CN120791105B - A welding fixture for automotive structural components - Google Patents

Abstract

This invention discloses a welding fixture for automotive structural components, relating to the field of automotive structural component welding technology. It includes a welding table, with a support platform mounted on the center of the top wall of the welding table to support the workpiece. Welding mechanisms are symmetrically arranged at the front and rear of the top wall of the welding table. Main clamping mechanisms, mounted on the top wall of the welding table, are symmetrically arranged at the front and rear of the support platform, and auxiliary clamping mechanisms are mounted on the main clamping mechanisms. The advantages are: the contour block, upper clamping frame, and lower clamping frame work together to comprehensively clamp the arc-shaped connection, avoiding gaps at the welding point and preventing weak or incomplete welds, while also enhancing clamping stability; the welding mechanism and auxiliary clamping mechanism work together, with the movement of the welding mechanism driving the contour block to make way for spot welding operations, preventing interference with the welding; simultaneously, the arc-shaped connection at the spot welding position is pressed and smoothed, avoiding gaps around the weld point, which is beneficial for improving welding quality.

Description

Welding fixture for automobile structural part

Technical Field

The invention relates to the technical field of welding of automobile structural parts, in particular to a welding fixture for automobile structural parts.

Background

The automobile structural part is a metal part for forming an automobile body framework and bearing main loads (such as impact force, gravity and torsion), and the main structural part comprises front and rear longitudinal beams, A/B/C/D columns, a roof longitudinal beam, a cross beam and the like, wherein an upper longitudinal beam in a front longitudinal beam system is a specific part in a front automobile body structure, and in order to improve the bending strength and torsional rigidity of the upper longitudinal beam, a double-sided resistance spot welding mode is adopted for spot welding the upper longitudinal beam body and a reinforcing frame during processing.

The welding method comprises the steps of carrying out welding in a double-sided resistance spot welding mode, clamping and positioning an upper longitudinal beam body and a reinforcing plate, ensuring the firmness and accuracy of welding, carrying out partial spot welding connection of the upper longitudinal beam body and the reinforcing frame to form an arc shape, carrying out partial clamping on an arc structure in a plurality of point location clamping modes, or carrying out sectional large-area clamping through a profiling block fit contour, preventing the arc structure from being deformed in the welding process, wherein when the arc structure is partially clamped in the plurality of point location clamping modes, the situation that the arc connection between clamping points is not tightly attached exists, the upper plate at the arc connection is not firmly adhered to the lower plate after being melted during welding, so that weak welding and weak welding are caused, the welding quality is reduced, and secondly, carrying out large-area clamping through the profiling block fit contour, the position after clamping of a clamp is relatively fixed, and the situation that interference is generated at the welding position can occur, so that flexible welding is influenced.

Therefore, in order to improve the stability and the tightness of clamping and improve the welding quality, the invention provides the welding fixture for the automobile structural part.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a welding fixture for an automobile structural part.

In order to achieve the aim, the technical scheme is that the welding fixture for the automobile structural part comprises a welding table, wherein a supporting table for supporting a workpiece to be machined is arranged in the middle of the top wall of the welding table, welding mechanisms are symmetrically arranged at the front and rear parts of the top wall of the welding table, main clamping mechanisms assembled on the top wall of the welding table are symmetrically arranged at the front and rear parts of the supporting table, and auxiliary clamping mechanisms are arranged on the main clamping mechanisms.

The main clamping mechanism comprises two supporting seats which are correspondingly arranged on the top wall of the welding table through bolts, a lower clamping frame and an upper clamping frame which are used for carrying out lower bearing and upper pressing on a workpiece to be processed are arranged on the two supporting seats together, and the middle parts of the lower clamping frame and the upper clamping frame are arc-shaped and are matched with the workpiece to be processed.

