Intermittent automatic feeding clamp

Abstract

The invention provides an intermittent automatic feeding clamp, and relates to the field of metal plate processing, the intermittent automatic feeding clamp comprises a welding platform, a gantry crane and a rotating table are sequentially arranged along the opening direction of the welding platform, and the intermittent automatic feeding clamp further comprises an execution unit, a lower clamp and an upper clamp which are matched with workpieces are arranged above the linear sliding tables, a conveying bed frame is arranged at an opening of the welding platform, a plurality of conveying belts are arranged in the conveying bed frame at equal intervals, a plurality of L-shaped blocks are arranged below the gantry crane in parallel, and a plurality of electric control lifting rods are arranged below the conveying belts in a rectangular array mode; a positioning rod is arranged on the surface of the lower clamp; the control unit comprises a pre-inspection path planning module, a grading jacking module and a dynamic compensation module, through cooperation between the control unit and the execution unit, the automatic clamping, positioning and conveying functions are achieved, inconvenience of manual operation is reduced, and the welding efficiency of workpieces is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of metal sheet processing, and particularly to an intermittent automatic feeding fixture. Background Art

[0002] An automobile body is usually welded by a variety of sheet metal parts, and there are hierarchical and sequential relationships in the welding matching relationships of the sheet metal parts;

[0003] When producing larger automobile sheet metal spot welding component assemblies at present, due to the long and wide shape of the spot welding assembly components, the volume of the corresponding production tooling fixture also becomes extremely large and wide. It becomes difficult for the operator to install the workpiece on the positioning device where the part should be. Moreover, there are problems such as the overlapping sequence relationship of the components of the large spot welding assembly itself, the long distance for installing large workpieces, inconvenient operation for the operator, the workpiece not being clamped in place, and the wrong installation sequence. 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 functions of high-precision, stable and safe automatic clamping and positioning and conveying of the workpiece through the cooperation between the control unit and the execution unit, reduces the inconvenience of manual operation, and improves the welding efficiency of the workpiece.

[0005] To solve the above technical problem, the technical solution of the present invention is 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] A plurality of linear slides are arranged on the surface of the welding platform, a lower fixture and an upper fixture adapted to the workpiece are arranged above each linear slide, the lower fixture and the upper fixture are used for clamping and fixing the workpiece, a transfer bed frame is arranged at the opening of the welding platform, a plurality of conveyor belts are equidistantly arranged inside the transfer bed frame, a plurality of L-shaped blocks are arranged in parallel below the gantry crane, a plurality of workstations are arranged in a circular array on the surface of the rotating table, an avoidance groove corresponding to the L-shaped block is opened at each position where the workstation is located on the surface of the rotating table, a plurality of electric control lifting rods are arranged in a rectangular array below the conveyor belt, a support head is fixedly connected to the end of each electric control lifting rod, and the electric control lifting rod is used for lifting the workpiece so that the lower fixture and the upper fixture clamp and fix the workpiece;

[0008] A positioning rod is arranged on the surface of the lower fixture, and the positioning rod is used for engaging with a reserved hole groove on the surface of the corresponding workpiece to position the workpiece with the corresponding lower fixture;

[0009] The control unit includes:

[0010] A pre-inspection path planning module, which is used to predict the lifting units that may have kinematic interference with it through a three-dimensional kinematic model according to the target operation trajectories of the clamping unit and the positioning unit, and generate a list of disabled lifting units;

[0011] A hierarchical lifting module, which is used to only activate the non-disabled lifting units, and generate an asymmetric lifting instruction according to the positions of the activated lifting units relative to the center of gravity of the workpiece, so as to lift the workpiece to a set height, and at the same time ensure that the support areas of the non-disabled lifting units have no geometric intersection with the moving paths of the clamping unit and the positioning unit;

[0012] A dynamic compensation module, which is used to monitor the relationship between the actual paths of the clamping unit and the positioning unit and the support areas of the activated lifting units in real time. If it is detected that the clamping unit and the positioning unit invade the support area of a non-disabled lifting unit, immediately trigger the lifting force compensation of the adjacent non-disabled lifting unit, and switch the invaded lifting unit to the disabled state and retract it to the reset position.

