Rivet conveying device and welding control mode thereof

Abstract

A rivet conveying device comprises a fixed support, a first sliding support, a second sliding support, a rivet discharging nozzle, a double-row swing rod, a rivet grabbing component, a telescopic driver, a rotary driver, a first elastic assembly and a second elastic assembly. The fixing support is installed on the electrode connecting rod, the two nail discharging nozzles are symmetrically installed on the two sides of the fixing support in a sliding mode, the double-row swing rod is rotatably installed on the portion, between the nail discharging nozzles and the electrode, of the fixing support through a second sliding support, and the nail grabbing components are installed at the two ends of the double-row swing rod. Sliding of the second sliding support and the nail discharging nozzle away from the electrode is driven by the telescopic driver, and complete reset needs to be driven by combining the first elastic assembly and the second elastic assembly. The driver is rotated to enable the double rows of swing rods to swing in a reciprocating mode, the nail grabbing heads of the nail grabbing component grab the rivets from the two nail discharging nozzles in turn and convey the rivets to the electrode, and the nail grabbing heads can smoothly release the rivets and avoid electrode welding under extrusion of the electrode. The invention further provides a welding control mode of the rivet conveying device, and the automatic and continuous rivet conveying and welding process of the equipment is achieved.

Description

Technical Field

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

[0002] The connection of dissimilar metal components is very common in automobile bodies, such as the connection of aluminum alloy and steel components. Due to the huge differences in physical and chemical properties between dissimilar metals, brittle intermetallic compounds and cracks are easily formed when welding using traditional welding processes, 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 hot melt tapping (FDS). However, in recent years, with the widespread application of high-strength steel and ultra-high-strength steel, integrated die-cast aluminum alloys with poor elongation have also gradually become popular, resulting in the use of mechanical connection processes to connect dissimilar metal components represented by aluminum alloy and steel. Therefore, in order to achieve reliable connection between high-strength steel and aluminum alloy, the welding-rivet combination connection process has gradually become popular. The most typical one is resistance element welding (REW), which is achieved by prefabricating steel rivets to aluminum alloy workpieces, and then welding steel rivets and steel plates by resistance spot welding to achieve the connection of aluminum / steel dissimilar metal components. However, the welding-rivet connection process has the same problem as the mechanical connection process, that is, rivets must be continuously delivered to the connection area during welding (or connection). The difficulty is that the welding-rivet connection process usually requires the connection equipment to retain the function of welding itself, and the size and specifications of the rivets involved are larger than those of mechanical connection rivets, such as REW equipment and rivets. An external nail feeding device is required to continuously feed nails to the welding equipment, while preventing the external nail feeding device from interfering with the welding process, and ensuring that the external nail feeding device is compact in size and the nail feeding process is stable and efficient. This has become a technical problem in this field.

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

[0004] Patent documents CN 111182995 A and CN 113165100 A respectively disclose a jacket assembly and a rivet distribution system for a fastener (herein referred to as a rivet) feeding device, wherein the jacket assembly is used to be installed around the welding electrode of a welding tongs (or welding gun) to clamp the rivets required for welding; and the rivet distribution system is installed on the side of the welding electrode of the welding tongs to continuously deliver rivets to the jacket assembly. On the one hand, the device has a relatively complex mechanism, which makes it difficult to coordinate the control of various mechanisms. After each weld, the rivet distribution system delivers a rivet to the jacket assembly, and when delivering the rivet, the rivet distribution system and the jacket assembly need to be transferred to the designated position at the same time after the previous weld is completed, which leads to the problem of low welding efficiency and poor stability of rivet feeding. On the other hand, the rivet distribution system is large in size and occupies a large space of the welding tongs, which is prone to interference when the welding tongs are welding complex parts.

[0005] Patent document CN217316356U discloses a swing-type sheet conveying device, which has the effects of compact structure and high conveying efficiency, but the device is suitable for conveying thin sheet-shaped sheets, and the device is suitable for conveying light-weight sheets with an outer diameter larger than the outer diameter of the welding electrode. For the rivets disclosed in patent document CN118720377A, the feeder rack suction of this device is difficult to stably clamp, especially during the rotation and swinging process. In addition, in actual application of welding rivets, the outer diameter of which is smaller than the outer diameter of the welding electrode, the device cannot effectively solve the problem of the feeder rack releasing the rivets smoothly and avoiding the feeder rack interfering with the welding process for such rivets. Therefore, the art is in urgent need of a rivet conveying device with a more reasonable structural design, which can efficiently and stably convey rivets while ensuring the size and compact structure of the device, and also realize the function of the rivet feeding mechanism avoiding interference with the welding process. Summary of the invention