The auxiliary clamping mechanism comprises a movable clamping assembly arranged on a lower clamping frame and an upper clamping frame, the movable clamping assembly, the corresponding lower clamping frame and the corresponding upper clamping frame are jointly provided with a cooling avoidance assembly, the movable clamping assembly and the lower clamping frame are matched to comprehensively support a workpiece to be processed, the movable clamping assembly and the upper clamping frame are matched to comprehensively press the workpiece to be processed, the workpiece to be processed is fully clamped in the upper direction and the lower direction before welding, the movable clamping assembly and the cooling avoidance assembly are matched to carry out deflection avoidance on a processing point position during welding processing, and the welding point position is cooled and avoided after welding is finished.

In the above-mentioned automobile structure spare welding jig, welding mechanism includes the welding manipulator of welding bench roof assembly, and the welding manipulator corresponds from top to bottom and is equipped with upper welding head and lower welding head, and upper welding head and lower welding head keep away from the tip of welding end and all cup joint the toper cover.

In the welding fixture for the automobile structural part, the left end and the right end of the lower clamping frame and the left end and the right end of the upper clamping frame are connected through the electric push rod, the supporting seat is fixedly connected between the bottom wall of the left end and the right end of the lower clamping frame and the top wall of the welding table, and the heights of the two supporting seats are respectively suitable for the heights of the two ends of the lower clamping frame.

In the above-mentioned automobile structural member welding jig, the activity clamping assembly includes movable groove one, and a plurality of movable grooves one of orientation around all having been seted up along circumferencial direction equidistance on lower holder and the last holder, and symmetrical sliding connection has L type frame around the last spring one of movable groove one, and the semicircle groove has been seted up in the middle part of one side that the horizontal segment of L type frame is close to each other.

In the welding fixture for the automobile structural part, the middle part of the vertical section of the L-shaped frame is fixedly connected with the L-shaped traction part, the outer part of the L-shaped traction part is sleeved with the profiling block, the inner part of the profiling block is provided with the first groove position for the L-shaped traction part to slide back and forth, the side wall, close to the workpiece to be machined, of the lower clamping frame and the upper clamping frame is provided with the second movable groove penetrating through the middle part of the first movable groove, and the second movable groove corresponds to the welding point.

The cooling avoidance assembly comprises a first wedge-shaped member, one side of the profiling block, which is close to the L-shaped frame, is fixedly connected with the first wedge-shaped member, and the top wall of the first wedge-shaped member is inclined.

In the welding fixture for the automobile structural part, the upper clamping frame and the lower clamping frame are symmetrically provided with the movable groove III which penetrates through the upper clamping frame and the lower clamping frame, the movable groove III is communicated with the movable groove I, and the movable groove III is internally provided with the wedge-shaped part II in an up-down sliding manner through the spring II.

In the welding fixture for the automobile structural part, the second wedge-shaped part consists of the sliding plate which is connected with the third movable groove in a sliding way and the wedge-shaped block which is fixed on the side wall of the sliding plate, the bottom wall of the wedge-shaped block is in an inclined shape which is matched with the first wedge-shaped part, and the bottom wall of the L-shaped frame is provided with the second groove for the third movable groove to pass through.

In the above welding fixture for an automobile structural member, the movable groove one is fixedly connected with four stoppers in a matrix shape, and one side of each stopper which is opposite to the other side is connected with movable protruding blocks in a sliding manner by means of springs in a three-left-right symmetry manner.

In the welding fixture for the automobile structural part, the end part of the movable lug, which is positioned outside the stop block, is in an arrow shape formed by two inclined surfaces, and the left side wall and the right side wall of the profiling block are provided with the groove III which is matched with the stop block.

Compared with the prior art, the clamping device has the advantages that 1, the arc-shaped connecting positions are comprehensively clamped through the cooperation of the profiling blocks, the upper clamping frame and the lower clamping frame, gaps are avoided in welding points, weak welding and virtual welding are prevented from being generated, clamping stability is enhanced, the arc-shaped connecting positions of the upper longitudinal beam body and non-welding positions of the arc-shaped connecting positions of the reinforcing frames are tightly clamped by the upper clamping frame and the lower clamping frame, and welding points which are not clamped by the lower clamping frame and the upper clamping frame are tightly clamped in the upper and lower directions by the two profiling blocks.