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

[0014] Dynamically adjust the lifting force distribution ratio of each unit according to the position distribution of the non-disabled lifting units relative to the center of gravity of the workpiece, so that the support area has no geometric intersection with the moving paths of the clamping unit and the positioning unit, and ensure that the total resultant moment generated by all lifting units on the workpiece is zero, thereby preventing the workpiece from rotating or tilting during the lifting process.

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

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

[0017] Further, several groups of first slide rails are arranged on the surface of the welding platform along the opening direction. Several groups of first slide rails are arranged on both sides of the opening on the surface of the welding platform. Each group of the first slide rails is arranged in parallel. The linear slide table is arranged above the corresponding first slide rail. A mounting plate is fixedly connected to the bottom surface of the linear slide table. First sliders are symmetrically and fixedly connected to the bottom surface of the mounting plate. The first sliders are slidably connected to the corresponding first slide rails. A bearing plate is fixedly connected to the slide surface of the linear slide table. A first telescopic cylinder is fixedly connected to the surface of the bearing plate. The lower clamp is fixedly connected to the end of the first telescopic cylinder.

[0018] Further, drive rotating rods are symmetrically arranged inside the conveyor bed frame. The drive rotating rods are rotatably connected to the first circular holes symmetrically formed 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. The end of the output shaft of the first motor is fixedly connected to one of the drive rotating rods. A number of drive wheels are equally spaced and fixedly connected to the surface of the drive rotating rods. The conveyor belt is drivingly connected to the surfaces of two corresponding drive wheels on the surfaces of the two drive rotating rods. The support heads are respectively located between the two corresponding conveyor belts, and the upper surface of the support head is coplanar with the upper surface of the conveyor belt.

[0019] Further, a connection frame is fixedly connected to the end of the boom of the gantry crane. A second motor is installed inside the connection frame. A connection rotating block is rotatably connected to the second circular groove formed on the bottom surface of the connection frame through a second bearing. A connection bar is fixedly connected to the surface of the connection rotating block. The L-shaped blocks are fixedly connected to the connection bar.

[0020] Further, a rotating sleeve is fixedly connected to the surface of the lower clamp. A second rotating rod is rotatably connected to the inside of the rotating sleeve through a third bearing. A third motor is installed on the bottom surface of the rotating sleeve. The output shaft of the third motor is fixedly connected to the second rotating rod. A first connecting arm is fixedly connected to the surface of the second rotating rod. A second connecting arm is fixedly connected to the surface of the first connecting arm. The positioning rod is inserted into the third circular groove formed on the surface of the second connecting arm. A third telescopic cylinder is arranged 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. A second telescopic cylinder is installed on the surface of the lower clamp. The end of the output shaft of the second telescopic cylinder is hinged to a first connecting rod. The end of the first connecting rod away from the second telescopic cylinder is hinged to the upper clamp.

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

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

[0023] The above scheme of the present invention has at least the following beneficial effects: Through the coordinated action of the pre-inspection path planning module, the hierarchical lifting module and the dynamic compensation module, stable and high-precision clamping and positioning of the workpiece are realized during the entire automatic feeding and clamping 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 stable transportation of the workpiece, reducing manual operation, 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 hierarchical lifting module generates an asymmetric lifting instruction according to the center of gravity position of the workpiece to maintain stability. The dynamic compensation module monitors the path intrusion situation in real time and performs lifting force compensation to improve the welding accuracy and stability of the workpiece.

[0025] By setting a gantry crane for the picking and placing transportation of the workpiece, the rotary table realizes the efficient rotation and positioning of the workpiece; by setting a first slide rail, a linear slide table, a bearing plate and a first telescopic cylinder, sliding and precise positioning and clamping are realized; through the combined clamping of the lower fixture and the upper fixture and the insertion and cooperation of the positioning rod for positioning, precise correction and reliable fixation of the workpiece position are realized.

[0026] The workpiece is efficiently and stably transported and lifted through a conveyor belt, an electric control lifting rod and a support head, and the transportation and handover of the workpiece are completed in cooperation with the L-shaped block; the lateral load of the linear slide table is reduced through the support sliding sleeve, the C-shaped support block and the first spring, improving the service life and stability of the moving mechanism. Description of the Drawings

[0027] Figure 1 is a schematic diagram of the control unit of the present invention.

