Electromagnetic self-piercing riveting device for ultrahigh-strength steel plate

Abstract

The utility model discloses an electromagnetic self-piercing riveting device for an ultrahigh-strength steel plate, which comprises a power supply system, an electromagnetic riveting force loading mechanism and a centering mechanism, the electromagnetic riveting force loading mechanism achieves riveting action through electromagnetic repulsive force generated by a discharge coil and a drive coil, and the centering mechanism ensures accurate centering of a punch and a riveting die in the riveting process. The using process comprises the three steps of preparation work, capacitor charging and riveting, the riveting force is adjusted by controlling the charging voltage, and self-piercing riveting of rivets with different plate thicknesses and different diameters is achieved. According to the device, the riveting problem of the ultrahigh-strength steel plate is solved by utilizing the characteristics of large electromagnetic riveting force and high-speed impact loading, and the device is good in centering performance, simple in technological process, stable in riveting quality and high in efficiency.

Description

Technical Field

[0001] The utility model belongs to the technical field of riveting, and in particular relates to an electromagnetic self-piercing riveting device for ultra-high strength steel plates. Background Art

[0002] Self-piercing riveting is a cold connection technology used to connect two or more plates. After the special rivet penetrates the top plate, the hollow structure at the tail of the rivet expands and penetrates without piercing the bottom plate under the action of the riveting die, thus forming a solid riveting point. With the continuous development of new energy vehicles, higher requirements are placed on the safety and lightweight of the car body and components. For this reason, ultra-high strength steel is applied to the car body during the car body manufacturing process. Ultra-high strength steel has the characteristics of high strength (1500Mpa), high hardness and low ductility. At present, ordinary self-piercing riveting equipment often has the problem that the rivet cannot penetrate the steel plate when riveting ultra-high strength steel plates, making it difficult to achieve riveting of ultra-high strength steel plates.

[0003] In summary, the existing self-piercing rivet riveting devices cannot meet the development needs of ultra-high-strength plate assembly, and a new technical solution is urgently needed to solve the problem of efficient self-piercing riveting of ultra-high-strength steel plates. Utility Model Content

[0004] The utility model aims at solving the problems existing in the prior art, and utilizes the characteristics of large riveting force and high loading rate of electromagnetic riveting process to solve the riveting problem of ultra-high strength steel plates, and provides an electromagnetic self-piercing riveting device for ultra-high strength steel plates, including a power supply system, an electromagnetic riveting force loading mechanism, and a centering mechanism;

[0005] The electromagnetic riveting force loading mechanism comprises a central shaft, a discharge coil, a drive coil, a stress wave amplifier, a spring, a punch and a shoulder bushing;

[0006] The discharge coil, the drive coil and the stress wave amplifier are arranged closely in sequence, and the drive coil is fixedly connected to the stress wave amplifier; the central axis passes through the discharge coil and the drive coil in sequence and is fixedly connected to the stress wave amplifier; the other end of the stress wave amplifier is fixedly connected to the punch, the outer side of the punch is sleeved with the shoulder bushing and is slidably connected to it, the spring is arranged between the shoulder bushing and the stress wave amplifier, the spring is sleeved on the punch, and the shoulder bushing is pressed against the punch shoulder by the spring, and the other end of the punch is used to install a self-piercing rivet;

[0007] The centering mechanism includes a C-beam, a centering support, a riveting die and a support;

[0008] The centering support is located above the support, and the centering support is fixedly connected to the centering fixture base through the C-beam. A centering hole is provided on the centering support, and the shoulder bushing is placed in the centering hole and slidably cooperates with the centering hole. The rivet die is fixedly connected to the support, and a clamping gap is formed between the rivet die and the centering support located above it, and the clamping gap is used to place the metal connector to be riveted;

[0009] The metal connector includes an ultra-high strength steel plate and a lower metal plate;

[0010] The power supply system is connected to the discharge coil and is used for discharging the discharge coil so as to generate an electromagnetic repulsive force between the discharge coil and the drive coil.

