CN212443964U

CN212443964U - Automobile pipe fitting welding jig

Info

Publication number: CN212443964U
Application number: CN202020864384.2U
Authority: CN
Inventors: 张生林; 王保平; 王胜
Original assignee: Nanjing Tianhe Auto Parts Co ltd
Current assignee: Nanjing Tianhe Auto Parts Co ltd
Priority date: 2020-05-21
Filing date: 2020-05-21
Publication date: 2021-02-02
Anticipated expiration: 2030-05-21

Abstract

The utility model provides an automobile pipe fitting welding fixture, which comprises a swing supporting mechanism and a first clamping mechanism; the swing support mechanism is used for supporting the workpiece and driving the workpiece to overturn and comprises a swing beam and swing arms fixedly connected to two ends of the swing beam, and the swing arms are mounted on the overturning arms of the robot; the first clamping mechanism is fixedly connected with the swing beam and used for clamping a main workpiece, and the main workpiece is provided with an arc bin wall; the first clamping mechanism comprises a supporting piece and a chuck component, the supporting piece is used for supporting the main workpiece, and the supporting piece is fixedly arranged on the swinging beam; the clamping head assembly comprises a first elbow clamp, a connecting plate and a floating clamping head, the first elbow clamp is fixedly mounted on the supporting piece, the connecting plate is mounted on a clamping arm of the first elbow clamp, the mounting angle of the floating clamping head and the connecting plate is adjustable, and the floating clamping head can compress the main workpiece. The utility model discloses welding to tubulose work piece does not have the dead angle, and is reliable to the clamp force of arc work piece, and it is effectual to weld.

Description

Automobile pipe fitting welding jig

Technical Field

The utility model belongs to the technical field of the car processing, concretely relates to car pipe fitting welding jig.

Background

Be equipped with the intake pipe, filter bin and the tail pipe that connect gradually on the floor middle section behind the car, need weld fixture with them during the equipment, because intake pipe and tail pipe all are the pipe form, need carry out 360 welding to the pipe end during the welding, otherwise appear the dead angle very easily, lead to welding strength not enough. In addition, due to accumulation of machining errors and positioning errors of various parts, too large or too small clamping force of the clamp on the workpiece can be caused, so that the clamping stability is reduced; and because the bulkhead of most filter bins is oval, because the error accumulation of filtering the storehouse can make the clamp plate of anchor clamps can't hug closely the bulkhead, cause the clamp force unreliable, influence the welding effect.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an automobile pipe fitting welding jig to solve the welding to tubular workpiece have the dead angle and to the unreliable, problem that influence the welding effect of clamp force of arc work piece.

The utility model provides a following technical scheme:

an automobile pipe fitting welding fixture comprises a swing supporting mechanism and a first clamping mechanism;

the swing support mechanism is used for supporting a workpiece and driving the workpiece to overturn and comprises a swing beam and swing arms fixedly connected to two ends of the swing beam, and the swing arms are mounted on an overturning arm of the robot;

the first clamping mechanism is fixedly connected with the swing beam and used for clamping a main workpiece, and the main workpiece is provided with an arc bin wall; the first clamping mechanism comprises a supporting piece and a chuck component, the supporting piece is used for supporting the main workpiece, and the supporting piece is fixedly arranged on the swinging beam; the clamping head assembly comprises a first elbow clamp, a connecting plate and a floating clamping head, the first elbow clamp is fixedly installed on a supporting piece, the connecting plate is installed on a clamping arm of the first elbow clamp, the installation angle of the floating clamping head and the connecting plate is adjustable, and the floating clamping head can compress a main workpiece.

Preferably, the floating chuck comprises a floating pressure plate and an inserting strip which are fixedly connected, the floating pressure plate can be tightly attached to the top of the main workpiece, and the inserting strip protrudes upwards out of the floating pressure plate; the bottom of the connecting plate is provided with a slot matched with the inserting strip, the inserting strip is embedded into the slot, the connecting plate is connected with the inserting strip through a positioning pin, and two ends of the positioning pin are provided with limiting heads.

Preferably, the vertex angles of the supporting pieces are respectively fixed with side pressing blocks extending upwards, the inner side walls of the side pressing blocks are provided with first plug sheets and buffer cushions, the first plug sheets are plugged between the side pressing blocks and the buffer cushions, and the buffer cushions can compress the side faces of the main workpiece.