[0028] Figure 2 is the overall structural schematic diagram provided by the present invention.

[0029] Figure 3 It is a schematic diagram of the 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 table; 205, support sliding 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 rotating rod; 303, transmission wheel; 304, conveyor belt; 305, first motor; 306, electric control lifting rod; 307, support head; 308, connecting bar; 309, L-shaped block; 310, connecting rotating block; 311, connecting frame; 312, second motor;

[0038] 401, bearing 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 implementation manners

[0039] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the 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. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art.

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

[0041] The control unit includes:

[0042] A pre-inspection path planning module, which is used to predict the lifting units that may have kinematic interference with it through a three-dimensional kinematic model according to the target operation trajectories of the clamping unit and the positioning unit, and generate a list of disabled lifting units;

[0043] A hierarchical lifting module, which is used to only activate the non-disabled lifting units, and generate an asymmetric lifting instruction according to the positions of the activated lifting units relative to the workpiece's center of gravity, so as to lift the workpiece to a set height, and at the same time ensure that the support areas of the non-disabled lifting units have no geometric intersection with the moving paths of the clamping unit and the positioning unit;

[0044] A dynamic compensation module, which is used to monitor the relationship between the actual paths of the clamping unit and the positioning unit and the support areas of the activated lifting units in real time. If it is detected that the clamping unit and the positioning unit invade the support area of a non-disabled lifting unit, immediately trigger the lifting force compensation of the adjacent non-disabled lifting unit, and switch the invaded lifting unit to the disabled state and retract it to its original position.

[0045] The hierarchical lifting module further includes:

[0046] According to the position distribution of the non-disabled lifting units relative to the workpiece's center of gravity, dynamically adjust the lifting force distribution ratio of each unit, so that the support area has no geometric intersection with the moving paths of the clamping unit and the positioning unit, and ensure that the resultant moment 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 further includes:

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

[0049] In the embodiments of the present invention, the starting point, ending point, and path curvature parameters of the clamping unit and the positioning unit are input into a three-dimensional kinematic model constructed based on the Denavit-Hartenberg (D-H) parameter method. The D-H parameter model in this embodiment adopts a standard parameter definition method, where each link segment uses four parameters: link length ( ), offset ( ), twist angle ( ), and joint rotation angle ( ) for definition. By calibrating the mechanical structure of the actual device, a complete parameter set of the clamping unit and the positioning unit is obtained, and an accurate forward kinematic equation is established, so as to calculate the set of trajectory points of the end effector. By enveloping these sets of trajectory points, a predicted trajectory bounding box is formed for interference detection.

[0050] Taking the center coordinates of each lifting unit as the origin, a circular area with a preset radius is defined as the physical occupancy area of the lifting unit. Using a spatial geometry superposition algorithm, a Boolean operation is performed on the physical occupancy areas of all lifting units and the predicted trajectory bounding boxes of the clamping unit and the positioning unit, and the lifting units with geometric intersections are marked as disabled lifting units. The numbers of the disabled lifting units obtained through the above Boolean operation are summarized to form a list of disabled lifting units for subsequent modules of the control unit to call.

[0051] In this embodiment, the geometric contour data of the workpiece is obtained in real time through a sensor installed on the fixture, and the centroid position of the workpiece is calculated by the polygon area weighting method. Subsequently, the proportion of the jacking force of each unit is dynamically adjusted according to the horizontal distance from the non-disabled lifting unit to the centroid of the workpiece. The calculation formula for the horizontal distance is: ;

[0052] where is the horizontal distance between the center of the th lifting unit and the centroid of the workpiece, is the center coordinate of the th lifting unit, and is the coordinate of the centroid of the workpiece.

[0053] The weight coefficient is determined according to the above calculation formula for the horizontal distance:

[0054] When the horizontal distance , the weight coefficient is the reciprocal of this distance: ;

[0055] When the horizontal distance is zero, that is, when the lifting unit is exactly at the center of gravity of the workpiece, to avoid division by zero and ensure mathematical stability, the weight coefficient is set to a large preset constant (for example, take ). According to these weight coefficients, calculate the jacking force of each lifting unit: ;

[0056] where is the jacking force allocated to the th lifting unit, is the total jacking force, determined by the weight of the workpiece, is the sum of the weight coefficients of all non-disabled lifting units.

