A lightweight automotive door sill welding device and welding method

Abstract

This invention relates to the field of automotive parts welding technology, specifically a lightweight automotive door sill welding device and method; it includes a housing and upper and lower electrode rods on the front side of the housing; a support is fixedly connected to the upper surface of the base at the bottom of the housing and located on the front side of the housing; two conveyor plates are fixedly connected to the top of the support; conveyor rollers are rotatably connected to the inner side of the conveyor plates; a conveyor belt is driven to the outer wall of the conveyor rollers; an inclined unloading hopper is fixedly connected to the right end of the conveyor plates; one of the conveyor rollers is driven by a motor; this invention uses the clamping plate of the tooling table to precisely limit the U-shaped workpiece to be welded, combined with the positioning of the lower electrode rod with the hole and the table hole, effectively avoiding the shaking of the workpiece and the conveyor belt during the welding process, thus improving welding efficiency while ensuring welding accuracy, thereby improving the quality of the door sill after welding and meeting the vehicle body anti-collision performance requirements.

Description

Technical Field

[0001] This invention relates to the field of automotive parts welding technology, specifically to a lightweight automotive door sill welding device and welding method. Background Technology

[0002] With the continuous upgrading of vehicle lightweighting and passive safety requirements, the sill beam, as a core load-bearing anti-collision component for the side of the vehicle body, needs to control the thickness of the sheet metal and material costs to reduce the overall weight of the vehicle, while also strengthening local impact resistance and bending resistance. The traditional one-piece sheet metal sill structure has a single form and cannot use thickened high-strength materials due to the limitations of lightweight design. It is prone to extrusion deformation under side collision conditions, and its protective performance has obvious shortcomings. The existing patent with publication number CN201534568U proposes a composite reinforcement structure design. This type of lightweight sill component is mainly composed of U-shaped transverse reinforcement and U-shaped longitudinal reinforcement cross splicing. The two separate components need to be pre-spot welded together to form an integral component, and then uniformly welded and fixed to the inside of the sill beam. This improves the overall structural strength and anti-collision performance of the sill area on the basis of lightweighting. It has now been widely used in the body structure optimization design of many family passenger cars.

[0003] The existing spot welding processing method for this type of U-shaped combined sill reinforcement is relatively traditional. Specifically, the workpiece to be welded is manually placed on the lower electrode head at the end of the lower electrode arm, and then the upper electrode arm is controlled to move the upper electrode head down to achieve welding. After welding, the workpiece still needs to be manually removed. Since the workpiece needs to be manually positioned during the welding process, the welding accuracy is poor, and the entire welding process is single-station welding, with a slow welding cycle and low welding efficiency. On the other hand, using a conveyor welding method will cause interference between the lower electrode arm and the conveyor belt. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention proposes a lightweight automotive door sill welding device and welding method. This invention uses a clamping plate on a tooling table to precisely limit the U-shaped workpiece to be welded, and combines the positioning of the lower electrode rod with the hole and the table hole to effectively prevent the workpiece and conveyor belt from shaking during the welding process. This improves welding efficiency while ensuring welding accuracy, thereby improving the quality of the door sill after welding and meeting the vehicle body's anti-collision performance requirements.

[0005] The technical solution adopted by this invention to solve its technical problem is as follows: A lightweight automotive door sill welding device of this invention includes a housing and an upper electrode rod and a lower electrode rod on the front side of the housing; a support is fixedly connected to the upper surface of the base at the bottom of the housing and located on the front side of the housing; two conveying plates are fixedly connected to the top of the support; conveying rollers are rotatably connected to the inner side of the conveying plates; a conveyor belt is driven to the outer wall of the conveying rollers; an inclined unloading hopper is fixedly connected to the right end of the conveying plates; one of the conveying rollers is driven by a motor; a square-shaped tooling table is uniformly connected to the outer wall of the conveyor belt; the four corners of the tooling table... A clamping plate is fixedly connected to the outward-facing position; the tooling table is used to position the workpiece to be welded; the tooling table is provided with table holes running through it vertically; the conveyor belt is provided with multiple belt holes along the conveying direction; the belt holes run through the conveyor belt; the two tooling tables on the outer wall of the conveyor belt can move between the upper electrode rod and the lower electrode rod; the upper electrode rod and the lower electrode rod can be controlled to move closer to each other; the outer diameter of the lower electrode rod is adapted to the belt holes and table holes; the ends of the upper electrode rod and the lower electrode rod are fixedly connected to the upper electrode head and the lower electrode head; the horizontal conveying roller is offset from the upper electrode rod and the lower electrode rod.

[0006] Preferably, the inner wall of the conveyor belt is provided with a conveying groove; the outer wall of the conveyor roller is provided with conveying teeth that can be engaged in the conveying groove; the inner wall of the conveyor belt is provided with a stepped replacement hole extending outward; the replacement hole passes through a first bolt; the first bolt is threadedly connected to the tooling table facing the conveyor belt.

[0007] Preferably, a cylinder is fixedly connected to the upper front side of the chassis; the upper electrode rod is fixedly connected to the cylinder's delivery end; an upper electrode seat is fixedly connected to the outer wall of the upper electrode rod; a central groove is provided inside the chassis; a gear is rotatably connected within the central groove; a strip-shaped left groove and a right groove are provided inside the chassis at positions to the left and right of the central groove; both the left and right grooves are connected to the central groove; a left rack that meshes with the gear is slidably connected to the left groove; a left connecting groove is provided through the left groove; a left connecting strip is slidably connected to the left connecting groove; the left connecting strip is fixedly connected to the upper electrode seat; a right rack that meshes with the gear is slidably connected to the right groove; a right connecting groove is provided through the right groove; a right connecting strip is slidably connected to the right connecting groove; the right connecting strip is fixedly connected to the lower electrode seat on the outer wall of the lower electrode rod.

