Welding and positioning tool for lower cross beam of front passenger door of passenger car

Abstract

The invention discloses a passenger car front passenger door lower cross beam welding positioning tool which comprises a lower cross beam welding table, and a supporting frame and a sliding base capable of moving along a sliding groove are arranged on the lower cross beam welding table. The plasma welding assembly comprises a plasma welding controller, a plasma arc welding connector, an electric telescopic rod and a mechanical hand, wherein the plasma welding controller is installed on the sliding base, and the electric telescopic rod drives the welding connector to move. The profiling positioning device consists of a profiling reference block and a transmission double-screw rod; the embedded water cooling device comprises a spiral water cooling channel embedded in the profiling reference block; through the synergistic effect of the snakelike groove of the profiling reference block and the transmission double screws, the profile of the special-shaped curved surface of the lower cross beam of the passenger car is accurately matched, and the problem that a workpiece is suspended or stressed unevenly is solved; the dynamic pressure adjusting mechanism detects and adjusts the contact pressure of the pressing ball in real time, it is guaranteed that clamping force is evenly distributed, the defects of misalignment, undercut and the like of weld joints are avoided, and the welding qualification rate is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of plasma arc welding equipment, and specifically to a welding positioning tooling for the lower cross beam of the front passenger door of a bus. Background Art

[0002] As a key load-bearing component of the vehicle body structure, the welding quality of the lower cross beam of the front passenger door of a bus directly affects the assembly accuracy of the door and the safety performance of the whole vehicle. In traditional welding processes, plasma arc welding technology is mostly used for the lower cross beam to achieve efficient and deep penetration weld formation. However, due to the generally adopted special-shaped curved thin-walled structure of the bus lower cross beam, its geometric complexity and material characteristics pose strict requirements on the welding positioning tooling. The existing technologies have the following significant defects in practical applications:

[0003] The lower cross beam of a bus mostly has a special-shaped curved surface structure. Traditional tooling relies on rigid fixtures or simple supports and cannot fit the curved surface contour, resulting in local suspension or uneven stress of the workpiece during welding, and defects such as edge misalignment or edge biting are likely to occur in the weld; the high temperature of plasma arc welding acts concentratedly on the thin-walled cross beam, and the tooling lacks local heat dissipation. After cooling, the shrinkage deformation amount of the cross beam exceeds the standard, affecting the assembly accuracy of the door. Summary of the Invention

[0004] The purpose of the present invention is to provide a welding positioning tooling for the lower cross beam of the front passenger door of a bus to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A welding positioning tooling for the lower cross beam of the front passenger door of a bus, including a lower cross beam welding table, on which a support frame and a sliding seat movable along a sliding groove are provided;

[0006] It further includes a plasma welding assembly, which includes a plasma welding controller, a plasma arc welding head, an electric telescopic rod and a mechanical arm for driving the welding head to move, and the plasma welding controller, the plasma arc welding head, the electric telescopic rod and the mechanical arm are all installed on the sliding seat;

[0007] A profiling positioning device, which consists of a profiling reference block and a transmission double screw. The surface of the profiling reference block is provided with a serpentine groove. The profiling positioning device includes a fixed seat, a positioning block and an abutting block. The abutting block makes the end of the abutting block abut against the lower cross beam welding body through an adjusting assembly;

[0008] An embedded water cooling device, which includes a spiral water cooling channel embedded in the profiling reference block and a cold water tank on the step of the lower cross beam welding table. A temperature sensor is inserted on the spiral water cooling channel, and the temperature sensor is electrically connected to the control center;

[0009] A dynamic pressure regulating mechanism, which includes an adjusting screw, a pressure ball and a pressure sensor arranged on the side seat. The pressure sensor detects the contact pressure in real time and feeds it back to the control center, and the pressing force is adjusted through the adjusting screw;

[0010] The abutting adjustment assembly includes a support, a receiving cavity, a limiting seat and a movable sealing block. It adjusts the opening and closing state of the spiral water-cooling channel by abutting and positioning through a profiling positioning device to facilitate timely and uniform heat dissipation. A cylinder is embedded in the limiting seat, and there is an electrical connection between the cylinder and the control center. When the temperature sensor detects a large temperature difference in the spiral water-cooling channel, the control center activates the cylinder to further push the movable sealing block to increase the opening of the through-port.

