Rivet conveying device and its welding control method

Abstract

A rivet conveying device includes a fixed bracket, first and second sliding brackets, a nail ejection nozzle, a double-row swing rod and a nail grasping member, a telescopic driver, a rotary driver, and first and second elastic components. The fixed bracket is installed on the electrode connecting rod. Two nail ejection nozzles are symmetrically and slidably installed on both sides of the fixed bracket. The double-row swing rod is rotatably installed on the fixed bracket between the nail ejection nozzle and the electrode through the second sliding bracket. The nail grasping member is installed at both ends of the double-row swing rod. The sliding of the second sliding bracket and the nail ejection nozzle away from the electrode is driven by the telescopic driver, and full reset requires driving in combination with the first and second elastic components. The rotary driver causes the double-row swing rod to reciprocate, enabling the nail grasping heads of the nail grasping member to alternately grasp rivets from the two nail ejection nozzles and transport them to the electrode. Under the extrusion of the electrode, the nail grasping heads can smoothly release the rivets and avoid the electrode welding. The present invention also provides a welding control method for the rivet conveying device to achieve automatic continuous rivet conveying and welding processes for this equipment.

Description

Technical Field

[0001] The present invention belongs to the field of welding equipment, and particularly relates to a rivet conveying device and a welding control method thereof for resistance spot welding. Background Art

[0002] The connection of dissimilar metal components is very common in automobile bodies, and a typical example is the connection of aluminum alloy and steel components. Due to the huge differences in physical and chemical properties between dissimilar metals, when using traditional welding processes for welding, it is easy to form brittle intermetallic compounds and cracks, etc., resulting in poor mechanical properties of the joints. At present, the connection of dissimilar metals (such as aluminum and steel) usually adopts mechanical connection processes, such as self-piercing riveting (SPR) and flow drill screwing (FDS), etc. However, in recent years, with the wide application of high-strength steel and ultra-high-strength steel, and at the same time, the gradually popularized integrated die-cast aluminum alloy with poor elongation rate has led to increasing difficulties in using mechanical connection processes to connect dissimilar metal components represented by aluminum alloy and steel. Therefore, in order to achieve reliable connection of high-strength steel and aluminum alloy, the combined welding-riveting connection process has gradually become popular, and the most typical one is resistance element welding (REW). By prefabricating steel rivets onto aluminum alloy workpieces and then resistance spot welding the steel rivets and steel plates together, the connection of aluminum / steel dissimilar metal components is realized. However, the combined welding-riveting connection process has the same problem as the mechanical connection process, that is, rivets need to be continuously conveyed to the connection area during welding (or connection). The difficulty is that for the combined welding-riveting connection process, its connection equipment usually needs to retain the function of welding itself, and the rivet sizes and specifications involved are relatively larger than those of mechanical connection rivets, such as REW equipment and rivets. It is necessary to provide an external rivet feeding device to continuously feed rivets for the welding equipment, while avoiding the interference of the external rivet feeding device with the welding process, and ensuring that the external rivet feeding device has a compact size and a stable and efficient rivet feeding process, which has become a technical problem in this field.

[0003] Patent document CN118720377A discloses a fastener (rivet) for welding dissimilar metals, which has a very excellent connection effect when connecting dissimilar metals such as high-strength steel and cast aluminum. However, this type of rivet belongs to the flat rivet type, that is, its diameter is greater than its height. When continuously feeding such rivets in a coaxial rivet feeding device, it is very easy to occur problems such as rivet inclination or jamming, resulting in ineffective guarantee of conveying stability and welding efficiency. In order to solve the problem of continuous conveying of such rivets, there is an urgent need to provide a stable and reliable rivet conveying equipment.

[0004] Patent documents CN 111182995 A and CN 113165100 A respectively disclose a collet assembly and a rivet distribution system for a fastener (referred to as a rivet herein) feeding device, wherein the collet assembly is used to be installed around the welding electrode of a welding tong (or called a welding gun) for clamping the rivets required for welding; while the rivet distribution system is installed on the side of the welding electrode of the welding tong to continuously supply rivets to the collet assembly. On the one hand, the mechanism of this device is relatively complex, resulting in difficult coordinated control of each mechanism. After each weld spot is welded, the rivet distribution system delivers one rivet to the collet assembly, and when delivering the rivet, after the previous weld spot is manufactured, it is required that the rivet distribution system and the collet assembly be transferred to the designated position simultaneously to feed the rivet, which has the problems of low welding efficiency and poor nail feeding stability. On the other hand, the size of the rivet distribution system is relatively large, occupying a large space of the welding tong, and it is easy to cause interference problems when the welding tong welds complex parts.

[0005] Patent document CN217316356U discloses a swing-type material sheet conveying device, which has the effects of compact structure and high conveying efficiency. However, this device is suitable for conveying thin sheet-like material sheets, and this device is suitable for conveying material sheets with light weight and outer diameter dimensions larger than the outer diameter dimension of the welding electrode. For the rivets disclosed in patent document CN118720377A, it is difficult for the feeding frame of this device to stably clamp them, especially during the rotation and swing process. In addition, in the actual welding of rivets, their outer diameter dimensions are usually smaller than the outer diameter of the welding electrode, and this device cannot effectively solve the problems of the feeding frame smoothly releasing the rivets and avoiding the feeding frame interfering with the welding process for such rivets. Therefore, there is an urgent need in the art for a rivet conveying device with a more reasonable structural design, which can efficiently and stably convey rivets while ensuring the compact size and structure of the device, and also realize the function of the nail feeding mechanism to avoid interfering with the welding process. Summary of the Invention

[0006] To overcome the deficiencies of the above-mentioned prior art, the present invention provides a rivet conveying device. Through the dynamic cooperation of a double-row swing rod and a nail grasping member, an elastic reset mechanism, multiple fixing technologies, and sensor-driven automatic control, it not only solves the problems of the stability and efficiency of rivet conveying in dissimilar metal welding, but also significantly reduces the equipment complexity and maintenance cost, and has high industrial application value.

[0007] The technical solution of the present invention is as follows:

[0008] A rivet conveying device, which continuously conveys rivets for an electrode to weld a workpiece at the end of an electrode connecting rod, includes: a fixed bracket installed on the electrode connecting rod of a welding tong. A first slider guide rail is laid on the upper part of the fixed bracket, and a second slider guide rail is laid on the lower part of the fixed bracket; two nail ejection nozzles are slidably installed on the first slider guide rail through a first sliding bracket, so that the two nail ejection nozzles are symmetrically distributed on both sides of the fixed bracket; a second sliding bracket is slidably installed on the fixed bracket through the second slider guide rail and is located between the nail ejection nozzles and the electrode; a double-row swing rod is rotatably installed in the middle of the second sliding bracket and is symmetrically formed by two swing rods that are parallel to each other and form an obtuse angle; a nail grasping member is rotatably installed at each end of the double-row swing rod, and two nail grasping members are installed at each end of the double-row swing rod. The nail grasping head side of the nail grasping member can elastically close towards the central plane of the two swing rods of the double-row swing rod, so that the nail grasping members are oppositely arranged in a "V" shape, and the nail grasping heads at the ends of the two nail grasping members are in contact and closed to form a rivet accommodating cavity; a telescopic driver is installed on the fixed bracket and is used to drive the nail ejection nozzles and the second sliding bracket to linearly move away from the electrode synchronously; a first elastic component and a second elastic component are installed on the telescopic rod of the telescopic driver and are respectively connected to the first sliding bracket and the telescopic rod, and the second sliding bracket and the telescopic rod, and are used to drive the first and second sliding brackets to fully reset to the position closest to the electrode; and a rotary driver is installed on the second sliding bracket and is used to drive the double-row swing rod to swing reciprocally, so that the nail grasping heads at the ends of the nail grasping members at both ends of the double-row swing rod alternately grab rivets from the positions of the two nail ejection nozzles and convey them to the position of the electrode. Under the extrusion of the electrode, the nail grasping heads can release the rivets and avoid the electrode welding.