2. The welding mechanism is matched with the auxiliary clamping mechanism, the profiling block is driven to avoid the yielding position for spot welding operation through movement of the welding mechanism, interference to welding is prevented, the taper sleeve drives the profiling block to avoid the yielding position for spot welding operation for downward movement of the upper welding head, and meanwhile the arc-shaped connection part of the spot welding position is pressed against and smoothed by the profiling block when the profiling block moves, so that gaps are avoided around welding spots, and welding quality is improved.

3. Through the cooperation of movable clamping assembly and cooling avoidance subassembly, two corresponding movable lugs lock the position behind the same profile modeling piece slip from two directions about, prevent that the profile modeling piece from causing the destruction to the spot welding face that just welds, give spot welding position cooling time, ensure welding quality.

Drawings

The invention is described in further detail below with reference to the attached drawing figures, wherein:

Fig. 1 is a schematic overall structure.

Fig. 2 (a) is a schematic structural view of the upper side member body, (b) is a schematic structural view of the reinforcing frame, and (c) is a schematic structural view of the upper side member body after welding with the reinforcing frame.

Fig. 3 is a schematic structural view of the welding mechanism.

Fig. 4 is a schematic structural view of the main clamping mechanism.

Fig. 5 is a partially exploded view of the movable clamp assembly.

Fig. 6 is an enlarged schematic view at a in fig. 5.

Fig. 7 (a) is a schematic view of the movable bump before the movable bump locks the copying block, and (b) is a schematic view of the movable bump after the movable bump locks the copying block.

Fig. 8 is a schematic cross-sectional view of a portion of the structure of the movable clamp assembly.

FIG. 9 is a schematic cross-sectional view of a portion of the structure of the cooling relief assembly.

Fig. 10 (a) is a schematic diagram of the position of the profiling block before welding, and (b) is a schematic diagram of the position of the profiling block during welding.

Fig. 11 (a) is a schematic diagram of the positions of the L-shaped frame and the L-shaped traction member at the time of welding, and (b) is a schematic diagram of the positions of the L-shaped frame and the L-shaped traction member after welding.

Fig. 12 (a) is a schematic view of the state of the profiling block before the wedge slides down, and (b) is a schematic view of the state of the profiling block after the wedge slides down.

The welding machine comprises a welding table 1, a supporting table 2, a welding mechanism 3, a welding manipulator 31, a welding head 32, a lower welding head 33, a conical sleeve 34, a main clamping mechanism 4, a supporting seat 41, a lower clamping frame 42, a lower clamping frame 43, an upper clamping frame 5, an auxiliary clamping mechanism 51, a movable clamping assembly 511, a movable groove I, a 512, an L-shaped frame 513, an L-shaped traction piece 514, a profiling block 515, a movable groove II, a 52, a cooling avoidance assembly 521, a wedge I, a 522, a movable groove III, a 523, a wedge II, a 524, a stop block 525 and a movable lug.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1 to 2, a welding fixture for an automobile structural member comprises a welding table 1, wherein a supporting table 2 for supporting a workpiece to be machined is arranged in the middle of the top wall of the welding table 1, welding mechanisms 3 are symmetrically arranged at the front and rear parts of the top wall of the welding table 1, main clamping mechanisms 4 assembled on the top wall of the welding table 1 are symmetrically arranged at the front and rear parts of the supporting table 2, and auxiliary clamping mechanisms 5 are arranged on the main clamping mechanisms 4.

The to-be-machined parts are the upper longitudinal beam workpiece and the reinforcing frame in the automobile structural part, and the arc-shaped joint of the upper longitudinal beam body and the reinforcing frame is subjected to spot welding in a double-sided spot welding mode during machining.

