An intermittent automatic feeding fixture

Abstract

The present invention provides an intermittent automatic feeding fixture, which relates to the field of metal plate processing, including a welding platform, a gantry crane and a rotating table are arranged in sequence along the opening direction of the welding platform, and also includes an execution unit: a plurality of linear slides are arranged on the surface of the welding platform, and a lower clamp and an upper clamp adapted to the workpiece are arranged above the linear slides, a conveying bed is arranged at the opening of the welding platform, and a plurality of conveyor belts are equidistantly arranged inside the conveying bed, a plurality of L-shaped blocks are arranged in parallel below the gantry crane, a plurality of electric-controlled lifting rods are arranged in a rectangular array below the conveyor belt, and a positioning rod is arranged on the surface of the lower clamp; the control unit includes: a pre-inspection path planning module, a graded jacking module, and a dynamic compensation module. The present invention realizes the automatic clamping, positioning and conveying functions through the collaboration between the control unit and the execution unit, reduces the inconvenience of manual operation, and improves the welding efficiency of the workpiece.

Description

Technical Field

[0001] The invention relates to the technical field of metal plate processing, in particular to an intermittent automatic feeding fixture. Background Art

[0002] Automobile bodies are usually welded together by various sheet metal parts, and the welding matching relationship between each sheet metal part has a hierarchical and sequential relationship.

[0003] Currently, large automotive sheet metal spot welding component assemblies are being produced. Due to the long and wide size of the spot welding assembly components, the corresponding production fixtures have also become unusually large, making it difficult for operators to install the workpieces on the positioning devices where the parts are supposed to be located. In addition, the components of large spot welding assemblies themselves have a sequence of overlapping connections, and the installation distance of large workpieces is far, making it inconvenient for operators to operate. The workpieces cannot be clamped in place, and the installation sequence is prone to errors. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an intermittent automatic feeding fixture, which realizes the high-precision, stable and safe automatic clamping, positioning and conveying functions of the workpiece through the collaboration between the control unit and the execution unit, reduces the inconvenience of manual operation, and improves the welding efficiency of the workpiece.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] An intermittent automatic feeding fixture includes a welding platform, a gantry crane and a rotating table are sequentially arranged along the opening direction of the welding platform, and also includes a control unit and an execution unit; the execution unit includes:

[0007] The surface of the welding platform is provided with several linear slides, and a lower clamp and an upper clamp adapted to the workpiece are provided above the linear slide, and the lower clamp and the upper clamp are used for clamping and fixing the workpiece, a conveying bed is provided at the opening of the welding platform, and several conveyor belts are equidistantly provided inside the conveying bed, and several L-shaped blocks are provided in parallel below the gantry crane, and a plurality of workstations are provided in a circular array on the surface of the rotating table, and avoidance grooves corresponding to the L-shaped blocks are provided at each workstation, and a plurality of electric lifting rods are provided in a rectangular array below the conveyor belt, and the ends of the electric lifting rods are fixedly connected to support heads, and the electric lifting rods are used for lifting and lowering the workpiece so that the lower clamp and the upper clamp can clamp and fix the workpiece;

[0008] A positioning rod is provided on the surface of the lower clamp, and the positioning rod is used to engage with a reserved hole groove on the surface of the corresponding workpiece to position the workpiece corresponding to the lower clamp;

[0009] The control unit comprises:

[0010] The pre-inspection path planning module is used to predict the lifting units that may interfere with the target operation trajectory of the gripping unit and positioning unit through a three-dimensional kinematic model, and generate a list of prohibited lifting units;

[0011] A hierarchical lifting module is used to activate only the lifting units that are not disabled and generate asymmetric lifting instructions based on the position of each activated lifting unit relative to the center of gravity of the workpiece to lift the workpiece to a set height while ensuring that the support areas of the non-disabled lifting units have no geometric intersection with the movement paths of the gripping unit and the positioning unit;

[0012] The dynamic compensation module is used to monitor in real time the relationship between the actual path of the gripping unit and the positioning unit and the support area of ​​the activated lifting unit. If it is detected that the gripping unit and the positioning unit invade the support area of ​​a non-disabled lifting unit, the lifting force compensation of the adjacent non-disabled lifting unit will be triggered immediately, and the invaded lifting unit will be switched to a disabled state and retracted to reset.

[0013] Furthermore, the hierarchical lifting module further includes:

[0014] According to the position distribution of the non-disabled lifting units relative to the center of gravity of the workpiece, the lifting force distribution ratio of each unit is dynamically adjusted so that there is no geometric intersection between the support area and the moving paths of the clamping unit and the positioning unit, and the resultant torque generated by all lifting units on the workpiece is zero, thereby preventing the workpiece from rotating or tilting during the lifting process.

[0015] Furthermore, the dynamic compensation module further includes:

[0016] By continuously tracking the geometric relationship between the actual path of the gripping unit and the positioning unit and the support area of ​​the activated lifting unit, when it is detected that the gripping unit and the positioning unit invade the support area of ​​the non-disabled lifting unit, the lifting force compensation of the adjacent non-disabled lifting unit is immediately triggered. The compensation amount is dynamically adjusted based on the geometric projection range of the intruded area. The invaded lifting unit shrinks to the initial position and remains disabled. The physical occupied area of ​​the invaded lifting unit does not participate in the lifting force distribution. The total lifting force error after compensation is eliminated through the coordinated adjustment of adjacent units.