[0009] Further, when the electrode pre-presses the first workpiece, the electrode extrudes the rivet on the nail grasping head onto the first workpiece; under the extrusion of the electrode, the two closed nail grasping heads are forced to open adaptively and release the rivet, and the second sliding bracket linearly slides in the direction away from the electrode under the push of the double-row swing rod. The first sliding bracket and the nail ejection nozzles linearly slide in the direction away from the electrode simultaneously under the push of the double-row swing rod (or the nail grasping member), resulting in the compression and energy storage of the first and second elastic components; after the electrode is withdrawn from the welding point, the nail grasping heads are separated from the workpiece contact, and the elastic energy of the first and second elastic components is released, driving the first sliding bracket, the nail ejection nozzles, the second sliding bracket and the double-row swing rod to reset.

[0010] Further, the telescopic driver is a double-headed cylinder, and the driving force output by it is greater than the maximum elastic force in the first elastic component and the second elastic component.

[0011] Furthermore, the two nail grabbing heads at the ends of the nail grabbing members are assembled to form a rivet accommodating cavity, the minimum width L1 of the inner wall of which is smaller than the outer diameter Φ1 of the rivet, and the height of the accommodating cavity is in the range of one to two times the height of the rivet.

[0012] Preferably, the nail grasping member is made of non-magnetic material, such as stainless steel, brass, titanium alloy, tungsten steel alloy, etc.

[0013] Furthermore, after the telescopic driver is fully extended toward the electrode side and reset, the first and second elastic components can fully drive the first and second sliding brackets to reset to the position closest to the electrode.

[0014] Furthermore, when the telescopic drive drives the second sliding bracket to move away from the electrode side, the closed nail grabbing heads of the two nail grabbing members at the electrode position are pushed against the electrode and are forced to open and release the grasped rivets, and the electrode at least partially protrudes outside the range surrounded by the two nail grabbing heads.

[0015] Furthermore, the rivet enters the rivet accommodating cavity from the end of the rivet grabbing head, and a supporting portion is provided in the rivet accommodating cavity on a side away from the end of the rivet grabbing head. The supporting portion is used to support the rivet transferred from the rivet ejecting nozzle to the rivet accommodating cavity, and a convex ridge structure is provided on one side of the end of the rivet grabbing head to limit the rivet from escaping from the rivet accommodating cavity when the double-row swing arm rotates.

[0016] Furthermore, the supporting portion and the ridge structure are compressible elastic structures, and when subjected to a certain external force, at least a portion of them will shrink into the nail grabbing head body.

[0017] Furthermore, a through pipe is provided inside the nail grabbing member and extends to the inner wall of the rivet accommodating cavity of the nail grabbing head. The through pipe is used for vacuuming to form a negative pressure in the rivet accommodating cavity to adsorb the rivet.

[0018] Furthermore, the rotation driver is a pneumatic driver, and the maximum rotation angle of its shaft is A. The second sliding bracket is provided with a first limit block for limiting the maximum rotation angle B of the double-row swing arm, and there is a relationship between angle A and angle B: A≥1.2×B.

[0019] Furthermore, a first sensor is provided near the nail ejection nozzle for monitoring the position information of the nail grabbing head, and a second sensor is provided for monitoring the position information of the rivet in the rivet accommodating cavity.

[0020] Optionally, a secondary air blowing channel is provided on the other side of the rivet ejection nozzle to assist in transferring the rivet into the rivet grabbing head. The high-pressure gas output by the secondary air blowing channel is also used to temporarily position the rivet in the rivet accommodating cavity of the rivet grabbing head. The total pressure formed by the high-pressure gas output by the secondary air blowing channel acting on the rivet surface is greater than the gravity of the rivet itself.

[0021] Furthermore, an expansion pin is provided near the rivet ejection nozzle, and the expansion pin is used to open the two closed rivet grabbing heads by a certain distance to expand the channel for the rivet to enter the rivet accommodating cavity, and the expansion pin also temporarily supports the rivet in the rivet accommodating cavity.

[0022] Further, the second sensor is mounted on the expansion pin.

[0023] Furthermore, the expansion pin has a magnetic adsorption capability and is used for stably adsorbing the rivet transferred from the rivet ejection nozzle to the rivet receiving cavity.

[0024] Optionally, the magnetic adsorption capability of the expansion pin is achieved by using a magnetic material to make the expansion pin, or installing a permanent magnet structure on the expansion pin, or installing an electromagnet disk.

[0025] Optionally, a vacuum channel is provided on the expansion pin for vacuuming to form an adsorption force to adsorb the rivet, thereby temporarily stabilizing the rivet in the rivet accommodating cavity.

[0026] Furthermore, the nail ejecting nozzle and the first sliding bracket are configured as an integrated structure.

[0027] Furthermore, the rivet has an outer cap portion and a central shaft portion, and the end face of the cap portion is flush with the end face of the central shaft portion, and the outer diameter Φ1 and the height H of the rivet are in a relationship of: Φ1 / H>2.

[0028] According to another aspect of the present invention, a control method for a rivet conveying device is also provided, so that any of the above-mentioned rivet conveying devices can continuously convey rivets to a resistance spot welding machine and cooperate with the resistance spot welding machine to complete the riveting process. The control process includes the following steps:

[0029] Nail cleaning stage: the rotary drive drives the double-row swing rods to rotate to the initial position, and the telescopic drive pushes the nail grabbing head on the electrode side to release the remaining rivets;

[0030] Nail feeding stage: The sensor monitors the position of the nail grabbing head and the state of grabbing rivets, and the nail feeding device replenishes rivets to the empty nail grabbing head;

[0031] Swinging stage: The rotary driver drives the nail grabbing head to carry the rivet from the nail spouting nozzle position to the electrode position, thereby driving the nail grabbing head at the electrode position to rotate to another nail spouting nozzle position;

[0032] Welding stage: The electrode presses the rivet head of the gripper to release the rivet, and the telescopic driver drives the gripper head to avoid electrode welding, applies current to the welding spot and completes the welding;

[0033] Returning stage: The telescopic driver and the elastic component drive the first and second sliding brackets to return to their original positions, and the above process is repeated.

[0034] Beneficial effects of the present invention:

[0035] (1) The structure and size of this rivet conveying device are compact, it occupies little space in the spot welding tongs of resistance spot welding, is not prone to interference problems, and is beneficial to the welding of complex parts.

[0036] (2) The parts involved in the rivet conveying device are simple and small in number, which is conducive to installation, disassembly and reassembly. It is installed on the electrode connecting rod of the welding machine through a fixed bracket, which is conducive to rapid integration into the existing welding equipment, reducing the manufacturing cost of the mechanism and the cost of equipment upgrading and transformation. In addition, the rivet conveying device only involves two drive units, namely the telescopic driver and the rotary driver, which is beneficial to simplifying the control mode and motion program of the device, improving the motion coordination and motion efficiency of each mechanism, and ensuring the rivet feeding efficiency and stability of the mechanism.

[0037] (3) The nail ejection nozzle and the second sliding bracket are respectively installed on the fixed bracket through the first slider guide rail and the second slider guide rail, improving the linear sliding effect of the nail ejection nozzle and the second sliding bracket, and realizing the simultaneous sliding effect of the nail ejection nozzle and the second sliding bracket driven by the telescopic driver. When the gripper head on the electrode position opens to release the rivet and avoids the welding process, it can ensure that the gripper head at the nail ejection nozzle position can align with the nail ejection nozzle and grab the rivet at the same time. In addition, when the electrode presses the first workpiece downward, the gripper head and the double-row swing rod on the electrode side move upward away from the electrode direction, and the gripper head or double-row swing rod on the other side can simultaneously push the nail ejection nozzle upward to slide, avoiding the nail ejection nozzle being fixed in place and interfering with the movement process of the double-row swing rod and the second sliding bracket, and realizing the smooth release of the rivet by the gripper head under the electrode pre-pressing of the first workpiece.