[0008] Preferably, a pull hole is provided through the central groove facing rearward; a pull rod is movably connected in the pull hole; the pull rod and the gear are centrally fixedly connected; the front and rear thickness of the central groove is greater than the thickness of the gear.

[0009] Preferably, an annular groove is provided on the rear side of the gear; an annular bar is rotatably connected in the annular groove; the annular bar is connected to the rear inner wall of the central groove by a spring.

[0010] Preferably, the card plate has clamping grooves connected on both sides; clamping blocks are slidably connected in the clamping grooves; the two clamping blocks are connected by a tension spring; the clamping grooves are connected to the inner wall of the stage hole and have trigger grooves; trigger blocks are slidably connected in the trigger grooves; the trigger blocks have two guide surfaces at one end of the trigger grooves; the end of the trigger blocks inside the stage hole is arc-shaped.

[0011] Preferably, the outer surface of the lower electrode rod is provided with a corrugated surface; the corrugated surface is in movable contact with one end of the trigger block located inside the stage hole.

[0012] Preferably, the trigger block is located at one end inside the platform hole, close to the surface of the conveyor belt.

[0013] A method for welding lightweight automotive door sill components, applicable to the aforementioned lightweight automotive door sill component welding apparatus, comprising the following steps: S1: Depending on the actual usage requirements, select manual or automatic mode, and invert the two U-shaped workpieces to be welded onto the tooling table on the outer wall of the conveyor belt in sequence, and use the clamping plate to initially limit the loading. S2: Start-up device, the motor output shaft drives one of the conveyor rollers to rotate, and through the meshing of the conveyor teeth and the conveyor groove, the conveyor belt is driven to smoothly transmit the workpieces to be welded to the welding station. S3: Control the cylinder to extend, causing the upper electrode rod to move down and the lower electrode rod to move up. The lower electrode rod calibrates the workpiece and clamps it through the corrugated surface and the trigger block. The upper electrode head and the lower electrode head simultaneously contact the workpiece to connect the power supply and complete the spot welding. S4: After welding is completed, the control cylinder shortens to reset the upper and lower electrode bars. The clamping block retracts under the action of the tension spring to unlock the workpiece. The conveyor belt continues to drive and transports the welded workpiece to the unloading hopper to complete the unloading.

[0014] The beneficial effects of this invention are as follows: 1. This invention uses the clamping plate of the tooling table to precisely limit the U-shaped workpiece to be welded, and combines the positioning of the lower electrode rod with the hole and the table hole to effectively prevent the workpiece and the conveyor belt from shaking during the welding process. This improves welding efficiency while ensuring welding accuracy, thereby improving the quality of the welded door sill parts and meeting the vehicle body anti-collision performance requirements.

[0015] 2. This invention utilizes a combination of a pull rod, a central groove, an annular groove, an annular bar, and a spring structure. By pulling the pull rod, the gear can be moved back and forth, allowing for flexible disengagement and engagement between the gear and the left and right racks. This facilitates individual adjustment of the positions of the upper and lower electrode heads, enabling precise alignment of the welding points on workpieces of different heights and specifications, thus solving the problem of inaccurate positioning of welding points on workpieces of different heights.

[0016] 3. This invention achieves optimized adaptation of the entire process of loading, welding, and unloading U-shaped workpieces through the coordinated structure of the clamping plate, clamping groove, clamping block, tension spring, trigger groove, and triggering block. During loading, the clamping block is in a retracted state, and the clamping plate and workpiece are in a clearance fit, facilitating rapid workpiece loading and reducing operational difficulty. During welding, the lower electrode rod moves upward to press the triggering block, and the guide surface drives the clamping block to overcome the tension of the tension spring and clamp the workpiece, compensating for the shortcomings of the original clamping plate's thinness and unstable positioning, ensuring that the workpiece does not shake during welding and improving welding accuracy. After welding, the lower electrode rod moves downward to disengage from the triggering block, the tension spring resets and drives the clamping block to retract, releasing the workpiece clamping, facilitating smooth workpiece release during unloading, avoiding jamming, and ensuring a continuous and efficient welding process. The overall structure is ingeniously designed, requiring no additional power drive, and only utilizing the movement of the lower electrode rod to achieve automatic switching between clamping and unlocking, which not only improves the stability of workpiece positioning but also takes into account the convenience of loading and unloading, further optimizing the performance of the device and adapting to the needs of mass production. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a perspective view of the welding apparatus in this invention; Figure 2 This is a cross-sectional view of the conveyor belt in this invention; Figure 3 This is a side sectional view of the conveyor belt in this invention; Figure 4 yes Figure 3 Enlarged view of point A in the middle; Figure 5 This is a perspective view of the gear, left rack, and right rack in this invention; Figure 6 yes Figure 5 Enlarged view of point B in the middle; Figure 7 This is a perspective view of the tooling table loading the workpiece to be welded in this invention; Figure 8 This is a perspective view of the tooling table in this invention; Figure 9 This is a cross-sectional view of the tooling table in this invention; Figure 10 yes Figure 9 Enlarged view of point C in the middle; Figure 11 This is a flowchart of the method of the present invention.