[0006] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a rivet conveying device, which, through the dynamic coordination of double-row swing arms and rivet grabbing components, elastic reset mechanism, multiple fixing technology and sensor-driven automatic control, not only solves the stability and efficiency problems 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: A rivet conveying device, a rivet conveying device, which continuously conveys rivets when the electrode at the end of the electrode connecting rod is welding a workpiece, comprises: a fixed bracket, which is installed on the electrode connecting rod of the welding clamp, a first slider guide is laid on the upper part of the fixed bracket, and a second slider guide is laid on the lower part of the fixed bracket; two nail spouting nozzles, the first slider guide is slidably installed through the first sliding bracket, so that the two nail spouting 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, and is located between the nail spouting nozzle and the electrode; a double-row swing rod, the middle part of which is rotatably installed on the second sliding bracket, and is symmetrically arranged by two swing rods that are parallel to each other and have obtuse angles; a nail grabbing member, which is rotatably installed at both ends of the double-row swing rod, and two nail grabbing members are installed on each end of the double-row swing rod, and the nail grabbing head side of the nail grabbing member can elastically move toward the double-row swing rod. The center planes of the two swing arms are closed, so that the nail grabbing members are opposed to each other in a "V" shape, and the nail grabbing heads at the ends of the two nail grabbing members are closed and contacted with each other to form a rivet accommodating cavity; a telescopic driver is installed on the fixed bracket, and is used to drive the nail spouting mouth and the second sliding bracket to move synchronously in a straight line away from the electrode direction; a first elastic component and a second elastic component are installed on the telescopic rod of the telescopic driver, and respectively connect 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 completely 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 arms to swing back and forth, so that the nail grabbing heads at the ends of the nail grabbing members at both ends of the double-row swing arms alternately grab rivets from the two nail spouting mouth positions and transport them to the position of the electrode. Under the pressure of the electrode, the nail grabbing heads can release the rivets and avoid electrode welding.

[0008] Furthermore, 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 nail grabbing member), so that the first and second elastic components are compressed and store energy; after the electrode is pulled away from the welding point, the nail grabbing head is separated from the contact with the workpiece, and the elastic energy of the first and second elastic components is released, driving the first sliding bracket, the nail spouting nozzle, the second sliding bracket and the double-row swing rod to reset.

[0009] Furthermore, the telescopic actuator 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.

[0010] 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.

[0011] Preferably, the nail grasping member is made of non-magnetic material, such as stainless steel, brass, titanium alloy, tungsten steel alloy, etc. 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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] Further, the second sensor is mounted on the expansion pin.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] Furthermore, the nail ejecting nozzle and the first sliding bracket are configured as an integrated structure.

[0025] 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.

[0026] 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: 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 the nail feeding device 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, thereby driving the nail grabbing head at the electrode position to rotate to another nail spouting nozzle position; Welding stage: the electrode squeezes the nail grabber to release the rivet, and the telescopic actuator drives the nail grabber to avoid electrode welding, applying current to the welding point and completing the welding; Return stage: the telescopic drive and the elastic component drive the first and second sliding brackets to return to their original positions, and the above process is repeated.

[0027] Beneficial effects of the present invention: (1) The rivet conveying device has a compact structure and size, occupies little space for the welding clamp of resistance spot welding, is not prone to interference problems, and is conducive to the welding of complex parts.

[0028] (2) The rivet conveying device involves simple parts and a small number, which is convenient for installation and disassembly. It is installed on the electrode connecting rod of the welding machine through a fixed bracket, which is convenient for rapid integration into existing welding equipment, reducing the manufacturing cost of the mechanism and the cost of equipment upgrade and transformation. In addition, the rivet conveying device only involves two drive units, the telescopic drive and the rotary drive, which is conducive to simplifying the control method and motion program of the device, improving the motion coordination and motion efficiency of each mechanism, and ensuring the efficiency and stability of the mechanism in delivering nails.

[0029] (3) The nail ejecting nozzle and the second sliding bracket are respectively installed on the fixed bracket through the first slider guide and the second slider guide, so as to enhance the linear sliding effect of the nail ejecting nozzle and the second sliding bracket, and realize the simultaneous sliding effect of the nail ejecting nozzle and the second sliding bracket under the drive of the telescopic drive. When the nail grabbing head at the electrode position opens to release the rivet and avoid the welding process, it can also ensure that the nail grabbing head at the nail ejecting nozzle position can aim at the nail ejecting nozzle and grab the rivet. In addition, when the electrode pre-presses the first workpiece downward, the nail grabbing head and the double-row swing rod on the electrode side move upward away from the electrode, and the nail grabbing head or the double-row swing rod on the other side can simultaneously push the nail ejecting nozzle to slide upward, avoiding the nail ejecting nozzle being fixed in place to interfere with the movement of the double-row swing rod and the second sliding bracket, so as to realize the nail grabbing head to smoothly release the rivet under the pre-pressing of the first workpiece by the electrode.

[0030] (4) The swing arms on both sides of the double-row swing arm are respectively placed across the two sides of the electrode connecting rod, which improves the rotation stability of the swing arm and helps ensure that the rivet grasped by the grasping member installed at its end forms a good centering effect with the electrode end. In addition, a grasping member with elastic splicing in a "V" shape is provided at the end of the double-row swing arm to improve the stability of the grasping head on the grasping member in clamping the rivet and the smoothness of releasing the rivet under electrode extrusion.

[0031] (5) An expansion pin of a nail grabbing member is provided on the nail dispensing nozzle, which can open the two closed nail grabbing heads to a certain gap, and lift the rivet into the channel of the rivet receiving cavity in the nail grabbing head, thereby avoiding the problem of flipping and nail jamming during the rivet transfer process. In addition, the expansion pin also temporarily supports the rivet in the rivet receiving cavity, thereby improving the stability of the rivet transfer process.

