A hydraulic support bending cover plate groove weld full penetration welding method

Abstract

The application discloses a hydraulic support bending cover plate groove weld full penetration welding method, relates to the full penetration welding technical field of a groove weld, and comprises the following steps: blanking; cutting a groove; bending; surfacing; assembling; robot backing welding; robot filling and cap welding; and has the beneficial effects that the groove size is stable through the control of the bending cover plate groove angle, the bending angle and the assembling angle with the front cross rib plate; a cover plate assembling position line is drawn on the front cross rib plate before surfacing, so that the surfacing layer position is accurate; the backing welding is guaranteed not to be missed through the supporting effect of the surfacing layer; the robot surfacing mode is used, batch operation is simple, the efficiency is high, the surfacing layer height, width and straightness are stable through the robot welding surfacing layer, the supporting quality is improved; the starting end of the backing weld adopts an arc striking parameter, the end adopts a welding mode of an arc collecting parameter and a welding wire back swing rotation, and arc striking and arc collecting cracks are avoided.

Description

Technical Field

[0001] This invention relates to the field of full penetration welding technology for bevel welds, and in particular to a full penetration welding method for bevel welds of hydraulic support bending cover plates. Background Technology

[0002] Hydraulic supports are a major piece of equipment in coal mining, and structural components are key load-bearing parts of these supports, directly bearing the pressure from the mine face. They are characterized by complex structures, large welding volumes, and high load-bearing capacity. Hydraulic support structural components are all customized products, characterized by small batches and multiple production runs. The top beam is one of the important structural components, generally welded together from high-strength steel parts such as main reinforcement assemblies, stiffening plates, and cover plates. The weld types of the various components on the top beam are mainly fillet welds and bevel welds. The bevel weld formed between the bent cover plate and the front transverse main reinforcement plate is particularly deep, requires a large amount of welding, necessitates multiple layers and passes, and is complex due to the thick steel plate, low bevel position, and the bend angle of the cover plate, making the weld difficult to weld.

[0003] The traditional welding process for the beveled cover plate of the hydraulic support top beam is as follows: material preparation → beveling → cover plate bending → assembly → manual root pass welding → robotic fill and cover pass welding. The process details are shown below:

[0004] Step (1) Material preparation:

[0005] Use a cutting machine to cut and blank parts such as the top beam cover plate and the front cross stiffener plate;

[0006] Step (2) Beveling:

[0007] Use a beveling machine to bevele the top beam cover plate according to the drawings, ensuring a blunt edge of 1-2mm.

[0008] Step (2) Bending:

[0009] Use tooling to locate the bending position of the top beam cover plate, and use a bending machine to bend the top beam cover plate;

[0010] Step (3) Assembly:

[0011] Use a grinding wheel to grind the areas with welds on the front transverse stiffener plate and the bending cover plate to expose the metal luster, and use tooling to adjust the relative position of the bending cover plate and the front transverse stiffener plate.

[0012] Step (4) Welding:

[0013] The top beam to be welded is fixed on the welding platform, and a robot is used to perform welding on the root pass.

[0014] The disadvantages of existing technology are as follows:

[0015] (1) The bending of the cover plate parts is difficult and the dimensional accuracy is poor; the bending radius and angle of the cover plate are inconsistent, resulting in different bending jigs for each batch of workpieces, which causes production difficulties and poor accuracy.

[0016] (2) The bending of the cover plate has a significant impact on the assembly accuracy. The bevel angle and root gap are inconsistent, which leads to poor dimensional accuracy of the bevel weld formed by the bent cover plate and the stiffening plate, and inconsistent gap: the bevel gap is generally irregularly varied between 1-4mm.

[0017] (3) The robot welding parameters are poorly adapted to the bevel weld between the bevel plate and the cross stiffener: if the welding parameters are large, the bevel weld is easily leaked and a void is formed; if the welding parameters are small, the root cannot be penetrated and a void is formed, and the two sides are prone to non-fusion defects. Summary of the Invention

[0018] The purpose of this invention is to provide a full penetration welding method for the bevel weld of the bending cover plate of a hydraulic support in order to solve the above-mentioned problems.

