: The invention comprises a robot, a servo welding clamp and a clamping device. The robot comprises a body and a robotic arm. The robotic arm is connected to the body by a ball joint. The other end of the robotic arm is connected to the servo welding clamp by a flange. A motor is fixed on the clamp body frame of the servo welding clamp, and a clamping device is fixed at the bottom of the transmission rod of the motor.

2. The aluminum-steel dissimilar metal resistance riveting welding system according to claim 1, characterized in that: The servo welding clamp includes a clamp body frame, a movable arm, a static arm and a connecting piece. A connecting piece is fixedly installed on one side of the clamp body frame, and the connecting piece is connected to one end of the robotic arm through a flange. The movable arm is fixedly installed on the side opposite to the connecting piece, and the static arm is fixedly installed on the vertical side of the connecting piece.

3. The aluminum-steel dissimilar metal resistance riveting welding system according to claim 2, characterized in that: A slide rail is fixedly installed on the inner side of the movable arm, a motor is fixedly installed between the clamp body frames, a guide block is sleeved on the transmission rod of the motor, and one side of the guide block is slidably installed on the slide rail of the movable arm.

4. The aluminum-steel dissimilar metal resistance riveting welding system according to claim 3, characterized in that: The clamping device includes a cylinder, a telescopic sleeve, an upper electrode support seat and an upper electrode. The upper electrode support seat is fixedly installed at the bottom of the transmission rod of the motor, and the upper electrode is fixedly installed at the bottom of the upper electrode support seat. The telescopic sleeve is sleeved between the bottom of the transmission rod and the upper electrode. The cylinder is sleeved outside the telescopic sleeve, and an air circuit joint is fixedly installed on the top of the cylinder.

5. The aluminum-steel dissimilar metal resistance riveting welding system according to claim 4, characterized in that: A lower electrode support seat is fixedly mounted at the port of the static arm, and a lower electrode is fixedly mounted on the lower electrode support seat. The lower electrode is arranged opposite to the upper electrode.

6. The aluminum-steel dissimilar metal resistance riveting welding system according to claim 1, characterized in that: The robot further comprises a moving device, which is arranged at the bottom of the body, wherein the moving device is wheeled or tracked.

7. The aluminum-steel dissimilar metal resistance riveting welding system according to claim 5, characterized in that: It also includes a pressure sensor and a control unit. A pressure sensor is provided on the inner side of the static arm, and the pressure sensor is connected to the control unit.

Images