[0038] (4) The swing rods on both sides of the double-row swing rod straddle both sides of the electrode connecting rod respectively, improving the rotational stability of the swing rod, and at the same time being beneficial to ensuring a good centering effect between the rivet grabbed by the gripper component installed at its end and the end of the electrode. In addition, the gripper component at the end of the double-row swing rod is set as a "V"-shaped elastic assembly, improving the stability of the gripper head on the gripper component for clamping the rivet and the smoothness of releasing the rivet under the extrusion of the electrode.

[0039] (5) An expansion pin with a nail-grabbing member is provided on the nail spitting nozzle, which can expand a certain gap between the two closed nail-grabbing heads, improve the channel for the rivet to enter the rivet receiving cavity in the nail-grabbing head, and avoid the problems of flipping and jamming of the rivet during the transfer process. In addition, the expansion pin also temporarily supports the rivet in the rivet receiving cavity, improving the stability of the rivet transfer process.

[0040] (6) Design the minimum inner diameter L1 of the inner wall of the nail-grabbing head to be smaller than the outer diameter Φ1 of the rivet. At the same time, design a convex rib structure near the end of the rivet receiving cavity in the nail-grabbing head, and set a vacuum pumping channel for vacuum pumping on the rivet receiving cavity, so that the nail-grabbing head forms multiple external force restraint effects of mechanical clamping, mechanical limiting and vacuum adsorption on the rivet, effectively maintaining the stability of the grabbed rivet when the double-row swing rod rotates. Description of the Drawings

[0041] Figure 1 Schematic diagram of a rivet conveying device according to an embodiment;

[0042] Figure 2 is Figure 1 Schematic diagram of the parts assembly of the device;

[0043] Figure 3 Integrated component diagram of the first sliding bracket, the material pipe and the nail spitting nozzle in another embodiment;

[0044] Figure 4 Schematic diagram of the rivet conveying device in another embodiment

[0045] Figure 5 is Figure 4 Connection state diagram of the telescopic driver and the upper and lower parts of the device;

[0046] Figure 6 is Figure 4 Another direction view of the device;

[0047] Figure 7 is Figure 4 Another direction view of the device;

[0048] Figure 8 Structural schematic diagrams of different second sliding brackets and double-row swing rods;

[0049] Figure 9 is Figure 4 Structure diagram of the double-row swing rod of the device;

[0050] Figure 10 is Figure 4 Cross-sectional view after installation of the second sliding bracket, double-row swing rod and rotary driver of the device;

[0051] Figure 11 Assembly drawing of the double-row swing rod and the nail-grabbing member;

[0052] Figure 12 Another view of the device in a different direction; Figure 4 Another view of the device in a different direction;

[0053] Figure 13 Schematic diagrams showing the swinging process of the swinging rod and the structures of different nail-gripping heads;

[0054] Figure 14 Schematic diagram of the structure of another nail-gripping head;

[0055] Figure 15 Schematic diagram showing the dimensions of the rivet accommodation cavity of the nail-gripping head and the dimensions of the rivets to be gripped;

[0056] Figure 16 Schematic diagram showing the transfer of the rivet from the nail ejection nozzle to the nail-gripping head;

[0057] Figure 17 Another; Figure 16 Schematic diagram showing the release of the rivet under electrode preloading after the improved dimensions of the nail-gripping head;

[0058] Figure 18 Schematic diagram of another improved structure of the nail-gripping head according to the present disclosure;

[0059] Figure 19 Schematic diagram of the nail-gripping head with another improved structure according to the present disclosure;

[0060] Figure 20 Schematic diagram of the nail-gripping head with another improved structure in the present disclosure;

[0061] Figure 21 Schematic diagram showing the effect of different opening states of the nail-gripping head on gripping the rivet in the present disclosure;

[0062] Figure 22 Schematic diagram showing the opening process of two closed nail-gripping heads after hitting the expansion pin in the present disclosure;

[0063] Figure 23 Schematic diagram of another design of the nail ejection nozzle structure in the present disclosure;

[0064] Figure 24 Another; Figure 23 Schematic diagram showing the transfer of the rivet from the nail ejection nozzle to the nail-gripping head in different orientations;

[0065] Figure 25 Schematic diagram of another structural arrangement of the expansion pin;

[0066] Figure 26 Schematic diagram of another structural scheme of the expansion pin;

[0067] Figure 27 In another embodiment of the present disclosure;

[0068] Figure 28 In yet another embodiment of the present disclosure, a design scheme for the staple head size;

[0069] Figure 29 is Figure 28 a schematic diagram of the structure of the side wall of the rivet receiving cavity of the staple head in

[0070] Figure 30 A schematic diagram of the sensor installation position in the rivet conveying device of the present disclosure;

[0071] Figure 31 A schematic diagram of the rivet conveying device according to still another embodiment of the present disclosure;

[0072] Figure 32 A schematic diagram of the rivet conveying device according to yet another embodiment of the present disclosure;

[0073] Figure 33 A schematic diagram of the welding system of the present disclosure;

[0074] Figure 34 A logical schematic diagram of the nail cleaning program of the welding device of the present disclosure;

[0075] Figure 35 A logical schematic diagram of the welding device mode of the present disclosure;

[0076] Figure 36 is a topographical map taken by an optical microscope of the surface of the solder joint after continuously welding aluminum / steel dissimilar metals using the device of the present invention in Example 1.

[0077] Correspondence table of numbers and names in the drawings:

[0078] Detailed implementation manners

[0079] The following is a detailed description of the device of the present invention through specific implementation manners and in conjunction with the drawings. It should be understood that the relevant dimensions mentioned herein are not limited by the dimensions or proportions of the schematic diagrams, and the description of the positions of the mechanisms, such as the terms "upper", "lower", "left", "right", and "outer side", etc., only relatively describes the relative positional relationship of each mechanism in combination with the placement posture of the mechanism in the drawings. For the descriptive terms of the mechanisms, such as "first..." and "second...", etc., are only used to distinguish one mechanism or part from another mechanism or part, and do not necessarily require or imply any such actual progressive or sorting relationship between these mechanisms or parts.

[0080] In the welding of a laminated structure of dissimilar metals, such as the welding of a laminated structure of aluminum alloy and steel, resistance spot welding is used to weld rivets into the weld spots, and forming a weld-rivet combined weld spot can achieve high-strength connection of dissimilar metals. Therefore, this type of process solution requires continuous feeding of rivets (or called fasteners) to the weld spots during the welding process. The present disclosure aims to solve the problem of continuously feeding rivets during the rivet welding of dissimilar metals by resistance spot welding. As Figure 1 shown, a rivet feeding device 908 is provided. This device is installed on the electrode connecting rod of a resistance spot welding tongs, and grabs rivets from two rivet ejection nozzle positions in turn by driving a swing rod and feeds the rivets to the electrode. Through the careful design and positioning installation of each mechanism and its movement trajectory, the reliability and stability of the mechanism movement are ensured, and the effect of continuously feeding rivets when resistance spot welding dissimilar metal workpieces is achieved.