[0032] (6) The minimum diameter L1 of the inner wall of the grabber head is designed to be smaller than the outer diameter Φ1 of the rivet. At the same time, a convex ridge structure is designed near the end of the rivet receiving chamber in the grabber head, and a vacuum channel for evacuating the rivet receiving chamber is provided. This allows the grabber head to simultaneously exert multiple external force constraints on the rivet, including mechanical clamping, mechanical limiting, and vacuum adsorption, thereby effectively maintaining the stability of the grasped rivet when the double-row swing arm rotates. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of a rivet conveying device according to one embodiment; Figure 2 for Figure 1 Schematic diagram of the parts assembly of the device; Figure 3 It is an integrated assembly diagram of a first sliding bracket, a material pipe and a nail ejection nozzle in another embodiment; Figure 4 A schematic diagram of a rivet conveying device in another embodiment Figure 5 for Figure 4 Diagram of the connection status of the telescopic drive and the upper and lower parts of the device; Figure 6 for Figure 4 Another directional view of the device; Figure 7 for Figure 4 Another view of the device; Figure 8 Schematic diagrams of the structures of different second sliding brackets and double-row swing rods; Fig. 9 for Figure 4 A structural diagram of the double-row swing bars of the device; Fig.10 for Figure 4 A cross-sectional view of the device after installation of the second sliding bracket, double-row swing rods and rotary drive; Fig.11 It is an assembly drawing of a double-row swing rod and a nail grabbing component; Fig.12 for Figure 4 Another directional view of the device; Fig.13 It is a schematic diagram of the swinging process of the swinging rod and a schematic diagram of the structure of different nail grabbing heads; Fig.14 This is another schematic diagram of the structure for grabbing the nail head; Fig.15 A schematic diagram showing the size of the rivet receiving cavity of the rivet grabbing head and the size of the rivet grabbed; Fig.16 Schematic diagram of the transfer of rivets from the rivet nozzle to the rivet head; Fig.17 for Fig.16 Schematic diagram of releasing the rivet under electrode pre-compression after the size of the gripping head is improved; Fig.18 A schematic diagram of another improved nail head structure of the present disclosure; Fig.19 A schematic diagram of a nail grabbing head with a further improved structure according to the present disclosure; Fig. 20 A schematic diagram of a nail grabbing head with another improved structure in the present disclosure; Fig.21 It is a schematic diagram of the effect of different opening states of the rivet grabbing head on rivet grabbing in the present disclosure; Fig. 22 A schematic diagram of the opening process of two closed nail grabbing heads of the present disclosure after they hit the expansion pin; Fig.23 This is a schematic diagram of another nail spouting nozzle structure design in the present disclosure; Fig.24 for Fig.23 Schematic diagram of the rivet nozzle transferring the rivet to the rivet head in different directions; Fig.25 A schematic diagram of another structural arrangement of an expansion pin; Fig.26 A schematic diagram of a structural scheme of another expansion pin; Fig. 27 In yet another embodiment of the present disclosure; Fig.28 It is a nail head size design scheme in yet another embodiment of the present disclosure; Fig.29 for Fig.28 A schematic diagram of the structural scheme of the side wall of the rivet receiving cavity for catching the rivet head; Fig.30 A schematic diagram of the installation position of the sensor in the rivet conveying device of the present disclosure; Fig.31 A schematic diagram of a rivet delivery device according to yet another embodiment of the present disclosure; Fig.32 A schematic diagram of a rivet delivery device according to yet another embodiment of the present disclosure; Fig.33 Schematic diagram of a welding system of the present disclosure; Fig.34 A logical diagram of a nail removal procedure of a welding device of the present disclosure; Fig.35 A logical schematic diagram of the welding device mode of the present disclosure; Fig.36 This is a morphology image of the weld surface taken with an optical microscope after continuous welding of aluminum / steel dissimilar metals using the device of the present invention in Example 1.

[0034] Comparison table of numbers and names in the attached drawings: DETAILED DESCRIPTION The following is a detailed description of the device of the present invention through specific embodiments and in conjunction with the accompanying 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 position of the mechanism, such as the terms "upper", "lower", "left", "right" and "outer", etc., are only used to relatively illustrate the relative position relationship of each mechanism in conjunction with the placement of the mechanism in the accompanying drawings. For mechanism descriptive terms, such as "first..." and "second...", etc., they 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 sequence relationship between these mechanisms or parts.

[0035] In the welding of stacked structures of dissimilar metals, such as the welding of stacked structures of aluminum alloy and steel, rivets are welded into the welding points by resistance spot welding to form welding-rivet combined welding points, which can achieve high-strength connection of dissimilar metals. Therefore, this type of process solution requires continuous delivery of rivets (or fasteners) to the welding points during the welding process. The present disclosure aims to solve the problem of continuous delivery of rivets during the process of dissimilar metal riveting welding by resistance spot welding. Figure 1 As shown, a rivet conveying device 908 is provided, which is installed on the electrode connecting rod of the resistance spot welding tongs. The rivets are grabbed from two rivet nozzle positions in turn by driving the swing rod and fed to the electrode. The reliability and stability of the mechanism movement are ensured by the careful design and positioning installation of each mechanism and its motion trajectory, thereby achieving the effect of continuous rivet conveying when welding dissimilar metal workpieces for resistance spot welding.