Before welding, the reinforcing frame is supported by the supporting table 2, the upper longitudinal beam body and the reinforcing frame are aligned and placed, the upper longitudinal beam body and the reinforcing frame are comprehensively clamped by the main clamping mechanism 4 and the auxiliary clamping mechanism 5 after being placed, during welding, spot welding operation is performed by the welding mechanism 3, during spot welding of different positions by the welding mechanism 3, the auxiliary clamping mechanism 5 is adjusted on the main clamping mechanism 4, so that machining points can be conveniently avoided during welding to prevent interference machining, and after welding is finished, the welding points can be prevented from being influenced by cooling. After the corresponding arc-shaped connection parts are clamped by the front and rear main clamping mechanisms 4, the two welding mechanisms 3 simultaneously perform spot welding processing.

Referring to fig. 1 and 3, the welding mechanism 3 includes a welding manipulator 31 assembled on the top wall of the welding table 1, an upper welding head 32 and a lower welding head 33 are correspondingly assembled on the upper and lower sides of the welding manipulator 31, and conical sleeves 34 are sleeved on the ends, far away from the welding ends, of the upper welding head 32 and the lower welding head 33.

Referring to fig. 1 and 4, the main clamping mechanism 4 comprises two supporting seats 41 correspondingly mounted on the top wall of the welding table 1 left and right through bolts, a lower clamping frame 42 and an upper clamping frame 43 for carrying out lower bearing and upper pressing on a workpiece to be machined are jointly arranged on the two supporting seats 41, the middle parts of the lower clamping frame 42 and the upper clamping frame 43 are arc-shaped and are matched with the workpiece to be machined, the left end part and the right end part of the lower clamping frame 42 and the right end part of the upper clamping frame 43 are connected through electric push rods, the supporting seats 41 are fixedly connected between the bottom walls of the left end part and the right end part of the lower clamping frame 42 and the top wall of the welding table 1, and the heights of the two supporting seats 41 are respectively adapted to the heights of the two end parts of the lower clamping frame 42.

Referring to fig. 1, fig. 4, fig. 5 and fig. 6, the auxiliary clamping mechanism 5 includes a movable clamping assembly 51 disposed on the lower clamping frame 42 and the upper clamping frame 43, the movable clamping assembly 51 and the corresponding lower clamping frame 42 are jointly disposed on the upper clamping frame 43, a cooling avoidance assembly 52 is disposed on the movable clamping assembly 51 and the corresponding lower clamping frame 42, the movable clamping assembly 51 and the lower clamping frame 42 cooperate to comprehensively support a workpiece, the movable clamping assembly 51 and the upper clamping frame 43 cooperate to comprehensively press the workpiece, the workpiece is sufficiently clamped from the upper direction and the lower direction before welding, the movable clamping assembly 51 and the cooling avoidance assembly 52 cooperate to carry out deflection avoidance on a processing point when welding processing, and the welding point is cooled and avoided after welding is finished.

Referring to fig. 4 to 9, the movable clamping assembly 51 includes a first movable groove 511, a plurality of first movable grooves 511 facing front and back are formed on the lower clamping frame 42 and the upper clamping frame 43 at equal intervals along the circumferential direction, the first movable groove 511 is connected with a first L-shaped frame 512 in a front-back symmetrical sliding manner through a first spring (not shown in the figure), a half groove is formed in the middle of one side of the horizontal section of the first L-shaped frame 512, which is close to each other, a L-shaped traction member 513 is fixedly connected to the middle of the vertical section of the first L-shaped frame 512, a profiling block 514 is sleeved on the outer portion of the L-shaped traction member 513, a first groove position for the first L-shaped traction member 513 to slide front and back is formed in the inner portion of the profiling block 514, a second movable groove 515 penetrating through the middle of the first movable groove 511 is formed on the side wall of the first lower clamping frame 42 and the upper clamping frame 43, which is close to a workpiece, and the second movable groove 515 corresponds to a welding point.