[0057] The asymmetric jacking instruction includes: comprehensively determining the magnitude and timing arrangement of the jacking force of each unit according to the spatial distribution of the non-disabled lifting units, the position of the center of gravity of the workpiece, and the path avoidance requirements of the clamping unit and the positioning unit. Specifically, it includes:

[0058] Timing control: The time interval between the execution of the jacking actions of adjacent non-disabled units is set to a safety delay parameter to avoid local overload caused by synchronous jacking.

[0059] Force value instruction: Generate the target jacking force values of each lifting unit according to the aforementioned jacking force calculation method.

[0060] Before generating the jacking instruction, the system performs geometric intersection verification. If it is detected that there is a geometric overlap between the support area of the non-disabled lifting unit and the moving paths of the clamping unit and the positioning unit, an alarm is triggered and the jacking operation is suspended for manual intervention and inspection.

[0061] Perform a moment balance check every certain period of time. Real-time monitor the tilt deviation of the workpiece through an inclination sensor. If the detected deviation exceeds the preset threshold, immediately trigger the fine-tuning of the jacking force of the adjacent lifting unit to ensure that the workpiece is always in a stable support state.

[0062] To achieve dynamic path interference compensation, the system real-time obtains the coordinate data of the ends of the clamping unit and the positioning unit, and uses a circular area with the center of the lifting unit as the center and a radius of R as the support area. When the end coordinates of the clamping unit or the positioning unit fall within the support area of the non-disabled lifting unit, the system determines that an "intrusion" has occurred.

[0063] When an intrusion is detected, the system immediately triggers the jacking force compensation of the adjacent non-disabled lifting unit. The compensation amount is determined by multiplying the geometric projection area of the intrusion area by the unit area support coefficient, that is: ;

[0064] where is the jacking force compensation amount, is the projected area of the intrusion area, is the support coefficient per unit area, which is preset or corrected in real time according to the workpiece material characteristics and surface conditions.

[0065] After the jacking force compensation is triggered, the invaded lifting unit immediately shrinks from the support state to the initial position and switches to the disabled state, and no longer participates in the subsequent jacking force distribution. Through the collaborative detection of the pressure sensor and the inclination sensor, if the total jacking force error after compensation is controlled within the set threshold then it is determined that the compensation is successful; otherwise, the secondary jacking force distribution of the adjacent lifting units is continued until the target balance state is reached.

[0066] Through the above closed-loop control process, it is possible to ensure that the workpiece is always stable and safe during the entire feeding and clamping positioning process, avoid path crossing interference, and achieve the high precision and reliability of the fixture feeding.

[0067] The execution unit includes:

[0068] Several linear slides 204 are arranged on the surface of the welding platform 101. Lower clamps 403 and upper clamps 406 adapted to the workpiece are arranged above the linear slides 204. The lower clamps 403 and the upper clamps 406 are used for clamping and fixing the workpiece. A transfer bed frame 301 is arranged at the opening of the welding platform 101. Several conveyor belts 304 are equidistantly arranged inside the transfer bed frame 301. Several L-shaped blocks 309 are arranged in parallel below the gantry crane 102. Several workstations are arranged in a circular array on the surface of the rotary table 103. Avoidance grooves corresponding to the L-shaped blocks 309 are opened at the positions of each workstation on the surface of the rotary table 103. Several electric control lifting rods 306 are arranged in a rectangular array below the conveyor belts 304. Support heads 307 are fixedly connected to the ends of the electric control lifting rods 306. The electric control lifting rods 306 are used for lifting the workpiece so that the lower clamps 403 and the upper clamps 406 can clamp and fix the workpiece;

[0069] Positioning rods 413 are arranged on the surface of the lower clamp 403. The positioning rods 413 are used to engage with the reserved holes and grooves on the surface of the corresponding workpiece so that the workpiece is positioned with the corresponding lower clamp 403;

