Welding method for flat fillet welding

Abstract

The invention discloses a flat fillet welding method which comprises the following steps: determining a center joint, and starting arc by taking the rightmost end of the center joint as an arcing point; the welding arc is controlled to advance to a first preset position along the left front portion of the bottom plate, and a first welding seam is formed on the bottom plate; the welding gun is controlled to return, the welding arc is made to advance towards the right rear portion and climb to a second preset position along the vertical plate, a second welding seam is formed, and the second welding seam is arranged above the first welding seam in an overlapped mode; the welding gun is controlled to return again, so that the welding arc moves downwards towards the left front side to a third preset position on the bottom plate, a third welding seam is formed between the bottom plate and the vertical plate, and the third welding seam is attached to the left sides of the first welding seam and the second welding seam; the third step and the fourth step are repeated till the center joint is completely welded; and sixthly, weld joints are cleaned. According to the welding method, the heat of the welding arc can be quickly dispersed, the temperature of the molten pool is quickly reduced, the conditions of undercut, molten pool liquid falling, overlarge welding seam convexity and the like are avoided, and the welding quality can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of welding, and in particular relates to a welding method for flat fillet welding. Background Art

[0002] In the manufacturing process of rail vehicles, there are a large number of flat fillet welding operations for parts. Flat fillet welding operations mainly weld the contact area of ​​two welded parts and form a flat fillet weld on the periphery of the contact area.

[0003] As the speed of high-speed rail increases, the quality requirements for high-speed rail are also getting higher and higher, and accordingly, the requirements for weld appearance are becoming more and more stringent. At present, flat fillet welding often has welding defects after welding, such as small weld, undercut, and excessive weld convexity.

[0004] When the above welding defects occur, they need to be repaired, which requires grinding and re-welding. On the one hand, grinding will splash and adhere to the parent material and the weld, and it will need to be cleaned with a wire brush later, which greatly increases the workload of the operator; on the other hand, grinding will also increase safety hazards. At the same time, repeated welding will increase the heat input around the parent material, reduce the fatigue strength of the heat-affected zone of the parent material, and reduce its internal quality, which is labor-intensive and material-intensive. Summary of the invention

[0005] The invention provides a flat fillet welding method, which can effectively increase the weld angle height of the flat fillet weld and avoid undercut and excessive weld convexity.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a method for flat fillet welding, comprising: Step 1: determine the center seam between the bottom plate and the vertical plate to be welded, and start the arc with the rightmost end of the center seam as the arc starting point; Step 2: Control the welding arc to move along the left front of the bottom plate to a first predetermined position to form a first weld on the bottom plate; Step 3: Control the welding gun to retract so that the welding arc moves toward the right rear and moves uphill along the vertical plate to a second predetermined position, forming a second weld between the bottom plate and the vertical plate, and the second weld is superimposed on the first weld; Step 4: Control the welding gun to return again, so that the welding arc moves downhill to the left front to a third predetermined position on the bottom plate, and a third weld is formed between the bottom plate and the vertical plate, and the third weld is close to the left side of the first weld and the second weld; Step 5: Repeat the above steps 3 and 4 until the middle seam is completely welded; Step 6: Clean the weld.

[0007] In some embodiments of the present application, the ratio of the height of the weld angle formed by the first weld on the vertical plate to the height of the weld angle formed by the second weld on the vertical plate is 3~7:3~5.

[0008] In some embodiments of the present application, the sum of the heights of the weld angles formed by the first weld and the second weld on the vertical plate is equal to the sum of the heights of the weld angles formed by the first weld and the second weld on the bottom plate.

[0009] In some embodiments of the present application, at the arc starting point, the axis of the welding gun nozzle is perpendicular to the center seam.

[0010] In some embodiments of the present application, the welding wire of the welding gun is fed in an oblique zigzag shape between the bottom plate and the vertical plate.

[0011] In some embodiments of the present application, in step 2 and step 4, left-hand welding is used for welding, and the forward inclination angle of the welding gun nozzle is 0°~25°.

[0012] In some embodiments of the present application, in step three, right-hand welding is adopted for welding, and the backward tilt angle of the welding gun nozzle is 0°~25°.

[0013] In some embodiments of the present application, a line connecting the third predetermined position and the first predetermined position is parallel to the center seam.

[0014] In some embodiments of the present application, the upper surface of the first weld is an inclined surface, and the first weld slopes downward from right to left.

