A gapless single-sided welding double-sided forming anti-cracking welding structure of a movable arm of an excavator

Abstract

The utility model relates to welding technical field, concretely is a kind of excavator movable arm gapless single-sided welding double-sided forming anti-cracking welding structure, including movable arm front plate and movable arm lower plate, the end face of movable arm front plate and movable arm lower plate butt joint is processed as V groove, the plane between the root of V groove to the inside of movable arm front plate is set as groove root datum plane, linear butt joint gap is formed between V groove, groove root datum plane and movable arm lower plate, 0.1mm-0.2mm micro gap is reserved between groove root datum plane and movable arm lower plate, the inside of movable arm front plate is provided with molten pool guide rib, the inside of movable arm lower plate is provided with the installation groove for molten pool guide rib embedding in cooperation, movable arm front plate, movable arm lower plate, molten pool guide rib material quality are all Q355B, the utility model is aimed at solving the problem that existing movable arm plate piece butt joint gap is difficult to control.

Description

Technical Field

[0001] This utility model relates to the field of welding technology, specifically to a gapless single-sided welding double-sided forming anti-cracking welding structure for excavator booms. Background Technology

[0002] The boom of an excavator is the core load-bearing component of the excavator. It bears alternating loads under complex working conditions such as frequent start-stop and heavy-load operation during excavation. As the key execution carrier for the excavator to realize its working functions, its welding quality not only directly determines the structural reliability, operational stability and service life of the boom itself, but also deeply relates to the overall operating efficiency, operational safety and comprehensive operating cost of the excavator. It is the core technical guarantee for ensuring the long-term stable operation of the equipment.

[0003] In the existing welding production process of excavator booms, controlling the butt gap of the components to be welded has always been a common problem faced by the industry. When manually aligning components using traditional assembly methods, it is difficult to ensure the consistency of the butt gap. This often results in uneven gaps in various places and excessive gaps in some areas. This unstable butt state directly affects the filling and fusion effect of the welding material during the welding process, making it difficult for the welding material to evenly wet the entire weld seam. This can easily lead to non-fusion defects, posing a hidden danger to the structural strength of the boom and its safety, which is prone to cracking under long-term use. Utility Model Content

[0004] The purpose of this utility model is to provide a gapless single-sided welding double-sided forming anti-cracking welding structure for excavator booms, so as to solve the problem of difficulty in controlling the joint gap of existing boom plates.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A gapless, single-sided welded, double-sided forming anti-cracking welding structure for an excavator boom includes a boom front plate and a boom lower plate. The end faces of the boom front plate and the boom lower plate are machined into V-shaped bevels. The plane between the root of the V-shaped bevel and the inner side of the boom front plate is set as the root reference plane of the bevel. A linear butt joint is formed between the V-shaped bevel, the root reference plane of the bevel, and the boom lower plate. A micro gap of 0.1mm-0.2mm is reserved between the root reference plane of the bevel and the boom lower plate. A molten pool guide rib is provided on the inner side of the boom front plate, and an installation groove for embedding the molten pool guide rib is provided on the inner side of the boom lower plate.

[0007] Preferably, the boom front plate, boom lower plate, and molten pool guide rib are all made of Q355B material.

[0008] Preferably, the thickness of the reference surface at the root of the bevel is 2 mm.

[0009] Preferably, the molten pool guide rib is integrally formed with the boom front plate.

[0010] Preferably, the height of the molten pool guide rib is designed to be 2mm-3mm, and the length of the molten pool guide rib is completely consistent with the linear butt joint formed by the boom front plate and the boom lower plate.

[0011] Preferably, the weld formed after the linear butt joint is welded includes a base layer, a filler layer, and a cover layer.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] 1. By utilizing the embedded mating structure of the molten pool guide rib integrally formed on the inner side of the boom front plate and the corresponding mounting groove on the boom lower plate, precise positioning of the docking assembly is achieved. This not only significantly improves assembly efficiency but also strictly controls the docking gap between the bevel root reference surface and the boom lower plate to 0.1mm-0.2mm from a structural perspective. This completely solves the industry problem of difficult-to-control docking gaps and uneven or excessively large gaps in traditional manual assembly. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the excavator boom of this utility model;

[0015] Figure 2 This is a schematic diagram of the welding structure of this utility model.

