Double-arc low-stress welding device and method for high-strength steel structural component

Abstract

According to the double-arc low-stress welding device and method for the high-strength steel structural part, two symmetrically-distributed welding mechanical arms are used for achieving symmetrical welding of welding seams on the two sides of the structural part, a vibration exciter vibrates along with welding in the welding process, and vibration aging is conducted after welding; the vibration pickup display screen can reflect vibration frequency, vibration time and vibration waves, and the ultrasonic stress detector monitors the welding stress state of the structural member in real time; double-arc symmetrical welding enables welding shrinkage to be generated uniformly, and welding deformation is reduced; welding stress and a molten pool can be regulated and controlled in real time along with vibration in the welding process, so that the welding molten pool is in a vibration state, slag inclusion and air hole escape is facilitated, and welding seam forming and organization are optimized; the ultrasonic stress detector monitors the welding stress state of the structural part in real time, quantitative control over the welding process of the structural part is achieved, and the stress state and welding deformation control consistency of the structural part is guaranteed. Welding deformation and welding residual stress can be effectively controlled, heat treatment after welding is not needed, and the component quality is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of welding manufacturing, and in particular relates to a double arc low stress welding device and method for high strength steel structural parts. Background Art

[0002] A high-strength steel welded structural part is an important part of the equipment product. It is subject to large impact loads and has high requirements for dimensional accuracy and welding residual stress. The main structure is welded by a high-strength steel cylinder and annular blades, and each blade is symmetrically welded to the cylinder on both sides. The structure is compact, the weld spacing is small, the welding residual stress is large, the stress is concentrated, and the welding deformation is large. It has an adverse effect on subsequent assembly and processing, increases the difficulty of subsequent production and affects product quality. It has a large residual stress concentration, reduces the fatigue strength of the product, and causes the risk of cracking when subjected to impact loads during the use of subsequent products. The traditional heat treatment annealing method is used to eliminate welding residual stress, which is prone to thermal deformation, requires secondary shaping, and will cause a certain degree of loss of parent material performance. At the same time, the heat treatment process has problems such as high energy consumption and greenhouse gas emissions, a long production cycle, and long-term occupation of the work site, which increases the manufacturing cost. Summary of the invention

[0003] The present invention provides a double arc low stress welding device and method for high strength steel structural parts, which solves the defects of the prior art.

[0004] In order to solve the above technical problems, the present invention provides a dual-arc low-stress welding device for high-strength steel structural parts, which is characterized by: comprising a welding robot arm 3, an all-position welding workbench 1, a rotary welding fixture 6, a roller bracket 10, an exciter (4), a vibration pickup 2, and an ultrasonic stress detector 8; the exciter 4 and the vibration pickup 2 are arranged on the all-position welding workbench 1; the rotary welding fixture 6 is fixed on the all-position welding workbench 1, and the neutral axes of the two are consistent; the ultrasonic stress detector 8 is fixed on the front welding robot arm using a support frame 9, and the position can be adjusted up and down; the structural part 7 is clamped and fixed using the rotary welding fixture 6 and the roller bracket 10.

[0005] A double arc low stress welding method for high strength steel structural parts, characterized in that the specific steps are as follows:

[0006] Step 1: Use a C-type clamp 5 to rigidly fix the vibration exciter 4 at the lower right corner of the all-position welding workbench 1, and place the vibration pickup 2 at the corresponding upper left corner of the all-position welding workbench 1. The vibration exciter and the vibration pickup are connected to the vibration aging control device;

[0007] Step 2: insert the positioning shaft of the rotary welding fixture 6 into the center hole of the all-position welding workbench 1, and fasten the rotary welding fixture 6 with bolts;

[0008] Step 3: Cleaning before welding;

[0009] Step 4: Fix the cylindrical body of the structural member using the three-jaw chuck of the rotary welding fixture 6, and support the other end using the roller bracket 10;

[0010] Step 5: Start the vibration exciter 4 and the vibration aging control device, set the vibration frequency to: 3500-4000Hz, and the vibration pickup 2 detects the vibration amplitude and vibration frequency during the vibration process;

[0011] Step 6: Position welding: assemble the blades of the structural component to the stopper of the main body of the structural component. After the assembly is in place, position welding is performed on each blade;

[0012] Step 7: According to the welding trajectory of the structural weld, control the two robots to weld both sides of the blade at the same time, use contact positioning to weld the welds between the blade and the body in sequence, and the weld form is a double-sided single-sided "V" groove weld. During the welding process, vibration aging is performed to relieve stress at the same time;

[0013] Step 8: Connect the ultrasonic stress detector 8 to the welding robot arm using a support frame 9;

[0014] Step 9: Start the ultrasonic stress detector and use the residual stress ultrasonic detection method to monitor the welding stress. The workpiece rotates and the stress detection probe moves with the welding gun. The detection position is always at the welding position for real-time detection.