[0019] The present invention achieves the above objectives through the following technical solutions:

[0020] A method for full penetration welding of the bevel weld of a hydraulic support bending cover plate includes the following steps:

[0021] Step S1: Material preparation:

[0022] Use plasma or laser cutting machines to cut and blank parts such as the top beam cover plate and the front cross stiffener plate;

[0023] Step S2: Cut the bevel:

[0024] Use a beveling machine to bevele the cover plate according to the drawings;

[0025] Step S3: Bending:

[0026] Place the workpiece on the three-point positioning bending platform, use the upper jig with R=75mm, find the bending position of the top beam cover plate, and press down to bend the top beam cover plate.

[0027] Step S4: Welding:

[0028] The welds and the two sides of the front transverse stiffener plate were ground with a grinding wheel to expose the metal luster. The assembly position line of the cover plate was marked on the front transverse stiffener plate. A welding robot was used to build up a weld below the assembly position line of the cover plate.

[0029] Step S5: Assembly:

[0030] Use a grinding wheel to grind the areas with welds on the front transverse stiffener plate and the bending cover plate to achieve a metallic luster, and use tooling to adjust the relative position of the bending cover plate and the front transverse stiffener plate.

[0031] Step S6: Robotic root pass welding:

[0032] The top beam to be welded is fixed on the welding platform, and a robot is used to perform overall root welding on the bevel between the front transverse stiffener plate and the bent cover plate.

[0033] Step S7: Robotic filling and capping welding:

[0034] After the initial welding, the robot directly performs the fill welding and the capping welding.

[0035] Preferably, in step S2, the bevel angle at the front end of the top beam cover plate is 55° and the blunt edge is 1-2mm.

[0036] Preferably, in step S3, the bending radius of the top beam cover plate is uniformly R = 80mm, and the bending angle is controlled within 15° ± 1°.

[0037] Preferably, in step S4, the surfacing welding uses ER50-6 welding wire with a diameter of φ1.6mm, and the welding parameters are welding current 440-480A, welding voltage 25-28V, wire feed speed 9m / min, and welding speed 60-70cm / min.

[0038] Preferably, in step S4, the weld height after welding is 4-6mm, the distance between the two ends of the weld and the edge of the horizontal stiffener plate is 1-2mm, and the distance between the edge of the weld and the assembly position line of the cover plate is 1-3mm.

[0039] Preferably, in step S5, the gap between the root of the bevel and the upper edge of the weld bead is 1-3mm, and the gap between the root and the front horizontal stiffener is 0-2mm.

[0040] Preferably, in step S6, the root pass welding uses a mixed gas shielded welding of Ar + 20% CO2, with a gas flow rate of 25-30 L / min, a solid core welding wire with a diameter of φ1.6 mm, a wire extension of 30-35 mm, an angle of 13-15° with the front transverse stiffener, and a welding travel angle of 5-10°.

[0041] Preferably, in step S6, the starting parameters for the first 2-3mm of the root pass weld are: current 200-220A, voltage 21-22V, wire feed speed 3-4m / min, and welding speed 20-25cm / min; the welding parameters for the middle section of the root pass weld are: welding current 420-450A, welding voltage 32-34V, wire feed speed 9.5-10m / min, welding speed 50-60cm / min, sinusoidal oscillation, and 1mm wide oscillation on both sides; the ending parameters for the last 3-5mm of the root pass weld are: current 180-200A, voltage 20-21V, wire feed speed 3-3.5m / min, and welding speed 15-20cm / min. During the ending process, the welding wire swings back and rotates until the crater is completely filled.

[0042] Preferably, in step S7, the welding wire extension is kept at 20-30mm, the angle between the welding wire and the front cross stiffener is 13-15°, and the welding travel angle remains unchanged at 5-10°.

[0043] Preferably, in step S7, only one pass is welded for the first layer. The welding parameters are: welding current 420-450A, welding voltage 30-33V, wire feed speed 7-9m / min, welding speed 45-55cm / min; an upward tilting method of 15° is adopted, with a double-sided tilting width of 4mm.

[0044] Other filler welding parameters: welding current 360-430A, welding voltage 30-33V, wire feed speed 7-10m / min, welding speed 45-55cm / min, sinusoidal oscillation, double-sided oscillation width 2-5mm;

[0045] The welding parameters for the cover are: welding current 350-380A, welding voltage 29-31V, wire feed speed 6-8m / min, welding speed 45-65cm / min, and double-sided swing width 2-6mm.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] 1. The bevel size is kept stable by controlling the bevel angle, bending angle, and assembly angle with the front cross stiffener plate of the bending cover plate.