[0016] In the diagram: 1. Front plate of boom; 2. Lower plate of boom; 3. Guide rib for molten pool; 4. V-groove; 5. Reference plane at the root of the groove. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Please see Figures 1 to 2 This utility model provides a technical solution.

[0019] A gapless single-sided welded double-sided forming anti-cracking welded structure for excavator booms includes a boom front plate 1 and a boom lower plate 2, all made of Q355B low alloy high strength steel.

[0020] The end face where the boom front plate 1 and boom lower plate 2 meet is machined into a V-groove 4. The V-groove 4 significantly widens the welding material deposition space, ensuring that the welding material fully wets the entire weld area. The plane between the root of the V-groove 4 and the inner side of the boom front plate 1 is set as the root reference surface 5 of the groove. The thickness of the root reference surface 5 of the groove is 2mm, which strengthens the structural rigidity of the joint root and prevents defects such as deformation due to excessive thinness of the root during welding. A linear butt joint is formed between the V-groove 4, the root reference surface 5 of the groove, and the boom lower plate 2. A micro gap of 0.1mm-0.2mm is reserved between the root reference surface 5 of the groove and the boom lower plate 2. The micro gap can ensure that the welding material is uniformly filled and fully fused, and can also effectively expel the gas generated during the welding process, significantly reducing the incidence of welding defects such as incomplete penetration and porosity, further improving the density and mechanical properties of the weld, and ultimately achieving a stable double-sided weld formation quality.

[0021] The inner side of the boom front plate 1 is provided with a molten pool guide rib 3, which is integrally formed with the boom front plate 1. The inner side of the boom lower plate 2 is provided with an installation groove for the molten pool guide rib 3 to be embedded. During assembly, by precisely embedding the molten pool guide rib 3 into the installation groove, the positioning and alignment of the boom front plate 1 and the boom lower plate 2 can be quickly achieved, greatly improving assembly efficiency. At the same time, this embedded mating structure can strictly standardize the gap between the bevel root reference surface 5 and the boom lower plate 2, ensuring that the gap at each mating position is stably controlled within 0.1mm. The -0.2mm design range avoids excessive gaps caused by human assembly errors, laying the foundation for the stable implementation of gapless single-sided welding. In addition, the molten pool guide rib 3 can also guide the flow of the molten pool during the welding process, prompting the welding material to fill the weld evenly along the guide rib, further improving the uniformity and density of the weld formation. Moreover, after assembly, there is no need to design and adapt new fixtures. Existing welding fixtures can be used to achieve stable fixation, taking into account both production convenience and process continuity, and effectively reducing production modification costs.

[0022] The molten pool guide rib 3 is made of the same material as the base material, Q355B low-alloy high-strength steel, ensuring good metallurgical compatibility with the boom front plate 1 and boom lower plate 2 during welding. This avoids problems such as compositional segregation and differences in thermal expansion coefficients caused by the fusion of dissimilar materials, reducing the risk of weld cracking from the material source. The height of the molten pool guide rib 3 is designed to be 2mm-3mm, which provides a stable guiding channel for the weld molten pool. The length of the molten pool guide rib 3 is completely consistent with the linear butt joint formed by the boom front plate 1 and boom lower plate 2, achieving full coverage of the molten pool guidance throughout the entire weld length. This avoids problems such as molten pool flow and uneven formation in local welds due to lack of guidance. During welding, the molten pool guide rib 3 can accurately guide the high-temperature molten pool metal to spread evenly along the butt joint, effectively inhibiting the displacement and accumulation of the molten pool due to gravity. It can force the molten pool metal to form a flat and continuous forming layer on the back of the weld, achieving one-time forming of the back of the weld.

[0023] The weld formed after linear butt welding adopts a three-layer welding structure design, which includes a bottom layer, a filler layer, and a cover layer. The welding materials used for each layer are matched with the base material Q355B (such as E50 series low alloy steel welding rods / wires) to ensure that the weld and the base material are consistent in key indicators such as tensile strength, yield strength, and impact toughness, and to achieve equal strength matching between the weld and the base material.