Referring to fig. 4 to 9, the cooling avoidance assembly 52 includes a first wedge 521, a first wedge 521 is fixedly connected to one side of the profiling block 514, which is close to the L-shaped frame 512, a top wall of the first wedge 521 is inclined, a third movable groove 522 penetrating vertically is symmetrically formed on the lower clamping frame 42 and the upper clamping frame 43, the third movable groove 522 is communicated with the first movable groove 511, a second wedge 523 is connected to the third movable groove 522 in a sliding manner through a second spring (not shown in the drawing) in an up-down sliding manner, the second wedge 523 is composed of a sliding plate connected to the third movable groove 522 in a sliding manner and a wedge block fixed on a side wall of the sliding plate, a bottom wall of the wedge block is inclined and matched with the first wedge 521, a second groove for the movable groove 522 to pass through is formed in a bottom wall of the L-shaped frame 512, four blocks 524 are fixedly connected to the first movable groove 511 in a matrix manner, one side, which is left and right opposite blocks 524 are mutually close to each other, movable blocks 525 are symmetrically connected in a sliding manner through the third spring (not shown in the drawing), and the end portions of the movable blocks located outside the blocks 524 are formed by two inclined surfaces, and the left side blocks 514 are provided with the upper side blocks and the profiling grooves matched with the third grooves.

The upper clamping frame 43 is adjusted to be close to the lower clamping frame 42 by the shrinkage of the output end of the hydraulic rod, and the arc-shaped connecting part of the upper longitudinal beam body and the non-welding part of the arc-shaped connecting part of the reinforcing frame are tightly clamped. The arc junction diapire of the enhancement frame pastes with the arc roof of lower holder 42, and the arc junction of going up the longeron body overlaps with the arc junction of enhancement frame, and the arc diapire of going up holder 43 pastes with the arc junction roof of going up the longeron body.

It should be noted that, the movable clamping assembly 51 and the cooling avoiding assembly 52 on the lower clamping frame 42 and the upper clamping frame 43 have the same part structure and working principle, but different installation directions and sizes, and the movable clamping assembly 51 on the lower clamping frame 42 and the movable clamping assembly 51 on the upper clamping frame 43 are arranged up and down relatively according to the radian and length adaptability of the middle parts of the lower clamping frame 42 and the upper clamping frame 43, and the cooling avoiding assembly 52 on the lower clamping frame 42 and the cooling avoiding assembly 52 on the upper clamping frame 43 are arranged up and down relatively.

Before welding, the initial states of the two profiling blocks 514 corresponding to each other in front and back are mutually close, the profiling blocks 514 on the lower clamping frame 42 and the profiling blocks 514 on the upper clamping frame 43 correspond to each other, welding points which are not clamped by the lower clamping frame 42 and the upper clamping frame 43 are tightly clamped in the two movable grooves 515 in the upper and lower directions, the profiling blocks 514, the upper clamping frame 43, the profiling blocks 514 and the lower clamping frame 42 are matched together to comprehensively clamp arc-shaped joints, gaps are avoided among the welding points, weak welding and virtual welding are prevented, and meanwhile clamping stability is enhanced.

During welding, the welding manipulator 31 drives the corresponding upper welding head 32 and lower welding head 33 to approach to the welding point, and the upper welding head 32 and lower welding head 33 respectively perform spot welding operation perpendicular to the point from the upper direction and the lower direction.

Taking fig. 10 as an example, when the upper welding head 32 approaches the corresponding welding point, a round hole is formed between the semicircular grooves on the two corresponding L-shaped frames 512, the top wall of the semicircular groove of the L-shaped frame 512 is chamfered, the upper welding head 32 passes through the round hole, and the taper sleeve 34 moves closer to and gradually pushes the two L-shaped frames 512 to change from the initial state of approaching to the state of moving away from each other.

While the two L-shaped frames 512 slide on the upper clamping frame 43 to be far away, the L-shaped traction piece 513 drives the profiling block 514 to slide in the second movable groove 515, the profiling block 514 performs spot welding operation for downward movement of the upper welding head 32 to avoid the position, and meanwhile, the arc-shaped connection part of the spot welding position is pressed and smoothed by the profiling block 514 in moving, so that gaps are avoided around welding spots, and welding quality is improved.

It should be noted that the profile block 514 is a detachable structure to facilitate the installation of the L-shaped traction member 513.