[0011] Preferably, a serpentine groove is formed on the profiling reference block, and the spiral water-cooling channel is embedded in the serpentine groove. One end of the spiral water-cooling channel is in circular communication with a cold water tank, a suction pump is arranged on the cold water tank, and a temperature sensor is inserted into the spiral water-cooling channel. There is an electrical connection between the temperature sensor and the control center.

[0012] Preferably, the two fixing seats are respectively distributed on both sides of the profiling reference block. A sliding groove is formed on the fixing seat, and a driving double screw is arranged in the sliding groove of the fixing seat. The driving double screw has a double-screw structure and the thread directions are opposite.

[0013] Preferably, sliders are arranged on both sides of the driving double screw. The sliders are connected with the driving double screw through internal and external threads. A connecting seat is arranged at the top of the slider, and a positioning block is arranged at the end of the connecting seat.

[0014] Preferably, the dynamic pressure adjustment mechanism includes a pressure sensor. Connecting rods are arranged on both sides of the positioning block, a side seat is arranged at the end of the connecting rod, an adjusting screw is screwed on the side seat, a pressing ball is rotatably connected to the bottom of the adjusting screw through a support block, and a pressure sensor is embedded at the bottom of the pressing ball.

[0015] Preferably, the abutting adjustment assembly includes a movable sealing block. A support is arranged on the lower crossbeam welding table, a limiting seat is arranged at the top of the support, the limiting seat is fixedly connected to one side of the spiral water-cooling channel, a receiving cavity is formed on the limiting seat, a movable sealing block is slidably inserted into the receiving cavity, and a second airbag is arranged between the movable sealing block and one side of the receiving cavity. The second airbag is communicated with a connecting pipe.

[0016] Preferably, a receiving cavity is formed on the positioning block, a first airbag is arranged in the receiving cavity, an installation block is arranged at the opening of the receiving cavity, a top block is slidably inserted into the installation block, the top block is bonded to the first airbag, and one end of the first airbag is fixedly communicated with a connecting pipe.

[0017] Preferably, the adjustment assembly includes a support block, one side of the positioning block is located above the top block and is fixedly connected to the support block, a square seat is arranged on the top of the support block, a sliding cavity is opened on the square seat, a fixing plate is arranged at the opening of the sliding cavity, the fixing plate is fixed to the square seat by screws, an abutment block is slidably inserted into the sliding cavity, the abutment block has an "L"-shaped structure, and the bottom has a semicircular arc structure, an abutment spring is arranged between the abutment block and the sliding cavity, a third airbag is arranged between the other end of the abutment block and the fixing plate, and a connecting tube is arranged between the third airbag and the first airbag.

[0018] Preferably, one side of the movable sealing block is fixedly connected to a side plate, the side plate is tightly attached to one side of the second airbag, the length of the side plate is greater than the width of the second airbag in the initial state, and a push plate is provided at the telescopic end of the cylinder, one side of the push plate abuts against the movable sealing block in the initial state.

[0019] Preferably, one end of the movable sealing block is plugged into the through-port section of the spiral water-cooling channel, and a return spring is provided between the movable sealing block and the other side of the receiving cavity.

[0020] Preferably, the end of the top block is protrudingly arranged, and one side of the positioning block is used to abut against the middle edge of the lower cross beam of the front passenger door of the bus.

[0021] Preferably, the plasma welding assembly further comprises a transmission main screw, a slideway is provided on the slide seat, a transmission main screw is arranged on the slide seat in the slideway, and the slide seat is sleeved on the transmission main screw.