Furthermore, a base plate is fixedly mounted on the swing beam, the first clamping mechanism and a second clamping mechanism used for clamping an air inlet pipe flange are mounted on the base plate, the air inlet pipe flange is mounted at the end part of an air inlet pipe, and the other end of the air inlet pipe is connected with a main workpiece; the second clamping mechanism comprises an adjusting bottom plate, a supporting block and a second elbow clamp, the adjusting bottom plate is installed on the base plate, the supporting block is installed on the adjusting bottom plate, the second elbow clamp is installed on the supporting block, an open-type arc-shaped chuck is installed on a clamping arm of the second elbow clamp, a positioning plate is arranged on the opposite side of the arc-shaped chuck, and the arc-shaped chuck can tightly press the air inlet pipe flange on the positioning plate.

Preferably, the second clamping mechanism still presss from both sides including the third elbow that is used for removing the locating plate, be equipped with the internal thread hole in the arm lock that the third elbow pressed from both sides, internal thread hole female connection dead lever, the tip that the dead lever stretches out outside the arm lock is equipped with the locking portion that longitudinal section is the I-shaped, locking portion chucking is on a linkage joint, the linkage is connected and is equipped with the T-slot, locking portion joint in the T-slot is interior.

Preferably, the fixing rod is provided with an adjusting nut for finely adjusting the length of the fixing rod extending out of the clamping arm, and the fixing rod is locked on the clamping arm by the adjusting nut.

Preferably, a guide seat is arranged between the positioning plate and the linkage joint, and the guide seat is fixedly connected with the supporting block; one side of the positioning plate, which is close to the supporting block, is fixedly provided with a guide pillar, the guide pillar penetrates through a guide pillar hole of the guide seat and then is fixedly connected with the linkage joint, and the third elbow clamp can push the guide pillar to move along the guide pillar hole.

Preferably, the adjusting bottom plate comprises a first mounting wall, a second plug piece, a third plug piece and a bottom plate fixing block, the first mounting wall and the second mounting wall extend in the end face direction parallel to the air inlet pipe flange and the end face direction perpendicular to the air inlet pipe flange respectively, the second plug piece is plugged in a gap between the first mounting wall and the bottom plate fixing block, the third plug piece is plugged in a gap between the second mounting wall and the bottom plate fixing block, and the thickness and the number of the second plug piece and the third plug piece are adjustable.

Further, still install the third clamping mechanism who is used for pressing from both sides tight intake pipe on the base plate, third clamping mechanism includes that first supporting seat, fourth elbow press from both sides and first conduit saddle, first supporting seat installs on the base plate, the fourth elbow press from both sides with first conduit saddle is all installed on first supporting seat, the fourth elbow press from both sides can with the intake pipe press in on the first conduit saddle.

Further, still install the fourth clamping mechanism who is used for pressing from both sides tight tail pipe on the base plate, fourth clamping mechanism includes that second supporting seat, fifth elbow press from both sides and the second conduit saddle, the second supporting seat is installed on the base plate, the fifth elbow press from both sides with the second conduit saddle is all installed on the second supporting seat, the fifth elbow press from both sides can press the tail pipe in on the second conduit saddle.

The utility model has the advantages that:

the utility model discloses can install on the upset arm of robot, the robot can carry out 360 upsets to this anchor clamps, realizes carrying out full angle automatic weld to main workpiece and each pipe fitting.

The utility model discloses a swing supporting mechanism includes swing beam and rigid coupling in the swing arm at swing beam both ends, forms a virtual columniform swing space during this anchor clamps of robot upset, and work piece and each clamping mechanism all are located this swing space during the upset, and for the supporting mechanism of a style of calligraphy, the mobile scope of soldered connection is big during the use of this anchor clamps, can not produce the welding dead angle.

The first clamping mechanism is used for clamping a main workpiece, the main workpiece can be a filtering bin at the middle section of a rear floor of an automobile, the main workpiece is provided with an arc bin wall, the first clamping mechanism is provided with a floating chuck for compressing the main workpiece, and the mounting angle of the floating chuck can be adjusted, so that the machining error and the mounting error of the main workpiece can be automatically compensated, the main workpiece can be reliably compressed, and the welding effect is not influenced.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic structural view of the clamping mechanisms of the present invention clamping a workpiece;

FIG. 3 is a schematic structural view of a second clamping mechanism clamping an intake pipe flange;

FIG. 4 is an enlarged schematic view of the adjustable base plate of the second clamping mechanism;

fig. 5 is a schematic view of the overall structure of the present invention from another perspective during the turning process;

fig. 6 is a schematic top view of the present invention.