[0048] 2. Through the supporting effect of the weld overlay, when the assembly gap of the bevel weld at the root of the bevel of the bending cover plate is inconsistent, the robot can ensure root penetration and prevent leakage of the root weld when performing root welding. Compared with manual root welding, the quality of root welding fusion is improved.

[0049] 3. Using robotic welding allows for batch operations, is simple to operate, and is highly efficient. Furthermore, the height, width, and straightness of the weld layer are stable due to robotic welding, thus improving the support quality.

[0050] 4. Before welding, mark the cover plate assembly position line on the front horizontal stiffener plate to ensure the accurate position of the weld layer; the two ends of the weld should be 1-2mm away from the edge of the horizontal stiffener plate, and the edge should be 1-3mm away from the cover plate assembly position line to avoid interference during assembly and to form a certain gap with the root of the cover plate, which is conducive to reverse fusion.

[0051] 5. The starting end of the root pass weld should use the arc-starting parameters, and the ending end should use the arc-ending parameters plus the welding wire swinging and rotating to avoid the occurrence of arc-starting and arc-ending cracks;

[0052] 6. Filler 1 adopts an upward swaying motion to improve the fusion of straight edges. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a partial structural diagram of the bending cover plate of the hydraulic support bending cover plate according to the present invention, which is a full penetration welding method for the bevel weld of the hydraulic support bending cover plate.

[0055] Figure 2 This is an enlarged view of point A in the full penetration welding method for the bevel weld of the bending cover plate of the hydraulic support described in this invention.

[0056] Figure 3 This is an enlarged view of section B of the full penetration welding method for the bevel weld of the bending cover plate of the hydraulic support described in this invention.

[0057] Figure 4 This is a schematic diagram of the three-point positioning of the cover plate forming process in the full penetration welding method of the bevel weld of the bending cover plate of the hydraulic support described in this invention.

[0058] Figure 5 This is a side view of the overlay structure on the front transverse stiffener plate of the full penetration welding method for the bevel weld of the bending cover plate of the hydraulic support described in this invention.

[0059] Figure 6 This is a schematic diagram of the main structure of the overlay welding on the front transverse stiffener plate of the full penetration welding method for the bevel weld of the bending cover plate of the hydraulic support described in this invention.

[0060] Figure 7 This is a schematic diagram of the assembly position of the front horizontal stiffener plate and the cover plate in the full penetration welding method of the bevel weld of the bending cover plate of the hydraulic support described in this invention.

[0061] Figure 8 This is a schematic diagram of the sinusoidal oscillation mode of the robotic welding torch in the full penetration welding method of the bevel weld of the hydraulic support bending cover plate described in this invention.

[0062] Figure 9 This is a schematic diagram of the robot welding torch swinging obliquely upwards in a full penetration welding method for the bevel weld of a hydraulic support bending cover plate according to the present invention.

[0063] Figure 10 This is a schematic diagram of the robot welding gun posture for a full penetration welding method for the bevel weld of a hydraulic support bending cover plate according to the present invention.

[0064] Figure 11This is a schematic diagram of the robot welding gun posture from another perspective of the full penetration welding method for the bevel weld of the hydraulic support bending cover plate described in this invention.

[0065] Figure 12 This is a schematic diagram of the weld bead layout for a full penetration welding method for the bevel weld of a hydraulic support bending cover plate according to the present invention.

[0066] The annotations in the attached figures are explained as follows:

[0067] 1. Cover plate; 2. Upper tire fixture; 3. Lower tire support point; 4. Front transverse stiffener plate; 5. Overlay welding; 6. Cover plate assembly position line; 7. Robot welding gun. Detailed Implementation

[0068] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. In addition, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0069] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection", and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood through the specific circumstances.

[0070] The present invention will be further described below with reference to the accompanying drawings:

[0071] Example 1

[0072] A method for full penetration welding of the bevel weld of a hydraulic support bending cover plate includes the following steps:

[0073] Step S1: Material preparation:

[0074] Use a plasma or laser cutting machine to cut and blank parts such as the top beam cover plate 1 and the front transverse stiffener plate 4.