[0022] Preferably, a manipulator is installed on one side of the slide seat, an electric telescopic rod is provided at the end of the manipulator, and a plasma arc welding joint is provided at the telescopic end of the electric telescopic rod.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention uses the synergistic effect of the serpentine groove of the profiling reference block and the transmission twin screws to accurately match the contour of the special-shaped curved surface of the lower cross beam of the bus, eliminating the problem of the workpiece being suspended or subjected to uneven force; the dynamic pressure adjustment mechanism detects and adjusts the contact pressure of the pressure ball in real time to ensure that the clamping force is evenly distributed, avoid defects such as weld misalignment and undercut, and improve the welding qualification rate.

[0025] 2. The present invention uses an embedded spiral water cooling channel combined with a contact trigger mechanism of the abutment adjustment component, and through the pressure change when the positioning block abuts the workpiece, the opening of the movable sealing block is adjusted in linkage, and the cooling water flow is dynamically controlled to achieve real-time matching and heat dissipation of the welding area. This design effectively suppresses the local thermal deformation of the thin-walled beam caused by the high temperature of the plasma arc, reduces the shrinkage deformation after cooling, and ensures the assembly accuracy of the door.

[0026] 3. The present invention is driven in cooperation by a plasma welding head, a manipulator, an electric telescopic rod, and the lateral sliding of a sliding seat, and can complete precise welding of complex three-dimensional weld paths, meet the diverse welding requirements of special-shaped curved lower crossbeams, improve the consistency and strength of welds, and a dynamic pressure sensor and a welding controller form a closed-loop feedback system, automatically adapting the clamping force, welding parameters, and heat dissipation intensity to the working conditions, reducing manual intervention.

[0027] 4. The present invention embeds a spiral water-cooling channel inside a profiling reference block to avoid spatial interference of external heat dissipation devices; the linkage design of a return spring and an airbag ensures the quick response and reset of the abutting adjustment assembly, the overall structure has strong stability, and the equipment life is extended.

[0028] 5. When the temperature sensor of the present invention detects a large temperature difference in the spiral water-cooling channel, the control center starts the cylinder to further push the movable sealing block to increase the opening degree of the through port, and the abutting block makes the end of the abutting block abut against the lower crossbeam welding body through the adjustment assembly, further increasing the fixing points, thereby improving the clamping stability of the lower crossbeam welding body. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic structural diagram of the welding positioning tooling for the lower crossbeam of the front passenger door of the bus according to the present invention.

[0030] Figure 2 It is a schematic structural diagram of one side of the welding positioning tooling for the lower crossbeam of the front passenger door of the bus according to the present invention.

[0031] Figure 3 It is a schematic structural diagram of the spiral water-cooling channel according to the present invention.

[0032] Figure 4 According to the present invention Figure 3 It is an enlarged schematic structural diagram of part A in

[0033] Figure 5 It is a schematic structural diagram of the profiling positioning device according to the present invention.

[0034] Figure 6 It is a schematic structural diagram of the dynamic pressure regulating mechanism according to the present invention.

[0035] Figure 7 According to the present invention Figure 6 It is an enlarged schematic structural diagram of part B in

[0036] Figure 8 It is a schematic structural diagram of the abutting adjustment assembly part according to the present invention.

[0037] Figure 9 According to the present invention Figure 8 It is an enlarged schematic structural diagram of part C in

[0038] Figure 10This is a cross-sectional view of the square base of the present invention.

[0039] Figure 11 For the present invention Figure 10 The enlarged schematic structural view at position D in the figure.

[0040] Figure 12 This is a schematic structural view of another part of the abutting adjustment assembly of the present invention.

[0041] Figure 13 For the present invention Figure 12 The enlarged schematic structural view at position E in the figure.