[0011] Further, the power supply system includes an AC power supply, a transformer, a rectifier element, a current limiting resistor, a capacitor and a discharge switch;

[0012] The AC power source is connected in series with the transformer, the transformer is connected in series with the rectifying element and the current limiting resistor, the transformer is connected in parallel with the capacitor and the discharge switch, and the discharge switch is connected in series with the discharge coil.

[0013] Furthermore, the driving coil is a metal disc structure, and the driving coil and the discharge coil have the same diameter.

[0014] Furthermore, the distance from the bottom surface of the centering support to the top surface of the metal connecting piece to be riveted is 3-5 mm.

[0015] Furthermore, the spring is a cylindrical helical spring.

[0016] Furthermore, four symmetrical threaded holes are provided on one side of the drive coil close to the stress wave amplifier, and the threaded holes are used to connect the drive coil and the stress wave amplifier by bolts.

[0017] Furthermore, the central shaft is connected to the stress wave amplifier via threads, the punch is connected to the stress wave amplifier via threads, and the riveting die is connected to the support via threads.

[0018] Furthermore, the discharge coil, drive coil, stress wave amplifier, spring, punch, shoulder bushing, centering support, riveting die, and support threaded hole are coaxial.

[0019] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0020] 1. This device has a large electromagnetic riveting force and a high loading rate, and can achieve cold self-piercing riveting of ultra-high strength steel plates;

[0021] 2. The electromagnetic riveting device includes a centering mechanism with good centering performance to achieve high-quality self-piercing riveting;

[0022] 3. High-rate impact loading can be achieved, which helps to improve the strength and fatigue life of riveted joints;

[0023] 4. The electromagnetic riveting process of this device is simple, the riveting quality is stable and the efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The utility model is a diagram of an electromagnetic self-piercing riveting device for ultra-high strength steel plates.

[0025] Reference numerals:

[0026] AC power supply 1, transformer 2, rectifier element 3, current limiting resistor 4, capacitor 5, discharge switch 6, center shaft 7, discharge coil 8, drive coil 9, bolt 10, stress wave amplifier 11, spring 12, punch 13, shoulder bushing 14, centering support 15, C-beam 16, self-piercing rivet 17, ultra-high strength steel plate 18, lower metal plate 19, rivet die 20, support 21. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0030] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the utility model product is usually placed when in use, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0031] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0032] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] The technical solution of the utility model will be explained below in conjunction with specific embodiments.

[0034] like Figure 1 As shown, an electromagnetic self-piercing riveting device for ultra-high strength steel plates is provided. Through the cooperation between the power supply system, the electromagnetic riveting force loading mechanism and the centering mechanism, the rivet gun and the connected plate can be quickly aligned, the electromagnetic self-piercing riveting process can be quickly completed, and the coaxiality of the rivet gun and the rivet die is effectively guaranteed.

[0035] The power supply system includes an AC power supply 1, a transformer 2, a rectifier element 3, a current limiting resistor 4, a capacitor 5, and a discharge switch 6;

[0036] The electromagnetic riveting force loading mechanism includes a central shaft 7, a discharge coil 8, a drive coil 9, a stress wave amplifier 11, a spring 12, a punch 13, and a shoulder bushing 14;

[0037] The centering mechanism includes a centering support 15, a C-beam 16, a riveting die 20, and a support 21;