[0081] As Figure 2 shown in A, the installation positions between the parts of the rivet feeding device 908 in an embodiment are shown. Among them, the fixed bracket 200 is fixedly installed on the periphery of the electrode connecting rod 101 through bolts, and all other parts of the device are installed on the fixed bracket, so that the rivet feeding device can be conveniently integrated or disassembled to the electrode connecting rod 101. As Figure 2 shown in A in this device, two first slider guides 301 are installed on the upper side of the fixed bracket 200, and they are installed symmetrically about the central plane. Another two second slider guides 302 are installed on the lower side of the fixed bracket 200, and they are also installed symmetrically about the central plane. The first sliding bracket 400 is slidably installed on the first slider guides 301, and two rivet ejection nozzles 502 are fixedly installed on the first sliding bracket, so that the two rivet ejection nozzles are symmetrically distributed on both sides of the fixed bracket. On the other hand, the second sliding bracket 600 is installed on the second slider guides, and the double-row swing rod 700 is installed on the second sliding bracket, so that the double-row swing rod can rotate around the installation position and slide up and down with the second sliding bracket. The rivet feeding device after the parts are installed is as Figure 2 shown in B, achieving the effect of a compact device structure, the effect of linear longitudinal sliding of the first and second sliding brackets and the reciprocating swing of the double-row swing rod.

[0082] In another embodiment, in order to reduce the number of parts, improve the installation accuracy of the parts and the compactness of the equipment, the first sliding bracket, the rivet ejection nozzle and the material pipe are integrated into an integral part, as Figure 3 shown. Two material pipes 500 for rivet feeding are symmetrically arranged, and their ends are connected to the rivet ejection nozzles 502.

[0083] Meanwhile, a certain area on the bodies of the two material pipes 500 is firmly connected together by a component, so that the two nail ejection nozzles and the two material pipes form an integral component. Two mounting ears 401 are provided on the integral component and are mounted on the first slider guide rail by bolts to achieve the function of sliding up and down. Of course, the material pipes connected to the nail ejection nozzles can be designed with adaptable shapes such as bending and rotating according to factors such as the space of the welding tongs and the shape and size of the rivet conveying device, as Figure 1 and Figure 4 show different material pipe shapes in the equipment of

[0084] See Figures 4 to 6 , the driving force source for the upward sliding of the nail ejection nozzle 502 and the second sliding bracket 600 is the telescopic driver 201 installed on the fixed bracket 200. In this embodiment, the telescopic driver 201 is a double-headed double-rod cylinder. The telescopic rod above 201 is connected to the mounting ear 401 on the nail ejection nozzle through the first coupling block 203 and the first elastic component 205. The telescopic rod below the first elastic component is connected to the second sliding bracket 600 through the second coupling block 204 and the second elastic component 206 ( Figure 6 C in Figure 6 B in

[0085] As Figure 5 and Figure 7 shown in B of Figure 7 B in

[0086] See Figure 8, a hollow mounting hole 601 is provided inside the body of the second sliding bracket 600. Installation positions for the second slider guide rails 302 are provided on both sides of the hollow mounting hole. When the second sliding bracket is sleeved onto the fixed bracket from bottom to top, both sides of the second sliding bracket are fixedly installed with the second slider guide rails 302 through bolts (which can be observed in conjunction with Figure 6 C in Figure 7 and B). A connecting rod portion 603 extends from one side of the body of the second sliding bracket. A drive mounting seat 604 is provided at the end of the connecting rod portion for mounting a rotary drive. A first limiting block 602 protrudes from the other side of the body of the connecting rod portion, which is used to limit the stroke when the double-row swing rod 700 reciprocates. It can be observed in conjunction with Figure 6 C. The positions where the swing rod contacts the first limiting block 602 at the left and right end positions of the rotation of the double-row swing rod are the two end positions. Further, the connecting rod portion 603 can also function as a second limiting block, playing the same limiting function on the rotation of the double-row swing rod on the other side, so that both sides of the double-row swing rod are subjected to balanced impacts. In addition, in order to reduce the impact force when the double-row swing rod contacts the first and second limiting blocks, an elastic shock-absorbing mechanism and a buffer pad can be appropriately provided on the first and second limiting blocks. Mounting shafts 605 are also provided on both sides of the second sliding bracket for mounting the double-row swing rod.

[0087] See Figure 8 and Figure 9 , the double-row swing rod 700 is composed of two first swing rods 701 and second swing rods 702 arranged in parallel at a certain distance. The first and second swing rods are distributed at an obtuse angle α with the rotation center as the vertex. According to the operating characteristics of the double-row swing rod, on the opposite side of the obtuse angle α ( Figure 9 the upper part in Figure 8 ), a transverse connecting portion 708 is provided to connect the first and second swing rods, so that the two swing rods are connected into one body to ensure synchronization during swinging. Of course, as Figure 8 shown in Figure 8 B, according to the structural characteristics of different second sliding brackets, it is required that the double-row swing rod meet different installation requirements. Therefore, the transverse connecting portion 708 can be designed as an integral structure ( A in

[0088] Figure 9

[0089] Figure 10 See Figure 10, when installing the double-row swing rod 700 onto the second sliding bracket 600, a bearing 606 is installed on the installation shaft 605, and the bearing mounting seat 703 of the double-row swing rod 700 is sleeved outside the bearing 606, enabling the double-row swing rod 700 to rotate smoothly around this shaft. The rotary drive 202 is installed on the drive mounting seat 604, with its rotary drive shaft coaxially installed with the shaft hole 704 of the double-row swing rod 700 to provide it with rotary driving force.

[0090] See Figure 11 In A of, two nail-grabbing members 800 are installed at one end of the double-row swing rod 700. (Here, to distinguish and describe these four nails, different numbers are used), and the two nail-grabbing members at the same end are marked as the first nail-grabbing member 800a and the second nail-grabbing member 800b, and the two at the other end are marked as the third nail-grabbing member 800c and the fourth nail-grabbing member 800d. Except for the difference in the position of the fourth limiting part 802, the structures of the four nail-grabbing members described here are the same. Additionally, due to the symmetric installation characteristics of the nail-grabbing members, the structures of the first and third nail-grabbing members are completely the same, and the structures of the second and fourth nail-grabbing members are completely the same. See Figure 11 In B of, Figure 12 In B and Figure 12 In C of, the nail-grabbing member 800 includes a handle part 801 and a nail head 803 extending from the handle part. During installation, the handle part 801 is rotatably installed on the U-shaped mounting seat 706 at the end of the first or second swing rod ( Figure 11 In A of). The third elastic component 207 is installed between the end of the handle part of the nail-grabbing member and the swing rod, driving the nail head of this nail-grabbing member to swing towards the central plane of the double-row swing rod. After the two nail heads on the same side are closed, the two nail-grabbing members are in an opposing "V" shape, and then they can cross the end of the electrode along with the swing of the double-row swing rod and be distributed on both sides of the electrode 102 (12B). The fourth limiting part 802 on the handle part of the nail-grabbing member fits with the third limiting part 705 on the double-row swing rod (see Figure 12 In B of), which serves to fix the termination position of the two nail heads after each closing, ensuring that the rivets grabbed by the nail heads each time can be centered with the axis of the electrode 102. When the closed nail heads are opened under the action of an external force, the third elastic component 207 stores elastic energy. After the external force is withdrawn, the third elastic component releases the elastic energy and drives the nail heads to return to the closed state. A rivet accommodation cavity 804 is formed after the two nail heads are closed for accommodating the rivet 900 ( Figure 12 In C of).

[0091] See Figure 12In A, the rotary drive 202 drives the double-row swing rod 700 to rotate reciprocally, so that the first and second nail-grabbing members 800a and 800b (not marked) at one end of the double-row swing rod move from the position of the right nail ejection nozzle 502 to the position of the electrode directly below, and the third and fourth nail-grabbing members 800c and 800d (not marked) at the other end move from the position of the electrode to the position of the nail ejection nozzle on the left. In this embodiment, the rotary drive adopts a pneumatic rotary drive, and there is a relationship between the maximum rotation angle A of its shaft part and the maximum rotation angle B of the double-row swing rod: A≥1.2×B. By setting the rotation angles of the two in this way, it can be ensured that the double-row swing rod can swing completely to the final positions set at both ends. As Figure 12 In B and Figure 12 As shown in C, in order to ensure that the nail-grabbing head 803 can be completely screwed into the position directly below the electrode from the side of the electrode 102, a minimum gap h1>0 is set between the end of the electrode 102 and the nail-grabbing head. Preferably, the range of h1 is: 2mm≤h1≤5mm.