[0017] Furthermore, the surface of the welding platform is provided with several groups of first slide rails along the opening direction, and the surface of the welding platform is provided with several groups of first slide rails on both sides of the opening, and each group of first slide rails is arranged parallel to each other, and the linear slide is arranged above the corresponding first slide rails, and the bottom surface of the surface of the linear slide is fixedly connected to a mounting plate, and the bottom surface of the mounting plate is symmetrically fixedly connected to a first slider, and the first slider is slidably connected to the corresponding first slide rail, and the slide surface of the linear slide is fixedly connected to a load-bearing plate, and the surface of the load-bearing plate is fixedly connected to a first telescopic cylinder, and the lower clamp is fixedly connected to the end of the first telescopic cylinder.

[0018] Furthermore, a transmission rotating rod is symmetrically arranged inside the conveying bed frame, and the transmission rotating rod is rotatably connected to the first circular hole symmetrically opened on the surface of the first slide rail through two first bearings. A first motor is installed on the surface of the first slide rail, and the end of the first motor output shaft is fixedly connected to one of the transmission rotating rods. A plurality of transmission wheels are fixedly connected to the surface of the transmission rotating rod at equal intervals. The conveyor belt transmission is connected to the two transmission wheel surfaces corresponding to the two transmission rotating rod surfaces. The support head is respectively located between the corresponding two conveyor belts, and the upper surface of the support head is coplanar with the upper surface of the conveyor belt.

[0019] Furthermore, the end of the gantry crane boom is fixedly connected to a connecting frame, a second motor is installed inside the connecting frame, a connecting block is rotatably connected to a second circular groove opened on the bottom surface of the connecting frame through a second bearing, a connecting bar is fixedly connected to the surface of the connecting block, and the L-shaped blocks are fixedly connected to the connecting bar.

[0020] Furthermore, the surface of the lower clamp is fixedly connected to a rotating sleeve, the interior of the rotating sleeve is rotatably connected to a second rotating rod through a third bearing, the bottom surface of the rotating sleeve is installed with a third motor, the output shaft of the third motor is fixedly connected to the second rotating rod, the surface of the second rotating rod is fixedly connected to the first connecting arm, the surface of the first connecting arm is fixedly connected to the second connecting arm, the positioning rod is inserted into a third circular groove opened on the surface of the second connecting arm, a third telescopic cylinder is provided below the positioning rod, the third telescopic cylinder is installed on the second connecting arm, the end of the output shaft of the third telescopic cylinder is fixedly connected to the positioning rod, the surface of the lower clamp is installed with a second telescopic cylinder, the end of the output shaft of the second telescopic cylinder is hinged to a first connecting rod, and the end of the first connecting rod away from the second telescopic cylinder is hinged to the upper clamp.

[0021] Furthermore, the surface of the mounting plate is symmetrically fixedly connected with C-shaped support blocks, and the C-shaped support blocks are distributed on both sides of the linear slide screw. The surface of the C-shaped support block is slidably connected with a support sleeve, and a first spring is provided inside the support sleeve. The two ends of the first spring are respectively fixedly connected to the support sleeve and the C-shaped support block. The upper surface of the support sleeve is always in conflict with the bottom surface of the bearing plate. A connecting push rod is provided above the two support sleeves, and the two support sleeves are fixedly connected to the connecting push rod.

[0022] Furthermore, the bottom surface of the mounting plate is fixedly connected to a vertical plate, the surface of the vertical plate is threadedly connected to a first threaded rod, the end of the first threaded rod is rotatably connected to a resistance block through a fourth bearing, and the resistance block is slidably connected to a first slide groove opened on the surface of the welding platform.

[0023] The above solution of the present invention has at least the following beneficial effects: by providing the pre-inspection path planning module, the graded lifting module and the dynamic compensation module to work together, stable and high-precision clamping and positioning of the workpiece is achieved during the entire automatic feeding and clamping and positioning process, effectively avoiding path interference between the clamping and positioning unit and the lifting unit, ensuring the safety of the feeding process and the smooth transportation of the workpiece, reducing manual operations and improving the welding efficiency of the workpiece;

[0024] The pre-inspection path planning module is used to predict interference and determine the disabled lifting units. The graded lifting module generates asymmetric lifting instructions based on the center of gravity of the workpiece to maintain stability. The dynamic compensation module monitors path intrusion in real time and compensates for lifting forces to improve the welding accuracy and stability of the workpiece.

[0025] A gantry crane is provided for the loading and unloading of workpieces, and a rotary table is provided for efficient rotation and positioning of workpieces. Sliding and precise positioning and clamping are achieved by providing a first slide rail, a linear slide, a load-bearing plate, and a first telescopic cylinder. The workpiece position is precisely corrected and reliably fixed by combining the clamping of the lower and upper fixtures and inserting and coordinating the positioning rods.

[0026] The workpieces are efficiently and smoothly transported and lifted through the conveyor belt, electric lifting rod and support head, and the L-shaped block is used to complete the transportation and handover of the workpieces. The support sleeve, C-shaped support block and first spring reduce the lateral load of the linear slide, thereby improving the service life and stability of the motion mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the control unit of the present invention.

[0028] Figure 2 It is a schematic diagram of the overall structure provided by the present invention.

[0029] Figure 3 It is a schematic diagram of the load-bearing plate in the present invention.