Labeled as: 11. a main workpiece; 12. an air inlet pipe; 13. an intake pipe flange; 14. a tail pipe; 20. a swing support mechanism; 21. a swing beam; 22. a swing arm; 23. turning over the locking plate; 24. a limiting groove; 25. a hoisting ring; 26. a substrate; 30. a first clamping mechanism; 31. a support member; 311. a first plug; 312. side pressing blocks; 313. a cushion pad; 32. a first elbow clip; 33. a connecting plate; 331. a slot; 34. a floating chuck; 341. a floating pressure plate; 342. inserting strips; 35. positioning pins; 40. a second clamping mechanism; 41. adjusting the bottom plate; 411. a first mounting wall; 412. a second mounting wall; 413. a second plug; 414. a third plug; 415. a bottom plate fixing block; 42. a support block; 43. a second elbow clip; 44. an adapter plate; 45. an arc-shaped chuck; 46. a third elbow clip; 461. a clamping arm of the third elbow clamp; 463. a locking portion; 464. a linkage joint; 465. a T-shaped slot; 466. adjusting the nut; 467. a guide seat; 468. a guide post; 47. positioning a plate; 50. a third clamping mechanism; 51. a first support base; 52. a fourth elbow clip; 53. a first pipe bracket; 60. a fourth clamping mechanism; 61. a second support seat; 62. a fifth elbow clip; 63. and a second pipe bracket.

Detailed Description

The embodiment provides an automobile pipe fitting welding jig for filter bin, intake pipe 12 and tail pipe 14 of fixed floor assembly middle section behind the car during welding operation, wherein, intake pipe 12 and tail pipe 14 need weld respectively in the left and right sides of filter bin. The fixture can turn 360 degrees, and full-angle welding of the workpiece is realized.

As shown in fig. 1 to 6, the present welding jig includes a swing support mechanism 20, a first clamping mechanism 30, a second clamping mechanism 40, a third clamping mechanism 50, and a fourth clamping mechanism 60.

As shown in fig. 1, the swing support mechanism 20 is used for supporting a workpiece and driving the workpiece to turn, the swing support mechanism 20 includes a swing beam 21 and swing arms 22 welded to two ends of the swing beam 21, a horizontal flip lock plate 23 is installed on the top of the swing arms 22, and the flip lock plate 23 is installed on a flip arm of the robot through bolts. Can set up the spacing groove 24 with the upset arm joint on upset jam plate 23 and fix a position upset jam plate 23 fast, improve the installation effectiveness. And a lifting ring 25 can be further arranged on the turnover locking plate 23, so that the clamp is convenient to transport.

The base plate 26 is fixedly mounted on the rocker beam 21, and the first clamping mechanism 30, the second clamping mechanism 40, the third clamping mechanism 50, and the fourth clamping mechanism 60 are all fixedly mounted on the base plate 26 by bolts. The applicability is further enhanced by replacing the base plate 26 to switch different welding jigs on the rocker beam 21. Similarly, lifting rings may be mounted on the base plate 26 to facilitate transport of the base plate and the clamping mechanism thereon.

As shown in fig. 2, the first clamping mechanism 30 is used for clamping the main workpiece 11, i.e., the filter bin, and the main workpiece 11 has an arc-shaped bin wall, as shown in fig. 1, and the cross section of the main workpiece is oval. The first clamping mechanism 30 includes a support member 31 and a chuck assembly, the support member 31 is used for supporting the main workpiece 11, and the support member 31 is fixedly mounted on the base plate 26. The four corners of the supporting member 31 are respectively fixed with a side press block 312 extending upwards, the inner side wall of the side press block 312 is provided with a first plug piece 311 and a buffer pad 313, the first plug piece 311 is plugged between the side press block 312 and the buffer pad 313 and fixed by bolts, and the buffer pad 313 can flexibly press the side surface of the main workpiece 11 without scratching the main workpiece. The number and thickness of the first plug pieces 311 can be adjusted appropriately so that the cushion pads 313 can press the main workpiece 11. The cushion 313 may be made of polyurethane.