[0019] In the diagram: 1. Chassis; 11. Base; 12. Support; 13. Cylinder; 14. Center groove; 15. Gear; 151. Annular groove; 152. Annular bar; 153. Spring; 16. Left groove; 161. Left rack; 162. Left connecting groove; 163. Left connecting bar; 17. Right groove; 171. Right rack; 172. Right connecting groove; 173. Right connecting bar; 18. Pull hole; 19. Pull rod; 2. Upper electrode rod; 21. Upper electrode head; 22. Upper electrode seat; 3. Lower electrode rod; 31. Lower electrode head; 32. Lower electrode seat; 4. Conveyor plate; 41. Conveyor roller; 42. Conveyor belt; 43. Unloading hopper; 44. Motor; 45. With hole; 46. Replacement hole; 47. First bolt; 5. Tooling table; 51. Clamping plate; 52. Table hole; 53. Clamping groove; 54. Clamping block; 55. Tension spring; 56. Trigger groove; 57. Trigger block; 57. Guide surface; 571. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0021] like Figures 1 to 11 As shown, the present invention includes the following embodiments: Example 1: A lightweight automotive door sill welding device includes a housing 1 and an upper electrode rod 2 and a lower electrode rod 3 on the front side of the housing 1; a support 12 is fixedly connected to the upper surface of the base 11 at the bottom of the housing 1 and located on the front side of the housing 1; two conveyor plates 4 are fixedly connected to the top of the support 12; conveyor rollers 41 are rotatably connected to the inner side of the conveyor plates 4; a conveyor belt 42 is driven to the outer wall of the conveyor rollers 41; an inclined unloading hopper 43 is fixedly connected to the right end of the conveyor plate 4; one of the conveyor rollers 41 is driven by a motor 44; a square tooling table 5 is evenly connected to the outer wall of the conveyor belt 42; clamping plates 51 are fixedly connected to the four corners of the tooling table 5 facing outwards; The tooling table 5 is used to position the workpiece to be welded; the tooling table 5 is provided with a table hole 52 running vertically through it; the conveyor belt 42 is provided with a plurality of belt holes 45 along the conveying direction; the belt holes 45 pass through the conveyor belt 42; the two tooling tables 5 on the outer wall of the conveyor belt 42 can move between the upper electrode rod 2 and the lower electrode rod 3; the upper electrode rod 2 and the lower electrode rod 3 can be controlled to approach each other; the outer diameter of the lower electrode rod 3 is adapted to the belt holes 45 and the table hole 52; the ends of the upper electrode rod 2 and the lower electrode rod 3 are fixedly connected to the upper electrode head 21 and the lower electrode head 31; the horizontal conveying roller 41 is offset from the upper electrode rod 2 and the lower electrode rod 3.

[0022] In this embodiment, the inner wall of the conveyor belt 42 is provided with a conveying groove; the outer wall of the conveyor roller 41 is provided with conveying teeth that can be inserted into the conveying groove; the inner wall of the conveyor belt 42 is provided with a stepped replacement hole 46 extending outward; the replacement hole 46 passes through the first bolt 47, and a single tooling table 5 is threadedly connected to two first bolts 47; the first bolts 47 are threadedly connected to the side of the tooling table 5 facing the conveyor belt 42.

[0023] In this embodiment, a cylinder 13 is fixedly connected to the upper front side of the chassis 1; the upper electrode rod 2 is fixedly connected to the conveying end of the cylinder 13; an upper electrode seat 22 is fixedly connected to the outer wall of the upper electrode rod 2; a central groove 14 is provided inside the chassis 1; a gear 15 is rotatably connected inside the central groove 14; a strip-shaped left groove 16 and a right groove 17 are provided inside the chassis 1 at positions to the left and right of the central groove 14; both the left groove 16 and the right groove 17 are connected to the central groove 14; the left groove 16 is slidably connected to a gear 15 that meshes with it. Left rack 161; a left connecting groove 162 is provided through the left groove 16 outwards; a left connecting strip 163 is slidably connected up and down in the left connecting groove 162; the left connecting strip 163 is fixedly connected to the upper electrode seat 22; a right rack 171 that meshes with the gear 15 is slidably connected up and down in the right groove 17; a right connecting groove 172 is provided through the right groove 17 outwards; a right connecting strip 173 is slidably connected up and down in the right connecting groove 172; the right connecting strip 173 is fixedly connected to the lower electrode seat 32 on the outer wall of the lower electrode rod 3.