[0015] In some embodiments of the present application, the bottom plate and the vertical plate are both made of steel plates.

[0016] Compared with the prior art, the advantages and positive effects of the present invention are as follows: the arc starting point of welding starts from the rightmost end of the middle seam, and the welding direction is from the right side of the middle seam to the left side; during welding, the welding arc is controlled to move along the left front side of the bottom plate to a first predetermined position, and a first weld is formed on the bottom plate; then the welding gun is controlled to return to the gun, so that the welding arc moves toward the right rear, uphill along the vertical plate to a second predetermined position, and a second weld is formed between the bottom plate and the vertical plate, and the second weld is superimposed on the first weld, and the welding gun is controlled to return to the gun again, so that the welding arc moves downhill toward the left front to a third predetermined position on the bottom plate, and a third weld is formed between the bottom plate and the vertical plate, and the third weld is close to the left side of the first weld and the second weld, and the welding arc adopts an uphill and downhill method; During welding, the welding gun nozzle swings left and right. In the same time and under the same heat input, the welding arc travels more than 1 times further, reducing the unevenness and poor forming of the weld. The heat of the welding arc is quickly dispersed, and the temperature of the molten pool is quickly reduced, avoiding the occurrence of undercut, liquid drop in the molten pool, and excessive weld convexity, which is beneficial to improving the strength of the weld and ensuring the welding quality of the weld. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 A schematic diagram of the welding structure of the flat fillet welding provided by the present invention; Figure 2 One of the structural schematic diagrams of the flat fillet welding gun nozzle and the center seam provided by the present invention; Figure 3 The second structural schematic diagram of the flat fillet welding gun nozzle and the center seam provided by the present invention; Figure 4 A schematic structural diagram of the rod transport method for flat fillet welding provided by the present invention.

[0019] Description of reference numerals: 1. Vertical board; 2. Bottom plate; 3. Middle seam; 4. First weld; 5. Second weld; 6. Welding gun nozzle. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0022] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0024] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0025] MAG welding is a welding method. Specifically, MAG welding is a type of consumable gas shielded arc welding. MAG welding uses a consumable electrode and an active gas or a mixture of active gas and inert gas as the arc medium to protect the molten metal droplets, the weld pool and the high-temperature metal in the weld zone.

[0026] Welding methods include forward method and backward method.

[0027] The forward method, also known as the left-hand welding method, means that the welding gun is pointed at the part to be welded during the welding process, the welding process is carried out from right to left, and the welding gun and welding wire move together.

[0028] Its characteristics are that the arc carries the molten pool, the arc heat does not directly act on the workpiece, the weld is flat and wide, which is convenient for the welder to observe the molten pool and weld, the gas protection effect is good, the melting depth is small, and the spatter is large.

[0029] Backward welding, also known as right-hand welding, means that during the welding process, the welding gun points to the right side of the completed weld, the welding process is carried out from left to right, and the welding gun moves in front of the welding wire.

[0030] Its characteristics are that the molten pool follows the arc, the arc heat acts directly on the workpiece, the melting depth is large, the spatter is small, the weld is not easy to observe, the weld is narrow and high, and the gas protection effect is better.

[0031] During the welding operation, the welding wire is vaporized into a gas state under the heat of current and voltage, with a temperature as high as 8000~12000℃. It is sprayed onto the steel plate and melts the surface of the steel plate at that position into liquid to form a molten pool, which is then gradually cooled into a solid.

[0032] During welding, due to the high temperature, the upper steel plate to be welded is easily melted to form liquid. Under the action of gravity, it falls into the molten pool, forming a bite edge on the upper steel plate, affecting the welding quality.

[0033] In the first aspect, combined Figures 1 to 4 As shown, the embodiment of the present disclosure provides a flat fillet welding method, the flat fillet welding method comprising: Step 1: Determine the center seam 3 between the bottom plate 2 and the vertical plate 1 to be welded, and use the rightmost end of the center seam 3 as the arc starting point to start the arc. The initial stage of welding mainly adopts the left-hand welding method. Figure 4 As shown in the figure, the white arrow indicates the general direction of welding, and the black arrow indicates the direction of the welding arc.

[0034] Specifically, preparation work needs to be done before arc starting, mainly equipment preparation and parameter setting of flat fillet welding.

[0035] Among them, the equipment used in welding is mainly welding machine, wire feeder and shielding gas supply equipment. The main function of the wire feeder is to feed the welding wire for the welding machine. The diameter of the welding wire fed by the wire feeder is 1.2mm.