[0030] Figure 4 It is a schematic diagram of the first slide rail in the present invention.

[0031] Figure 5 It is a schematic diagram of the conveyor belt in the present invention.

[0032] Figure 6 It is a schematic diagram of the first connecting rod in the present invention.

[0033] Figure 7 It is a schematic diagram of the first slider in the present invention.

[0034] Figure 8 It is a schematic diagram of the first spring in the present invention.

[0035] In the figure: 101, welding platform; 102, gantry crane; 103, rotating table;

[0036] 201, first slide rail; 202, first slider; 203, mounting plate; 204, linear slide; 205, support sleeve; 206, C-shaped support block; 207, first spring; 208, connecting push rod; 209, vertical plate; 210, first threaded rod; 211, resistance block;

[0037] 301, conveyor bed frame; 302, transmission rod; 303, transmission wheel; 304, conveyor belt; 305, first motor; 306, electric lifting rod; 307, support head; 308, connecting bar; 309, L-shaped block; 310, connecting block; 311, connecting frame; 312, second motor;

[0038] 401. Carrying plate; 402. First telescopic cylinder; 403. Lower clamp; 404. Second telescopic cylinder; 405. First connecting rod; 406. Upper clamp; 407. Rotating sleeve; 408. Third motor; 409. Second rotating rod; 410. First connecting arm; 411. Second connecting arm; 412. Third telescopic cylinder; 413. Positioning rod. DETAILED DESCRIPTION

[0039] The following describes exemplary embodiments of the present disclosure in more detail with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0040] like Figures 1 to 8As shown, an embodiment of the present invention provides an intermittent automatic feeding fixture, comprising a welding platform 101, a gantry crane 102 and a rotating table 103 arranged in sequence along the opening direction of the welding platform 101, and comprising a control unit and an execution unit.

[0041] The control unit includes:

[0042] The pre-inspection path planning module is used to predict the lifting units that may interfere with the target operation trajectory of the gripping unit and positioning unit through a three-dimensional kinematic model, and generate a list of prohibited lifting units;

[0043] A hierarchical lifting module is used to activate only the lifting units that are not disabled and generate asymmetric lifting instructions based on the position of each activated lifting unit relative to the center of gravity of the workpiece to lift the workpiece to a set height while ensuring that the support areas of the non-disabled lifting units have no geometric intersection with the movement paths of the gripping unit and the positioning unit;

[0044] The dynamic compensation module is used to monitor in real time the relationship between the actual path of the gripping unit and the positioning unit and the support area of ​​the activated lifting unit. If it is detected that the gripping unit and the positioning unit invade the support area of ​​a non-disabled lifting unit, the lifting force compensation of the adjacent non-disabled lifting unit will be triggered immediately, and the invaded lifting unit will be switched to a disabled state and retracted to reset.

[0045] The staged lifting module also includes:

[0046] According to the position distribution of the non-disabled lifting units relative to the center of gravity of the workpiece, the lifting force distribution ratio of each unit is dynamically adjusted so that there is no geometric intersection between the support area and the moving paths of the clamping unit and the positioning unit, and the resultant torque generated by all lifting units on the workpiece is zero, thereby preventing the workpiece from rotating or tilting during the lifting process.

[0047] The dynamic compensation module also includes:

[0048] By continuously tracking the geometric relationship between the actual path of the gripping unit and the positioning unit and the support area of ​​the activated lifting unit, when it is detected that the gripping unit and the positioning unit invade the support area of ​​the non-disabled lifting unit, the lifting force compensation of the adjacent non-disabled lifting unit is immediately triggered. The compensation amount is dynamically adjusted based on the geometric projection range of the intruded area. The invaded lifting unit shrinks to the initial position and remains disabled. The physical occupied area corresponding to the invaded lifting unit does not participate in the lifting force distribution. The total lifting force error after compensation is eliminated through the coordinated adjustment of adjacent units.

[0049] In the embodiment of the present invention, the starting point, end point and path curvature parameters of the gripping unit and the positioning unit are input into the three-dimensional kinematic model constructed based on the Denavit-Hartenberg (DH) parameter method. The DH parameter model in this embodiment adopts a standard parameter definition method, in which each connecting rod segment uses the connecting rod length ( )、Offset( ), torsion angle ( ) and joint angle ( ) are defined. By calibrating the actual mechanical structure of the device, a complete set of parameters for the gripping and positioning units is obtained, and accurate forward kinematic equations are established to calculate the trajectory points of the end effector. By enveloping these trajectory points, a predicted trajectory bounding box is formed for use in interference detection.

[0050] The center coordinates of each lifting unit are used as the origin, and the preset radius is defined. The circular area represents the physical footprint of the lifting unit. Using a spatial geometric overlay algorithm, a Boolean operation is performed on the physical footprints of all lifting units and the predicted trajectory bounding boxes of the gripping unit and positioning unit. Lifting units with geometric intersections are marked as disabled. The disabled lifting unit numbers obtained through these Boolean operations are summarized to form a disabled lifting unit list, which is then used by subsequent modules of the control unit.

[0051] In this embodiment, the geometric profile data of the workpiece is acquired in real time by sensors installed on the fixture, and the center of gravity of the workpiece is calculated using the polygon area weighting method. Subsequently, the lifting force proportion of each unit is dynamically adjusted based on the horizontal distance from the non-disabled lifting unit to the center of gravity of the workpiece. The calculation formula for the horizontal distance is:

[0052] ;

[0053] in For the The horizontal distance between the center of each lifting unit and the center of gravity of the workpiece, For the The center coordinates of the lifting units, is the coordinate of the center of gravity of the workpiece.