[0024] Before welding the lightweight automotive door sill (consisting of two U-shaped workpieces to be welded), the two U-shaped workpieces can be placed upside down on the fixture table 5 on the outer wall of the conveyor belt 42, either manually or automatically, depending on the actual usage requirements. The fixture table 5 has four corners fixedly connected to clamping plates 51, which precisely engage with the edges of the two U-shaped workpieces, providing stable positioning and preventing displacement or shaking during conveying and welding, thus ensuring accurate workpiece positioning. After the workpieces are placed, the device is started, and the motor 44 begins operation. The output shaft of the motor 44 drives one of the conveyor rollers 41 to rotate. The outer wall of the conveyor roller 41 is equipped with conveying teeth, and the inner wall of the conveyor belt 42 is correspondingly equipped with... The conveyor trough (the specific cooperation structure between the conveyor teeth and the conveyor trough is existing technology and is not shown in the figure, so it will not be described in detail here) enables the conveyor roller 41 to stably drive the conveyor belt 42 smoothly on the outer wall of multiple conveyor rollers 41 between the two conveyor plates 4 through the meshing cooperation between the conveyor teeth and the conveyor trough. The outer wall of the conveyor belt 42 is uniformly connected with square tooling tables 5. As the conveyor belt 42 is driven, the tooling tables 5 will drive the workpieces to be welded on them to move synchronously until the two tooling tables 5 (and the workpieces to be welded on one of the tooling tables 5) are precisely moved to the welding position between the upper electrode rod 2 and the lower electrode rod 3. At this time, the pre-set belt holes 45 on the conveyor belt 42 (set through the conveyor belt 42) will be connected to the tooling tables 5 through the vertically penetrating platform. Holes 52 are precisely aligned and correspond to the positions of the upper electrode rod 2 and the lower electrode rod 3. Simultaneously, because the horizontal conveying roller 41 is staggered from the upper electrode rod 2 and the lower electrode rod 3, interference between the conveying roller 41 and the electrode rods is effectively avoided, ensuring smooth welding operations. Subsequently, the cylinder 13, fixed to the upper front of the control housing 1, extends, and the conveying end of the cylinder 13 drives the upper electrode rod 2 downwards. The upper electrode seat 22, fixed to the outer wall of the upper electrode rod 2, moves downwards synchronously. When the upper electrode seat 22 moves downwards, it drives the left connecting strip 163, fixed to it, to slide downwards along the left connecting groove 162 extending outwards from the left groove 16. The left connecting strip 163 drives the left rack 161 to slide downwards synchronously within the left groove 16 inside the housing 1. The left rack 161 meshes with the gear 15 rotatably connected in the central groove 14. The downward movement of the left rack 161 drives the gear 15 to rotate in the central groove 14. At the same time, the gear 15 meshes with the right rack 171 slidably connected in the right groove 17. The rotation of the gear 15 drives the right rack 171 to slide upward in the right groove 17. The right rack 171 then drives the right connecting bar 173, which is fixed to it, to slide upward along the right connecting groove 172. The right connecting bar 173 then drives the lower electrode seat 32 on the outer wall of the lower electrode rod 3 to move upward synchronously, thus achieving the synchronous action of the upper electrode rod 2 moving downward and the lower electrode rod 3 moving upward. The outer diameter of the lower electrode rod 3 is adapted to the diameter of the hole 45 and the platform hole 52, and the lower electrode head 31 is set in a conical shape to facilitate smooth passage through the relevant holes.As the lower electrode rod 3 moves from bottom to top, it passes sequentially through the table hole 52 of the tooling table 5 on the lower surface of the conveyor belt 42 and the belt hole 45 at the lower part of the conveyor belt 42, enters the inner side of the conveyor belt 42, and then passes through the belt hole 45 at the upper part of the conveyor belt 42 and the table hole 52 on the tooling table 5 on the upper surface of the conveyor belt 42, finally extending to the bottom of the workpiece to be welded. At the same time, the upper electrode rod 2 drives the upper electrode head 21 to move down to the top of the workpiece to be welded until the upper electrode head 21 is in close contact with the upper surface of the workpiece to be welded, and the lower electrode head 31 is in close contact with the lower surface of the workpiece to be welded. At this time, the welding power supply is turned on, and the current flows through the upper electrode rod 2, the upper electrode head 21, the workpiece to be welded, the lower electrode head 31, and the lower electrode. The rod 3 forms a closed loop, and the contact area of ​​the two U-shaped workpieces to be welded melts due to the thermal effect of the current, completing the spot welding operation. After welding, the control cylinder 13 shortens rapidly, driving the upper electrode rod 2 and the upper electrode head 21 to move upward and detach from the upper surface of the workpiece to be welded. At the same time, the gear 15 rotates in the opposite direction, driving the right rack 171, the right connecting bar 173, the lower electrode seat 32, and the lower electrode rod 3 to move downward synchronously. The lower electrode head 31 detaches from the lower surface of the workpiece to be welded, and the lower electrode rod 3 moves out sequentially from the table hole 52 of the tooling table 5 and the belt hole 45 of the conveyor belt 42. During this process, the cooperation between the lower electrode rod 3 and the belt hole 45 and the table hole 52 not only realizes the welding process but also... Precise positioning effectively limits the swaying of the conveyor belt 42 and the tooling table 5, further improving welding accuracy. After the lower electrode rod 3 is removed, the motor 44 continues to drive the conveyor roller 41 to rotate, driving the conveyor belt 42 to continue transmission, conveying the welded workpiece and the corresponding tooling table 5 towards the unloading hopper 43. At the same time, the next tooling table 5 with the workpiece to be welded is conveyed to the welding station between the upper electrode rod 2 and the lower electrode rod 3, repeating the above welding process to achieve continuous automated welding. When the tooling table 5 with the welded workpiece moves to the inclined unloading hopper 43 position on the right side of the conveyor plate 4, the side of the tooling table 5 away from the conveyor belt 42 naturally tilts downwards, completing the welding threshold. The workpiece falls off the tooling table 5 under its own weight, and slides down the inclined unloading hopper 43 into the preset material box (not shown in the material box diagram), completing the automatic unloading of the workpiece. In addition, when it is necessary to change the tooling table 5 according to different specifications of the workpiece to be welded, the first bolt 47 passing through the replacement hole 46 (step type) in the inner wall of the conveyor belt 42 can be loosened. The first bolt 47 is threadedly connected to the side of the tooling table 5 facing the conveyor belt 42. After loosening the bolt, the existing tooling table 5 can be removed and replaced with an adapter tooling table 5 with a table hole 52 (to meet the requirement of the lower electrode rod 3 passing through). Then tighten the first bolt 47 to fix it. The operation is convenient and adaptable to the welding requirements of different specifications of workpieces. This invention uses the clamping plate 51 of the tooling table 5 to precisely limit the U-shaped workpiece to be welded. Combined with the positioning of the lower electrode rod 3 with the hole 45 and the table hole 52, it effectively avoids the workpiece and the conveyor belt 42 shaking during the welding process. This improves welding efficiency while ensuring welding accuracy, thus improving the quality of the welded door sill and meeting the vehicle body anti-collision performance requirements. This invention uses the motor 44 to drive the conveyor belt 42 to drive the tooling table 5 to continuously transport the workpiece. With the help of the cylinder 13 and the gear 15 rack mechanism, the upper and lower electrode rods 3 move synchronously, completing automatic welding and automatic unloading. This replaces the traditional single-station manual loading and unloading and single workpiece welding mode, greatly shortening the welding cycle time and significantly improving welding efficiency, adapting to the needs of mass production. This invention sets the horizontal conveyor roller 41 horizontally offset from the upper and lower electrode rods 3, effectively avoiding the interference problem between the conveyor roller 41 and the electrode rod during conveyor welding. At the same time, the gear 15 rack mechanism provides smooth transmission, ensuring that the upper and lower electrode rods 3 move synchronously, ensuring the long-term stable operation of the welding device and reducing the probability of equipment failure.