[0070] 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, pass through the avoidance groove of the rotating table 103 to lift the corresponding workpiece, and drive the L-shaped block 309 to move to the top of the first slide rail 201 through the gantry crane 102, and drive the L-shaped block 309 to fall through the gantry crane 102. 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 up to the set height by the corresponding supporting head 307, and 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 located below the corresponding reserved hole groove. In the process of the staff placing the workpiece at the corresponding workstation on the surface of the rotating 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, so that the positioning rod 413 The workpiece is not aligned with the reserved hole groove, and the positioning rod 413 is moved relative to the lower clamp 403 to align the positioning rod 413 with the corresponding reserved hole groove. The aligned positioning rod 413 is inserted into the corresponding reserved hole groove 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 to fit the workpiece with the corresponding surface groove of the lower clamp 403, and then the upper clamp 406 is buckled to clamp the workpiece between the lower clamp 403 and the upper The clamp 406 is positioned between the workpieces to prevent the workpiece from being scratched against 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 entire workpiece after welding is supported by the support head 307. The support head 307 is made to fall back to its initial position, so that the entire workpiece is transferred to the position of the L-shaped block 309. The L-shaped block 309 transfers the entire workpiece to the corresponding workstation for processing by the staff. At the same time, the rotating 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.

[0071] The surface of the welding platform 101 is provided with several groups of first slide rails 201 along the opening direction. Several groups of first slide rails 201 are provided on both sides of the opening on the surface of the welding platform 101. Each group of first slide rails 201 is arranged in parallel. The linear slide table 204 is arranged above the corresponding first slide rail 201. The bottom surface of the surface of the linear slide table 204 is fixedly connected with a mounting plate 203. The bottom surface of the mounting plate 203 is symmetrically and fixedly connected with first sliders 202. The first sliders 202 are slidably connected with the corresponding first slide rails 201. The slide surface of the linear slide table 204 is fixedly connected with a bearing plate 401. The surface of the bearing plate 401 is fixedly connected with a first telescopic cylinder 402. The lower clamp 403 is fixedly connected to the end of the first telescopic cylinder 402.

[0072] In the embodiment of the present invention, according to different workpiece welding operations, the required number of lower clamps 403 can be arranged above each group of first slide rails 201. The lower clamp 403 is fixed to the end of the output shaft of the first telescopic cylinder 402. The first telescopic cylinder 402 is fixedly connected with the slide of the linear slide table 204 through the bearing plate 401. After the mounting plate 203 slides on the surface of the first slide rail 201 through the first slider 202 to the set position and the mounting plate 203 is fixed relative to the first slide rail 201, when the linear slide table 204 drives the lower clamp 403 to move, the workpiece can be fixedly clamped and fixed at the set position, so as to facilitate the welding of the welding device.

[0073] The inside of the conveyor bed frame 301 is symmetrically provided with drive rotating rods 302. The drive rotating rods 302 are rotatably connected to the first circular holes symmetrically opened on the surface of the first slide rail 201 through two first bearings. A first motor 305 is installed on the surface of the first slide rail 201. The end of the output shaft of the first motor 305 is fixedly connected with one of the drive rotating rods 302. The surface of the drive rotating rod 302 is equidistantly and fixedly connected with several drive wheels 303. The conveyor belt 304 is drivingly connected to the surfaces of two corresponding drive wheels 303 on the surfaces of the two drive rotating rods 302. The support heads 307 are respectively located between the two corresponding conveyor belts 304, and the upper surfaces of the support heads 307 are coplanar with the upper surfaces of the conveyor belts 304.

[0074] In the embodiment of the present invention, through the operation of the first motor 305, the drive rotating rod 302 connected to the output shaft of the first motor 305 drives the conveyor belt 304 to rotate through the drive wheels 303. The rotation of the conveyor belt 304 causes the workpiece on its surface to be conveyed to the set position. Then, the support heads 307 are driven by the corresponding position and corresponding number of electric control 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.