[0075] Step S2: Cut the bevel:

[0076] Using a beveling machine, cut the bevel of the cover plate according to the drawing, such as... Figures 1-2 As shown, ensure that the bevel angle at the front end of the top beam cover plate 1 is 55° and the blunt edge is 1-2mm;

[0077] Step S3: Bending:

[0078] like Figures 3-4 As shown, the workpiece is placed on a three-point positioning bending platform. Using the upper jig 2 with R=75mm, the bending position of the top beam cover plate 1 is found. The top beam cover plate 1 is pressed down and bent. The bending radius of the top beam cover plate 1 is uniformly R=80mm, and the bending angle is controlled within 15°±1°.

[0079] Step S4: Welding 5:

[0080] like Figures 5-6 As shown, the weld beads and the two sides of the front transverse stiffener plate 4 are ground with a grinding wheel to expose the metal luster. The assembly position line of the cover plate 1 is marked on the front transverse stiffener plate 4. Using a welding robot, a weld 5 is built up below the assembly position line of the cover plate 1. The weld 5 uses ER50-6 welding wire with a diameter of φ1.6mm. The welding parameters are welding current 440-480A, welding voltage 25-28V, wire feed speed 9m / min, welding speed 60-70cm / min, to ensure that the weld height is 4-6mm after welding, the two ends of the weld are 1-2mm away from the edge of the transverse stiffener plate, and the edge of the weld is 1-3mm away from the assembly position line of the cover plate 1.

[0081] Step S5: Assembly:

[0082] Using a grinding wheel, the areas with weld beads on the front transverse stiffener 4 and the bent cover plate 1 are ground to a metallic luster. The relative positions of the bent cover plate 1 and the front transverse stiffener 4 are then adjusted using tooling. Figure 7 As shown, ensure that the gap between the root of the bevel and the upper edge of the weld 5 is 1-3mm, and the gap between the root and the front horizontal stiffener 4 is 0-2mm;

[0083] Step S6: Robotic root pass welding:

[0084] The top beam to be welded is fixed on the welding platform. A robot is used to perform overall root pass welding on the bevel between the front transverse stiffener plate 4 and the bent cover plate 1. The root pass welding uses Ar + 20% CO2 mixed gas shielded welding, with a gas flow rate of 25-30 L / min, a φ1.6 mm diameter solid welding wire, a wire extension of 30-35 mm, an angle of 13-15° with the front transverse stiffener plate 4, and a welding travel angle of 5-10°. The starting parameters for the first 2-3 mm of the root pass weld are as follows: current 200-220 A, voltage 21-22 V, and wire feed speed 3-4 m / min. The welding speed is 20-25 cm / min; the welding parameters for the middle section of the root pass are: welding current 420-450A, welding voltage 32-34V, wire feed speed 9.5-10m / min, welding speed 50-60cm / min, sinusoidal oscillation, double-sided oscillation width 1mm; the arc-closing parameters are used for the last 3-5mm of the root pass: current 180-200A, voltage 20-21V, wire feed speed 3-3.5m / min, welding speed 15-20cm / min, during the arc-closing process, the welding wire swings back and rotates until the crater is completely filled;

[0085] Step S7: Robotic filling and capping welding:

[0086] like Figure 12 As shown, after the initial welding, the robot directly performs filler and capping welding, as follows: Figures 10-11 As shown, during welding, the welding wire extension should be kept at 20-30mm, the angle between the welding wire and the front transverse stiffener plate 4 should be 13-15°, and the welding travel angle should remain unchanged at 5-10°.

[0087] The first layer of filler is welded only once. Welding parameters: welding current 420-450A, welding voltage 30-33V, wire feed speed 7-9m / min, welding speed 45-55cm / min; Figure 9 As shown, it adopts an upward tilting method of 15°, with a double-sided swing width of 4mm;

[0088] Other filler welding parameters: welding current 360-430A, welding voltage 30-33V, wire feed speed 7-10m / min, welding speed 45-55cm / min, etc. Figure 8 As shown, it exhibits a sinusoidal oscillation with a bilateral swing width of 2-5mm;

[0089] The welding parameters for the cover are: welding current 350-380A, welding voltage 29-31V, wire feed speed 6-8m / min, welding speed 45-65cm / min, and double-sided swing width 2-6mm.

[0090] Working principle: Standardization of the bending method, bending angle, and bending radius of the cover plate 1; welding and overlaying 5 layers on the front transverse stiffener plate 4 to support the molten pool of the root weld; the root weld is oscillating at the end of the arc to prevent cracks; the first filler is oscillating upwards to improve fusion; the gap between the second filler and the bevel edge is controlled to improve the root fusion of the third filler.