[0036] like Figure 2 As shown in Figure A, the installation positions of the various parts of the rivet delivery device 908 in one embodiment are shown. The fixing bracket 200 is fastened to the periphery of the electrode connecting rod 101 by bolts, and the other parts of the device are all installed on the fixing bracket, so that the rivet delivery device can be easily integrated or disassembled into the electrode connecting rod 101. Figure 2In this device, two first slider rails 301 are installed on the upper side of the fixed bracket 200, and they are installed symmetrically in the center plane. The other two second slider rails 302 are installed on the lower side of the fixed bracket 200, and they are also installed symmetrically in the center plane. The first sliding bracket 400 is slidably installed on the first slider rail 301, and the two nail ejecting nozzles 502 are fixedly installed on the first sliding bracket so that the two nail ejecting 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 rail, 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 conveying device after the parts are installed is as shown in FIG. Figure 2 As shown in B, the device achieves a compact structure, linear longitudinal sliding of the first and second sliding brackets, and reciprocating swinging of the double-row swing rods.

[0037] In another embodiment, in order to reduce the number of parts, improve the installation accuracy of parts and the compactness of equipment, the first sliding bracket, the nail ejection nozzle and the material pipe are integrated into an integral part, such as Figure 3 Two rivet conveying pipes 500 are symmetrically arranged, and the ends thereof are connected to the rivet ejecting nozzles 502 .

[0038] At the same time, a certain area on the two material tubes 500 is firmly connected together by a component, so that the two rivet ejection nozzles and the two material tubes form an integrated component. Two mounting ears 401 are set on the integrated component and installed on the first slider guide rail by bolts to realize the function of sliding up and down. Of course, the material tube connected to the rivet ejection nozzle can be bent and rotated according to factors such as the space of the welding clamp and the shape and size of the rivet conveying device. Figure 1 and Figure 4 The equipment shows different tube shapes.

[0039] See also Figures 4 to 6 The driving force for the nail ejection nozzle 502 and the second sliding bracket 600 to slide upward comes from 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 connecting 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 connecting block 204 and the second elastic component 206 ( Figure 6 Middle C and Figure 6B). Furthermore, the first and second elastic components are mounted on the first and second connecting blocks through pins, and the pins can slide relative to the mounting position. When the telescopic rod of the telescopic driver is stretched upward, the first and second connecting blocks will respectively pull the pins in the first and second elastic components to move upward, thereby simultaneously driving the nail ejection nozzle 502 and the second sliding bracket 600 to slide upward. However, when the telescopic rod is extended downward to reset, the pins in the first and second elastic components will slide relative to each other at the mounting positions of the first and second connecting blocks, respectively, so that the springs on the first and second elastic components are compressed to a certain extent, and then the nail ejection nozzle 502 and the second sliding bracket 600 slide downward under the push of the springs. Finally, after the telescopic rod is extended downward and fully reset, the springs on the first and second elastic components are at least partially compressed, so that the nail ejection nozzle and the second sliding bracket are completely pressed down to the position closest to the electrode side.

[0040] like Figure 5 and Figure 7 As shown in FIG. 2B , a guide block stopper 303 is provided on the lower side of the two first slider guide rails 301. By adjusting the guide block stopper to control the sliding stroke of the first slider guide rail, the distance between the nail ejection nozzle and the nail grabbing head on the side can be adjusted. A telescopic stopper 304 ( Figure 7 Middle B), used to adjust the upward stretching stroke of the telescopic rod 201, thereby adjusting the upward displacement of the nail ejecting nozzle and the second sliding bracket 600.

[0041] See also Figure 8 The second sliding bracket 600 has a hollow installation channel 601 in its body, and installation positions of the second slider rail 302 are provided on both sides of the hollow installation channel. When the second sliding bracket is mounted on the fixed bracket from bottom to top, the second sliding bracket is fastened to the second slider rail 302 by bolts on both sides (can be combined with Figure 6 Middle C and Figure 7 A connecting rod 603 is extended from one side of the second sliding bracket body. A driver mounting seat 604 is provided at the end of the connecting rod for mounting a rotating driver. A first stopper 602 protrudes from the other side of the connecting rod body for limiting the stroke of the double-row swinging rod 700 when it swings back and forth. Figure 6 Observe from center C. The left and right end positions of the double-row swing arm's rotation are the positions where the swing arm contacts the first limit block 602. Furthermore, the connecting rod portion 603 can also function as a second limit block, and play the same limit function on the rotation of the double-row swing arm on the other side, so that both sides of the double-row swing arm are subjected to balanced impact. In addition, in order to reduce the impact force of the double-row swing arm contacting the first and second limit blocks, elastic shock absorbing mechanisms and buffer pads can be appropriately set on the first and second limit blocks. Mounting shafts 605 are also provided on both sides of the second sliding bracket for mounting the double-row swing arm.