The clamping head assembly comprises a first elbow clamp 32, a connecting plate 33 and a floating clamping head 34, wherein the first elbow clamp 32 is a vertical elbow clamp, the first elbow clamp 32 is fixedly arranged on a support member 31, and the connecting plate 33 is arranged on the clamping arms of the first elbow clamp 32. The floating clamp 34 is connected to the connection plate 33 and is adjustable in installation angle with the connection plate 33, and the floating clamp 34 is used to flexibly press the main workpiece 11. Specifically, the floating clamp 34 includes a floating clamp plate 341 and a plug strip 342, which are fixedly connected, the floating clamp plate 341 can be tightly attached to the top of the main workpiece 11, and preferably, the bottom surface of the floating clamp plate 341 has a certain curvature to better fit the main workpiece 11. The plugging strip 342 protrudes upward from the floating press plate 341; the bottom of the connecting plate 33 is provided with a slot 331 matched with the insertion strip 342, the insertion strip 342 is inserted into the slot 331, and the slot 331 of the connecting plate 33 is connected with the insertion strip 342 by the positioning pin 35, so that when the first toggle clamp 32 presses down the floating clamp 34, the floating press plate 341 is automatically slightly adjusted in pressing angle by the reverse force of the top of the main workpiece 11, so that the floating press plate can be tightly attached to the top of the main workpiece 11, thereby compensating the processing error and the installation error of the main workpiece 11, and reliably clamping the main workpiece 11. The limiting heads are arranged at the two ends of the positioning pin 35, and certain pressing force and frictional resistance are arranged between the limiting heads and the outer wall of the slot, so that the floating pressing plate 341 is prevented from freely rotating relative to the positioning pin 35.

As shown in fig. 3 and 4, the second clamping mechanism 40 is used for fixing the air inlet pipe flange 13, the air inlet pipe flange 13 is mounted on the end portion of the air inlet pipe 12, and the other end of the air inlet pipe 12 needs to be welded on the side wall of the main workpiece 11. The second clamping mechanism 40 includes an adjusting base plate 41, a supporting block 42 and a second elbow clamp 43, the adjusting base plate 41 is mounted on the base plate 26, an upwardly extending adapter plate 44 is mounted on the adjusting base plate 41, an L-shaped supporting block 42 is mounted on the adapter plate 44, the second elbow clamp 43 is mounted on the supporting block 42, the second elbow clamp 43 is a vertical elbow clamp, and an open arc-shaped clamping head 45 is mounted on a clamping arm of the second elbow clamp 43 for clamping the air inlet pipe flange 13.

As shown in fig. 4, in order to fine-tune the installation position of the second toggle clamp 43, the adjusting base plate 41 of the present clamp includes a first installation wall 411, a second installation wall 412, a second plug piece 413, a third plug piece 414 and a base plate fixing block 415, the first installation wall 411 and the second installation wall 412 respectively extend in a direction parallel to the end face of the air inlet pipe flange 13 and in a direction perpendicular to the end face of the air inlet pipe flange 13, the second plug piece 413 is plugged in a gap between the first installation wall 411 and the base plate fixing block 415, the third plug piece 414 is plugged in a gap between the second installation wall 412 and the base plate fixing block 415, the second plug piece 413 and the third plug piece 414 are locked by bolts, and the thicknesses and the numbers of the second plug piece 413 and the third plug piece 414 can be properly adjusted as required to eliminate the positioning error of the air inlet pipe flange 13. The bottom plate fixing block 415 is mounted on the base plate 26 by bolts.

The second clamping mechanism 40 further comprises a third elbow clamp 46, the third elbow clamp 46 is a push-pull elbow clamp, a positioning plate 47 opposite to the arc-shaped clamp 45 is mounted on the third elbow clamp 46, a groove (not shown in the figure) for avoiding the air inlet pipe flange is formed in the positioning plate 47, and the arc-shaped clamp 45 can press the air inlet pipe flange 13 into the groove of the positioning plate 47. The locating plate 47 presss from both sides telescopic cooperation and presss from both sides tight intake pipe flange 13 between 46 and the arc chuck 45 through the third elbow, and the locating plate 47 can be retreated to the third elbow clamp 46 promptly, is convenient for take away the product after the welding fast from the locating plate, and the intake pipe flange card is stagnated in the recess of locating plate 47 during the prevention unloading.