[0091] Example 2

[0092] A method for full penetration welding of the bevel weld of a hydraulic support bending cover plate includes the following steps:

[0093] Step S1: Material preparation:

[0094] Use a plasma or laser cutting machine to cut and blank parts such as the top beam cover plate 1 and the front transverse stiffener plate 4.

[0095] Step S2: Cut the bevel:

[0096] Using a beveling machine, beveling the cover plate 1 according to the drawings, ensuring that the beveling angle at the front end of the top beam cover plate 1 is 55° and the blunt edge is 1mm.

[0097] Step S3: Bending:

[0098] Place the workpiece on the three-point positioning bending platform, use the upper jig 2 with R=75mm, find the bending position of the top beam cover plate 1, and press down to bend the top beam cover plate 1. The bending radius of the top beam cover plate 1 is uniformly R=80mm, and the bending angle is controlled at 14°.

[0099] Step S4: Welding 5:

[0100] The weld beads and the two sides of the front transverse stiffener plate 4 were ground with a grinding wheel to expose the metal luster. The assembly position line of the cover plate 1 was marked on the front transverse stiffener plate 4. Using a welding robot, a weld 5 was built up below the assembly position line of the cover plate 1. The weld 5 was built up with ER50-6 welding wire with a diameter of φ1.6mm. The welding parameters were 440A welding current, 25V welding voltage, 9m / min wire feed speed, and 60cm / min welding speed. The weld height was 4mm after welding, and the distance between the two ends of the weld and the edge of the transverse stiffener plate was 1mm. The distance between the edge of the weld and the assembly position line of the cover plate 1 was 1mm.

[0101] Step S5: Assembly:

[0102] A grinding wheel is used to grind the areas with welds on the front horizontal stiffener plate 4 and the bent cover plate 1 to a metallic luster. The tooling is used to adjust the relative positions of the bent cover plate 1 and the front horizontal stiffener plate 4 to ensure that the gap between the root of the bevel and the upper edge of the weld 5 is 1mm and the gap between the root of the bevel and the front horizontal stiffener plate 4 is 0mm.

[0103] Step S6: Robotic root pass welding:

[0104] The top beam to be welded was fixed on the welding platform. A robot was used to perform overall root pass welding on the bevel between the front transverse stiffener plate 4 and the bent cover plate 1. The root pass welding used Ar + 20% CO2 mixed gas shielded welding, with a gas flow rate of 25L / min, a φ1.6mm diameter solid welding wire, a wire extension of 30mm, an angle of 13° with the front transverse stiffener plate 4, and a welding travel angle of 5°. The starting parameters for the first 2mm of the root pass weld were: current 200A, voltage 21V, wire feed speed 3m / min, and welding speed 20cm / min. The welding parameters for the middle section of the root pass weld were: welding current 420A, welding voltage 32V, wire feed speed 9.5m / min, welding speed 50cm / min, sinusoidal oscillation, and a double-sided oscillation width of 1mm. The ending parameters for the last 3mm of the root pass weld were: current 180A, voltage 20V, wire feed speed 3m / min, and welding speed 15cm / min. During the ending process, the welding wire oscillated and rotated until the crater was completely filled.

[0105] Step S7: Robotic filling and capping welding:

[0106] After the initial welding, the robot directly performs fill welding and cover welding. During welding, the welding wire extension is kept at 20mm, the angle between the welding wire and the front cross stiffener is 13°, and the welding travel angle remains unchanged at 5°.

[0107] The first layer is filled with only one weld. Welding parameters: welding current 420A, welding voltage 30V, wire feed speed 7m / min, welding speed 45cm / min; the upward tilting method is adopted with a 15° upward tilt and a double-sided tilting width of 4mm.

[0108] Other filler welding parameters: welding current 360A, welding voltage 30V, wire feed speed 7m / min, welding speed 45cm / min, etc. Figure 8 As shown, it exhibits a sinusoidal oscillation with a bilateral swing width of 2mm;

[0109] The welding parameters for the cover plate are: welding current 350A, welding voltage 29V, wire feed speed 6m / min, welding speed 45cm / min, and double-sided swing width 2mm.

[0110] Example 3

[0111] A method for full penetration welding of the bevel weld of a hydraulic support bending cover plate includes the following steps:

[0112] Step S1: Material preparation:

[0113] Use a plasma or laser cutting machine to cut and blank parts such as the top beam cover plate 1 and the front transverse stiffener plate 4.