[0042] See also Figure 8 and Fig. 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, and 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 ( Fig. 9 In the upper part of the figure, a transverse connecting part 708 is provided to connect the first and second swing rods, so that the two swing rods are connected as one body, ensuring that they can swing synchronously. Figure 8 As shown, according to different second sliding bracket structural characteristics, the double-row swing rod is required to meet different installation requirements, so the transverse connecting portion 708 can be designed as an integrated type ( Figure 8 A) or a split structure ( Figure 8 Middle B).

[0043] See also Fig. 9 , bearing mounting seats 703 are symmetrically arranged at the rotation center of the two swing rods. An axial hole 704 extends outwardly from the bearing mounting seat 703 of the first swing rod 701 for matching and mounting with the rotating shaft of the rotary driver. A U-shaped mounting seat 706, a spring mounting seat 707 and a third limiting portion 705 are arranged at the end of any swing rod.

[0044] See also Fig.10 When the double-row swing lever 700 is mounted on the second sliding bracket 600, a bearing 606 is mounted on the mounting shaft 605, and the bearing mounting seat 703 of the double-row swing lever 700 is sleeved outside the bearing 606, so that the double-row swing lever 700 can smoothly rotate around the shaft. The rotation driver 202 is mounted on the driver mounting seat 604, so that its rotation drive shaft is coaxially mounted with the shaft hole 704 of the double-row swing lever 700, providing it with a rotation driving force.

[0045] See also Fig.11 In Figure A, two gripping nail members 800 are installed at one end of the double-row swing rod 700 (different numbers are used here to distinguish the four gripping nails). The two gripping nail members at the same end are marked as the first gripping nail member 800a and the second gripping nail member 800b, and the two gripping nail members at the other end are marked as the third gripping nail member 800c and the fourth gripping nail member 800d. The four gripping nail members described here have the same structure except that the position of the fourth limiter 802 is different. In addition, due to the symmetrical installation characteristics of the gripping nail members, the structures of the first and third gripping nail members are exactly the same, and the structures of the second and fourth gripping nail members are exactly the same. See Fig.11 Middle B, Fig.12 Medium B and Fig.12In the middle C, the nail grasping member 800 includes a handle 801 and a nail grasping head 803 extending from the handle. When installed, the handle 801 is rotatably mounted on the U-shaped mounting seat 706 at the end of the first or second swing rod ( Fig.11 A). The third elastic component 207 is installed between the end of the handle of the grasping nail member and the swing rod, driving the grasping nail head of the grasping nail member to swing toward the center plane of the double-row swing rod, so that the two grasping nail heads on the same side are closed, so that the two grasping nail members are arranged in a "V" shape, and then can cross the electrode end with the swing of the double-row swing rod and be distributed to both sides of the electrode 102 (12B). The fourth limit portion 802 on the handle of the grasping nail member fits with the third limit portion 705 on the double-row swing rod (see Fig.12 B), serves to fix the end position of the two nail grabbing heads after each closure, ensuring that the rivet grabbed by the nail grabbing heads can be aligned with the axis of the electrode 102 each time. When the closed nail grabbing heads are opened under the action of external force, the third elastic group 207 stores elastic energy. After the external force is removed, the third elastic component releases the elastic energy and drives the nail grabbing heads to return to the closed state. After the two nail grabbing heads are closed, a rivet accommodating cavity 804 is formed to accommodate the rivet 900 ( Fig.12 Middle C).

[0046] See also Fig.12 In A, the rotary driver 202 drives the double-row swing rod 700 to rotate back and forth, 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 right nail-spitting nozzle 502 position to the electrode position directly below, and the third and fourth nail-grabbing members 800c and 800d (not marked) at the other end move from the electrode position to the left nail-spitting nozzle position. In this embodiment, the rotary driver adopts a pneumatic rotary driver, and the maximum rotation angle A of its shaft is related to the maximum rotation angle B of the double-row swing rod: A ≥ 1.2 × B. Setting the rotation angles of the two in this way can ensure that the double-row swing rod can fully swing to the final position set at both ends. Fig.12 Medium B and Fig.12 As shown in C, in order to ensure that the nail grabber 803 can be completely screwed into the electrode 102 from the side to the bottom of the electrode, a minimum gap h1>0 is set between the end of the electrode 102 and the nail grabber, and preferably the range of h1 is: 2mm≤h1≤5mm.

[0047] like Fig.12 In middle C, in order to enable the rivet accommodating cavity 804 of the rivet grabbing head to firmly grasp the rivet, a through pipe 809 is provided inside the rivet grabbing component and extends to the inner wall of the rivet accommodating cavity 804 of the rivet grabbing head. When the rivet grabbing head grasps the rivet 900, the through pipe 809 is connected to the vacuum pump to draw vacuum, so that negative pressure is formed in the rivet accommodating cavity 804 and the rivet 900 is more firmly adsorbed.

[0048] See also Fig.13In one embodiment, due to the fast rotation and swinging speed of the double-row swinging rod 700 and the large impact force after swinging into place, the rivet 900 is still easy to fall off the vacuum-adsorbed rivet head 803. In order to improve the firmness of the rivet grasping by the rivet grasping head, the rivet grasping head structure is changed from Fig.13 Medium B is optimized to Fig.13 In the middle C, a convex ridge structure 807 is provided on the lower end surface of the rivet receiving cavity 804 to prevent the rivet 900 from falling from the rivet head when the double-row swing rod rotates.