[0025] Example 2: A pull hole 18 is provided through the central groove 14 to the rear; a pull rod 19 is movably connected in the pull hole 18; the pull rod 19 and the gear 15 are centrally fixed; the front and rear thickness of the central groove 14 is greater than the thickness of the gear 15.

[0026] In this embodiment, an annular groove 151 is provided on the rear side of the gear 15; an annular bar 152 is rotatably connected in the annular groove 151; the annular bar 152 is connected to the rear inner wall of the central groove 14 by a spring 153.

[0027] Both the left rack 161 and the right rack 171 mesh with the gear 15 in the central groove 14. During normal welding, the downward movement of the left rack 161 will drive the gear 15 to rotate, which in turn will drive the right rack 171 to move upward, so that the upper electrode rod 2 (driving the upper electrode head 21) and the lower electrode rod 3 (driving the lower electrode head 31) can synchronously approach the welding point of the workpiece to be welded. However, for U-shaped workpieces of different heights, the height of the welding point will change (the welding point moves upward when the workpiece is higher, and downward when the workpiece is lower). In order to ensure that the upper and lower electrode heads 31 can be synchronously and accurately aligned with the welding point, the welding point position needs to be adjusted. First, the operator can hold the pull rod 19 to the back. The portion protruding from the pull hole 18 (a pull ring can be provided at the end of the pull rod 19 for easy gripping and pulling) is used to pull the pull rod 19 backward. Since the pull rod 19 is centrally fixed to the gear 15, and the central groove 14 has a pull hole 18 through it for the pull rod 19 to move, pulling the pull rod 19 will drive the gear 15 to move backward along its own central axis. At the same time, the front and rear thickness of the central groove 14 is greater than the thickness of the gear 15, providing sufficient space for the gear 15 to move back and forth, ensuring that the gear 15 can move smoothly backward until it is completely disengaged from the meshing state of the left rack 161 and the right rack 171. At this time, the left rack 161 and the right rack 171 are no longer constrained by the gear 15. It can move independently up and down; an annular groove 151 is provided on the rear side of gear 15, and an annular bar 152 is rotatably connected in the annular groove 151. The annular bar 152 is connected to the rear inner wall of the central groove 14 by a spring 153; when the gear 15 is pulled to move backward, the gear 15 will drive the annular groove 151 to move backward synchronously, and at the same time, the annular bar 152 will compress the spring 153, so that the spring 153 is in a stored state; the rotational cooperation between the annular bar 152 and the annular groove 151 effectively avoids the interference of the spring 153 on the rotation of the gear 15, ensuring that the gear 15 can move smoothly and does not affect the subsequent rotational function; when the gear 15 is completely disengaged from the left After the racks 161 and 171 are engaged, the lower electrode rod 3 can be moved upward independently, driving the lower electrode head 31 to make precise contact with the welding point on the lower surface of the workpiece to be welded. Then, the upper electrode rod 2 can be moved downward independently, driving the upper electrode head 21 to make precise contact with the welding point on the upper surface of the workpiece to be welded, thus completing the positioning calibration of the welding point. After calibration, the pull rod 19 is released. At this time, the spring 153, which is in a stored state, will generate a reset force, pushing the ring bar 152 forward. The ring bar 152 drives the gear 15 to move forward along the central axis until the gear 15 re-engages with the left rack 161 and 171, thus completing the adjustment of the welding point position.After adjustment, subsequent welding operations can proceed normally. When the cylinder 13 extends and drives the upper electrode rod 2 to move down, the left rack 161 moves down and drives the gear 15 to rotate. The gear 15 simultaneously drives the right rack 171 to move up, so that the upper electrode head 21 and the lower electrode head 31 approach each other synchronously and act precisely on the preset welding point, ensuring that workpieces of different heights and specifications can be accurately welded, avoiding problems such as the electrode head contacting the workpiece in advance or the contact position being deviated. This invention utilizes the coordinated structure of pull rod 19, central groove 14, annular groove 151, annular bar 152, and spring 153. By pulling pull rod 19, gear 15 can be moved back and forth, enabling gear 15 to flexibly disengage and engage with left and right racks 171. This facilitates the individual adjustment of the positions of the upper and lower electrode heads 31, allowing for precise alignment of welding points on workpieces of different heights and specifications, thus solving the problem of inaccurate positioning of welding points on workpieces of different heights.