[0114] Step S2: Cut the bevel:

[0115] Using a beveling machine, beveling the cover plate 1 according to the drawings, ensuring that the beveling angle at the front end of the top beam cover plate 1 is 55° and the blunt edge is 2mm.

[0116] Step S3: Bending:

[0117] Place the workpiece on the three-point positioning bending platform, use the upper jig 2 with R=75mm, find the bending position of the top beam cover plate 1, and press down to bend the top beam cover plate 1. The bending radius of the top beam cover plate 1 is uniformly R=80mm, and the bending angle is controlled at 15°.

[0118] Step S4: Welding 5:

[0119] The weld beads and the two sides of the front transverse stiffener plate 4 were ground with a grinding wheel to expose the metal luster. The assembly position line of the cover plate 1 was marked on the front transverse stiffener plate 4. Using a welding robot, a weld 5 was built up below the assembly position line of the cover plate 1. The weld 5 was built up with ER50-6 welding wire with a diameter of φ1.6mm. The welding parameters were: welding current 480A, welding voltage 28V, wire feed speed 9m / min, welding speed 70cm / min. The weld height was 6mm after welding, the distance between the two ends of the weld and the edge of the transverse stiffener plate was 2mm, and the distance between the edge of the weld and the assembly position line of the cover plate 1 was 3mm.

[0120] Step S5: Assembly:

[0121] A grinding wheel is used to grind the areas with welds on the front horizontal stiffener plate 4 and the bent cover plate 1 to a metallic luster. The tooling is used to adjust the relative positions of the bent cover plate 1 and the front horizontal stiffener plate 4 to ensure that the gap between the root of the bevel and the upper edge of the weld 5 is 3mm and the gap between the root of the bevel and the front horizontal stiffener plate 4 is 2mm.

[0122] Step S6: Robotic root pass welding:

[0123] The top beam to be welded was fixed on the welding platform. A robot was used to perform overall root pass welding on the bevel between the front transverse stiffener plate 4 and the bent cover plate 1. The root pass welding used Ar + 20% CO2 mixed gas shielded welding, with a gas flow rate of 30L / min, a φ1.6mm diameter solid welding wire, a wire extension of 35mm, an angle of 15° with the front transverse stiffener plate 4, and a welding travel angle of 10°. The starting parameters for the first 3mm of the root pass weld were: current 220A, voltage 22V, wire feed speed 4m / min, and welding speed 25cm / min. The welding parameters for the middle section of the root pass weld were: welding current 450A, welding voltage 34V, wire feed speed 10m / min, welding speed 60cm / min, sinusoidal oscillation, and a double-sided oscillation width of 1mm. The ending parameters for the last 5mm of the root pass weld were: current 200A, voltage 21V, wire feed speed 3.5m / min, and welding speed 20cm / min. During the ending process, the welding wire oscillated and rotated until the crater was completely filled.

[0124] Step S7: Robotic filling and capping welding:

[0125] like Figure 12 As shown, after the root pass welding, the robot directly performs filler and capping welding. During welding, the welding wire extension is kept at 30mm, the angle between the welding wire and the front cross stiffener plate 4 is 15°, and the welding travel angle remains unchanged at 10°.

[0126] The first layer is filled with only one weld. Welding parameters: welding current 450A, welding voltage 33V, wire feed speed 9m / min, welding speed 55cm / min; the upward tilting method is adopted with a 15° upward tilt and a double-sided tilting width of 4mm.

[0127] Other filler welding parameters: welding current 430A, welding voltage 33V, wire feed speed 10m / min, welding speed 55cm / min, sinusoidal oscillation, double-sided oscillation width 5mm;

[0128] The welding parameters for the cover plate are: welding current 380A, welding voltage 31V, wire feed speed 8m / min, welding speed 65cm / min, and double-sided swing width 6mm.