[0054] The weight coefficient is determined according to the calculation formula of the above horizontal distance:

[0055] When the horizontal distance When the weight coefficient is the reciprocal of this distance:

[0056] ;

[0057] When the horizontal distance is zero, that is, the lifting unit is exactly at the center of gravity of the workpiece, in order to avoid division by zero and ensure mathematical stability, the weight coefficient is set to a larger preset constant (For example, take ). Based on these weight coefficients, calculate the lifting force of each lifting unit:

[0058] ;

[0059] in For the The lifting force distributed by each lifting unit, is the total lifting force, which is determined by the weight of the workpiece. It is the sum of the weight coefficients of all non-disabled lifting elements.

[0060] Asymmetric lifting instructions include: comprehensively determining the lifting force and timing of each unit based on the spatial distribution of non-disabled lifting units, the center of gravity of the workpiece, and the path avoidance requirements of the gripping unit and positioning unit. Specifically, it includes:

[0061] Timing control: The time interval for executing the lifting actions of adjacent non-disabled units is set as a safety delay parameter to avoid local overload caused by synchronous lifting.

[0062] Force value instruction: Generate the target lifting force value of each lifting unit according to the above-mentioned lifting force calculation method.

[0063] Before generating the lifting instruction, the system performs geometric intersection verification. If it detects that the support area of ​​the non-disabled lifting unit has geometric overlap with the moving path of the clamping unit and the positioning unit, an alarm is triggered and the lifting operation is suspended, and manual intervention and inspection are carried out.

[0064] A torque balance check is performed at regular intervals, and the tilt deviation of the workpiece is monitored in real time through the inclination sensor. If the deviation exceeds the preset threshold, the lifting force of the adjacent lifting unit is immediately triggered to fine-tune the lifting force to ensure that the workpiece is always in a stable support state.

[0065] To achieve dynamic path interference compensation, the system acquires coordinate data of the end points of the gripping and positioning units in real time, using a circular area with a radius R, centered at the center of the lifting unit, as the support area. When the coordinates of the end points of the gripping or positioning units fall into the support area of ​​an undisabled lifting unit, the system determines that an "intrusion" has occurred.

[0066] When an intrusion is detected, the system immediately triggers the lifting force compensation of the adjacent non-disabled lifting units. The compensation amount is determined by multiplying the geometric projection area of ​​the intrusion area by the unit area support coefficient, that is:

[0067] ;

[0068] in is the lifting force compensation, is the projected area of ​​the intrusion region, It is the support coefficient per unit area, which is preset or modified in real time according to the material properties and surface condition of the workpiece.

[0069] After the lifting force compensation is triggered, the invaded lifting unit will immediately retract from the support state to the initial position and switch to the disabled state, and will no longer participate in the subsequent lifting force distribution. The pressure sensor and the inclination sensor will be used for coordinated detection. If the total lifting force error after compensation is controlled within the set threshold If the value is within the range of 0.05, the compensation is considered successful; otherwise, the secondary lifting force distribution of the adjacent lifting units is continued until the target equilibrium state is reached.

[0070] Through the above closed-loop control process, it can be ensured that the workpiece is always stable and safe during the entire feeding and clamping positioning process, avoiding path cross interference and achieving high precision and reliability of fixture feeding.

[0071] The execution unit includes:

[0072] The surface of the welding platform 101 is provided with several linear slides 204, and the upper part of the linear slides 204 is provided with a lower clamp 403 and an upper clamp 406 adapted to the workpiece, and the lower clamp 403 and the upper clamp 406 are used for clamping and fixing the workpiece, and a conveying bed frame 301 is provided at the opening of the welding platform 101, and a plurality of conveyor belts 304 are equidistantly provided inside the conveying bed frame 301, and a plurality of L-shaped blocks 309 are arranged in parallel below the gantry crane 102, and a plurality of workstations are arranged in a circular array on the surface of the rotating table 103, and avoidance grooves corresponding to the L-shaped blocks 309 are provided at the position of each workstation, and a plurality of electric lifting rods 306 are provided in a rectangular array below the conveyor belt 304, and the ends of the electric lifting rods 306 are fixedly connected to the support heads 307, and the electric lifting rods 306 are used for lifting and lowering the workpiece so that the lower clamp 403 and the upper clamp 406 can clamp and fix the workpiece;

[0073] A positioning rod 413 is provided on the surface of the lower fixture 403. The positioning rod 413 is used to engage with a reserved hole groove on the surface of the corresponding workpiece to position the workpiece and the corresponding lower fixture 403.