[0075] A connection frame 311 is fixedly connected to the end of the boom of the gantry crane 102. A second motor 312 is installed inside the connection frame 311. A connection rotating block 310 is rotatably connected through a second bearing in a second circular groove opened on the bottom surface of the connection frame 311. A connection bar 308 is fixedly connected to the surface of the connection rotating block 310, and L-shaped blocks 309 are fixedly connected to the connection bar 308.

[0076] In the embodiment of the present invention, the boom of the gantry crane 102 drives the connection frame 311 to move. The movement of the connection frame 311 drives the L-shaped blocks 309 on the surface of the connection bar 308 to move through the connection rotating block 310. By operating the second motor 312, the L-shaped blocks 309 can rotate relative to the connection frame 311 to complete the transfer of the workpiece from the station of the rotating table 103 to the surface of the conveyor belt 304.

[0077] A rotating sleeve 407 is fixedly connected to the surface of the lower clamp 403. A second rotating rod 409 is rotatably connected through a third bearing inside the rotating sleeve 407. A third motor 408 is installed on the bottom surface of the rotating sleeve 407. The output shaft of the third motor 408 is fixedly connected to the second rotating rod 409. A first connecting arm 410 is fixedly connected to the surface of the second rotating rod 409. A second connecting arm 411 is fixedly connected to the surface of the first connecting arm 410. A positioning rod 413 is inserted into a third circular groove opened on the surface of the second connecting arm 411. 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.

[0078] A second telescopic cylinder 404 is installed on the surface of the lower clamp 403. The end of the output shaft of the second telescopic cylinder 404 is hinged to a first connecting rod 405, and the end of the first connecting rod 405 away from the second telescopic cylinder 404 is hinged to the upper clamp 406.

[0079] In the 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 control 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 table 204 to move towards the workpiece, that is, the lower fixture 403 is moved towards the workpiece until the positioning rod 413 moves near the reserved hole slot. 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. The rotation of the second rotating rod 409 causes the second connecting arm 411 fixed to the second rotating rod 409 through the first connecting arm 410 to rotate, and further causes the positioning rod 413 to move in an arc trajectory. By coordinating with the movement of the slide of the linear slide table 204, the positioning rod 413 is aligned with the corresponding reserved hole slot. 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 slot and lift the corresponding workpiece. By driving the movement of the positioning rod 413 by the third motor 408 and the movement of the slide of the corresponding linear slide table 204, the position of the workpiece lifted by the positioning rod 413 is corrected. Then, the third telescopic cylinder 412 is contracted, 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 fixture 403. At this time, by contracting the second telescopic cylinder 404, the contraction of the second telescopic cylinder 404 drives the upper fixture 406 to rotate around the rotation center where the first connecting rod 405 is hinged to the upper fixture 406 through the first connecting rod 405 until the upper fixture 406 presses the workpiece against the surface of the lower fixture 403. At this time, the workpiece is fixed by the lower fixture 403 and the upper fixture 406;

[0080] C-shaped support blocks 206 are symmetrically and fixedly connected to the surface of the mounting plate 203. The C-shaped support blocks 206 are distributed on both sides of the lead screw of the linear slide table 204. A support sliding sleeve 205 is slidably connected to the surface of the C-shaped support block 206. A first spring 207 is arranged inside the support sliding sleeve 205. The two ends of the first spring 207 are respectively fixedly connected to the support sliding sleeve 205 and the C-shaped support block 206. The upper surface of the support sliding sleeve 205 always abuts against the bottom surface of the carrier plate 401. A connecting push rod 208 is arranged above the two support sliding sleeves 205. Both support sliding sleeves 205 are fixedly connected to the connecting push rod 208.