[0049] like Fig.14 As shown, in one embodiment, the convex ridge structure on the lower end surface of the rivet accommodating cavity 804 is set to a compressible ball-type telescopic limiter 808. After the rivet 900 is squeezed by the electrode 102 and moves downward to contact the ball-type telescopic limiter 808, the ball-type telescopic limiter will at least partially shrink into the rivet head body, ensuring that the rivet 900 can be smoothly squeezed onto the workpiece surface.

[0050] like Fig.15 As shown, in one embodiment, the rivet receiving cavity 804 formed by the two rivet grabbing heads 803 is assembled, and the minimum diameter L1 of the inner wall of the cavity is smaller than the outer diameter Φ1 of the rivet, and the height h3 of the receiving cavity and the height h2 of the rivet 900 are in the relationship: h2<h3<2×h2, so that the stability of the rivet receiving cavity 804 in grabbing the rivet 900 is ensured. The rivet 900 has a peripheral 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 h2 of the rivet are in the relationship: Φ1 / h2>2.

[0051] See also Fig.16 In Figure A, after the nail grabbing head 803 is aligned with the nail outlet 503 of the nail outlet nozzle 502, the 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 chamber 804 from the end of the nail grabbing head almost in the axial direction of the rivet. In order to improve the stability of the rivet transferred to the nail grabbing head, a secondary air channel 504 is provided on the upper side of the nail outlet 503. After the rivet is close to the nail outlet 503, part of the high-pressure gas can enter the secondary air channel 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 away from the end of the nail grabbing head in the rivet receiving chamber 804, and the supporting portion 805 is used to support the rivet transferred from the nail outlet nozzle to the rivet receiving chamber. Generally speaking, the larger the transverse width d1 of the supporting portion 805, the more conducive it is to supporting the rivet and ensuring the stability of the rivet. However, during the welding process, if the lateral width d1 is too large, the electrode will be squeezed to the supporting portion 805 and will not be able to smoothly open the assembled nail grabbing head, resulting in the failure of the nail grabbing head to release the rivet. Fig.16 As shown in B. In order to improve the smoothness of releasing the rivet by grasping the rivet head during welding, Fig.17 As shown in Figure A, the lateral width d1 of the support portion 805 is reduced to d1' (preferably, d1'≤3 mm), thereby increasing the minimum diameter Φ2 of the through hole formed by the nail head, and at the same time reducing the longitudinal height h4 of the support portion 805 (preferably, h4<2.5 mm), thereby reducing the stroke of the electrode 102 squeezing the rivet 900. Fig.17 As shown in B, when the electrode 102 pre-presses the rivet 900, the end of the electrode can quickly contact the rivet, thereby smoothly pushing the rivet onto the surface of the first workpiece 901. Fig.17 As shown in C, under the pull of the telescopic drive, the nail grabber can also smoothly open and slide to the side of the electrode to prevent the nail grabber from interfering with the welding process of the electrode.

[0052] See also Fig.18 In one embodiment, the outer diameter of the rivet 900 is much smaller than the diameter of the welding electrode 102 body, for example, the outer diameter of the rivet is 10 mm and the outer diameter of the electrode is 16 mm. In order to prevent the nail head 803 from interfering with the process of pre-pressing the rivet by the electrode, the supporting part is set as an elastic supporting part 806, and a fourth elastic component 208 is provided at the rotation position. Fig.18 As shown in B, after the electrode 102 pushes the rivet, the elastic supporting portion 806 is forced to swing and avoid the electrode pressing process, so that the electrode can smoothly squeeze the rivet onto the surface of the first workpiece 901 for welding.

[0053] See also Fig.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 electrode body is directly 16 mm. In order to allow the electrode to be smoothly squeezed onto the rivet and the rivet head to smoothly release the rivet, on the one hand, the lateral width d1'' of the supporting portion 805 is further reduced, preferably d1''≤1.2mm, and the longitudinal height of the supporting portion 805 does not exceed 2mm. In addition, the longitudinal height and curvature of the electrode curved surface 105 between the electrode end face 103 and the electrode side face 104 are adaptively increased, so that before the electrode side face 104 contacts the supporting portion 805, the electrode end face 103 has squeezed the rivet 900 onto the surface of the first workpiece.

[0054] See also Fig. 20 In one embodiment, the supporting part on the rivet head can also be set as a ball-type telescopic stopper 808. The elastic structure 808 retracts into the rivet head body after being squeezed by the electrode, which is beneficial for the electrode 102 to extend into the rivet head to push the rivet onto the workpiece. Fig. 20As shown in B, when the nail grabber opens and lifts toward 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 replacing the electrode of the welding equipment or grinding and refurbishing the electrode end surface. At the same time, this makes the nail grabber structure more efficiently adaptable to the welding clamp devices on the market.

[0055] pass Fig.17 Middle A, Fig.19 and Fig. 20 The strategy in the middle A reduces the size of the support part, which is beneficial for the electrode to squeeze the rivet onto the surface of the workpiece. However, the small size of the support part causes the minimum diameter Φ2 of the through hole on the rivet receiving cavity to be too large. The rivet 900 ejected from the rivet ejection nozzle 502 is prone to tipping over when entering the rivet receiving cavity of the rivet head. Fig.21 As shown in A. On the other hand, the minimum width of the inner wall of the rivet receiving 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 enter the rivet receiving cavity smoothly. Fig.21 To 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 Fig.30 Observe the position of the expansion pin 402). Fig.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. Fig. 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.