[0036] Specifically, parameter settings mainly include the current and voltage settings of the welding machine, as well as the control of the welding speed to ensure the stability and control of the molten pool.

[0037] Exemplarily, the current parameter is 260A±10%; the voltage parameter is 25~30V.

[0038] Step 2: Control the welding arc to move along the left front of the bottom plate 2 to a first predetermined position to form a first weld 4 on the bottom plate 2. After the welding gun starts the arc, the welding wire continuously melts to form a molten pool during the welding process.

[0039] Specifically, the upper surface of the first weld 4 is an inclined surface, and is inclined downward from the vertical plate 1 side toward the bottom plate 2 side.

[0040] Specifically, the first weld 4 is sloped. During welding, at the first predetermined position, it is necessary to ensure that the weld angle width of the first weld 4 on the base plate 2 meets the set requirements, and the weld angle height of the first weld 4 on the vertical plate 1 reaches about 50% of the total weld angle height set on the vertical plate 1.

[0041] Specifically, the first weld 4 is in a downward slope from right to left.

[0042] Specifically, the first weld 4 is formed on the bottom plate 2. The first weld 4 is the first step of welding and provides a basis and support for subsequent welding layers. The quality of the first weld 4 directly affects the strength and weld angle size of the entire weld, so its welding quality and position are very important.

[0043] Specifically, the diameter of the molten pool during welding is about 5~8mm.

[0044] Step 3: Control the welding gun to retract so that the welding arc moves toward the right rear and uphill along the vertical plate 1 to a second predetermined position, forming a second weld 5 between the bottom plate 2 and the vertical plate 1, and the second weld 5 is superimposed on the first weld 4.

[0045] Specifically, the welding gun is controlled to return, and when the welding gun is returned, the middle part of the first weld 4 is in a semi-solidified state; when the welding arc moves toward the right rear, the welding adopts the right-hand welding method. The welding method changes from the left-hand welding method to the right-hand welding method. The welding arc goes uphill along the vertical plate 1 to the second predetermined position, so that the second weld 5 is superimposed on the first weld 4, which is conducive to raising the size of the weld angle.

[0046] Step 4: Control the welding gun to return again, so that the welding arc moves downhill toward the left front to the third predetermined position on the base plate 2, forming a third weld between the base plate 2 and the vertical plate 1, and the third weld is adjacent to the left side of the first weld 4 and the second weld 5.

[0047] Specifically, the welding gun is controlled to return again so that the welding arc moves downhill toward the left front to the third predetermined position on the bottom plate 2. In this process, the speed of the welding gun returning again is faster than the speed of the welding gun returning in step three.

[0048] Specifically, in step 4, when the welding gun is returned again, since the molten pool is in a molten iron state, the welding arc goes downhill, and the height of the weld angle of the second weld 5 is hardly increased.

[0049] Specifically, the speed of returning the welding gun in step 4 is 1.5 to 2.5 times the speed of returning the welding gun in step 3.

[0050] For example, the speed of returning the welding gun in step 4 is twice the speed of returning the welding gun in step 3. This is because the temperature of the welding arc is high, and fast returning the welding gun can avoid the occurrence of undercutting.

[0051] Step 5: Repeat the above steps 3 and 4 until the center seam 3 is completely welded; and make the width of the weld angle on the bottom plate 2 and the height of the weld angle on the vertical plate 1 reach the set value size requirements.

[0052] Specifically, repeat the above steps 3 and 4, so that the overall direction of welding is toward the left side.

[0053] Step 6: Clean the weld. Use appropriate tools to clean the weld surface and remove welding slag, spatter, etc.

[0054] Specifically, during welding, the welding arc is directed to the left front, and then the welding gun is controlled to retract so that the welding arc is directed to the right rear. In the same amount of time and under the same heat input conditions, the welding arc travels more than twice as far, reducing the uneven weld formation and poor weld shape. The heat of the welding arc is quickly dispersed, and the temperature of the molten pool is quickly reduced, avoiding undercutting and the drop of molten pool liquid that causes undercutting and excessive weld convexity.

[0055] In some embodiments of the present application, at the arc starting point, the axis of the welding gun nozzle 6 is perpendicular to the center seam 3 .