[0038] In the present invention, the driving coil 9 is a metal disc structure with low resistivity and is arranged on the lower side of the discharge coil 8. A hole for connecting the central axis 7 is provided at the center position of the surface of one side of the driving coil 9 close to the discharge coil 8, and four symmetrical threaded holes are provided on the side close to the stress wave amplifier 11 for connecting with the stress wave amplifier 11 through bolts 10, and the central axis 7 is connected to the stress wave amplifier 11 through threads. Before electromagnetic self-piercing riveting, the driving coil 9 is close to one side of the discharge coil 8, wherein the diameter of the discharge coil 8 is the same as that of the driving coil 9; the shoulder bushing 14 is located on the top of the riveting die 20, the punch 13 is placed in the center hole of the shoulder bushing 14 and the two are slidably connected, the punch 13 is connected to the stress wave amplifier 11 through threads, and the shoulder bushing 14 is pressed against the shoulder of the punch 13 by a spring 12 between the shoulder bushing 14 and the stress wave amplifier 11. The shoulder bushing 14 is placed in the centering support 15 and is slidably matched with the centering support 15. The punch 13 is in close contact with the self-piercing rivet 17, and the shoulder bushing 14 and the self-piercing rivet 17 are pressed against the ultra-high strength steel plate 18. The rivet die 20 is connected to the support 21 by threads. The coaxiality of the installation holes of the centering support 15, the shoulder bushing 14 and the support 21 of the rivet die 20 ensures the coaxiality of the rivet gun punch, the self-piercing rivet 17 and the rivet die 20, and the self-piercing rivet 20 is installed in a centered manner. The centering fixture can realize the connection of self-piercing rivets of different plate thicknesses by changing the length of the C-beam 16.

[0039] During electromagnetic self-piercing riveting, the AC power supply 1 is stepped up by the transformer 2 and rectified by the rectifier element 3 to charge the capacitor 5. After reaching the specified voltage, the discharge switch 6 is closed to discharge the discharge coil 8 through the cable. The electromagnetic repulsion generated between the discharge coil 8 and the drive coil 9 is used to move the drive coil 9, the stress wave amplifier 11 and the punch 13 downward. At the same time, the spring 12 is continuously compressed to keep the shoulder bushing 14 pressed against the ultra-high strength steel plate 18. The self-piercing rivet 17 is driven downward by the electromagnetic force, penetrates the ultra-high strength steel plate 18, and then penetrates the lower metal plate 19. The lower metal plate 19 is fully deformed to fill the rivet die 20, and a self-locking structure is formed on the side where the lower metal plate 19 contacts the ultra-high strength steel plate 18, completing the self-piercing riveting.

[0040] The method for using the electromagnetic self-piercing riveting device for ultra-high strength steel plates includes the following steps:

[0041] Step 1: Before riveting, select the corresponding self-piercing rivet according to the self-piercing riveting standard, place the self-piercing rivet 17 and fix the riveting die 20, then move the riveting gun downward to press the shoulder bushing 14 against the ultra-high strength steel plate 18, so that the driving coil 9 is close to the discharge coil 8, and the preparation work is completed;

[0042] Step 2: Use the input AC power 1 to charge the capacitor 5 after the step-up transformer 2 steps up the voltage and the rectifying element 3 rectifies it. The capacitor 5 is charged to the specified voltage within 1 minute. The charging time of the capacitor 5 is mainly determined by the energy storage energy required by the capacitor 5 and the current limiting resistor 4. The energy storage energy required by the capacitor 5 is determined by the material properties and thickness of the connected parts.

[0043] Step 3: After reaching the specified voltage, the discharge switch 6 is closed and the discharge coil 8 is discharged through the wire. An instantaneous current is generated inside the discharge coil 8. The current generates a changing pulse magnetic field around the coil and passes through the drive coil 9, inducing eddy currents. The instantaneous magnetic field and eddy currents generate electromagnetic repulsion acting on the drive coil 9 and the stress wave amplifier 11. The front punch 13 of the stress wave amplifier 11 acts on the self-piercing rivet 17. The self-piercing rivet 17 is subjected to the impact pressure and penetrates the upper ultra-high strength steel plate 18. Under the action of the rivet die 20, a self-locking structure is formed on the side where the lower metal plate 19 contacts the ultra-high strength steel plate 18, completing the self-piercing riveting.

[0044] The above embodiments are preferred examples for implementing the present invention, and the present invention is not limited to the above embodiments. Any non-essential additions and substitutions made by those skilled in the art based on the technical features of the present invention are within the protection scope of the present invention.