Be equipped with the internal thread hole in the arm lock 461 that the third elbow pressed from both sides, a dead lever of internal thread hole internal thread connection, the dead lever stretches out the outer tip of arm lock and is equipped with the locking portion 463 that the longitudinal section is I-shaped, and locking portion 463 chucking is equipped with T-slot 465 on a linkage joint 464 on the linkage joint 464, the joint of locking portion 463 in T-slot 465. The pushing force of the arm 461 of the third toggle clamp is transmitted to the link joint 464 and the positioning plate 47 by the connection of the locking portion 463 and the T-shaped groove 465. The fixing rod is provided with an adjusting nut 466 for finely adjusting the length of the fixing rod extending out of the clamping arm, and the adjusting nut 466 locks the fixing rod on the clamping arm.

A guide seat 467 is arranged between the positioning plate 47 and the linkage joint 464, and the guide seat 467 is fixedly connected with the adapter plate 44; one side fixed mounting that locating plate 47 is close to the supporting shoe has guide pillar 468, and guide pillar 468 runs through behind the guide pillar hole fixed connection linkage 464 in the guide holder 467, and third elbow presss from both sides 46 and can promote guide pillar 468 and remove along the guide pillar hole to the flexible accurate direction of locating plate 47.

Because the air inlet pipe flange 13 also has a certain processing error and installation error, the position of the positioning plate 47 needs to be adjusted to reliably match with the air inlet pipe flange, the length of the fixed rod extending out of the clamping arm can be changed at this time, and then the fixed rod is locked on the clamping arm of the third toggle clamp by using the adjusting nut 466, so that the extending distance of the positioning plate 47 is finely adjusted.

As shown in fig. 1 and 6, a third clamping mechanism 50 for clamping the air inlet pipe 12 is further mounted on the base plate 26, the third clamping mechanism 50 includes a first supporting seat 51, a fourth elbow clamp 52 and a first pipe bracket 53, the first supporting seat 51 is mounted on the base plate, the fourth elbow clamp 52 and the first pipe bracket 53 are both mounted on the first supporting seat 51, and the fourth elbow clamp 52 can press the air inlet pipe 12 onto the first pipe bracket 53, so as to more stably clamp the air inlet pipe.

The fourth clamping mechanism 60 is used for clamping the tail pipe 14, the fourth clamping mechanism 60 includes a second supporting seat 61, a fifth elbow clamp 62 and a second pipe support 63, the second supporting seat 61 is installed on the base plate, the fifth elbow clamp 62 and the second pipe support 63 are both installed on the second supporting seat 61, and the fifth elbow clamp 62 can press the tail pipe on the second pipe support 63.

The use method of the welding fixture comprises the following steps:

the base plate 26 is installed on the swing beam 21, the main workpiece 11 is placed on the support 31, the main workpiece 11 is flexibly fixed by the cushion pads on the four side pressing blocks 312, then the first toggle clamp 32 is pressed down, so that the floating pressing plate 341 presses the top of the main workpiece 11, and in the process, the floating pressing plate 341 can automatically adjust the pressing angle under the reaction force of the main workpiece 11 until the floating pressing plate is tightly attached to the main workpiece 11, so as to compensate the positioning error of the main workpiece.

Then the air inlet pipe 12 is placed on the first pipe support 53, the positioning plate 47 is in an extending state at the moment, the position of the flange at the end part of the air inlet pipe is adjusted, the flange extends into the groove of the positioning plate 47, and the second elbow clamp 43 is pressed down, so that the arc-shaped clamp 45 tightly presses the flange 13 of the air inlet pipe on the positioning plate 47; and then the fourth elbow clamp 52 is pressed down to clamp the air inlet pipe 12 on the first pipe bracket 53, and the air inlet pipe is clamped and fixed completely.

The liner 14 is placed on the second pipe bracket 63 and the fifth elbow clip 62 is pressed down to clamp the liner 14 to the second pipe bracket 63.

Then the swing supporting mechanism 20 is arranged on the turning arm of the robot, the fixture is turned over while the workpiece is welded until the air inlet pipe 12 and the tail pipe 14 are welded and fixed on the two side walls of the filter bin.