In the process that the two L-shaped frames 512 slide away on the upper clamping frame 43, the inclined surfaces of the movable protruding blocks 525 are gradually pushed by the side walls of the profiling blocks 514, slide into the corresponding stop blocks 524, when the sliding is stopped, the springs three compress and rebound to drive the movable protruding blocks 525 to enter the corresponding groove three, and the left and right corresponding movable protruding blocks 525 lock the sliding positions of the same profiling blocks 514 from the left and right directions (as shown in fig. 7).

The profiling block 514 drives the first wedge 521 to move close to the second wedge 523 until the top wall of the first wedge 521 is attached to the top wall of the second wedge 523, and the second wedge 523 is in a state that the bottom of the sliding plate is attached to the arc-shaped connection part of the upper longitudinal beam body, the second spring is extruded, and the bottom of the sliding plate is in the same height as the bottom of the upper clamping frame 43, and the state is shown in the diagram (b) of fig. 10.

After the welding of the single welding point is finished, the welding manipulator 31 drives the upper welding head 32, the lower welding head 33 and the corresponding conical sleeve 34 to be far away from the welding point, and repeated operation is continued to be carried out on the next welding point.

Taking fig. 11 as an example, along with the resetting of the taper sleeve 34, the spring one rebound drives the two L-shaped frames 512 to gradually reset from a mutually far state to a mutually near state, during resetting, the L-shaped traction piece 513 slides on the groove one in the profiling block 514, when the L-shaped traction piece slides to the state shown in the diagram (b) in fig. 11, the resetting is finished, the resetting process of the L-shaped frames 512 can not drive the profiling block 514 to move to a position, the profiling block 514 is prevented from damaging the spot welding surface just welded, and the cooling time is given to the spot welding position to ensure the welding quality.

When all the welding points are finished in the welding operation, the hydraulic rod drives the lower clamping frame 42 and the upper clamping frame 43 to be away from each other, and clamping is released.

Taking fig. 12 as an example, when the clamping is released, the bottom wall of the upper clamping frame 43 is not tightly attached to the top wall of the arc-shaped joint any more, the bottom of the second wedge 523 is not pressed any more, the second wedge 523 and the second spring of the upper clamping frame 43 rebound to drive the second wedge 523 to slide downwards on the third movable groove 522, the first wedge 521 is pushed to move by the wedge block of the second wedge 523, the profiling block 514 is changed from a state of being far away from each other to a state of being close to each other, the positions of the L-shaped traction member 513 and the profiling block 514 are relatively changed, and the resetting is completed, so that the next welding and clamping operation is facilitated.

In the invention, the arc-shaped connection part is comprehensively clamped through the cooperation of the profiling block 514, the upper clamping frame 43 and the lower clamping frame 42 in the movable clamping assembly 51, gaps are avoided at welding points, weak welding and virtual welding are prevented, clamping stability is enhanced, meanwhile, the movement of the welding mechanism 3 and the cooperation of the driving cooling avoidance assembly 52 are utilized, the profiling block 514 in the movable clamping assembly 51 is driven to avoid a yielding position for spot welding operation, interference to welding is prevented, pressing is carried out in the avoidance process, gaps are avoided around the welding points, welding quality is improved, position locking is carried out after avoidance, and damage to a spot welding surface is prevented.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and to simplify the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," "first," and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "first", "second", "first", "second" may include at least one such feature, either explicitly or implicitly. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed, mechanically connected, electrically connected, directly connected, indirectly connected through an intervening medium, or in communication between two elements or in an interaction relationship between two elements, unless otherwise explicitly specified. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

The embodiments of the present invention are all preferred embodiments of the present invention, and therefore, the present invention is not limited to the above-mentioned embodiments, and all equivalent changes according to the structure, shape and principle of the present invention should be covered in the scope of the present invention.