[0056] like Fig.23 As shown, in one embodiment, a first sensor 407 is provided near the expansion pin to monitor the position of the nail head. Fig.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. Fig.23As 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 Fig.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. Fig.24 Medium B and Fig.24 In case of medium C, the vacuum adsorption force of the central pipe 809 may not be able to stabilize the rivet in the rivet head. Therefore, the secondary blowing channel 505 can continuously output high-pressure gas to act on the rivet surface to form pressure, ensuring that the rivet can be stabilized in the rivet head and prevent the rivet from falling.

[0057] See also Fig.25 In one embodiment, in order to further stabilize the rivet entering the rivet receiving cavity, a magnetic material 403 is laid on the expansion pin 403. When the steel rivet enters the rivet receiving cavity, the magnetic material can quickly absorb the rivet and temporarily fix the rivet.

[0058] See also Fig.26 Middle A and Fig.26 In B, in one embodiment, the second sensor 408 is arranged on the side of the secondary air blowing channel 505; a vacuum channel 406 is arranged on the expansion pin 402 for vacuuming to form an adsorption force to adsorb the rivet 900. Providing a vacuum channel on the expansion pin can reduce the difficulty of connecting an external vacuum pump and the complexity of the air pipe arrangement, while improving the ability of vacuum adsorption of rivets. In addition, the hollow material channel 501 in the rivet ejection nozzle forms an angle γ with the horizontal plane, so that when the rivet 900 is transported to the rivet outlet, part of the rivet area enters the rivet head, further ensuring that the rivet can be smoothly transferred to the rivet accommodating cavity of the rivet head.

[0059] See also Fig. 27 Middle A and Fig. 27In Figure B, two nail grabbing heads 803 are assembled to form a U-shaped groove 810 on one side, and the expansion pin 402 is inserted into the interior of the nail grabbing head from one side of the U-shaped groove 810, reducing the impact force of the expansion pin hitting the nail grabbing head, and realizing a stable opening and closing of the nail grabbing head. The width of the tip of the expansion pin 402 is less than the width d4 of the U-shaped groove 810, and the maximum width d5 ​​of the expansion pin 402 body is greater than the width d4 of the U-shaped groove 810. Preferably, there is a relationship between d4 and d5: 1.5 mm < d5-d4 < 3.5 mm.

[0060] See also Fig.28 In A, in one embodiment, the joint surface of the two closed nail grabbing heads 803 is in the vertical direction, the maximum width L2 of the inner wall of the rivet receiving cavity 804 on the joint surface is greater than the outer diameter Φ1 of the rivet 900, and the inner diameter L1 of the inner wall of the rivet receiving cavity in the horizontal direction is smaller than the outer diameter Φ1 of the rivet. In addition, the convex ridge structure 807 on the nail grabbing head is arranged in a crescent shape, and the maximum transverse width d6 is arranged in the horizontal direction, preferably d6 < 1.5 mm. See Fig.28 In 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 Fig.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.

[0061] See also Fig.30In 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.

[0062] See also Fig.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.

[0063] See also Fig.32 In one embodiment, according to the structural characteristics of the welding tongs and electrode connecting rods of different welding equipment. For example, when the 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 first sliding bracket 400 of a larger size 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. Furthermore, the fixed bracket 200 and the first sliding bracket 400 can be designed as a hollow guide column and a guide sleeve respectively, wherein the hollow guide column is installed on the electrode connecting rod, and the guide sleeve serves as the first sliding bracket. Appropriate balls are set between the hollow guide column and the guide sleeve for sliding, so as to achieve the up and down sliding effect of the double-row swing rod.

[0064] like Fig.33As shown, the rivet conveying device 908 of the present invention is installed on the electrode connecting rod of the welding clamp 100, and specifically also includes an integrated nail separation unit and a control unit integrated nail feeding controller 905. In an implementation case, the whole set of welding devices also includes a central controller 907, a welding controller 906 and a robot controller 904, and the nail feeding controller 905 interacts and communicates with the welding controller 906 and the robot controller 904 through the central controller 907. By setting a specific control mode for the welding device, it is realized that the resistance spot welding machine continuously conveys rivets and cooperates with the resistance spot welding machine to complete the riveting process. The specific control program includes a nail cleaning control program and a welding control program. The nail cleaning control program is used to identify and remove the rivets that grab the nail head on the electrode side before the first welding. Specifically, before making the first welding point, the nail cleaning program is started, and the rotary driver drives the double-row swing arm to rotate to the set initial position, so that the nail grabbing heads on the nail grabbing components at both ends of the swing arm are respectively swung to the position of the electrode side and the position of the nail spouting mouth side. The first sensor feedbacks the position of the nail grabbing head and feedbacks information a. Then the nail feeding controller controls the telescopic driver to start, so that the nail grabbing head on the electrode side is pushed to the electrode and forced to open, releasing the rivets that may exist on the nail grabbing head on this side. The specific control flow is as follows Fig.34 shown.