[0074] In the embodiment of the present invention, before welding, the gantry crane 102 is operated to drive the L-shaped block 309 to move to the bottom of the corresponding workstation of the rotating table 103, and move from bottom to top, passing through the avoidance groove of the rotating table 103 to lift the corresponding workpiece, and the gantry crane 102 drives the L-shaped block 309 to move to the top of the first slide rail 201, and the gantry crane 102 drives the L-shaped block 309 to fall. During the falling process, the L-shaped block 309 passes through the gap between the conveyor belts 304 and continues to move downward, while the workpiece on the surface of the L-shaped block 309 remains on the conveyor belt 304. The workpiece is moved to the set position through the transmission of the conveyor belt 304, and the corresponding electric-controlled lifting rod 306 is controlled to extend so that the workpiece is lifted to the set height by the corresponding support head 307. At the same time, the lower clamp 403 drives the positioning rod 413 to move in the direction close to the corresponding workpiece until the positioning rod 413 is near the bottom of the corresponding reserved hole groove. During the process of the staff placing the workpiece at the corresponding workstation on the surface of the rotary table 103 and the process of the L-shaped block 309 transporting the workpiece, the position of the workpiece will deviate from the preset position, causing the positioning rod 413 to move closer to the workpiece. The workpiece is not aligned with the reserved hole slot, and the positioning rod 413 is moved relative to the lower clamp 403 to align the positioning rod 413 with the corresponding reserved hole slot. After the alignment, the positioning rod 413 is inserted into the corresponding reserved hole slot and then continues to be lifted to lift the workpiece. The position of the workpiece is corrected by the movement of the positioning rod 413 and the coordinated extension and contraction of the left and right telescopic groups. When the position of the workpiece is corrected, the positioning rod 413 falls synchronously, so that the workpiece is engaged with the corresponding groove on the surface of the lower clamp 403, and then the upper clamp 406 is buckled, so that the workpiece is clamped between the lower clamp 403 and the upper The clamps 406 are positioned between the workpieces to avoid scratches between the workpiece and the lower clamp 403 during the fitting process. When the welding work is completed, the electrically controlled lifting rod 306 is lifted so that the welded workpiece is supported by the support head 307. The support head 307 is dropped back to its initial position, and the workpiece is transferred to the position of the L-shaped block 309. The L-shaped block 309 transfers the workpiece to the corresponding workstation for processing by the staff. At the same time, the rotary table 103 is rotated so that the L-shaped block 309 continues to transfer the next round of welding workpieces to complete the intermittent automatic feeding action.

[0075] The surface of the welding platform 101 is provided with several groups of first slide rails 201 along the opening direction, and the surface of the welding platform 101 is provided with several groups of first slide rails 201 on both sides of the opening. Each group of first slide rails 201 is arranged parallel to each other, and the linear slide 204 is arranged above the corresponding first slide rail 201. The bottom surface of the surface of the linear slide 204 is fixedly connected to the mounting plate 203, and the bottom surface of the mounting plate 203 is symmetrically fixedly connected to the first slider 202. The first slider 202 is slidingly connected to the corresponding first slide rail 201. The slide surface of the linear slide 204 is fixedly connected to the supporting plate 401, and the surface of the supporting plate 401 is fixedly connected to the first telescopic cylinder 402. The lower clamp 403 is fixedly connected to the end of the first telescopic cylinder 402.

[0076] In an embodiment of the present invention, according to different workpiece welding operations, a required number of lower clamps 403 can be set above each group of first slide rails 201, and the lower clamps 403 are fixed to the end of the output shaft of the first telescopic cylinder 402. The first telescopic cylinder 402 is fixedly connected to the slide of the linear slide 204 through the supporting plate 401, so that the mounting plate 203 is slid to the set position on the surface of the first slide rail 201 through the first slider 202, and the mounting plate 203 is fixed relative to the first slide rail 201, so that when the linear slide 204 drives the lower clamp 403 to move, the workpiece can be fixedly clamped and fixed in the set position to facilitate welding of the welding device.

[0077] The interior of the conveying bed frame 301 is symmetrically provided with a transmission rotating rod 302, which is rotatably connected to the first circular hole symmetrically opened on the surface of the first slide rail 201 through two first bearings. The surface of the first slide rail 201 is installed with a first motor 305, and the end of the output shaft of the first motor 305 is fixedly connected to one of the transmission rotating rods 302. The surface of the transmission rotating rod 302 is evenly fixedly connected with a number of transmission wheels 303. The conveyor belt 304 is transmission-connected to the surfaces of the two transmission wheels 303 corresponding to the surfaces of the two transmission rotating rods 302. The support head 307 is respectively located between the corresponding two conveyor belts 304, and the upper surface of the support head 307 is coplanar with the upper surface of the conveyor belt 304.

[0078] In an embodiment of the present invention, through the operation of the first motor 305, the transmission rod 302 connected to the output shaft of the first motor 305 drives the conveyor belt 304 to rotate through the transmission wheel 303. The rotation of the conveyor belt 304 causes the workpiece on its surface to be transported to the set position, and then the support head 307 is driven by the corresponding position and corresponding number of electric-controlled lifting rods 306 to lift the workpiece to the set position, so as to facilitate the positioning and clamping of the workpiece by the lower clamp 403, the upper clamp 406 and the positioning rod 413.

[0079] The end of the lifting arm of the gantry crane 102 is fixedly connected to a connecting frame 311, and a second motor 312 is installed inside the connecting frame 311. A connecting rotating block 310 is rotatably connected to the second circular groove opened on the bottom surface of the connecting frame 311 through a second bearing. The surface of the connecting rotating block 310 is fixedly connected to a connecting bar 308, and the L-shaped blocks 309 are all fixedly connected to the connecting bar 308.

[0080] In an embodiment of the present invention, the lifting arm of the gantry crane 102 drives the connecting frame 311 to move, and the movement of the connecting frame 311 drives the L-shaped block 309 on the surface of the connecting bar 308 to move through the connecting turn block 310. Through the operation of the second motor 312, the L-shaped block 309 can rotate relative to the connecting frame 311 to complete the transfer of the workpiece from the work station of the rotating table 103 to the surface of the conveyor belt 304.