[0042] In the figure: lower crossbeam welding table 1; support frame 2; sliding seat 21; plasma welding controller 22; plasma welding head 23; electric telescopic rod 24; manipulator 25; driving main screw 26; profiling reference block 3; serpentine groove 31; spiral water-cooling channel 4; temperature sensor 41; fixed seat 5; sliding groove 51; driving double screw 52; slider 53; connecting seat 54; positioning block 55; connecting rod 56; side seat 57; adjusting screw 58; pressing ball 59; pressure sensor 591; cold water tank 6; support 7; limiting seat 71; storage cavity 72; movable sealing block 73; second airbag 74; return spring 75; side plate 76; air cylinder 77; push plate 78; accommodating cavity 8; first airbag 81; mounting block 82; top block 83; connecting pipe 84; support block 9; square base 91; fixing plate 92; third airbag 93; abutting block 94; abutting spring 95; communicating pipe 96. Detailed implementation manners

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0044] Please refer to Figure 1 This is a schematic structural view of the welding positioning tooling for the lower crossbeam of the front passenger door of a bus according to the present invention. The present invention provides a technical solution: a welding positioning tooling for the lower crossbeam of the front passenger door of a bus, including a lower crossbeam welding table 1, a support frame 2 fixedly connected to one side of the lower crossbeam welding table 1, and a sliding seat 21 that can move along the sliding groove 51; it further includes a plasma welding assembly, including a plasma welding controller 22, a plasma arc welding head 23 mounted on the sliding seat 21, an electric telescopic rod 24 for driving the movement of the welding head, and a manipulator 25.

[0045] Figure 2This is a schematic structural diagram of one side of the welding positioning tooling for the front passenger door lower crossbeam of the bus of the present invention. The plasma welding assembly further includes a driving main screw 26. A slideway is provided on the slide seat 21. The driving main screw 26 is rotatably connected in the slideway on the slide seat 21 through a bearing. The slide seat 21 is sleeved on the driving main screw 26. A manipulator 25 is installed on one side of the slide seat 21. An electric telescopic rod 24 is fixedly installed at the end of the manipulator 25. The telescopic end of the electric telescopic rod 24 is fixedly connected to a plasma arc welding head 23.

[0046] The lower crossbeam welding table 1 serves as a workpiece positioning base. The slide seat 21 realizes lateral movement through the chute 51. The plasma welding controller 22 regulates the welding parameters, drives the manipulator 25 to drive the electric telescopic rod 24 and the welding head 23 for multi-degree-of-freedom adjustment. The electric telescopic rod 24 precisely controls the longitudinal displacement of the welding head 23. Combining with the lateral sliding of the slide seat 21, a complex weld track is completed.

[0047] Figure 3 This is a schematic structural diagram of the spiral water-cooling channel of the present invention. The profiling positioning device is composed of a profiling reference block 3 and a driving double screw 52. A serpentine groove 31 is provided on the surface of the profiling reference block 3. One end of the driving double screw 52 is equipped with a motor, and the start of the motor drives the driving double screw 52 to rotate; the surface of the profiling reference block 3 is adapted to the contour of the workpiece.

[0048] The embedded water-cooling device includes a spiral water-cooling channel 4 embedded in the profiling reference block 3 and a cold water tank 6 on the step of the lower crossbeam welding table 1;

[0049] A serpentine groove 31 is provided on the profiling reference block 3. The spiral water-cooling channel 4 is embedded in the serpentine groove 31. One end of the spiral water-cooling channel 4 is in circular communication with the cold water tank 6. A temperature sensor 41 is inserted on the spiral water-cooling channel 4. The temperature sensor 41 is electrically connected to the control center. A suction pump is installed on the cold water tank 6. The spiral water-cooling channel 4 is embedded inside the profiling reference block 3. The cold water tank 6 pumps cooling water into the channel through a stepped structure for circulation, absorbs the welding heat and then returns to the tank for cooling, forming a continuous heat dissipation loop to maintain the temperature stability of the device.

[0050] Figure 4 For the present invention Figure 3 This is an enlarged structural schematic diagram at position A in the present invention. The profiling positioning device includes a fixed seat 5. The two fixed seats 5 are respectively distributed on both sides of the profiling reference block 3. A chute 51 is provided on the fixed seat 5. The driving double screw 52 is rotatably connected in the chute 51 on the fixed seat 5 through a bearing. One end of the driving double screw 52 is equipped with a driving motor. The model of the driving motor can be selected according to the actual working conditions. The driving double screw 52 has a double-screw structure and the thread helix directions are opposite.