[0092] As Figure 12 In C, in order to enable the rivet receiving cavity 804 of the nail-grabbing head to firmly grasp the rivet, a through-channel 809 is provided inside the nail-grabbing member and extends to the inner wall of the rivet receiving cavity 804 of the nail-grabbing head. When the nail-grabbing head grabs the rivet 900, the through-channel 809 is connected to a vacuum pump to extract vacuum, so that a negative pressure is formed in the rivet receiving cavity 804 to more firmly adsorb the rivet 900.

[0093] See Figure 13 In A, in one embodiment, since the double-row swing rod 700 rotates and swings at a high speed, and there is a large impact force after swinging in place, which causes the nail-grabbing head to vibrate, the rivet 900 is still likely to fall off from the vacuum-adsorbed nail-grabbing head 803. In order to improve the firmness of the nail-grabbing head's grasping of the rivet, the structure of the nail-grabbing head is optimized from Figure 13 In B to Figure 13 In C, that is, a convex rib structure 807 is provided on the lower end surface of the rivet receiving cavity 804 to prevent the rivet 900 from falling off the nail-grabbing head when the double-row swing rod rotates.

[0094] As Figure 14 shown, in one embodiment, the convex rib structure on the lower end surface of the rivet receiving cavity 804 is set as a compressible ball-type telescopic stopper 808. After the rivet 900 moves downward after being squeezed by the electrode 102 and contacts the ball-type telescopic stopper 808, at least part of the ball-type telescopic stopper will shrink into the nail-grabbing head body to ensure that the rivet 900 can be smoothly squeezed onto the workpiece surface.

[0095] As Figure 15As shown, in one embodiment, the rivet receiving cavity 804 formed by the joining of two rivet heads 803 has an inner wall minimum diameter L1 in the cavity that is smaller than the outer diameter Φ1 of the rivet. There is a relationship between the height h3 of the receiving cavity and the height h2 of the rivet 900: h2 < h3 < 2×h2. With such a setting, the stability of the rivet receiving cavity 804 for gripping the rivet 900 is ensured. The rivet 900 has an outer cap portion and a central shaft portion, and the end face of the cap portion is flush with the end face of the central shaft portion. There is a relationship between the outer diameter Φ1 of the rivet and the height h2: Φ1 / h2 > 2.

[0096] See Figure 16 In A, after the rivet head 803 is aligned with the nail outlet 503 of the nail ejecting nozzle 502, high-pressure gas pushes the rivet 900 from the hollow material channel 501 in the material tube to the nail outlet 503, and enters the rivet receiving cavity 804 almost in the axial direction of the rivet from the end of the rivet head. To improve the stability of the rivet transferred to the rivet head, a secondary air duct 504 is provided above the nail outlet 503. After the rivet approaches the nail outlet 503, part of the high-pressure gas can enter the secondary air duct 504, increasing the pressure of the high-pressure gas from top to bottom and stabilizing the directionality of the rivet ejected from the nail outlet 503. A supporting portion 805 is provided on the side of the rivet receiving cavity 804 away from the end of the rivet head. The supporting portion 805 is used to support the rivet transferred from the nail ejecting nozzle to the rivet receiving cavity. Generally speaking, the larger the transverse width d1 of the supporting portion 805, the more beneficial it is to support the rivet and ensure the stability of gripping the rivet. However, during the welding process, if the transverse width d1 is too large, after the electrode presses against the supporting portion 805, the joined rivet heads cannot be smoothly opened, resulting in the failure of the rivet heads to release the rivet, as shown in Figure 16 shown in B. To improve the smoothness of the rivet heads releasing the rivet during the welding process, as shown in Figure 17 shown in A, the transverse width d1 of the supporting portion 805 is reduced to d1' (preferably, d1' ≤ 3 mm), thereby expanding the minimum diameter Φ2 of the through hole formed by the rivet heads. At the same time, the longitudinal height h4 of the supporting portion 805 is reduced (preferably, h4 < 2.5 mm), reducing the stroke of the electrode 102 pressing against the rivet 900. With such a setting, as shown in Figure 17 shown in B, when the electrode 102 pre-presses the rivet 900, the end of the electrode can quickly contact the rivet, and then smoothly push the rivet onto the surface of the first workpiece 901. As shown in Figure 17 shown in C, under the pulling of the telescopic driver, the rivet heads can also be smoothly opened and slide to the side of the electrode, avoiding the interference of the rivet heads with the welding process of the electrode.

[0097] See Figure 18In A, in one embodiment, the outer diameter of the rivet 900 is much smaller than the diameter of the welding electrode 102 body. For example, in the case where the outer diameter of the rivet is 10 mm and the outer diameter of the electrode is 16 mm. In order to prevent the rivet head 803 from interfering with the process of the electrode pre-pressing the rivet, the supporting portion is set as an elastic supporting portion 806, and a fourth elastic component 208 is provided at the rotating position. As Figure 18 As shown in B, after the electrode 102 presses the rivet, the elastic supporting portion 806 is forced to swing and avoid the downward pressing process of the electrode, so that the electrode can smoothly extrude the rivet onto the surface of the first workpiece 901 for welding.

[0098] See Figure 19 , in one embodiment, when the outer diameter Φ1 of the rivet 900 is smaller than the diameter Φ3 of the welding electrode 102 body, for example, the outer diameter of the rivet is 15 mm and the direct diameter of the electrode body is 16 mm. In order to enable the electrode to smoothly extrude the rivet and the rivet head can smoothly release the rivet, on the one hand, the lateral width d1’’ of the supporting portion 805 is further reduced, preferably d1’’ ≤ 1.2 mm, and the longitudinal height of the supporting portion 805 does not exceed 2 mm. In addition, the longitudinal height and the radian of the electrode curved surface 105 between the electrode end face 103 and the electrode side face 104 are adapted to increase, so that before the electrode side face 104 contacts the supporting portion 805, the electrode end face 103 has already extruded the rivet 900 onto the surface of the first workpiece.

[0099] See Figure 20 As shown in A, in one embodiment, the supporting portion on the rivet head can also be set as a ball-type telescopic stopper 808. The elastic structure of 808 retracts into the rivet head body after being extruded by the electrode. On the one hand, it is beneficial for the electrode 102 to extend into the rivet head to push the rivet onto the workpiece. On the other hand, as Figure 20 As shown in B, when the rivet head opens and lifts towards the side of the electrode connecting rod 101, it can more smoothly cross the electrode installation gap 106 between the electrode and the electrode connecting rod, which is beneficial for the welding equipment to replace the electrode or grind and refurbish the electrode end face. At the same time, this makes the rivet head structure more efficiently adapted to the welding tongs devices on the market.

[0100] By Figure 17 in A, Figure 19 and Figure 20 in A, the strategy of reducing the size of the supporting portion, although it is beneficial for the electrode to extrude the rivet onto the workpiece surface, but the too small size of the supporting portion results in too large a minimum diameter Φ2 of the through hole in the rivet accommodating cavity. When the rivet 900 ejected from the nail ejection nozzle 502 enters the rivet accommodating cavity of the rivet head, it is easy to fall over, as Figure 21 shown in A. On the other hand, the minimum inner wall width of the rivet accommodating cavity 804 of the rivet head 803 does not exceed the outer diameter of the rivet, which also makes it difficult for the rivet to smoothly enter the rivet accommodating cavity. In order to solve the problem as Figure 21To solve the problem of rivet tipping and jamming as shown in A, and to ensure that the rivet smoothly entering the rivet receiving cavity can stay stably, an expansion pin 402 (which can be combined with a rivet spout 502) is provided near the rivet spout 502. Figure 3 and Figure 30 Observe the position of the expansion pin 402). Figure 21 As shown in FIG. 8B , the expansion pin 402 is used to open the two closed nail grabbing heads (803) by a certain distance to expand the passage of the rivet 900 into the rivet receiving cavity. On the other hand, the expansion pin 402 is placed between the two nail grabbing heads to temporarily support the rivet and stabilize the state of the rivet entering the rivet receiving cavity. Figure 22 The diagram shows the process of the expansion pin 402 opening two closed nail grabbing heads 803. The expansion pin 402 is designed to be similar to a half shuttle-shaped structure. After the double-row swing rod rotates and swings, the nail grabbing heads hit the expansion pins downward, and the nail grabbing heads gradually open and stay on both sides of the expansion pins. On the other hand, since the nail grabbing heads have an elastic closing tendency, the friction sliding process between them and the expansion pins plays a decelerating role on the nail grabbing heads, reducing the impact force of the nail grabbing heads hitting the first limit block.