[0065] The logic diagram of the welding control program is as follows: Fig.35 As shown, the sensors (including the first, second and third sensors) automatically monitor the position of the mechanism and the position of the rivets, and quickly respond after feeding back the relevant information to the controller, so as to realize the intelligent movement of the mechanism, automatic feeding of the rivets, the mechanism avoiding welding, and the process in which the mechanism automatically returns to its position and feeds the rivets to the next welding point after the robot welds the rivets to the workpiece. Specifically, the following steps are included: A) First nail feeding stage: The second sensor feeds back the rivet in place information in the nail grabbing head at the nail spouting position. When there is no rivet in the nail grabbing head, the nail feeding controller controls the nail feeding device to start and feed the rivet to the nail grabbing head until the rivet is in place, and then the second sensor feeds back the rivet in place information. B) Swinging stage: The rotary drive is started, so that the rivet grabbing head that has successfully grabbed the rivet at the current rivet ejection nozzle position rotates to the electrode position, and the rivet grabbing head at the electrode position rotates to another rivet ejection nozzle position; C) Release rivet welding stage: the electrode pre-presses the rivet head on that side, and the rivet head is forced to open and release the rivet. When the electrode presses the rivet to 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 rivet head upward, so that the electrode side rivet head is further opened and away from the workpiece surface. When the electrode pre-pressing time reaches the set value, the welding current is applied to the welding point to complete the process of welding the rivet to the workpiece.

[0066] D) Second nail feeding stage: After the first sensor on the other nail spouting mouth side detects that the nail grabbing head is in place, the nail feeding device is started to deliver rivets to the nail grabbing head on this side, and the second sensor monitors and feeds back the rivet in place information of the nail grabbing head on this side; E) Returning stage: After welding is completed, the electrode connecting rod of the welding clamp moves the electrode away from the welding spot surface for a certain distance, and the telescopic drive moves toward the electrode, so that the nail ejection nozzle and the second sliding bracket are completely returned to their positions under the push of the first and second elastic components, and the nail grabbing head on the electrode side is returned to its position and closed at the same time; F) Next solder joint stage: Repeat the process of stage B → stage C → stage D → stage E.

[0067] Optionally, stage D may be performed before, after or simultaneously with stage C.

[0068] Example 1 The rivet conveying device of the present invention (see Figure 4 ), the first workpiece 901 and the second workpiece 902 are welded, wherein the first workpiece is a 2.0 mm thick 6111 aluminum alloy, and the second workpiece is a 1.6 mm thick Al-Si coated hot-formed steel. The rivets used for welding are 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 rivet heads in turn through the rivet spouting nozzles on both sides of the electrode connecting rod, and the rivets are fed to the electrodes under the swing of the double-row swing rod. During the welding process, the telescopic drive executes the welding process in which the rivet head avoids the electrode, realizing the effect of continuous and efficient welding of aluminum / steel dissimilar metals by the welding equipment. Fig.36 The surface morphology of the weld obtained after continuous welding is photographed using an optical microscope. It can be seen that the rivet 900 is successfully welded to the workpiece, the weld is well formed, and there are no defects such as serious distortion and cracking at the weld, indicating that the device of the present invention can achieve the effect of continuously conveying rivets and firmly welding dissimilar metals.

[0069] In the above embodiment, the double-row swing rod is composed of two parallel and obtuse-angled swing rods. The nail grabbing components are installed at both ends of the swing rod in a "V"-shaped opposite manner. After closing, a rivet accommodating cavity is formed, thereby realizing the precise grasping and release of the rivet. At the same time, the elastic closing mechanism (such as the third elastic component) ensures that the rivet is stably fixed during the swinging process. The obtuse-angle layout of the swing rod expands the range of motion of the nail grabbing head, allowing it to cross both sides of the electrode to avoid interference with the welding electrode. Compared with the traditional single swing rod structure, the double-row design significantly improves the symmetry and stability of rivet delivery. The automatic reset function of the sliding bracket is realized by the cooperation of the first elastic component and the second elastic component with the double-headed cylinder (telescopic drive). When the electrode is welded, the elastic component releases the stored energy and drives the nail spouting nozzle and the sliding bracket to quickly return to a position close to the electrode. The output force of the telescopic drive is greater than the maximum elastic force of the elastic component, ensuring that the elastic resistance is overcome first during the driving process, avoiding reset lag, simplifying the complexity of the mechanical structure, and 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 to reduce the external occupied space. The bending 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 cleaning, nail feeding, swinging, welding, and homing. Each stage is seamlessly connected through sensor feedback. For example, the residual rivets are automatically removed during the nail cleaning stage, and the current is triggered according to the electrode pressure or sensor signal during the welding stage to ensure the welding quality. During the welding stage, the telescopic drive drives the nail grabber away from the electrode area to avoid damage to the conveying mechanism due to high temperature or current, while improving the life of the equipment.

[0070] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also 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 fill pattern is only for distinguishing layers, without any other limitation.

[0071] It should be understood that the purpose of the above embodiments is only to illustrate the technical concept of the present invention for the convenience of understanding by those skilled in the art, and is not intended 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, falls 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 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 receiving 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 described in 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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