[0024] The bottom layer of welding mainly seals the root of the bevel and ensures the quality of the initial fusion, effectively sealing the micro gaps at the root. The filler layer, as the core load-bearing layer of the weld, gradually increases the weld thickness through multiple weld passes, evenly dispersing the welding stress and providing a foundation for the overall load-bearing capacity. The cover layer is used to optimize the surface formation of the weld, eliminate the weld marks of the filler layer, reduce surface defects, and at the same time improve the corrosion resistance and fatigue strength of the weld. Finally, the total weld thickness is controlled at 8mm-10mm.

[0025] The specific steps of this solution are as follows: The boom front plate 1 and boom lower plate 2 are hoisted to the welding station. After aligning the docking area, the molten pool guide rib 3 on the inner side of the boom front plate 1 is precisely embedded into the corresponding mounting groove of the boom lower plate 2. The two plates are quickly positioned and aligned through this embedded mating structure. A gap gauge is used to check the gap between the bevel root reference surface 5 and the boom lower plate 2 segment by segment to ensure that the gap at each docking position is stably controlled within the design range of 0.1mm-0.2mm. After confirming that the gap meets the standard, the two plates are firmly fixed using the original welding special fixture to avoid displacement during the welding process and to ensure the continuity of the process after assembly.

[0026] Start the welding equipment and perform layered welding operations according to the preset parameters. The entire process adopts a single-sided welding method. First, perform the bottom layer welding, select E50 series matching welding materials, and weld with appropriate welding current and voltage parameters. Focus on sealing the root of V-groove 4, fully fill the micro gap between the reference surface and the lower plate 2 of the boom, and ensure the initial fusion quality. With the guidance of the weld pool guide rib 3, the welding material is evenly wetted into the root of the groove, while welding gas is discharged to avoid porosity and incomplete penetration defects. After the bottom layer welding is completed, perform the filler layer welding. Gradually increase the weld thickness by stacking multiple weld passes. Finally, perform the capping layer welding to optimize the weld surface formation, eliminate filler layer weld traces, reduce surface defects, and ensure that the total weld thickness is controlled at 8mm-10mm and has a natural and smooth transition with the base material.

[0027] After welding is completed, the weld is allowed to cool naturally to room temperature. Non-destructive testing methods, such as ultrasonic testing and penetrant testing, are used to check the weld quality, focusing on defects such as lack of fusion, porosity, and cracks. The weld density and uniformity are confirmed to meet the standards. At the same time, the weld dimensions are checked to ensure that the corrosion resistance and fatigue strength of the capping layer meet the requirements.

[0028] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A gapless single-sided welded double-sided forming anti-cracking welded structure for an excavator boom, comprising a boom front plate (1) and a boom lower plate (2), characterized in that: The end face where the boom front plate (1) and the boom lower plate (2) meet is machined into a V-shaped bevel (4). The plane between the root of the V-shaped bevel (4) and the inner side of the boom front plate (1) is set as the root reference surface (5). A linear butt joint is formed between the V-shaped bevel (4), the root reference surface (5), and the boom lower plate (2). A micro gap of 0.1mm-0.2mm is reserved between the root reference surface (5) and the boom lower plate (2). A molten pool guide rib (3) is provided on the inner side of the boom front plate (1). An installation groove for embedding the molten pool guide rib (3) is provided on the inner side of the boom lower plate (2).

2. The gapless single-sided welding double-sided forming anti-cracking welded structure for an excavator boom according to claim 1, characterized in that, The boom front plate (1), boom lower plate (2), and molten pool guide rib (3) are all made of Q355B.

3. The gapless single-sided welding double-sided forming anti-cracking welded structure for an excavator boom according to claim 1, characterized in that, The thickness of the reference surface (5) at the root of the bevel is 2 mm.

4. The gapless single-sided welding double-sided forming anti-cracking welded structure for an excavator boom according to claim 1, characterized in that, The molten pool guide rib (3) is integrally formed with the boom front plate (1).

5. The gapless single-sided welding double-sided forming anti-cracking welded structure for an excavator boom according to claim 1, characterized in that, The height of the molten pool guide rib (3) is designed to be 2mm-3mm, and the length of the molten pool guide rib (3) is completely consistent with the linear butt joint formed by the boom front plate (1) and the boom lower plate (2).

6. The gapless single-sided welding double-sided forming anti-cracking welded structure for an excavator boom according to claim 1, characterized in that, The weld formed after the linear butt joint is welded includes a base layer, a filler layer, and a cover layer.

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