[0101] like Figure 23 As shown, in one embodiment, a first sensor 407 is provided near the expansion pin to monitor the position of the nail head. Figure 23 As shown, a second sensor 408 is also provided on the expansion pin 402 for monitoring the position of the rivet 900 in the rivet receiving cavity. Figure 23 As shown, during the process of transferring the rivet 900 from the rivet ejection nozzle 502 to the rivet grabbing head 803, it is preferably ensured that the rivet 900 moves in the direction of its axis to avoid the problem of the rivet tipping over during the transfer process. In addition, in order to ensure that the rivet is transferred from the hollow material channel to the rivet grabbing head 803 faster and more stably, the thickness d2 of the material tube side wall on the side close to the rivet grabbing head is not more than 3 mm, preferably 0.5 to 1.5 mm. In addition, the minimum gap d3 between the rivet ejection nozzle and the rivet grabbing head is set to not more than 5 mm. Preferably, the range of d3 is 1~3 mm. According to another aspect of this embodiment, a secondary air blowing channel 505 is provided on the other side of the rivet ejection nozzle 502 away from the rivet grabbing head 803, which is used to assist the rivet 900 to be transferred into the rivet grabbing head. In addition, under the complex working conditions of actual welding, the high-pressure gas output by the secondary air blowing channel is also used to assist the rivet 900 to be temporarily fixed in the rivet accommodating cavity of the rivet grabbing head. As shown Figure 24 In the case of A, the rivet is transferred to the rivet head, and the vacuum suction force of the central through pipe 809 can stabilize the rivet, without the need for secondary air duct assistance. Figure 24 Medium B and Figure 24In the case of C, the vacuum adsorption force of the through - middle pipeline 809 may not be able to stably hold the rivet in the nail - grasping head. Therefore, the high - pressure gas continuously output by the secondary air duct 505 acts on the surface of the rivet to form pressure, ensuring that the rivet can be stable in the nail - grasping head and preventing the rivet from falling off.

[0102] See Figure 25 , in one embodiment, in order to further stabilize the rivet entering the rivet accommodation cavity, a magnetic material 403 is laid on the expansion pin 402. When the steel rivet enters the rivet accommodation cavity, the magnetic material can quickly adsorb the rivet, playing a role in temporarily fixing the rivet.

[0103] See Figure 26 In A and Figure 26 In B, in one embodiment, the second sensor 408 is arranged on the side of the secondary air duct 505; a vacuum - pumping channel 406 is arranged on the expansion pin 402 for pumping vacuum to form an adsorption force to adsorb the rivet 900. Arranging the vacuum - pumping channel on the expansion pin can reduce the difficulty of its external vacuum pump and the complexity of the air - pipe layout, and at the same time improve the ability to vacuum - adsorb the rivet. In addition, the hollow material channel 501 in the nail - spitting nozzle forms an angle γ with the horizontal plane, so that when the rivet 900 is conveyed to the nail - outlet, part of the rivet area enters the nail - grasping head, further ensuring that the rivet can be smoothly transferred to the rivet accommodation cavity of the nail - grasping head.

[0104] See Figure 27 In A and Figure 27 In B, after the two nail - grasping heads 803 are joined together, a U - shaped groove 810 is formed on one side. The expansion pin 402 penetrates into the interior of the nail - grasping head from one side of the U - shaped groove 810, reducing the impact force of the expansion pin hitting the nail - grasping head and realizing the stable opening and closing of the nail - grasping head. The width of the tip part of the expansion pin 402 is less than the width d4 of the U - shaped groove 810, while the maximum width d5 of the expansion pin 402 body is greater than the width d4 of the U - shaped groove 810. Preferably, the relationship between d4 and d5 is: 1.5 mm < d5 - d4 < 3.5 mm.

[0105] See Figure 28 In A, in one embodiment, the joining surface of the two closed nail - grasping heads 803 is in the vertical direction. The maximum width L2 of the inner wall of the rivet accommodation cavity 804 on the joining surface is greater than the outer diameter Φ1 of the rivet 900, while the inner diameter L1 of the inner wall of the rivet accommodation cavity in the horizontal direction is less than the outer diameter Φ1 of the rivet. In addition, the convex rib structure 807 on the nail - grasping head is set in a crescent shape, and the maximum transverse width d6 is set in the horizontal direction. Preferably, d6 < 1.5 mm. See Figure 28In Figure B, when the two joined nail grabbing heads are stretched apart from the joint surface by the expansion pin 402, the above-mentioned structure and size design can ensure that the opening size of the nail grabbing head after the horizontal opening is completely larger than the outer diameter of the rivet in the circumferential direction, so that the rivet can smoothly enter the rivet receiving cavity of the nail grabbing head. Because of the size design of L1<Φ1, when the nail grabbing head is closed, the side wall of the rivet receiving cavity can exert a certain mechanical clamping force on the rivet in the horizontal direction. On the other hand, if Figure 29 As shown, longitudinal ridges 811 are provided on the side walls of the rivet receiving cavity 804 to expand the contact points of the rivet receiving cavity side walls with the rivets and improve the stability of grabbing the rivets. Further, these longitudinal ridges 811 can be configured as elastic mechanisms to apply elastic pressure to the periphery of the rivet on the side.

[0106] See also Figure 30 In one embodiment, a support rod 405 is provided on the first sliding bracket 400, and the support rod is used to support the support platform 709 on the lateral connection part of the double-row swing rod 700 on this side, so that the spacing and position state between the nail grabbing head and the nail spouting mouth on this side can also be maintained stable during the welding process. The specific process is: when the electrode pre-presses the rivet of the lower nail grabbing head, as the nail grabbing head contacts the surface of the workpiece, the double-row swing rod 700 as a whole gradually moves upward by a certain distance. At this time, the support platform 709 applies a force to the support rod 405 to push the first sliding bracket 400 to move upward synchronously, ensuring that the nail spouting mouth 502 and the nail grabbing head 803 maintain a set spacing, which is conducive to the welding equipment being able to stably deliver rivets 900 to the nail grabbing head 803 on this side during pre-pressing or welding. On the other hand, the first sensor 407 is set on the left and right support rods 405, and the second sensor 408 is set on the left and right expansion pins 402, so as to realize real-time monitoring of the position of the nail grabbing head and the rivet in place state. The third sensor 409 is arranged on the side of the first slider guide rail 301. Its specific function is that when the electrode pre-presses the rivet to the workpiece, the double-row swing rod will push the first sliding bracket to move upward for a certain distance, and the corresponding slider of the first slider guide rail will slide upward. After the third sensor 409 detects that the slider has reached the predetermined position information, it transmits a signal to drive the telescopic drive upward, thereby stretching the first and second sliding brackets to move upward, thereby realizing automatic grasping of the nail head to open and avoiding the welding process.

[0107] See also Figure 31 In one embodiment, according to the structural characteristics of the welding clamp and the electrode connecting rod of different welding equipment, the first elastic component 205 is arranged between the fixed bracket 200 and the first sliding bracket 400, and the second elastic component 206 is arranged between the fixed bracket 200 and the second sliding bracket 600. Such a design further improves the compactness of the equipment.