[0056] Specifically, by aligning the axis of the welding gun nozzle 6 with the center seam 3 at the arc starting point, the penetration depth of the bottom plate 2 and the vertical plate 1 at the center seam 3 during arc starting can be increased, thereby improving the welding quality at the arc starting point.

[0057] During the welding operation, the axis of the welding gun nozzle 6 swings left and right relative to a position perpendicular to the center seam 3 .

[0058] Specifically, after arcing, the angle between the advancing direction of the welding arc on the bottom plate 2 and the middle seam 3 is 20° to 45°.

[0059] Exemplarily, after arc starting, the angle between the forward direction of the welding arc on the base plate 2 and the center seam 3 is one of 20°, 22°, 25°, 26°, 27°, 28°, 29°, 30°, 32°, 35°, 40° or 45°.

[0060] In some embodiments of the present application, Figure 1 As shown, the ratio of the weld angle height L1 formed by the first weld 4 on the vertical plate 1 to the weld angle height L2 formed by the second weld 5 on the vertical plate 1 is 3-7:3-5.

[0061] Specifically, when the required total weld angle height is relatively large, for example, when the required weld angle height reaches 10 mm, the weld angle height formed by the first weld 4 on the vertical plate 1 is generally greater than the weld angle height formed by the second weld 5 on the vertical plate 1; when the required weld angle height is not too large, for example, when the required weld angle height is about 8 mm, the weld angle height formed by the first weld 4 on the vertical plate is basically the same as the weld angle height formed by the second weld 5 on the vertical plate, or the weld angle height formed by the first weld 4 on the vertical plate is slightly greater than the weld angle height formed by the second weld 5 on the vertical plate, or the weld angle height formed by the first weld 4 on the vertical plate is slightly less than the weld angle height formed by the second weld 5 on the vertical plate.

[0062] In some embodiments of the present application, the sum of the weld angle heights formed by the first weld 4 and the second weld 5 on the vertical plate 1 is equal to the sum of the weld angle widths formed by the first weld 4 and the second weld 5 on the bottom plate 2, that is, L1+L2=L3.

[0063] Specifically, this helps to ensure symmetrical arrangement of the weld angles and reduce the occurrence of poor weld surface shape and the like.

[0064] In some embodiments of the present application, Figure 2 As shown, in step 2 and step 4, the left-hand welding method is used for welding, the welding gun nozzle 6 swings to the left, and the forward inclination angle of the welding gun nozzle 6 is R1, and R1 is 0°~25°. Figure 2 The white arrow in the middle indicates the welding direction.

[0065] Specifically, in step 2 and step 4, the welding gun nozzle 6 is swung to the left with a swing amplitude of 90-115 degrees, so that the welding arc moves toward the left front, and welding is performed by the left-hand welding method.

[0066] In some embodiments of the present application, Figure 3 As shown, in step 3, the welding gun nozzle 6 swings to the right with a swing amplitude of 90-115°, and the welding is performed using the right-hand welding method. The backward tilt angle R2 of the welding gun nozzle 6 is 0°-25°. Figure 3 The white arrow in the middle indicates the welding direction.

[0067] Specifically, in step three, the welding arc moves toward the right rear, and welding is performed by the right-hand welding method.

[0068] Here, the inclination angle of the welding gun nozzle 6 is generally referred to as the welding gun angle.

[0069] Specifically, the distance between the end point of the first weld 4 and the middle seam 3 needs to be set according to the current, voltage, heat input, and the required size of the weld angle to avoid the occurrence of undercut.

[0070] In the disclosed embodiment, the angle of the welding gun nozzle 6 is variable, and can be specifically changed according to the current, voltage, heat input, and the size of the required welding angle.

[0071] In actual welding, the welding method can lengthen or shorten the length of the weld by controlling the amplitude of each left and right swing unit according to the thickness of the plate, the thermal conductivity, the required weld angle, the temperature of the weld, etc. The swing speed and swing length of the welding gun nozzle 6 can also be controlled to disperse the heat and adjust it to the heat required for the weld to avoid undercutting, lack of fusion, etc.

[0072] For example, under the same voltage and current, when welding thinner plates, the swing speed of the welding gun nozzle 6 is faster; when welding thicker plates, the swing speed of the welding gun nozzle 6 is slower.

[0073] In actual operation, if poor fusion occurs on both sides of the weld or the bottom plate and the vertical plate are not melted, it means that the heat is too small, and the swing distance of the welding gun nozzle 6 can be reduced to make the heat more concentrated and achieve better fusion. On the contrary, when undercutting occurs on both sides of the weld or the molten pool falls, it means that the heat is too large, and the swing distance of the welding gun nozzle 6 can be increased.