Claims (5)

1. The welding fixture for the automobile structural part comprises a welding table and is characterized in that a supporting table for bearing a workpiece to be machined is arranged in the middle of the top wall of the welding table, welding mechanisms are symmetrically arranged at the front and rear parts of the top wall of the welding table, main clamping mechanisms assembled on the top wall of the welding table are symmetrically arranged at the front and rear parts of the supporting table, and auxiliary clamping mechanisms are arranged on the main clamping mechanisms;

The main clamping mechanism comprises two supporting seats which are correspondingly arranged on the top wall of the welding table left and right through bolts, a lower clamping frame and an upper clamping frame which are used for carrying out lower bearing and upper pressing on a workpiece to be processed are arranged on the two supporting seats together, and the middle parts of the lower clamping frame and the upper clamping frame are arc-shaped and are matched with the workpiece to be processed;

The auxiliary clamping mechanism comprises a movable clamping assembly arranged on a lower clamping frame and an upper clamping frame, the movable clamping assembly, the corresponding lower clamping frame and the upper clamping frame are jointly provided with a cooling avoidance assembly, the movable clamping assembly and the lower clamping frame are matched to comprehensively support a workpiece to be processed, the movable clamping assembly and the upper clamping frame are matched to comprehensively press the workpiece to be processed, the workpiece to be processed is fully clamped in the upper direction and the lower direction before welding, the movable clamping assembly and the cooling avoidance assembly are matched to carry out deflection avoidance on a processing point position during welding processing, and the welding point position is cooled and avoided after welding;

the movable clamping assembly comprises a movable groove I, a plurality of movable grooves I facing front and back are formed in the lower clamping frame and the upper clamping frame at equal intervals along the circumferential direction, the movable groove I is connected with an L-shaped frame in a front-back symmetrical sliding manner through a spring I, and a semicircular groove is formed in the middle of one side, close to each other, of the horizontal section of the L-shaped frame;

The middle part of the vertical section of the L-shaped frame is fixedly connected with an L-shaped traction piece, the outer part of the L-shaped traction piece is sleeved with a profiling block, a first groove for the L-shaped traction piece to slide back and forth is formed in the profiling block, a second movable groove penetrating through the middle part of the first movable groove is formed in the side wall, close to a workpiece to be machined, of the lower clamping frame and the upper clamping frame, and the second movable groove corresponds to a welding point;

the cooling avoidance assembly comprises a first wedge-shaped piece, one side of the profiling block, which is close to the L-shaped frame, is fixedly connected with the first wedge-shaped piece, and the top wall of the first wedge-shaped piece is inclined;

The upper clamping frame and the lower clamping frame are provided with a movable groove III which penetrates up and down symmetrically in front and back, the movable groove III is communicated with the movable groove I, and a wedge-shaped piece II is connected in the movable groove III in an up and down sliding manner through a spring II;

The second wedge piece is composed of a sliding plate which is connected with the third movable groove in a sliding mode and a wedge block which is fixed on the side wall of the sliding plate, the bottom wall of the wedge block is in an inclined shape which is matched with the first wedge piece, and the bottom wall of the L-shaped frame is provided with the second groove for the third movable groove to pass through.

2. The welding fixture of claim 1, wherein the welding mechanism comprises a welding manipulator assembled by a top wall of the welding table, an upper welding head and a lower welding head are correspondingly assembled on the welding manipulator up and down, and conical sleeves are sleeved at the ends of the upper welding head and the lower welding head far away from the welding end.

3. The welding fixture for the structural members of the automobile according to claim 1, wherein the left end and the right end of the lower clamping frame and the upper clamping frame are connected through electric push rods, the supporting seats are fixedly connected between the bottom walls of the left end and the right end of the lower clamping frame and the top wall of the welding table, and the heights of the two supporting seats are respectively adapted to the heights of the two ends of the lower clamping frame.

4. The welding fixture for automotive structural parts according to claim 1, wherein the first movable groove is fixedly connected with four stoppers in a matrix shape, and two sides of the stoppers, which are opposite to each other, are respectively connected with movable bumps by means of springs in a three-side-to-side symmetrical sliding manner.

5. The welding fixture for the structural parts of the automobile according to claim 4, wherein the end part of the movable protruding block, which is positioned outside the stop block, is formed into an arrow shape by two inclined surfaces, and the left side wall and the right side wall of the profiling block are provided with three grooves which are matched with the stop block.