[0081] The surface of the lower clamp 403 is fixedly connected to a rotating sleeve 407, and the interior of the rotating sleeve 407 is rotatably connected to the second rotating rod 409 through a third bearing. The bottom surface of the rotating sleeve 407 is installed with a third motor 408, and the output shaft of the third motor 408 is fixedly connected to the second rotating rod 409. The surface of the second rotating rod 409 is fixedly connected to the first connecting arm 410, and the surface of the first connecting arm 410 is fixedly connected to the second connecting arm 411. The positioning rod 413 is inserted into a third circular groove opened on the surface of the second connecting arm 411, and a third telescopic cylinder 412 is arranged below the positioning rod 413. The third telescopic cylinder 412 is installed on the second connecting arm 411, and the end of the output device of the third telescopic cylinder 412 is fixedly connected to the positioning rod 413.

[0082] A second telescopic cylinder 404 is mounted on the surface of the lower clamp 403 . A first connecting rod 405 is hinged to the end of the output shaft of the second telescopic cylinder 404 . An end of the first connecting rod 405 away from the second telescopic cylinder 404 is hinged to the upper clamp 406 .

[0083] In an embodiment of the present invention, after the workpiece is lifted to a set height by the support head 307 at the end of the electric-controlled lifting rod 306, the first telescopic cylinder 402 on the surface of the carrier plate 401 is driven by the slide of the linear slide 204 to move toward the direction close to the workpiece, even if the lower clamp 403 moves toward the direction close to the workpiece, until the positioning rod 413 moves to the vicinity of the reserved hole groove, by operating the third motor 408 at the bottom of the second rotating rod 409, the operation of the third motor 408 drives the second rotating rod 409 inside the rotating sleeve 407 to rotate, and the rotation of the second rotating rod 409 causes the second connecting arm 411 fixed to the second rotating rod 409 by the first connecting arm 410 to rotate, thereby causing the positioning rod 413 to move in an arc trajectory, and by coordinating with the movement of the slide of the linear slide 204, the positioning rod 413 is aligned with the corresponding reserved hole groove. , by extending the third telescopic cylinder 412, the extension of the third telescopic cylinder 412 causes the positioning rod 413 to be inserted upward into the corresponding reserved hole groove, and the corresponding workpiece is lifted up, and the third motor 408 drives the movement of the positioning rod 413 and the movement of the corresponding linear slide 204 slide, so that the position of the workpiece lifted by the positioning rod 413 is returned to the correct position, and then the third telescopic cylinder 412 is retracted, so that the positioning rod 413 drives the workpiece to fall until the workpiece is engaged with the groove on the surface of the lower clamp 403. At this time, by retracting the second telescopic cylinder 404, the contraction of the second telescopic cylinder 404 drives the upper clamp 406 to rotate around the rotation center of the hinge between the first connecting rod 405 and the upper clamp 406 through the first connecting rod 405, until the upper clamp 406 presses the workpiece onto the surface of the lower clamp 403, and the workpiece is fixed by the lower clamp 403 and the upper clamp 406;

[0084] The surface of the mounting plate 203 is symmetrically fixedly connected with a C-shaped support block 206, which is distributed on both sides of the screw rod of the linear slide 204. The surface of the C-shaped support block 206 is slidably connected with a support sleeve 205. A first spring 207 is provided inside the support sleeve 205. The two ends of the first spring 207 are fixedly connected to the support sleeve 205 and the C-shaped support block 206 respectively. The upper surface of the support sleeve 205 is always in conflict with the bottom surface of the bearing plate 401. A connecting push rod 208 is provided above the two support sleeves 205, and the two support sleeves 205 are fixedly connected to the connecting push rod 208.

[0085] In the embodiment of the present invention, the slide of the linear slide 204 is fixedly connected to the bottom surface of the carrier plate 401 away from the position of the conveying bed frame 301, and the first telescopic cylinder 402 is fixedly connected to the upper surface of the carrier plate 401 close to the position of the conveying bed frame 301. When the movement of the carrier plate 401 causes the positive projection of the carrier plate 401 to exceed the positive projection of the linear slide 204, the carrier plate 401 will push the connecting push rod 208, so that the connecting push rod 208 drives the two supporting sleeves 205 to move with the movement of the carrier plate 401. This process causes the two first springs 207 to stretch. When the movement of the carrier plate 401 causes the positive projection of the carrier plate 401 to gradually exceed the positive projection of the linear slide 204, the carrier plate 401 will push the connecting push rod 208, so that the connecting push rod 208 drives the two supporting sleeves 205 to move with the movement of the carrier plate 401. When it gradually coincides with the orthographic projection of the linear slide 204, the two supporting sleeves 205 move along with the movement of the supporting plate 401 under the action of the elastic potential energy of the first spring 207. The surface of the supporting sleeve 205 is smooth. When the orthographic projection of the supporting plate 401 does not exceed the orthographic projection of the linear slide 204, the supporting plate 401 does not contact the connecting push rod 208, and the position of the supporting sleeve 205 remains unchanged. During the movement of the supporting plate 401, it is always supported by the slide of the linear slide 204 and the supporting sleeve 205 and the C-shaped support block 206 to reduce the lateral load of the slide of the linear slide 204 and extend the service life of the linear slide 204.