[0051] Figure 5This is a schematic structural diagram of the profiling and positioning device of the present invention. Sliders 53 are sleeved on both sides of the driving double screw 52. The sliders 53 are connected to the driving double screw 52 through internal and external threads. A connecting seat 54 is fixedly connected to the top of the slider 53, and a positioning block 55 is fixedly connected to the end of the connecting seat 54.

[0052] The fixed seats 5 are symmetrically distributed on both sides of the profiling reference block 3. The driving double screw 52 in the sliding groove 51 thereof is driven to rotate by a driving motor. The thread directions on both sides of the double screw 52 are opposite, driving the two sliders 53 to move synchronously and in opposite directions along the sliding groove 51, and pushing the positioning block 55 to approach or separate from the center of the workpiece through the connecting seat 54, realizing rapid centering and clamping.

[0053] Figure 6 This is a schematic structural diagram of the dynamic pressure regulating mechanism of the present invention. The dynamic pressure regulating mechanism includes an adjusting screw 58, a pressure ball 59 and a pressure sensor 591 arranged on the side seat 57. The pressure sensor 591 detects the contact pressure in real time and feeds it back to the control center, and adjusts the pressing force through the adjusting screw 58;

[0054] Figure 7 For the present invention Figure 6 This is an enlarged structural diagram at B in the present invention. The dynamic pressure regulating mechanism includes a pressure sensor 591. Connecting rods 56 are fixedly connected to both sides of the positioning block 55. A side seat 57 is fixedly connected to the end of the connecting rod 56. An adjusting screw 58 is screwed on the side seat 57. The bottom of the adjusting screw 58 is rotatably connected to a pressure ball 59 through a support block, and a pressure sensor 591 is embedded at the bottom of the pressure ball 59.

[0055] Both sides of the positioning block 55 fix the side seat 57 through the connecting rod 56. The adjusting screw 58 is screwed on the side seat 57. The bottom is connected to the pressure ball 59 through a support block. The pressure sensor 591 is embedded at the bottom of the pressure ball 59, detecting the contact pressure between the pressure ball 59 and the workpiece in real time and feeding it back to the control system. By rotating the adjusting screw 58, the height of the pressure ball 59 is adjusted to dynamically balance the pressing force and ensure that the clamping force is evenly controllable.

[0056] The abutting and adjusting assembly includes a support 7 and a receiving cavity 8. By abutting and positioning through the profiling and positioning device, the opening and closing state of the spiral water cooling channel 4 is adjusted to facilitate timely and uniform heat dissipation.

[0057] Figure 8 This is a schematic structural diagram of the abutting and adjusting assembly part of the present invention, Figure 9 For the present invention Figure 8Schematic diagram of the enlarged structure at position C in the figure. A receiving cavity 8 is provided on the positioning block 55. A first airbag 81 is arranged in the receiving cavity 8. An installation block 82 is fixed to the opening of the receiving cavity 8 by screws. A top block 83 is slidably inserted into the installation block 82. The top block 83 is bonded to the first airbag 81. One end of the first airbag 81 is fixedly connected to a connecting pipe 84. The end of the top block 83 protrudes. One side of the positioning block 55 is used to abut against the middle edge of the lower cross beam of the passenger door in front of the bus.

[0058] When the positioning block 55 abuts against the workpiece, the first airbag 81 in its receiving cavity 8 is compressed, pushing the top block 83 to slide inward, squeezing the gas in the first airbag 81 and transporting it to the second airbag 74 through the connecting pipe 84.

[0059] Figure 10 Cross-sectional view of the square seat of the present invention, Figure 11 For the present invention Figure 10 Schematic diagram of the enlarged structure at position D in the figure. The adjusting assembly includes a support block 9. A support block 9 is fixedly connected above the top block 83 on one side of the positioning block 55. A square seat 91 is fixedly connected to the top of the support block 9. A sliding cavity is provided on the square seat 91. A fixing plate 92 is arranged at the opening of the sliding cavity. The fixing plate 92 is fixed to the square seat 91 by screws.