[0129] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are only illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from the spirit and scope of the present invention, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for full penetration welding of the bevel weld of a hydraulic support bending cover plate, characterized in that: Includes the following steps: Step S1: Material preparation: Use a plasma or laser cutting machine to cut and blank parts such as the top beam cover plate (1) and the front cross stiffener plate (4); Step S2: Cut the bevel: Using a beveling machine, beveling the cover plate (1) according to the drawings; Step S3: Bending: Place the workpiece on the three-point positioning bending platform, use the upper jig (2) with R=75mm, find the bending position of the top beam cover plate (1), and press down to bend the top beam cover plate (1); Step S4: Welding (5): The weld bead and the two sides of the front transverse stiffener plate (4) were ground with a grinding wheel to expose the metal luster. The assembly position line of the cover plate (1) was marked on the front transverse stiffener plate (4). A welding robot was used to build up a weld (5) below the assembly position line of the cover plate (1). The weld (5) used ER50-6 welding wire with a diameter of φ1.6mm. The welding parameters were welding current 440-480A, welding voltage 25-28V, wire feeding speed 9m / min, and welding speed 60-70cm / min. Step S5: Assembly: A grinding wheel is used to grind the welded areas on the front horizontal stiffener plate (4) and the bent cover plate (1) to produce a metallic luster. The relative positions of the bent cover plate (1) and the front horizontal stiffener plate (4) are adjusted using tooling. Step S6: Robotic root pass welding: The top beam to be welded is fixed on the welding platform, and a robot is used to perform overall root pass welding on the bevel between the front transverse stiffener plate (4) and the bent cover plate (1). The root pass welding uses Ar + 20% CO2 mixed gas shielded welding, with a gas flow rate of 25-30 L / min, a φ1.6 mm diameter solid welding wire, a wire extension of 30-35 mm, an angle of 13-15° with the front transverse stiffener plate (4), and a welding travel angle of 5-10°. The starting parameters for the root pass weld are as follows: 2-3 mm at the beginning of the weld, current 200-220 A, voltage 21-22 V, and wire feed speed 3-4 m / s. For the middle section of the root pass weld, the welding parameters are as follows: welding current 420-450A, welding voltage 32-34V, wire feed speed 9.5-10m / min, welding speed 50-60cm / min, sinusoidal oscillation, double-sided oscillation width 1mm; for the last 3-5mm of the root pass weld, the arc-closing parameters are as follows: current 180-200A, voltage 20-21V, wire feed speed 3-3.5m / min, welding speed 15-20cm / min, during the arc-closing process, the welding wire swings back and rotates until the crater is completely filled. Step S7: Robotic filling and capping welding: After the initial welding, the robot directly performs fill welding and capping welding; the first layer of fill welding is welded only once, with the following welding parameters: welding current 420-450A, welding voltage 30-33V, wire feed speed 7-9m / min, welding speed 45-55cm / min; the robot uses an upward tilting method with a 15° upward tilt and a 4mm width on both sides. Other filler welding parameters: welding current 360-430A, welding voltage 30-33V, wire feed speed 7-10m / min, welding speed 45-55cm / min, sinusoidal oscillation, double-sided oscillation width 2-5mm; The welding parameters for the cover are: welding current 350-380A, welding voltage 29-31V, wire feed speed 6-8m / min, welding speed 45-65cm / min, and double-sided swing width 2-6mm.

2. The method for full penetration welding of the bevel weld of a hydraulic support bending cover plate according to claim 1, characterized in that: In step S2, ensure that the bevel angle of the front end of the top beam cover plate (1) is 55° and the blunt edge is 1-2mm.

3. The method for full penetration welding of the bevel weld of a hydraulic support bending cover plate according to claim 1, characterized in that: In step S3, the bending radius of the top beam cover plate (1) is uniformly R=80mm, and the bending angle is controlled at 15°±1°.

4. The method for full penetration welding of the bevel weld of a hydraulic support bending cover plate according to claim 1, characterized in that: In step S4, ensure that the weld height is 4-6mm after welding, the distance between the two ends of the weld and the edge of the horizontal stiffener plate is 1-2mm, and the distance between the edge of the weld and the assembly position line of the cover plate (1) is 1-3mm.

5. The method for full penetration welding of the bevel weld of a hydraulic support bending cover plate according to claim 1, characterized in that: In step S5, ensure that the gap between the root of the bevel and the upper edge of the weld overlay (5) is 1-3mm and the gap between the root of the bevel and the front horizontal stiffener (4) is 0-2mm.

6. The method for full penetration welding of the bevel weld of a hydraulic support bending cover plate according to claim 1, characterized in that: In step S7, the welding wire extension is kept at 20-30mm, the angle between the welding wire and the front transverse stiffener (4) is 13-15°, and the welding travel angle remains unchanged at 5-10°.

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