[0086] The bottom surface of the mounting plate 203 is fixedly connected to a vertical plate 209, and the surface of the vertical plate 209 is threadedly connected to a first threaded rod 210. The end of the first threaded rod 210 is rotatably connected to a resistance block 211 through a fourth bearing, and the resistance block 211 is slidably connected to a first slide groove opened on the surface of the welding platform 101.

[0087] In an embodiment of the present invention, after the linear slide 204 moves to a set position on the surface of the first slide rail 201 through the first slider 202, the static friction between the resistance block 211 and the welding platform 101 is increased by rotating the first threaded rod 210 on the surface of the vertical plate 209, thereby maintaining a stable relative fixed state between the mounting plate 203 and the welding platform 101, and thus maintaining stable movement of the corresponding lower clamp 403.

[0088] It should be noted that the welding platform 101 is C-shaped so that the conveyor belt 304 in the first slide rail 201 can convey the workpiece to a position close to the corresponding lower clamp 403. The lifting arm of the gantry crane 102 can move in the vertical direction to drive the L-shaped block 309 to move. At the same time, the lifting arm of the gantry crane 102 can move along the crossbeam of the gantry crane 102 so that the L-shaped block 309 can transfer the workpiece from the rotating table 103 to the surface of the conveyor belt 304. The working principle and use process of the gantry crane 102 and the rotating table 103 are well known in the prior art and will not be described in detail here.

[0089] DH parameters are applicable to joint configurations of various serial mechanisms, including rotary joints and sliding joints. No matter how the structure changes, as long as each joint has a clear spatial relationship and a defined motion axis, the DH parameters can be used to construct a three-dimensional spatial model. In this embodiment, the linear slide 204, the first telescopic cylinder 402, the third telescopic cylinder 412 and the positioning rod 413 serve as mobile joints, the third motor 408, the rotating sleeve 407, the second rotating rod 409, the first connecting arm 410 and the second connecting arm 411 serve as rotating joints, and the upper clamp 406, the first connecting rod 405 and the second telescopic cylinder 404 also serve as rotating joints.

[0090] The lifting unit in this embodiment specifically refers to the electric lifting rod 306 and the support head 307. Each set of the electric lifting rod 306 and the support head 307 is an independent lifting unit.

[0091] The gripping unit in this embodiment specifically refers to the linear slide 204, the carrying plate 401, the first telescopic cylinder 402, the lower clamp 403, the second telescopic cylinder 404, the first connecting rod 405, and the upper clamp 406. The positioning unit in this embodiment specifically refers to the rotating sleeve 407, the third motor 408, the second rotating rod 409, the first connecting arm 410, the second connecting arm 411, the third telescopic cylinder 412, and the positioning rod 413.

[0092] In this embodiment, each workpiece is provided with at least two sets of positioning rods 413, thereby facilitating the correction of the workpiece position;

[0093] In this embodiment, the number of the lower clamp 403 and the upper clamp 406 can be adaptively adjusted according to the shape of the workpiece. The upper clamp 406 may not be provided, and the workpiece can be supported only by the positioning rod 413. For example, in this case: the welding involves three workpieces, two of which are stacked on top of each other. The clamping unit corresponding to the workpiece located below can be set to only have the lower clamp 403 and the positioning rod 413 to support the workpiece, and the clamping and fixation of each workpiece can be achieved by pressing down on the other two workpieces to maintain the stability of each workpiece during welding.

[0094] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An intermittent automatic feeding fixture, comprising a welding platform, a gantry crane and a rotating table arranged in sequence along the opening direction of the welding platform, characterized in that: including a control unit and an execution unit; The execution unit includes: The surface of the welding platform is provided with several linear slides, and a lower clamp and an upper clamp adapted to the workpiece are provided above the linear slide, and the lower clamp and the upper clamp are used for clamping and fixing the workpiece, a conveying bed is provided at the opening of the welding platform, and several conveyor belts are equidistantly provided inside the conveying bed, and several L-shaped blocks are provided in parallel below the gantry crane, and a plurality of workstations are provided in a circular array on the surface of the rotating table, and avoidance grooves corresponding to the L-shaped blocks are provided at each workstation, and a plurality of electric lifting rods are provided in a rectangular array below the conveyor belt, and the ends of the electric lifting rods are fixedly connected to support heads, and the electric lifting rods are used for lifting and lowering the workpiece so that the lower clamp and the upper clamp can clamp and fix the workpiece; A positioning rod is provided on the surface of the lower clamp, and the positioning rod is used to engage with a reserved hole groove on the surface of the corresponding workpiece to position the workpiece corresponding to the lower clamp; The control unit comprises: The pre-inspection path planning module is used to predict the lifting units that may interfere with the target operation trajectory of the gripping unit and positioning unit through a three-dimensional kinematic model, and generate a list of prohibited lifting units; A hierarchical lifting module is used to activate only the lifting units that are not disabled and generate asymmetric lifting instructions based on the position of each activated lifting unit relative to the center of gravity of the workpiece to lift the workpiece to a set height while ensuring that the support areas of the non-disabled lifting units have no geometric intersection with the movement paths of the gripping unit and the positioning unit; The dynamic compensation module is used to monitor in real time the relationship between the actual path of the gripping unit and the positioning unit and the support area of ​​the activated lifting unit. If it is detected that the gripping unit and the positioning unit invade the support area of ​​a non-disabled lifting unit, the lifting force compensation of the adjacent non-disabled lifting unit will be triggered immediately, and the invaded lifting unit will be switched to a disabled state and retracted to reset.