[0028] Example 3: The card plate 51 has clamping grooves 53 connected on both sides; two clamping blocks 54 are slidably connected in the clamping grooves 53; the two clamping blocks 54 are connected by a tension spring 55; the clamping grooves 53 and the inner wall of the platform hole 52 are connected to a trigger groove 56, and the trigger groove 56 is connected to the clamping grooves 53; a trigger block 57 is slidably connected in the trigger groove 56; the trigger block 57 is provided with two guide surfaces 571 at one end of the trigger groove 56; the end of the trigger block 57 inside the platform hole 52 is arc-shaped.

[0029] When loading the U-shaped workpiece to be welded, clamping grooves 53 are connected on both sides of the clamping plate 51. Clamping blocks 54 are slidably connected in the clamping grooves 53, and the two clamping blocks 54 are connected by a tension spring 55. At this time, the tension spring 55 is in a naturally extended state, which drives the two clamping blocks 54 to move closer to each other, and the clamping blocks 54 do not protrude from the inside of the clamping plate 51 and are retracted into the clamping grooves 53. Since the clamping plate 51 itself is relatively thin and the clamping blocks 54 are in a retracted state, a certain gap is formed between the clamping plate 51 and the edge of the U-shaped workpiece. The gap fit method makes it easy for the operator to quickly invert the U-shaped workpiece to be welded onto the tooling table 5, realizing convenient loading of the workpiece without having to overcome clamping force and reducing loading difficulty. After the workpiece is loaded, the tooling table is driven by the conveyor belt 42. 5. The U-shaped workpiece is moved to the welding station between the upper electrode rod 2 and the lower electrode rod 3. At this time, the belt hole 45 of the conveyor belt 42 is precisely aligned with the table hole 52 of the tooling table 5. The lower electrode rod 3 begins to move from bottom to top, ready for welding. Since the clamping groove 53 is connected to the inner wall of the table hole 52 and a trigger groove 56 is provided, a trigger block 57 is slidably connected in the trigger groove 56, and one end of the trigger block 57 located inside the table hole 52 is set in a conical shape. When the lower electrode rod 3 moves upward with the lower electrode head 31 and passes through the table hole 52, the lower electrode head 31 will squeeze the conical end of the trigger block 57 located inside the table hole 52. After being squeezed by the lower electrode head 31, the trigger block 57 will move away from the center of the table hole 52, that is, along the trigger groove 56 towards the clamping groove. The slide is 53-way; the trigger block 57 is located at one end of the trigger groove 56 and has two guide surfaces 571. During the sliding process, the guide surfaces 571 will precisely press the two clamping blocks 54 in the clamping groove 53, forcing the two clamping blocks 54 to overcome the tension of the tension spring 55 and move away from each other. At this time, the tension spring 55 is stretched and enters the storage state. The design of the guide surfaces 571 can ensure that the clamping blocks 54 are evenly stressed and slide smoothly, avoiding jamming. As the two clamping blocks 54 move away from each other, they will gradually approach and press the edge of the U-shaped workpiece to be welded on the fixture table 5, realizing precise clamping of the U-shaped workpiece. At this time, the workpiece is firmly fixed on the fixture table 5, avoiding welding position deviation caused by slight shaking of the workpiece during the welding process, and ensuring welding accuracy. This solves the problems of the original clamping plate 51 being too thin, unable to effectively clamp the workpiece, and having poor positioning effect. After the spot welding operation is completed, the control cylinder 13 shortens, driving the upper electrode rod 2 and the upper electrode head 21 to move upward and separate from the upper surface of the workpiece. At the same time, the lower electrode rod 3 moves downward synchronously and gradually moves out of the table hole 52 of the tooling table 5. When the lower electrode rod 3 and the lower electrode head 31 are completely separated from the table hole 52 and no longer press the trigger block 57, the trigger block 57 loses the external force. At this time, the tension spring 55, which is in the stored state, generates a reset elastic force, pulling the two clamping blocks 54 closer to each other and gradually retracting into the clamping groove 53. The clamping blocks 54 no longer press the edge of the U-shaped workpiece, releasing the clamping lock on the workpiece, realizing the workpiece unlocking, and the trigger block 57 also resets.After the workpiece is unlocked, the conveyor belt 42 continues to drive, moving the tooling table 5 and the welded workpiece toward the unloading hopper 43. When the tooling table 5 moves to the position of the inclined unloading hopper 43, the side of the tooling table 5 away from the conveyor belt 42 naturally tilts downward. Since the workpiece has been released from clamping, it can quickly fall off the tooling table 5 under its own gravity and slide down the unloading hopper 43 into the preset material box. Compared with the unlocked state, this effectively avoids the problem of the workpiece getting stuck on the tooling table 5 and being unable to be unloaded smoothly, realizing convenient unloading of the workpiece and ensuring the continuity of the welding process. This invention achieves optimized adaptation of the entire process of loading, welding, and unloading the U-shaped workpiece by the coordinated structure of clamping plate 51, clamping groove 53, clamping block 54, tension spring 55, trigger groove 56, and trigger block 57. During loading, clamping block 54 is in a retracted state, and clamping plate 51 is in clearance fit with the workpiece, facilitating rapid workpiece loading and reducing operational difficulty. During welding, the lower electrode rod 3 moves upward to press the trigger block 57, and the guide surface 571 drives clamping block 54 to overcome the tension of tension spring 55 and clamp the workpiece, thus overcoming the shortcomings of the original clamping plate 51, which was thin and had unstable positioning. The lower electrode rod 3 ensures that the workpiece does not wobble during welding, improving welding accuracy. After welding, the lower electrode rod 3 moves down and disengages from the trigger block 57. The tension spring 55 resets and drives the clamping block 54 to retract, releasing the workpiece clamping and facilitating its smooth unloading during unloading, avoiding jamming and ensuring a continuous and efficient welding process. The overall structure is ingeniously designed, requiring no additional power drive. It automatically switches between clamping and unlocking by simply moving the lower electrode rod 3, which improves the stability of workpiece positioning and also takes into account the convenience of loading and unloading, further optimizing the performance of the device and adapting to the needs of mass production.