[0060] A contact block 94 is slidably inserted into the sliding cavity. The contact block 94 has an "L" - shaped structure and a semi - circular arc - shaped bottom. A contact spring 95 is fixedly connected between the contact block 94 and the sliding cavity. A third airbag 93 is bonded between the other end of the contact block 94 and the fixing plate 92. A communicating pipe 96 is connected between the third airbag 93 and the first airbag 81.

[0061] When the first airbag 81 is compressed, the gas in the first airbag 81 is transmitted to the third airbag 93 through the communicating pipe 96. The third airbag 93 expands and squeezes the contact block 94 to move downward. Then, the end of the contact block 94 abuts against the lower cross - beam welded body, further increasing the fixing points, thereby improving the clamping stability of the lower cross - beam welded body.

[0062] Figure 12 Schematic diagram of another part of the contact adjusting assembly of the present invention, Figure 13 For the present invention Figure 12 Schematic diagram of the enlarged structure at position E in the figure. The contact adjusting assembly includes a movable sealing block 73. A support 7 is arranged on the lower cross - beam welding table 1. A limit seat 71 is fixedly connected to the top of the support 7. The limit seat 71 is fixedly connected to one side of 4. A receiving cavity 72 is provided on the limit seat 71. A movable sealing block 73 is slidably inserted into the receiving cavity 72. A second airbag 74 is bonded between the movable sealing block 73 and one side of the receiving cavity 72. The second airbag 74 is communicated with the connecting pipe 84. One end of the movable sealing block 73 is inserted into the cross - section of the opening of the spiral water - cooling channel 4. A return spring 75 is fixedly connected between the movable sealing block 73 and the other side of the receiving cavity 72.

[0063] The second airbag 74 is inflated and expanded, pushing the movable sealing block 73 to extend from the receiving cavity 72 against the resistance of the return spring 75, partially opening the port cross-section of the spiral water-cooling channel 4 and increasing the cooling water flow rate; when the workpiece disengages from the abutment, the first airbag 81 resets, the gas in the second airbag 74 flows back, and the return spring 75 pulls the movable sealing block 73 to reset and close the port, reducing the flow rate.

[0064] After the workpiece is positioned, the positioning block 55 abuts against its edge to trigger the top block 83 to squeeze the first airbag 81, and the gas drives the second airbag 74 to expand through the connecting pipe 84, pushing the movable sealing block 73 to open the spiral water-cooling channel 4 and enhancing heat dissipation; when disengaging from the abutment, the system automatically resets, forming a closed-loop control of contact - pressurization - heat dissipation, ensuring that the heat in the welding area is adjusted in real time according to the pressure change, avoiding local overheating or heat dissipation lag, and improving the welding accuracy and equipment reliability.

[0065] One side of the movable sealing block 73 is fixedly connected with a side plate 76. The side plate 76 is closely attached to one side of the second airbag 74. The length of the side plate 76 is greater than the width of the second airbag 74 in the initial state. A cylinder 77 is embedded in the limit seat 71. The cylinder 77 is electrically connected to the control center. The telescopic end of the cylinder 77 is fixedly connected with a push plate 78. One side of the push plate 78 abuts against the movable sealing block 73 in the initial state.

[0066] When the temperature sensor 41 detects a large temperature difference in the spiral water-cooling channel 4, the control center starts the cylinder 77. The telescopic end of the cylinder 77 pushes the push plate 78 to squeeze the movable sealing block 73. The end of the movable sealing block 73 moves away from the port cross-section of the spiral water-cooling channel 4, further increasing the port opening and enhancing the cooling effect.