[0015] Beneficial effects: The present invention uses two symmetrically distributed welding mechanical arms to achieve symmetrical welding of double-sided welds of structural parts. The exciter vibrates during the welding process, and vibration aging is performed after welding. The vibration pickup display can reflect the vibration frequency, vibration time and vibration wave, and the ultrasonic stress detector monitors the welding stress state of the structural parts in real time. The double arc symmetrical welding makes the welding shrinkage uniform and reduces welding deformation. The welding process can adjust the welding stress in real time, oscillate the molten pool, and make the welding molten pool in a vibrating state, which is conducive to the escape of slag inclusions and pores, and optimizes the weld formation and organization. The ultrasonic stress detector monitors the welding stress state of the structural parts in real time, guides the optimization of welding process parameters and vibration parameters, realizes quantitative control of the welding process of the structural parts, and ensures the consistency of the stress state of the structural parts and the control of welding deformation. The present invention can effectively control welding deformation and welding residual stress, does not need heat treatment after welding, improves the quality of components, saves energy and is environmentally friendly, and has high production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the welding process of the present invention;

[0017] Figure 2 Spin welding fixture

[0018] Figure 3 Welding Stress Testing Process

[0019] Figure 4 for Figure 1 BB View

[0020] Among them: 1 all-position welding workbench, 2 vibration pickup, 3 welding robot arm, 4 vibration exciter, 5 C-type clamp, 6 rotary welding fixture, 7 workpiece, 8 ultrasonic stress detector, 9 support frame, 10 roller bracket; 11 base plate, 12 motor, 13 rotating shaft, 14 connecting plate, 15 three-jaw chuck. DETAILED DESCRIPTION

[0021] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below.

[0022] The present invention provides a high-strength steel structural member double arc low stress welding device, comprising a welding robot arm 3, an all-position welding workbench 1, a rotary welding fixture 6, a roller bracket 10, an exciter (4), a vibration pickup 2, and an ultrasonic stress detector 8;

[0023] The vibrator 4 is fixed to the lower right corner of the all-position welding workbench 1 using a C-clamp 5, and the vibration pickup 2 is placed at the upper left corner of the all-position welding workbench 1; the rotary welding fixture 6 is fixed to the all-position welding workbench 1 using bolts, and the neutral axes of the two are consistent; the ultrasonic stress detector 8 is fixed to the front welding robot arm using a support frame 9, and its position can be adjusted up and down; the structural member 7 is clamped and fixed using the rotary welding fixture 6 and the roller bracket 10.

[0024] The rotary welding fixture 6 comprises a base plate 11, a motor 12, a rotating shaft 13, a connecting plate 14, and a three-jaw chuck 15 which are connected in sequence; a positioning shaft is provided at the bottom of the base plate 11 for assembling and positioning with the all-position welding workbench 1; the motor (12) is fixed to the base plate 11 with bolts to provide power for the rotation of the frame component during the welding process; the rotating shaft 13 is welded to the connecting plate 14; the three-jaw chuck 15 is fixed to the connecting plate 14 with bolts to clamp and fix the frame component.

[0025] The support frame 9 includes a horizontal support rod and a vertical support rod connected to each other. The end of the vertical support rod is connected to the welding robot arm 3 in the front, and the end of the horizontal support rod extends into the structural member 7 and is connected to the ultrasonic stress detector 8. There is a waist-shaped hole on the vertical support rod, and the horizontal support rod can be adjusted up and down relatively to adjust the upper and lower positions of the ultrasonic stress detector 8.

[0026] A double arc low stress welding method for high strength steel structural parts, the specific steps are as follows:

[0027] Step 1: Use a C-type clamp 5 to rigidly fix the vibration exciter 4 at the lower right corner of the all-position welding workbench 1, and place the vibration pickup 2 at the corresponding upper left corner of the all-position welding workbench 1. The vibration exciter and the vibration pickup are connected to the vibration aging control device;

[0028] Step 2: Insert the positioning shaft of the rotary welding fixture 6 into the center hole of the all-position welding workbench 1, and fasten the rotary welding fixture 6 with bolts.