[0074] In some embodiments of the present application, Figure 1 and Figure 4 As shown, the black arrow in the figure indicates the direction of the welding wire feeding. Between the bottom plate 2 and the vertical plate 1, the welding wire feeding of the welding gun is in an oblique zigzag shape.

[0075] Specifically, the welding method in which the welding wire of the welding gun is fed in an oblique zigzag shape is conducive to the rapid dispersion of heat during welding, avoiding heat concentration, and thus eliminating undercut and the like.

[0076] In conjunction with the left and right swing of the welding gun nozzle 6, the welding arc moves up and downhill, and the welding wire is fed in an oblique zigzag shape. In this way, within the same time and under the same heat input premise, the arc travels at least 1 times farther, reducing the uneven and poorly formed welds. The arc heat can also be quickly dispersed, and the temperature of the molten pool can be quickly reduced, so as to avoid undercutting and undercutting caused by the falling of the molten pool liquid and excessive weld convexity.

[0077] At the same time, with the same number of welds, the height of the weld angle can be increased by 20%, reducing the situation where the weld angle is too small and improving the quality of the weld.

[0078] In some embodiments of the present application, a line connecting the third predetermined position and the first predetermined position is parallel to the middle seam 3 ; a distance between the second predetermined position and the middle seam 3 is equal to a distance between the third predetermined position and the middle seam 3 .

[0079] Specifically, by making the line connecting the third predetermined position and the first predetermined position parallel to the center seam 3, the distance between the second predetermined position and the center seam 3 is equal to the distance between the third predetermined position and the center seam 3, which is helpful to ensure the symmetrical arrangement of the weld angles and reduce the occurrence of surface defects such as insufficient weld width or excessive weld width.

[0080] In some embodiments of the present application, welding is performed under the protection of a metal-active gas.

[0081] Specifically, during welding, the heating arc generates high temperature, instantly vaporizes the metal welding wire and sprays it to form a molten pool, and then the molten pool solidifies to connect the bottom plate 2 and the vertical plate 1. Active gas plays an important role in this process. Active gas can improve welding speed and quality. The specific effects are as follows: First of all, the active gas can protect the molten pool and the weld, isolate the harmful gases such as air and water vapor around the molten pool and the weld, and form a protective gas cover during the welding process to prevent the molten pool liquid from being oxidized and avoid the occurrence of defects such as single pores or honeycomb pores.

[0082] Secondly, active gas can reduce the oxygen content and humidity during welding, thereby reducing the occurrence of quality problems such as thermal cracks, pores, inclusions, etc., and improving welding quality.

[0083] Thirdly, the active gas can act as an arc medium, smoothly vaporizing the melting electrode metal and continuously transitioning it to the middle of the molten pool to form a continuous weld.

[0084] In some embodiments of the present application, the active gas includes, by volume fraction: 80% argon and 20% carbon dioxide; or the active gas includes 100% carbon dioxide.

[0085] Specifically, the flow rate of the active gas is 18-20 L / min.

[0086] In some embodiments of the present application, the bottom plate 2 and the vertical plate 1 are both made of steel plates.

[0087] Specifically, metal active gas welding is suitable for ferrous metal plates and has the advantages of stable arc and high weld quality.

[0088] Of course, this welding method can also be used for MIG stainless steel welding.

[0089] In addition, in actual operation, when the gas shielding is not affected, the forward and backward tilt angles during welding can be appropriately increased or decreased; the distance of the forward and backward swing of the welding torch can also be appropriately increased or decreased; the distance of the left and right swing of the welding torch can also be appropriately increased or decreased to adapt to the welding of non-equilateral triangle welds. Flat fillet welding can be tilted at a certain angle to increase or decrease the size of the weld angle.

[0090] Of course, the welding method of the present application includes but is not limited to flat fillet welding, and can also be used in multi-layer and multi-pass welding to increase the height of the weld fillet or reduce the number of welding layers and passes.

[0091] Embodiment 1: When the required welding angle height is 10 mm.

[0092] Welding methods for flat fillet welding include: S1, starting the arc with the rightmost end of the center seam 3 between the bottom plate 2 and the vertical plate 1 as the arc starting point.