[0067] During actual use, the serpentine groove 31 on the surface of the profiling reference block 3 matches the curved surface contour of the lower crossbeam to ensure that the workpiece fits without suspension; the driving double screw 52 drives the two side sliders 53 to move synchronously and reversely, driving the positioning block 55 to center and clamp towards the center of the workpiece, eliminating the positioning deviation caused by the non-matching curved surface of the traditional rigid fixture. In the dynamic pressure regulating mechanism, the pressure ball 591 detects the contact pressure in real time through the pressure sensor 591. After feedback to the control system, the height of the adjusting screw 58 is automatically adjusted to make the clamping force evenly distributed in the curved surface contact area, avoiding local stress concentration or loosening, and preventing welding edge misalignment and undercut defects;

[0068] The plasma welding head 23 is driven by the manipulator 25 and the electric telescopic rod 24. Combined with the lateral sliding of the sliding seat 21 along the driving main screw 26, precise trajectory control of the welding head in three-dimensional space is realized to adapt to the complex weld path of the lower crossbeam. During the welding process, the plasma welding controller 22 dynamically adjusts parameters such as current and gas flow rate to ensure the efficient penetration and weld forming quality of the thin-walled crossbeam.

[0069] When the positioning block 55 abuts against the workpiece, the first airbag 81 is compressed to convey gas to the second airbag 74 through the connecting pipe 84, pushing the movable sealing block 73 to open the opening of the spiral water-cooling channel 4 and increasing the cooling water flow rate; when the abutment is disengaged, the return spring 75 pulls the movable sealing block 73 to reset and close the opening; the spiral water-cooling channel 4 is embedded inside the profiling reference block 3, and the cooling water circulates through the cold water tank 6 to absorb the concentrated heat in the welding area; the greater the contact pressure, the greater the opening degree of the water-cooling channel, forming a dynamic matching between the welding heat input and the heat dissipation intensity, suppressing the shrinkage deformation of the crossbeam caused by high temperature, and ensuring the assembly accuracy of the car door; when the first airbag 81 is compressed, the gas in the first airbag 81 is transmitted to the third airbag 93 through the communicating pipe 96, and the third airbag 93 expands and squeezes the abutting block 94 to move downward, and then the end of the abutting block 94 abuts against the lower crossbeam welded body, further increasing the fixing points, thereby improving the clamping stability of the lower crossbeam welded body.

[0070] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A welding positioning tooling for the lower cross beam of the front passenger door of a passenger car, including a lower cross beam welding table, characterized in that: A support frame and a sliding seat movable along a chute are provided on the lower crossbeam welding table; It further includes a plasma welding assembly, which includes a plasma welding controller, a plasma arc welding head, an electric telescopic rod for driving the welding head to move, and a mechanical manipulator installed on the sliding seat; A profiling positioning device, which consists of a profiling reference block and a driving double screw. The surface of the profiling reference block is provided with a serpentine groove. The profiling positioning device includes a fixed seat, a positioning block, and an abutting block. The abutting block makes the end of the abutting block abut against the lower crossbeam welding body through an adjusting assembly; An embedded water cooling device, which includes a spiral water cooling channel embedded inside the profiling reference block and a cold water tank on the step of the lower crossbeam welding table. A temperature sensor is inserted on the spiral water cooling channel, and the temperature sensor is electrically connected to the control center; A dynamic pressure regulating mechanism, which includes an adjusting screw, a pressing ball, and a pressure sensor provided on the side seat. The pressure sensor detects the contact pressure in real time and feeds it back to the control center, and the pressing force is adjusted through the adjusting screw; An abutting adjusting assembly, which includes a support, a receiving cavity, a limiting seat, and a movable sealing block. The opening and closing state of the spiral water cooling channel is adjusted by the abutting positioning of the profiling positioning device to facilitate timely and uniform heat dissipation. A cylinder is embedded in the limiting seat, and the cylinder is electrically connected to the control center. When the temperature sensor detects a large temperature difference in the spiral water cooling channel, the control center starts the cylinder to further push the movable sealing block to increase the opening degree of the through port.

2. The welding positioning tooling for the lower cross beam of the front passenger door of a passenger car according to claim 1, characterized in that: The profiling reference block is provided with a serpentine groove, and the spiral water cooling channel is embedded in the serpentine groove. One end of the spiral water cooling channel is connected to the cold water tank in a circulating manner, and a suction pump is provided on the cold water tank.

3. A welding positioning tooling for the lower cross beam of the front passenger door of a passenger car according to claim 1, characterized in that: The two fixed seats are respectively distributed on both sides of the profiling reference block. A chute is provided on the fixed seat, and a driving double screw is arranged in the chute on the fixed seat. The driving double screw has a double screw structure and the thread directions are opposite.