[0029] Step 3: Cleaning before welding: Before welding, clean the oil, rust, moisture and other impurities on both sides of the welding part (20-30mm) to reveal the metallic luster.

[0030] Step 4: Fix the cylindrical body of the structural component using the three-jaw chuck of the rotary welding fixture 6, and support the other end using the roller bracket 10.

[0031] Step 5: Start the vibration exciter 4 and the vibration aging control device, set the vibration frequency to 3500-4000 Hz, and during the vibration process, the vibration pickup 2 detects the vibration amplitude and vibration frequency.

[0032] Step 6: Positioning welding: Assemble the blades of the structural component to the stop of the main body of the structural component. After assembly, position weld each blade, weld three points evenly in the circumferential direction, and the weld length is 5 to 10 mm.

[0033] Step 7: According to the welding trajectory of the structural weld, control the two robots to weld both sides of the blade at the same time, use contact positioning to weld the welds between the blade and the body in sequence, and the weld form is a double-sided single-sided "V" groove weld. During the welding process, vibration aging is performed to relieve stress at the same time;

[0034] Step 8: Connect the ultrasonic stress detector 8 to the welding robot arm using the support frame 9, adjust the position, tighten it with bolts, and apply coupling agent between the ultrasonic stress detector 8 and the contact surface of the workpiece.

[0035] Step 9: Start the ultrasonic stress detector, use the residual stress ultrasonic detection method to monitor the welding stress, the workpiece rotates, the stress detection probe moves with the welding gun, and the detection position is always at the welding position for real-time detection;

[0036] Step 10: After welding is completed, the workpiece can be cooled and then ultrasonic stress detection equipment can be used to detect welding residual stress.

[0037] Implementation Cases:

[0038] Case 1

[0039] A heat dissipation device is welded by a cylindrical body and annular heat dissipation blades. The blades are evenly distributed in the axial direction of the body, and the weld is a double-sided single-sided "V" groove weld. Currently, manual semi-automatic melting pole process is used for welding, and tempering is required after welding to relieve stress, and the welding efficiency is low. In addition, the welding environment is harsh, and workers are prone to danger if they are in such a working environment for a long time.

[0040] Based on the above-mentioned double arc low stress welding method for high-strength steel structural parts, the specific implementation steps are as follows:

[0041] Step 1: Use a C-clamp to rigidly fix the vibration exciter at the lower left corner of the all-position welding workbench, place the vibration pickup at the corresponding diagonal upper right corner of the all-position welding workbench, and connect the vibration exciter and the vibration pickup to the vibration aging control device.

[0042] Step 2: Insert the positioning shaft of the spin welding fixture into the center hole of the full-position welding workbench and tighten the spin welding fixture with bolts.

[0043] Step 3: Cleaning before welding: Before welding, clean the oil, rust, moisture and other impurities on both sides of the welding part (20-30mm) to reveal the metallic luster.

[0044] Step 4: Fix the cylindrical body of the heat sink using the three-jaw chuck of the rotary welding fixture, and support the other end with a roller bracket.

[0045] Step 5: Start the vibration exciter and the vibration aging control device, set the vibration frequency, and during the vibration process, the vibration pickup 2 detects the vibration amplitude and vibration frequency.

[0046] Step 6: Position welding, assemble the blades of the heat sink to the stopper of the body. After assembly, position weld each blade, weld 3 points evenly in the circumferential direction, and the weld length is 5 to 10 mm.

[0047] Step 7: Call the predetermined welding program in the robot control system, use contact positioning to weld the welds between the blade and the body in sequence, and the weld form is a double-sided single-sided "V" groove weld. During the welding process, vibration aging is performed to relieve stress at the same time, and ultrasonic stress detection equipment is used to detect welding residual stress.

[0048] Step 8: Connect the ultrasonic stress detector to the welding robot arm using a support frame. After adjusting the position, tighten it with bolts and apply coupling agent between the ultrasonic stress detector and the contact surface of the workpiece.

[0049] Step 9: Start the ultrasonic stress detector, and the stress detection probe moves with the welding gun, and the detection position is always at the welding position.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A double arc low stress welding device for high strength steel structure parts, Features: The invention comprises a welding robot arm 3, an all-position welding workbench 1, a rotary welding fixture 6, a roller bracket 10, an exciter (4), a vibration pickup 2, and an ultrasonic stress detector 8; the exciter 4 and the vibration pickup 2 are arranged on the all-position welding workbench 1; the rotary welding fixture 6 is fixed on the all-position welding workbench 1, and the neutral axes of the two are consistent; the ultrasonic stress detector 8 is fixed on the front welding robot arm using a support frame 9, and the position can be adjusted up and down; the structural member 7 is clamped and fixed using the rotary welding fixture 6 and the roller bracket 10.