[0108] See also Figure 32, in one embodiment, according to the characteristics of the electrode holder and electrode connecting rod structures of different welding devices. For example, when the body diameter of the electrode connecting rod 101 changes little, the nail ejection nozzle 502 and the double-row swing rod 700 can be installed on the larger-sized first sliding bracket 400 at the same time, and only the first elastic component 205 needs to be installed between the fixed bracket 200 and the first sliding bracket 400. Further, the fixed bracket 200 and the first sliding bracket 400 can be respectively designed as a hollow guide post and a guide sleeve. Among them, the hollow guide post is installed on the electrode connecting rod, and the guide sleeve serves as the first sliding bracket. Appropriate balls are arranged between the hollow guide post and the guide sleeve for sliding to achieve the effect of the up-and-down sliding of the double-row swing rod.

[0109] As Figure 33 shown, the rivet conveying device 908 of the present invention is installed on the electrode connecting rod of the electrode holder 100. Specifically, it further includes a nail feeding controller 905 that integrates the nail collecting unit and the control unit. In one implementation case, the entire welding device further includes a central controller 907, a welding controller 906, and a robot controller 904. The nail feeding controller 905 communicates with the welding controller 906 and the robot controller 904 through the central controller 907. By setting a specific control method for the welding device, continuous rivet feeding for the resistance spot welding machine and cooperation with the resistance spot welding machine to complete the riveting and welding process are realized. The specific control program includes a nail clearing control program and a welding control program. The nail clearing control program is used to identify and remove the rivets on the nail grasping head on the electrode side before the first welding. Specifically, before manufacturing the first weld point, the nail clearing program is started, the rotary driver drives the double-row swing rod to rotate to the set initial position and be in place, so that the nail grasping heads on the two ends of the swing rod swing to the positions on the electrode side and the position on the side of a nail ejection nozzle respectively. The first sensor feeds back the in-place state of the nail grasping head and feeds back information a. Subsequently, the nail feeding controller controls the telescopic driver to start, so that the nail grasping head on the electrode side is pushed against the electrode and forced to open, releasing the possible rivets on the nail grasping head on this side. The specific control process is as Figure 34 shown.

[0110] The logic diagram of the welding control program is as Figure 35 shown. By sensors (including the first, second, and third sensors), information such as the in-place situation of the mechanism and the in-place situation of the rivets is automatically monitored, and after feeding back relevant information to the controller, a quick response is made to realize the process of the intelligent movement of the mechanism, automatic nail feeding, the mechanism avoiding welding, and after the robot welds the rivet to the workpiece, the mechanism automatically returns to its original position and feeds nails for the next weld point. Specifically, it includes the following steps:

[0111] A) The first nail feeding stage: The second sensor feeds back the rivet in-place information in the nail grasping head at the current nail ejection nozzle position. When there is no rivet in the nail grasping head, the nail feeding controller controls the nail feeding device to start and convey rivets to the nail grasping head until the second sensor feeds back the rivet in-place information after the rivet is in place;

[0112] B) Swing stage: The rotary drive is started, causing the nail gripper head that has successfully grasped the rivet at the nail ejection nozzle position to rotate to the electrode position, while the nail gripper head at the electrode position rotates to another nail ejection nozzle position;

[0113] C) Rivet release and welding stage: The electrode pre-presses the nail gripper head on this side, forcing the nail gripper head to open and release the rivet. When the electrode presses the rivet against the first workpiece and reaches the set electrode pressure value (or the signal given by the third sensor), the telescopic drive is started to lift the nail gripper head upward, causing the nail gripper head on the electrode side to open further and move away from the workpiece surface. When the electrode pre-pressing time reaches the set value, a welding current is applied to the solder joint to complete the process of welding the rivet to the workpiece.

[0114] D) Second nail feeding stage: After the first sensor on the other nail ejection nozzle side monitors that the nail gripper head is in place, the nail feeding device is started to feed the rivet to the nail gripper head on this side, and the second sensor monitors and feeds back the information of the rivet in place on the nail gripper head on this side;

[0115] E) Home position stage: After welding is completed, after the electrode connecting rod of the welding tongs moves the electrode away from the solder joint surface by a certain distance, the telescopic drive moves towards the electrode, causing the nail ejection nozzle and the second sliding bracket to be completely returned under the push of the first and second elastic components, and the nail gripper head on the electrode side is simultaneously returned and closed;

[0116] F) Next solder joint stage: Repeat the process of stage B → stage C → stage D → stage E.

[0117] Optionally, stage D can be set before, after or simultaneously with stage C.

[0118] Embodiment 1

[0119] In Embodiment 1, the rivet conveying device of the present invention is adopted (see Figure 4 ), and the first workpiece 901 and the second workpiece 902 are welded. The first workpiece is 6111 aluminum alloy with a thickness of 2.0 mm, and the second workpiece is Al-Si coated hot-formed steel with a thickness of 1.6 mm. The rivet used for welding is the rivet structure disclosed in Patent CN118720377A, and the welding process parameters are set by the method disclosed in Patent CN114211104 B. During the welding process, the rivets are fed to the two nail gripper heads alternately through the nail ejection nozzles on both sides of the electrode connecting rod, and the rivets are fed to the electrode under the swing of the double-row swing rod. During the welding process, the telescopic drive is used to implement the welding process of the nail gripper head avoiding the electrode, achieving the effect of continuous and efficient welding of aluminum / steel dissimilar metals by the welding equipment. Figure 36The figure shows the surface topography of the solder joints obtained after continuous welding, as captured by an optical microscope. It can be seen that the rivet 900 has been successfully welded to the workpiece, with well-formed solder joints and no serious defects such as severe distortion or cracking. This indicates that the device of the present invention can achieve the effect of continuously transporting and firmly welding rivets to dissimilar metals.

[0120] In the above embodiment, the double-row swing rod is composed of two parallel swing rods that form an obtuse angle. The nail-grabbing members are installed at both ends of the swing rods in a "V"-shaped opposing manner, forming a rivet receiving cavity after closing, thereby achieving precise grasping and releasing of the rivets. At the same time, through an elastic closing mechanism (such as the third elastic component), it is ensured that the rivets are stably fixed during the swinging process. The obtuse angle layout of the swing rods expands the movement range of the nail-grabbing heads, enabling them to span both sides of the electrode and avoiding interference with the welding electrodes. Compared with the traditional single swing rod structure, the double-row design significantly improves the symmetry and stability of rivet transportation. Through the cooperation of the first elastic component and the second elastic component with the double-headed cylinder (the telescopic actuator), the automatic reset function of the sliding bracket is achieved. When the electrode finishes welding, the elastic component releases the stored energy, driving the nail ejection nozzle and the sliding bracket to quickly return to the position close to the electrode. The output force of the telescopic actuator is greater than the maximum elastic force of the elastic component, ensuring that the elastic resistance is preferentially overcome during the driving process to avoid reset lag, simplifying the complexity of the mechanical structure and at the same time improving the response speed of the device. The fixed bracket is directly installed on the electrode connecting rod, and the nail ejection nozzle and the sliding bracket adopt an integrated structure, reducing the external occupied space. The curved adaptation design of the material tube and the nail ejection nozzle further adapts to complex welding scenarios. The control method is divided into five stages: nail clearing, nail feeding, swinging, welding, and returning. Each stage is seamlessly connected through sensor feedback. For example, in the nail clearing stage, the residual rivets are automatically cleared, and in the welding stage, the current is triggered according to the electrode pressure or sensor signal to ensure the welding quality. During the welding stage, the telescopic actuator drives the nail-grabbing heads away from the electrode area, avoiding damage to the conveying mechanism caused by high temperature or current, and at the same time increasing the service life of the equipment.