[0081] In an embodiment of the present invention, the slide of the linear slide table 204 is fixedly connected to the bottom surface of the carrier plate 401 at a position away from the transfer bed frame 301, and the first telescopic cylinder 402 is fixedly connected to the upper surface of the carrier plate 401 at a position close to the transfer bed frame 301. When the movement of the carrier plate 401 causes the orthographic projection of the carrier plate 401 to exceed the orthographic projection of the linear slide table 204, the carrier plate 401 will push the connecting push rod 208, so that the connecting push rod 208 drives the two support sliding sleeves 205 to move along with the movement of the carrier plate 401. During this process, the two first springs 207 are stretched. When the movement of the carrier plate 401 causes the orthographic projection of the carrier plate 401 to gradually coincide with the orthographic projection of the linear slide table 204, the two support sliding sleeves 205 move along with the movement of the carrier plate 401 under the action of the elastic potential energy of the first springs 207. The surface of the support sliding sleeve 205 is smooth. When the orthographic projection of the carrier plate 401 does not exceed the orthographic projection of the linear slide table 204, the carrier plate 401 does not contact the connecting push rod 208, and the position of the support sliding sleeve 205 remains unchanged. During the movement of the carrier plate 401, the slide of the linear slide table 204 and the support sliding sleeve 205 are always used to support the C-shaped support block 206 to reduce the lateral load on the slide of the linear slide table 204 and extend the service life of the linear slide table 204.

[0082] A vertical plate 209 is fixedly connected to the bottom surface of the mounting plate 203. A first threaded rod 210 is threadedly connected to the surface of the vertical plate 209. The end of the first threaded rod 210 is rotatably connected to a resistance block 211 through a fourth bearing. The resistance block 211 is slidably connected to a first chute opened on the surface of the welding platform 101.

[0083] In an embodiment of the present invention, when the linear slide table 204 moves to a set position on the surface of the first slide rail 201 through the first slider 202, by rotating the first threaded rod 210 on the surface of the vertical plate 209, the static friction force between the resistance block 211 and the welding platform 101 is increased, so that the mounting plate 203 and the welding platform 101 maintain a stable relative fixed state, and thus the corresponding lower clamp 403 maintains a stable movement.

[0084] It should be noted that: the shape of 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 boom 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 boom of the gantry crane 102 can move along the cross beam 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 principles and usage processes of the gantry crane 102 and the rotating table 103 are well known in the prior art and will not be elaborated in detail here;

[0085] The D-H parameters are applicable to the joint configurations of various serial mechanisms, including rotational joints of the rotary type and prismatic joints of the sliding type. Regardless of how the structure changes, as long as each segment of the joint has a clear spatial relationship and a defined axis of motion, the D-H parameters can be used to construct a three-dimensional space 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 prismatic joints, and 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 rotational joints. The upper fixture 406, the first connecting rod 405, and the second telescopic cylinder 404 are also rotational joints;

[0086] For the lifting unit, in this embodiment, it specifically refers to the electric control lifting rod 306 and the support head 307. Each set of the electric control lifting rod 306 and the support head 307 is an independent lifting unit;

[0087] For the clamping unit, in this embodiment, it specifically refers to the linear slide 204, the carrier plate 401, the first telescopic cylinder 402, the lower fixture 403, the second telescopic cylinder 404, the first connecting rod 405, and the upper fixture 406. For the positioning unit, in this embodiment, it 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;

[0088] In this embodiment, each workpiece is provided with at least two groups of positioning rods 413, which facilitates the correction of the workpiece position;

[0089] In this embodiment, the number of the lower fixture 403 and the upper fixture 406 can be adjusted adaptively according to the shape of the workpiece. The upper fixture 406 can be not provided, and the workpiece can be supported only by the positioning rods 413. For example, in this case: when welding three workpieces, two of the workpieces are stacked on top of another workpiece. The clamping unit corresponding to the workpiece located below can be set to be provided with only the lower fixture 403 and the positioning rods 413 to support the workpiece, and the clamping and fixing of each workpiece can be achieved by the downward pressure of the other two workpieces, so as to maintain the stability of each workpiece during welding.