After the welding operation is completed, the first elbow clip 32, the second elbow clip 43, the fourth elbow clip 52 and the fifth elbow clip 62 are released, and the third elbow clip 46 is pulled back to remove the product from the welding fixture.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The automobile pipe fitting welding fixture is characterized by comprising a swinging support mechanism and a first clamping mechanism;

2. The automobile pipe fitting welding fixture according to claim 1, wherein the floating chuck comprises a floating pressure plate and an inserting strip which are fixedly connected, the floating pressure plate can be tightly attached to the top of the main workpiece, and the inserting strip protrudes upwards out of the floating pressure plate; the bottom of the connecting plate is provided with a slot matched with the inserting strip, the inserting strip is embedded into the slot, the connecting plate is connected with the inserting strip through a positioning pin, and two ends of the positioning pin are provided with limiting heads.

3. The automobile pipe fitting welding jig of claim 2, wherein the top corners of the supporting members are respectively fixed with a side pressing block extending upwards, the inner side walls of the side pressing blocks are provided with a first plug sheet and a buffer cushion, the first plug sheet is plugged between the side pressing blocks and the buffer cushion, and the buffer cushion can press the side face of the main workpiece.

4. The automobile pipe fitting welding fixture of claim 2, wherein a base plate is fixedly mounted on the swing beam, the first clamping mechanism and a second clamping mechanism for clamping an air inlet pipe flange are mounted on the base plate, the air inlet pipe flange is mounted at the end of an air inlet pipe, and the other end of the air inlet pipe is connected with a main workpiece; the second clamping mechanism comprises an adjusting bottom plate, a supporting block and a second elbow clamp, the adjusting bottom plate is installed on the base plate, the supporting block is installed on the adjusting bottom plate, the second elbow clamp is installed on the supporting block, an open-type arc-shaped chuck is installed on a clamping arm of the second elbow clamp, a positioning plate is arranged on the opposite side of the arc-shaped chuck, and the arc-shaped chuck can tightly press the air inlet pipe flange on the positioning plate.

5. The automobile pipe fitting welding jig of claim 4, wherein the second clamping mechanism further comprises a third elbow clamp for moving the positioning plate, an internal thread hole is formed in the arm lock of the third elbow clamp, a fixing rod is screwed in the internal thread hole, a locking portion with an I-shaped longitudinal section is arranged at the end of the fixing rod extending out of the arm lock, the locking portion is clamped on a linkage joint, a T-shaped groove is formed in the linkage joint, and the locking portion is clamped in the T-shaped groove.

6. The automobile pipe welding jig of claim 5, wherein the fixing rod is provided with an adjusting nut for finely adjusting the length of the fixing rod extending out of the clamping arm, and the adjusting nut locks the fixing rod to the clamping arm.

7. The automobile pipe fitting welding jig of claim 5, wherein a guide seat is arranged between the positioning plate and the linkage joint, and the guide seat is fixedly connected with the supporting block; one side of the positioning plate, which is close to the supporting block, is fixedly provided with a guide pillar, the guide pillar penetrates through a guide pillar hole of the guide seat and then is fixedly connected with the linkage joint, and the third elbow clamp can push the guide pillar to move along the guide pillar hole.

8. The automobile pipe fitting welding jig of claim 4, wherein the adjustment base plate comprises a first mounting wall, a second plug piece, a third plug piece and a base plate fixing block, the first mounting wall and the second mounting wall extend in a direction parallel to the end face of the air inlet pipe flange and in a direction perpendicular to the end face of the air inlet pipe flange, the second plug piece is plugged in a gap between the first mounting wall and the base plate fixing block, the third plug piece is plugged in a gap between the second mounting wall and the base plate fixing block, and the thickness and the number of the second plug piece and the third plug piece are adjustable.

9. The automobile pipe fitting welding fixture according to any one of claims 4 to 8, wherein a third clamping mechanism for clamping the air inlet pipe is further mounted on the base plate, the third clamping mechanism comprises a first supporting seat, a fourth elbow clamp and a first pipe bracket, the first supporting seat is mounted on the base plate, the fourth elbow clamp and the first pipe bracket are both mounted on the first supporting seat, and the fourth elbow clamp can press the air inlet pipe onto the first pipe bracket.

10. The automotive pipe fitting welding jig of any one of claims 4 to 8, wherein a fourth clamping mechanism for clamping the tail pipe is further mounted on the base plate, the fourth clamping mechanism comprises a second support base, a fifth elbow clamp and a second pipe bracket, the second support base is mounted on the base plate, the fifth elbow clamp and the second pipe bracket are mounted on the second support base, and the fifth elbow clamp can press the tail pipe onto the second pipe bracket.