[0121] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. At the same time, in the drawings of the present invention, the filling patterns are only for distinguishing layers and are not subject to any other limitations.

[0122] It should be understood that the purpose of the above embodiments is only to illustrate the technical concept of the present invention for the understanding of those skilled in the art, rather than to limit the protection scope of the present invention. Within the scope of the claims of the present invention, any improvement and equivalent replacement of the parts, structures or method steps involved in the above embodiments, especially the combination of different embodiments without structural or principle conflicts, fall within the protection scope of the present invention.

Claims

1. A rivet conveying device for continuously conveying rivets when welding workpieces to the electrode at the end of the electrode connecting rod, characterized in that: include: A fixed bracket (200) is mounted on the electrode connecting rod (101) of the welding clamp, a first slider guide rail (301) is laid on the upper part of the fixed bracket (200), and a second slider guide rail (302) is laid on the lower part of the fixed bracket (200); The first sliding bracket (400) is slidably mounted on the first sliding block guide rail (301), and two nail ejection nozzles (502) are symmetrically mounted on both sides. A second sliding bracket (600) is slidably mounted on the second sliding block guide rail (302) and is located between the nail ejecting nozzle and the electrode; A double row of swing rods (700), the middle portion of which is rotatably mounted on the second sliding bracket, and is composed of two swing rods that are parallel to each other and form an obtuse angle and are symmetrically arranged; The nail grabbing components (800) are rotatably mounted on both ends of the double-row swing rod (700), and each end of the double-row swing rod is provided with two nail grabbing components, and the nail grabbing heads (803) of the nail grabbing components can be elastically closed to form a "V"-shaped opposing structure, and after closing, a rivet accommodating cavity (804) is formed; A telescopic driver (201) is mounted on the fixed bracket (200) and is used to drive the nail ejecting nozzle and the second sliding bracket to move synchronously and linearly away from the electrode direction; A first elastic component (205) and a second elastic component (206) are respectively mounted on the telescopic rod of the telescopic driver (201), and are respectively connected to the first sliding bracket and the telescopic rod, and the second sliding bracket and the telescopic rod, and are used to drive the first and second sliding brackets to return to a position close to the electrode; as well as The rotary driver (202) is mounted on the second sliding bracket (600) and is used to drive the double-row swinging rod (700) to swing back and forth, so that the nail grabbing head (803) at the end of the nail grabbing member alternately grabs the rivets from the two nail spouting nozzles (502) and transports them to the position of the electrode, and releases the rivets under the pressure of the electrode to avoid electrode welding.

2. The rivet conveying device according to claim 1, characterized in that: When the electrode pre-presses the first workpiece, the electrode squeezes the rivet on the nail grabbing head onto the first workpiece; under the squeezing of the electrode, the two closed nail grabbing heads are forced to open adaptively and release the rivet, and the second sliding bracket slides linearly in the direction away from the electrode under the push of the double-row swing rod, and the first sliding bracket and the nail spouting nozzle slide linearly in the direction away from the electrode at the same time under the push of the double-row swing rod or the nail grabbing member, so that the first and second elastic components are compressed and stored energy; After the electrode is pulled away from the welding point, the nail grabbing head is separated from the workpiece, and the elastic energy of the first and second elastic components is released, driving the first sliding bracket, the nail ejecting nozzle, the second sliding bracket and the double-row swing rod to reset.

3. The rivet conveying device according to claim 2, characterized in that: The telescopic driver (201) is a double-headed cylinder, the driving force output by which is greater than the maximum elastic force of the first elastic component and the second elastic component.

4. The rivet conveying device according to claim 1, characterized in that: The minimum width L1 of the inner wall of the rivet accommodating cavity is smaller than the outer diameter Φ1 of the rivet, and the height of the rivet accommodating cavity is 1 to 2 times the height of the rivet.

5. The rivet conveying device according to claim 4, characterized in that: A supporting portion (805) is provided in the rivet accommodating cavity at a side away from the end of the rivet grabbing head, the supporting portion being used to support the rivet transferred from the rivet ejecting nozzle into the rivet accommodating cavity, and a convex ridge structure (807) is provided at one side of the end of the rivet grabbing head for limiting the rivet from being separated from the rivet accommodating cavity when the double-row swinging rod rotates.

6. The rivet conveying device according to claim 5, characterized in that: The supporting portion and the ridge structure are compressible elastic structures, and when subjected to external force, they are partially retracted into the nail grabbing head (803).

7. The rivet conveying device according to claim 1, characterized in that: After the telescopic driver is fully extended toward the electrode side and reset, the first and second elastic components can fully drive the first and second sliding brackets to reset to the position closest to the electrode.

8. The rivet conveying device according to claim 1, characterized in that: When the telescopic drive drives the second sliding bracket to move away from the electrode side, the closed nail grabbing heads of the two nail grabbing members at the electrode position are pushed against the electrode and are forced to open and release the grasped rivets, and the electrode at least partially protrudes outside the range surrounded by the two nail grabbing heads.

9. The rivet conveying device according to claim 1, characterized in that: The interior of the nail grasping member is provided with a vacuum channel extending to the inner wall of the rivet accommodating cavity of the nail grasping head, and the vacuum channel is used for vacuuming to form a negative pressure in the rivet accommodating cavity to adsorb the rivet.

10. The rivet conveying device according to claim 1, characterized in that: The rotary driver is a pneumatic driver, and the maximum rotation angle of the shaft is A. The second sliding bracket is provided with a first limit block for limiting the maximum rotation angle B of the double-row swing arm, and the angle A and the angle B are in a relationship: A≥1.2×B.

11. The rivet conveying device according to claim 1, characterized in that: A first sensor is provided near the nail ejection nozzle for monitoring the position information of the nail grabbing head, and a second sensor is provided for monitoring the position information of the rivet in the rivet accommodating cavity.

12. The rivet feeding device according to claim 11, characterized in that: An expansion pin is provided near the rivet ejection nozzle, which is used to prop open the closed rivet grabbing head (803) to expand the rivet entry channel and temporarily support the rivet.

13. The rivet feeding device according to claim 12, characterized in that: The second sensor is mounted on the expansion pin.

14. The rivet feeding device according to claim 13, characterized in that: The expansion pin has magnetic adsorption capability and is used for stably adsorbing the rivet transferred from the rivet ejection nozzle to the rivet accommodating cavity.

15. The rivet conveying device according to claim 1, characterized in that: The rivet ejection nozzle and the first sliding bracket are arranged as an integrated structure, and are connected to a material pipe (500) for conveying rivets.

16. The rivet conveying device according to claim 1, characterized in that: The rivet has a peripheral cap portion and a central shaft portion, and the end surface of the cap portion is flush with the end surface of the central shaft portion. The outer diameter Φ1 and the height H of the rivet are in a relationship of: Φ1 / H>2.

17. A welding control method for a rivet conveying device, used to control the rivet conveying device according to any one of claims 1 to 16 to continuously convey rivets to a resistance spot welding machine and cooperate with the resistance spot welding machine to complete the riveting process, characterized in that: It includes the following stages: Nail cleaning stage: the rotary drive drives the double-row swing rods to rotate to the initial position, and the telescopic drive pushes the nail grabbing head on the electrode side to release the remaining rivets; Nail feeding stage: The sensor monitors the position of the nail grabbing head and the state of grabbing rivets, and replenishes rivets to the empty nail grabbing head; Swinging stage: The rotary driver drives the nail grabbing head to carry the rivet from the nail spouting nozzle position to the electrode position, and at the same time, drives the nail grabbing head at the electrode position on the other side to rotate to another nail spouting nozzle position; Welding stage: the electrode squeezes the nail grabber to release the rivet, and the telescopic drive drives the nail grabber to avoid the welding area, applying current to the welding point and completing the welding; Return stage: the telescopic driver and the elastic component drive the first and second sliding brackets to return to their original positions, and the above steps are repeated.

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