2. The intermittent automatic feeding fixture according to claim 1, characterized in that: The hierarchical lifting module further comprises: According to the position distribution of the non-disabled lifting units relative to the center of gravity of the workpiece, the lifting force distribution ratio of each unit is dynamically adjusted so that there is no geometric intersection between the support area and the moving paths of the clamping unit and the positioning unit, and the resultant torque generated by all lifting units on the workpiece is zero, thereby preventing the workpiece from rotating or tilting during the lifting process.

3. The intermittent automatic feeding fixture according to claim 1, characterized in that: The dynamic compensation module also includes: By continuously tracking the geometric relationship between the actual path of the gripping unit and the positioning unit and the support area of ​​the activated lifting unit, when it is detected that the gripping unit and the positioning unit invade the support area of ​​the non-disabled lifting unit, the lifting force compensation of the adjacent non-disabled lifting unit is immediately triggered. The compensation amount is dynamically adjusted based on the geometric projection range of the intruded area. The invaded lifting unit shrinks to the initial position and remains disabled. The physical occupied area of ​​the invaded lifting unit does not participate in the lifting force distribution. The total lifting force error after compensation is eliminated through the coordinated adjustment of adjacent units.

4. The intermittent automatic feeding fixture according to claim 3, characterized in that: The surface of the welding platform is provided with several groups of first slide rails along the opening direction, and the surface of the welding platform is provided with several groups of first slide rails on both sides of the opening, and each group of first slide rails is arranged parallel to each other, and the linear slide is arranged above the corresponding first slide rail, and the bottom surface of the surface of the linear slide is fixedly connected with a mounting plate, and the bottom surface of the mounting plate is symmetrically fixedly connected with a first slider, and the first slider is slidably connected to the corresponding first slide rail, and the slide surface of the linear slide is fixedly connected with a load-bearing plate, and the surface of the load-bearing plate is fixedly connected with a first telescopic cylinder, and the lower clamp is fixedly connected to the end of the first telescopic cylinder.

5. The intermittent automatic feeding fixture according to claim 4, characterized in that: A transmission rotating rod is symmetrically arranged inside the conveying bed frame, and the transmission rotating rod is rotatably connected to the first circular hole symmetrically opened on the surface of the first slide rail through two first bearings. A first motor is installed on the surface of the first slide rail, and the end of the first motor output shaft is fixedly connected to one of the transmission rotating rods. A plurality of transmission wheels are fixedly connected to the surface of the transmission rotating rod at equal distances. The conveyor belt transmission is connected to the two transmission wheel surfaces corresponding to the two transmission rotating rod surfaces. The support head is respectively located between the corresponding two conveyor belts, and the upper surface of the support head is coplanar with the upper surface of the conveyor belt.

6. The intermittent automatic feeding fixture according to claim 5, characterized in that: The end of the gantry crane boom is fixedly connected to a connecting frame, a second motor is installed inside the connecting frame, a connecting rotating block is rotatably connected to a second circular groove opened on the bottom surface of the connecting frame through a second bearing, a connecting strip is fixedly connected to the surface of the connecting rotating block, and the L-shaped blocks are all fixedly connected to the connecting strip.

7. The intermittent automatic feeding fixture according to claim 6, characterized in that: The surface of the lower clamp is fixedly connected to a rotating sleeve, and the interior of the rotating sleeve is rotatably connected to a second rotating rod through a third bearing. The bottom surface of the rotating sleeve is installed with a third motor, and the output shaft of the third motor is fixedly connected to the second rotating rod, and the surface of the second rotating rod is fixedly connected to the first connecting arm, and the surface of the first connecting arm is fixedly connected to the second connecting arm. The positioning rod is inserted into a third circular groove opened on the surface of the second connecting arm, and a third telescopic cylinder is provided below the positioning rod, and the third telescopic cylinder is installed on the second connecting arm. The end of the output device of the third telescopic cylinder is fixedly connected to the positioning rod, and the second telescopic cylinder is installed on the surface of the lower clamp, and the end of the output shaft of the second telescopic cylinder is hinged to the first connecting rod, and the end of the first connecting rod away from the second telescopic cylinder is hinged to the upper clamp.

8. The intermittent automatic feeding fixture according to claim 7, characterized in that: The surface of the mounting plate is symmetrically fixedly connected with a C-shaped support block, and the C-shaped support blocks are distributed on both sides of the linear slide screw. The surface of the C-shaped support block is slidably connected with a support sleeve, and a first spring is provided inside the support sleeve. The two ends of the first spring are fixedly connected to the support sleeve and the C-shaped support block respectively. The upper surface of the support sleeve is always in conflict with the bottom surface of the bearing plate. A connecting push rod is provided above the two support sleeves, and the two support sleeves are fixedly connected to the connecting push rod.

9. The intermittent automatic feeding fixture according to claim 8, characterized in that: The bottom surface of the mounting plate is fixedly connected to a vertical plate, the surface of the vertical plate is threadedly connected to a first threaded rod, the end of the first threaded rod is rotatably connected to a resistance block through a fourth bearing, and the resistance block is slidably connected to a first slide groove opened on the surface of the welding platform.

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