[0030] Example 4: The outer surface of the lower electrode rod 3 is provided with a corrugated surface; the corrugated surface is in contact with one end of the trigger block 57 located inside the stage hole 52.

[0031] In this embodiment, the trigger block 57 is located at one end inside the platform hole 52, close to the surface of the conveyor belt 42.

[0032] As the lower electrode rod 3, carrying the lower electrode head 31, moves upward through the stage hole 52 of the tooling table 5, a small section of corrugated surface on its outer surface begins to contact the end of the trigger block 57 located inside the stage hole 52. The end of the trigger block 57 located inside the stage hole 52 is positioned close to the surface of the conveyor belt 42. This design allows the corrugated surface of the lower electrode rod 3 to contact the trigger block 57 as much as possible, extending the contact stroke and ensuring a stable and sufficient subsequent oscillation effect. The height of the corrugated surface on the outer surface of the lower electrode rod 3 is less than the height of the stage hole 52, ensuring that the lower electrode rod 3 has an arc-shaped, corrugated outer surface. The wall can smoothly enter the inner side of the stage hole 52, preparing for the subsequent triggering of the trigger block 57; as the lower electrode rod 3 continues to move upward, the conical end of the trigger block 57 located inside the stage hole 52 will contact the crests and troughs of the corrugated surface in sequence, forming a periodic squeezing and releasing action: when the trigger block 57 contacts the crest of the corrugated surface, the crest will exert a squeezing force on the trigger block 57 in a direction away from the center of the stage hole 52, pushing the trigger block 57 to slide along the trigger groove 56 towards the clamping groove 53, thereby squeezing the clamping block 54 in the clamping groove 53, causing the clamping block 54 to extend outward against the tension of the tension spring 55; when the trigger block When 57 moves to the trough of the corrugated surface, the squeezing force on the trigger block 57 disappears, and the tension spring 55, which is in a stored state, generates a restoring force, pulling the clamping block 54 back into the clamping groove 53, while simultaneously driving the trigger block 57 to reset towards the center of the stage hole 52. This periodic squeezing and releasing action generated by the interaction between the corrugated surface and the trigger block 57 will cause the clamping block 54 to squeeze and calibrate the U-shaped workpieces to be welded on the tooling table 5 back and forth. Through this repeated squeezing and releasing, the two U-shaped workpieces to be welded can be better fitted together under vibration, and the workpieces can be accurately calibrated to ensure that the two workpieces are properly aligned. The contact parts of the workpieces are aligned to avoid welding position deviations caused by workpiece placement offsets. At the same time, it can also make the workpiece and the tooling table 5 fit more closely and eliminate gaps. When the lower electrode rod 3 continues to move upward, its outer surface without corrugations moves to contact the trigger block 57. The trigger block 57 is no longer subjected to periodic fluctuations of pressure, but is stably pressed against by the arc-shaped outer wall of the lower electrode rod 3, maintaining an extended state towards the clamping groove 53. At this time, the clamping block 54 is also stably pressed against the edge of the U-shaped workpiece, realizing a firm clamping of the workpiece, providing stable positioning for subsequent spot welding operations, and ensuring welding accuracy. The present invention uses the corrugated surface of the outer surface of the lower electrode rod 3 to cooperate with the trigger block 57 to form a periodic squeezing and releasing action before welding clamping, which drives the clamping block 54 to squeeze the workpiece back and forth to calibrate the position of the workpiece, avoid welding deviation caused by workpiece placement offset, and at the same time make the two workpieces to be welded fit together better, ensuring the subsequent welding accuracy.

[0033] Example 5: A lightweight automotive door sill welding method, applicable to the aforementioned lightweight automotive door sill welding apparatus, the steps of which are as follows: S1: According to actual usage requirements, select manual or automatic mode, and invert the two U-shaped workpieces to be welded onto the tooling table 5 on the outer wall of the conveyor belt 42 in sequence, and use the clamping plate 51 to initially limit the loading. S2: Start-up device, the output shaft of motor 44 drives one of the conveyor rollers 41 to rotate, and through the meshing of the conveyor teeth and the conveyor groove, the conveyor belt 42 is driven to smoothly transmit the workpiece 5 to the welding station. S3: Control cylinder 13 extends, driving the upper electrode rod 2 to move down and the lower electrode rod 3 to move up. The lower electrode rod 3 calibrates the workpiece and clamps it through the corrugated surface and the trigger block 57. The upper electrode head 21 and the lower electrode head 31 simultaneously contact the workpiece to connect the power supply and complete the spot welding. S4: After welding is completed, the control cylinder 13 shortens to reset the upper electrode rod 2 and the lower electrode rod 3. The clamping block 54 retracts under the action of the tension spring 55 to unlock the workpiece. The conveyor belt 42 continues to drive, transporting the welded workpiece to the unloading hopper 43 to complete the unloading.