[0093] S2, control the welding arc to move along the left front of the bottom plate 2, wherein the angle between the forward direction of the welding arc and the middle seam is 30°, and a first weld 4 is formed on the bottom plate 2, the upper surface of the first weld 4 is a slope surface, the left end height of the first weld 4 is less than the right end height, the weld angle height L1 of the first weld 4 on the vertical plate 1 is 6 mm, and the weld angle width of the first weld 4 on the bottom plate 2 is 10 mm; S3, control the welding gun to retract, so that the welding arc moves toward the right rear, and goes uphill along the vertical plate 1, forming a second weld 5 between the bottom plate 2 and the vertical plate 1. The second weld 5 is superimposed on the first weld 4, and the height L2 formed by the second weld 5 on the vertical plate 1 is 4 mm.

[0094] S4, control the welding gun to return again, so that the welding arc moves downhill to the left front to the bottom plate 2, forming a third weld between the bottom plate 2 and the vertical plate 1, and the third weld is close to the left side of the first weld 4 and the second weld 5.

[0095] S5, repeat the above steps S3 and S4 until the middle seam 3 is completely welded so that the width and height of the weld angle both reach 10 mm.

[0096] Embodiment 2: When the required weld angle height is 10 mm, the welding method is similar to the above embodiment 1, except that the weld angle height L1 formed by the first weld 4 on the vertical plate 1 is 7 mm, and the height L2 formed by the second weld 5 on the vertical plate 1 is 3 mm.

[0097] Embodiment 3: When the required weld angle height is 8 mm, the welding method is similar to the above embodiment 1, except that the weld angle height L1 formed by the first weld 4 on the vertical plate is 5 mm, and the height L2 formed by the second weld 5 on the vertical plate 1 is 3 mm.

[0098] Embodiment 4: When the required weld angle height is 8 mm, the welding method is similar to the above embodiment 1, except that the weld angle height L1 formed by the first weld 4 on the vertical plate 1 is 4 mm, and the height L2 formed by the second weld 5 on the vertical plate 1 is 4 mm.

[0099] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0100] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present invention.

Claims

1. A flat fillet welding method, characterized in that: include: Step 1: determine the center seam between the bottom plate and the vertical plate to be welded, and start the arc with the rightmost end of the center seam as the arc starting point; Step 2: Control the welding arc to move along the left front of the bottom plate to a first predetermined position to form a first weld on the bottom plate; Step 3: Control the welding gun to retract so that the welding arc moves toward the right rear and moves uphill along the vertical plate to a second predetermined position, forming a second weld between the bottom plate and the vertical plate, and the second weld is superimposed on the first weld; Step 4: Control the welding gun to return again, so that the welding arc moves downhill to the left front to a third predetermined position on the bottom plate, and a third weld is formed between the bottom plate and the vertical plate, and the third weld is close to the left side of the first weld and the second weld; Step 5: Repeat the above steps 3 and 4 until the middle seam is completely welded; Step 6: Clean the weld.

2. The flat fillet welding method according to claim 1, characterized in that: The ratio of the height of the weld angle formed by the first weld on the vertical plate to the height of the weld angle formed by the second weld on the vertical plate is 3-7:3-5.

3. The flat fillet welding method according to claim 1, characterized in that: The sum of the heights of the weld corners formed by the first weld and the second weld on the vertical plate is equal to the sum of the heights of the weld corners formed by the first weld and the second weld on the bottom plate.

4. The flat fillet welding method according to claim 1, characterized in that: At the arc starting point, the axis of the welding gun nozzle is perpendicular to the center seam.

5. The flat fillet welding method according to claim 1, characterized in that: Between the bottom plate and the vertical plate, the welding wire of the welding gun is transported in an oblique zigzag shape.

6. The flat fillet welding method according to claim 1, characterized in that: In step 2 and step 4, left-hand welding is used for welding, and the forward inclination angle of the welding gun nozzle is 0°~25°.

7. The flat fillet welding method according to claim 1, characterized in that: In step three, right-hand welding is used for welding, and the backward tilt angle of the welding gun nozzle is 0°~25°.

8. The flat fillet welding method according to claim 1, characterized in that: A line connecting the third predetermined position and the first predetermined position is parallel to the center seam.

9. The flat fillet welding method according to claim 1, characterized in that: The upper surface of the first weld is an inclined surface, and the first weld is in a downward slope from right to left.

10. The flat fillet welding method according to claim 1, characterized in that: The bottom plate and the vertical plate are both made of steel plates.

Images