[0090] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle described in the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An intermittent automatic feeding fixture, comprising a welding platform, a gantry crane and a rotating table are sequentially arranged along the opening direction of the welding platform, and it is characterized in that, It includes a control unit and an execution unit; The execution unit includes: Several linear slides are arranged on the surface of the welding platform. Lower clamps and upper clamps adapted to workpieces are arranged above the linear slides. The lower clamps and the upper clamps are used for clamping and fixing the workpieces. A conveying bed frame is arranged at the opening of the welding platform. Several conveyor belts are equidistantly arranged inside the conveying bed frame. Several L-shaped blocks are arranged in parallel below the gantry crane. Several workstations are arranged in a circular array on the surface of the rotating table. Avoidance grooves corresponding to the L-shaped blocks are opened at the positions of each workstation on the surface of the rotating table. Several electric control lifting rods are arranged in a rectangular array below the conveyor belt. Support heads are fixedly connected to the ends of the electric control lifting rods. The electric control lifting rods are used for lifting the workpieces so that the lower clamps and the upper clamps can clamp and fix the workpieces; Positioning rods are arranged on the surface of the lower clamp. The positioning rods are used to engage with the reserved hole grooves on the surface of the corresponding workpiece so as to position the workpiece with the corresponding lower clamp; The control unit includes: A pre-inspection path planning module, which is used to predict the lifting units that may have motion interference with it through a three-dimensional kinematic model according to the target operation trajectories of the clamping unit and the positioning unit, and generate a list of disabled lifting units; A hierarchical lifting module, which is used to only activate the non-disabled lifting units, and generate an asymmetric lifting instruction according to the positions of the activated lifting units relative to the center of gravity of the workpiece, so as to lift the workpiece to a set height, and at the same time ensure that the support areas of the non-disabled lifting units have no geometric intersection with the moving paths of the clamping unit and the positioning unit; A dynamic compensation module, which is used to monitor the relationship between the actual paths of the clamping unit and the positioning unit and the support areas of the activated lifting units in real time. If it is detected that the clamping unit and the positioning unit invade the support area of a non-disabled lifting unit, immediately trigger the lifting force compensation of the adjacent non-disabled lifting unit, and switch the invaded lifting unit to the disabled state and retract and reset it.

2. The intermittent automatic feeding fixture according to claim 1, wherein The hierarchical lifting module further includes: Dynamically adjust the lifting force distribution ratio of each unit according to the position distribution of the non-disabled lifting units relative to the center of gravity of the workpiece, so that the support area has no geometric intersection with the moving paths of the clamping unit and the positioning unit, and ensure that the resultant moment 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, wherein The dynamic compensation module further includes: By continuously tracking the geometric relationship between the actual paths of the clamping unit and the positioning unit and the support areas of the activated lifting units, when it is detected that the clamping unit and the positioning unit invade the support area of a non-disabled lifting unit, immediately trigger the lifting force compensation of the adjacent non-disabled lifting unit. The compensation amount is dynamically adjusted based on the geometric projection range of the invaded area. The invaded lifting unit shrinks to the initial position and remains in the disabled state. The physical occupancy 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 the 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 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 bearing plate, and the surface of the 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 first circular holes 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 two surfaces of the transmission wheels corresponding to the two surfaces of the transmission rotating rods. The support heads are 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, wherein 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 in a second circular groove opened on the bottom surface of the connecting frame via a second bearing, a connecting strip is fixedly connected to the surface of the connecting rotating block, and the L-shaped blocks are fixedly connected to the connecting strip.

7. The intermittent automatic feeding fixture according to claim 6, wherein A rotating sleeve is fixedly connected to the surface of the lower clamp, and a second rotating rod is rotatably connected to the interior of the rotating sleeve through a third bearing. A third motor is installed on the bottom surface of the rotating sleeve, and an output shaft of the third motor is fixedly connected to the second rotating rod. A first connecting arm is fixedly connected to the surface of the second rotating rod, and a second connecting arm is fixedly connected to the surface of the first 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 arranged below the positioning rod and installed on the second connecting arm. An end of the output device of the third telescopic cylinder is fixedly connected to the positioning rod, and a second telescopic cylinder is installed on the surface of the lower clamp, and a first connecting rod is hinged on the end of the output shaft of the second telescopic cylinder, and an 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 and 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 arranged inside the support sleeve, and the two ends of the first spring are respectively fixedly connected to the support sleeve and the C-shaped support block, and the upper surface of the support sleeve is always in conflict with the bottom surface of the bearing plate, and a connecting push rod is arranged 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, wherein The bottom surface of the installation plate is fixedly connected with a vertical plate. The surface of the vertical plate is threadedly connected with a first threaded rod. The end of the first threaded rod is rotatably connected with a resistance block through a fourth bearing. The resistance block is slidably connected in a first chute opened on the surface of the welding platform.

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