[0034] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the appendix. Figure 1 The orientations or positional relationships shown are for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of the present invention. In addition, the terms "first," "second," "third," etc. are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of the present invention, "fixed connection" refers to a fixed connection. In the description of the present invention, "sliding connection" refers to a connection where the two parts can only slide and cannot be separated. Specifically, the groove can be set to be concave and the block can be set to be convex, and the specific design can be adjusted according to the actual situation. "Sliding fit" refers to a connection where the two parts can slide and separate. In the description of the present invention, "rotational connection" refers to a connection where the two parts can only rotate and cannot produce axial displacement. Specifically, an annular groove can be provided on the inner wall of the hole, and a ring that is rotatably connected to the groove can be fixed to the outer wall of the shaft.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A lightweight automobile door sill welding device, comprising a machine box and upper and lower electrode rods on the front side of the machine box; characterized in that: The support is fixedly connected to the upper surface of the base at the bottom of the chassis and located on the front side of the chassis; Two conveyor plates are fixedly connected to the top of the support; conveyor rollers are rotatably connected to the inner side of the conveyor plates; a conveyor belt is driven to the outer wall of the conveyor rollers; an inclined unloading hopper is fixedly connected to the right end of the conveyor plate; one of the conveyor rollers is driven by a motor; square tooling tables are evenly connected to the outer wall of the conveyor belt; clamping plates are fixedly connected to the four corners of the tooling table facing outwards; the tooling table is used to position the workpiece to be welded; the tooling table has table holes running through it vertically; the conveyor belt has multiple belt holes along the conveying direction; the belt holes pass through the conveyor belt; the two tooling tables on the outer wall of the conveyor belt can move between the upper electrode rod and the lower electrode rod; the upper electrode rod and the lower electrode rod can be controlled to move closer to each other; the outer diameter of the lower electrode rod is adapted to the belt holes and table holes; The upper electrode rod and the lower electrode rod are fixedly connected to the upper electrode head and the lower electrode head at their ends; the horizontal conveying roller is offset from the upper electrode rod and the lower electrode rod.

2. The lightweight automotive door sill welding device according to claim 1, characterized in that: The inner wall of the conveyor belt is provided with a conveying groove; the outer wall of the conveyor roller is provided with conveying teeth that can be engaged in the conveying groove; the inner wall of the conveyor belt is provided with a stepped replacement hole that runs through it; the replacement hole passes through a first bolt; the first bolt is threadedly connected to the tooling table facing the conveyor belt.

3. The lightweight automotive door sill welding device according to claim 1, characterized in that: A cylinder is fixedly connected to the upper front side of the chassis; the upper electrode rod is fixedly connected to the cylinder's delivery end; an upper electrode seat is fixedly connected to the outer wall of the upper electrode rod; a central groove is provided inside the chassis; a gear is rotatably connected within the central groove; a strip-shaped left groove and a right groove are provided inside the chassis, located to the left and right of the central groove; both the left and right grooves are connected to the central groove; a left rack that meshes with the gear is slidably connected to the left groove; a left connecting groove is provided through the left groove; a left connecting strip is slidably connected to the left connecting groove; the left connecting strip is fixedly connected to the upper electrode seat; a right rack that meshes with the gear is slidably connected to the right groove; a right connecting groove is provided through the right groove; a right connecting strip is slidably connected to the right connecting groove; the right connecting strip is fixedly connected to the lower electrode seat on the outer wall of the lower electrode rod.

4. The lightweight automotive door sill welding device according to claim 3, characterized in that: A pull hole is provided through the central groove facing rearward; a pull rod is movably connected in the pull hole; the pull rod and the gear are centrally fixedly connected; the front and rear thickness of the central groove is greater than the thickness of the gear.

5. The lightweight automotive door sill welding device according to claim 4, characterized in that: An annular groove is provided on the rear side of the gear; an annular bar is rotatably connected inside the annular groove; the annular bar is connected to the rear inner wall of the central groove by a spring.

6. The lightweight automotive door sill welding device according to claim 3, characterized in that: The card plate has clamping grooves on both sides; clamping blocks are slidably connected in the clamping grooves; two clamping blocks are connected by a tension spring; the clamping grooves are connected to the inner wall of the platform hole and have trigger grooves; trigger blocks are slidably connected in the trigger grooves; the trigger blocks have two guide surfaces at one end of the trigger groove; the end of the trigger blocks inside the platform hole is arc-shaped.

7. The lightweight automotive door sill welding device according to claim 6, characterized in that: The outer surface of the lower electrode rod is configured as a corrugated surface; the corrugated surface is in active contact with one end of the trigger block located inside the stage hole.

8. The lightweight automotive door sill welding device according to claim 6, characterized in that: The trigger block is located at one end inside the platform hole, close to the surface of the conveyor belt.

9. A method for welding lightweight automotive door sill parts, the method being applicable to the lightweight automotive door sill part welding apparatus described in any one of claims 1-8, characterized in that: The steps of this method are as follows: S1: Depending on the actual usage requirements, select manual or automatic mode, and invert the two U-shaped workpieces to be welded onto the tooling table on the outer wall of the conveyor belt in sequence, and use the clamping plate to initially limit the loading. S2: Start-up device, the motor output shaft drives one of the conveyor rollers to rotate, and through the meshing of the conveyor teeth and the conveyor groove, the conveyor belt is driven to smoothly transmit the workpieces to be welded to the welding station. S3: Control the cylinder to extend, causing the upper electrode rod to move down and the lower electrode rod to move up. The lower electrode rod calibrates the workpiece and clamps it through the corrugated surface and the trigger block. The upper electrode head and the lower electrode head simultaneously contact the workpiece to connect the power supply and complete the spot welding. S4: After welding is completed, the control cylinder shortens to reset the upper and lower electrode bars. The clamping block retracts under the action of the tension spring to unlock the workpiece. The conveyor belt continues to drive and transports the welded workpiece to the unloading hopper to complete the unloading.

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