Claims

1. An electromagnetic self-piercing riveting device for ultra-high strength steel plates, characterized in that: Including power supply system, electromagnetic riveting force loading mechanism, centering mechanism; The electromagnetic riveting force loading mechanism comprises a central shaft (7), a discharge coil (8), a drive coil (9), a stress wave amplifier (11), a spring (12), a punch (13) and a shoulder bushing (14); The discharge coil (8), the drive coil (9) and the stress wave amplifier (11) are arranged closely in sequence, and the drive coil (9) is fixedly connected to the stress wave amplifier (11); the central axis (7) passes through the discharge coil (8) and the drive coil (9) in sequence and is fixedly connected to the stress wave amplifier (11); the other end of the stress wave amplifier (11) is fixedly connected to the punch (13), the outer side of the punch (13) is sleeved with the shoulder bushing (14) and is slidably connected to the punch, the spring (12) is arranged between the shoulder bushing (14) and the stress wave amplifier (11), the spring (12) is sleeved on the punch (13), and the shoulder bushing (14) is pressed against the shoulder of the punch (13) by the spring (12), and the other end of the punch (13) is used to install a self-piercing rivet (17); The centering mechanism comprises a C-shaped beam (16), a centering support member (15), a riveting die (20) and a support (21); The centering support member (15) is located above the support (21), and the centering support member (15) and the support (21) are fixedly connected via the C-shaped beam (16); a centering hole is provided on the centering support member (15), the shoulder bushing (14) is placed in the centering hole and slidably cooperates with the centering hole; the rivet die (20) is fixedly connected to the support (21), and a clamping gap is formed between the rivet die (20) and the centering support member (15) located above the rivet die (20), and the clamping gap is used to place a metal connector to be riveted; The power supply system is connected to the discharge coil (8) and is used to discharge the discharge coil (8) so as to generate an electromagnetic repulsive force between the discharge coil (8) and the drive coil (9).

2. The electromagnetic self-piercing riveting device for ultra-high strength steel plates according to claim 1, characterized in that: The power supply system comprises an AC power supply (1), a transformer (2), a rectifier element (3), a current limiting resistor (4), a capacitor (5) and a discharge switch (6); The AC power source (1) is connected in series with the transformer (2), the transformer (2) is connected in series with the rectifier element (3) and the current limiting resistor (4), the transformer (2) is connected in parallel with the capacitor (5) and the discharge switch (6), and the discharge switch (6) is connected in series with the discharge coil (8).

3. The electromagnetic self-piercing riveting device for ultra-high strength steel plates according to claim 1, characterized in that: The driving coil (9) is a metal disc structure, and the driving coil (9) and the discharge coil (8) have the same diameter.

4. The electromagnetic self-piercing riveting device for ultra-high strength steel plates according to claim 1, characterized in that: The distance from the bottom surface of the centering support (15) to the top surface of the metal connecting piece to be riveted is 3-5 mm.

5. The electromagnetic self-piercing riveting device for ultra-high strength steel plates according to claim 1, characterized in that: The spring (12) is a cylindrical helical spring.

6. The electromagnetic self-piercing riveting device for ultra-high strength steel plates according to claim 1, characterized in that: Four symmetrical threaded holes are provided on a side of the driving coil (9) close to the stress wave amplifier (11), and the threaded holes are used to connect the driving coil (9) and the stress wave amplifier (11) via bolts (10).

7. The electromagnetic self-piercing riveting device for ultra-high strength steel plates according to claim 1, characterized in that: The central shaft (7) is connected to the stress wave amplifier (11) via threads, the punch (13) is connected to the stress wave amplifier (11) via threads, and the riveting die (20) is connected to the support (21) via threads.

8. The electromagnetic self-piercing riveting device for ultra-high strength steel plates according to claim 1, characterized in that: The discharge coil (8), the drive coil (9), the stress wave amplifier (11), the spring (12), the punch (13), the shoulder bushing (14), the centering support (15), the riveting die (20), and the threaded holes of the support (21) are coaxial.

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