2. A double arc low stress welding device for high strength steel structural parts according to claim 1, Features: The rotary welding fixture 6 comprises a base plate 11, a motor 12, a rotating shaft 13, a connecting plate 14, and a three-jaw chuck 15 which are connected in sequence; a positioning shaft is provided at the bottom of the base plate 11 for assembling and positioning with the all-position welding workbench 1; the motor (12) is fixed on the base plate 11 to provide power for the rotation of the structural member during the welding process; the rotating shaft 13 is welded to the connecting plate 14; the three-jaw chuck 15 is fixed on the connecting plate 14 to clamp the fixed frame member.

3. A double arc low stress welding device for high strength steel structural parts according to claim 1, Features: The support frame 9 includes a horizontal support rod and a vertical support rod connected to each other. The end of the vertical support rod is connected to the welding robot arm 3 in the front, and the end of the horizontal support rod extends into the structural member 7 and is connected to the ultrasonic stress detector 8. There is a waist-shaped hole on the vertical support rod, and the horizontal support rod can be adjusted up and down relatively to adjust the upper and lower positions of the ultrasonic stress detector 8.

4. A double arc low stress welding device for high strength steel structural parts according to claim 1, Features: The vibration exciter 4 is fixed at the lower right corner of the all-position welding workbench 1 by using a C-clamp 5 , and the vibration pickup 2 is placed at the upper left corner of the all-position welding workbench 1 .

5. A double arc low stress welding device for high strength steel structural parts according to claim 1, Features: The structural member is welded by a cylindrical body and annular heat dissipation blades, the blades are evenly distributed in the axial direction of the body, and the weld is in the form of a double-sided single-sided "V"-shaped groove weld.

6. A double arc low stress welding method for high strength steel structure parts, It is characterized in that The specific steps are as follows: Step 1: Use a C-type clamp 5 to rigidly fix the vibration exciter 4 at the lower right corner of the all-position welding workbench 1, and place the vibration pickup 2 at the corresponding upper left corner of the all-position welding workbench 1. The vibration exciter and the vibration pickup are connected to the vibration aging control device; Step 2: insert the positioning shaft of the rotary welding fixture 6 into the center hole of the all-position welding workbench 1, and fasten the rotary welding fixture 6 with bolts; Step 3: Cleaning before welding; Step 4: Fix the cylindrical body of the structural member using the three-jaw chuck of the rotary welding fixture 6, and support the other end using the roller bracket 10; Step 5: Start the vibration exciter 4 and the vibration aging control device, set the vibration frequency to: 3500-4000Hz, and the vibration pickup 2 detects the vibration amplitude and vibration frequency during the vibration process; Step 6: Position welding: assemble the blades of the structural component to the stopper of the main body of the structural component. After the assembly is in place, position welding is performed on each blade; Step 7: According to the welding trajectory of the structural weld, control the two robots to weld both sides of the blade at the same time, use contact positioning to weld the welds between the blade and the body in sequence, and the weld form is a double-sided single-sided "V" groove weld. During the welding process, vibration aging is performed to relieve stress at the same time; Step 8: Connect the ultrasonic stress detector 8 to the welding robot arm using a support frame 9; Step 9: Start the ultrasonic stress detector and use the residual stress ultrasonic detection method to monitor the welding stress. The workpiece rotates and the stress detection probe moves with the welding gun. The detection position is always at the welding position for real-time detection.

7. A double arc low stress welding method for high strength steel structural parts according to claim 6, It is characterized in that In step 3, before welding, clean up the impurities on both sides of the welding part to reveal the metallic luster.

8. A double arc low stress welding method for high strength steel structural parts according to claim 6, It is characterized in that In step 6, during welding, three points are welded evenly in the circumferential direction, and the weld length is 5 to 10 mm.

9. A double arc low stress welding method for high strength steel structural parts according to claim 6, It is characterized in that A coupling agent is applied between the contact surface of the ultrasonic stress detector 8 and the workpiece.

10. A double arc low stress welding method for high strength steel structural parts according to claim 6, It is characterized in that Step 10: After welding is completed, the workpiece can be cooled and then ultrasonic stress detection equipment can be used to detect welding residual stress.

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