4. A welding positioning tooling for the lower cross beam of the front passenger door of a passenger car according to claim 1, characterized in that: Sliding blocks are arranged on both sides of the driving double screw. The sliding blocks are connected with the driving double screw through internal and external threads. A connecting seat is arranged on the top of the sliding block, and a positioning block is arranged at the end of the connecting seat.

5. A welding positioning tooling for the lower cross beam of the front passenger door of a passenger car according to claim 1, characterized in that: The dynamic pressure regulating mechanism includes a pressure sensor. Connecting rods are arranged on both sides of the positioning block, and a side seat is arranged at the end of the connecting rod. An adjusting screw is screwed on the side seat. The bottom of the adjusting screw is rotatably connected with a pressing ball through a support block, and a pressure sensor is embedded at the bottom of the pressing ball.

6. The welding positioning tooling for the lower cross beam of the front passenger door of a passenger car according to claim 1, characterized in that: The abutting adjusting assembly includes a movable sealing block. A support is arranged on the lower crossbeam welding table. A limiting seat is arranged on the top of the support. The limiting seat is fixedly connected to one side. A receiving cavity is arranged on the limiting seat, and a movable sealing block is slidably inserted into the receiving cavity. A second airbag is arranged between the movable sealing block and one side of the receiving cavity, and the second airbag is communicated with a connecting pipe.

7. A welding positioning tooling for the lower cross beam of the front passenger door of a passenger car according to claim 4, characterized in that: A receiving cavity is arranged on the positioning block, and a first airbag is arranged in the receiving cavity. An installation block is arranged at the opening of the receiving cavity, and a top block is slidably inserted into the installation block. The top block is bonded to the first airbag, and one end of the first airbag is fixedly communicated with a connecting pipe.

8. A welding positioning tooling for the lower cross beam of the front passenger door of a passenger car according to claim 1, characterized in that: The adjusting assembly includes a support block. One side of the positioning block is located above the top block and fixedly connected to the support block. A square seat is arranged on the top of the support block. A sliding cavity is formed in the square seat. A fixing plate is arranged at the opening of the sliding cavity. The fixing plate is fixed to the square seat by screws. A butting block is slidably inserted into the sliding cavity. The butting block is in an "L" shape and has a semi-circular arc shape at the bottom. A butting spring is arranged between the butting block and the sliding cavity. A third airbag is arranged between the other end of the butting block and the fixing plate. A communicating pipe is arranged between the third airbag and the first airbag.

9. A welding positioning tool for the lower cross beam of the front passenger door of a bus according to claim 6, characterized in that: One side of the movable sealing block is fixedly connected to a side plate. The side plate is closely attached to one side of the second airbag. The length of the side plate is greater than the width of the second airbag in the initial state. A push plate is arranged at the telescopic end of the cylinder. One side of the push plate abuts against the movable sealing block in the initial state.

10. A welding positioning tooling for the lower cross beam of the front passenger door of a bus according to claim 6, characterized in that: One end of the movable sealing block is inserted into the cross-section of the opening of the spiral water-cooling channel. A return spring is arranged between the movable sealing block and the other side of the storage cavity.

11. A welding positioning tooling for the lower cross beam of the front passenger door of a bus according to claim 7, characterized in that: The end of the top block protrudes. One side of the positioning block is used to abut against the middle edge of the lower cross beam of the front passenger door of the bus.

12. A welding positioning tooling for the lower cross beam of the front passenger door of a passenger car according to claim 1, characterized in that: The plasma welding assembly further includes a driving main screw. A slideway is formed in the slide seat. The driving main screw is arranged in the slideway on the slide seat. A slide seat is sleeved on the driving main screw.

13. A welding positioning tooling for the lower cross beam of the front passenger door of a bus according to claim 12, characterized in that: A manipulator is installed on one side of the slide seat. An electric telescopic rod is arranged at the end of the manipulator. A plasma arc welding head is arranged at the telescopic end of the electric telescopic rod.

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