Method for manufacturing an excavator super long arm

Abstract

The application discloses a manufacturing method of an excavator super-long arm, which comprises the following steps: (1) segmentally assembling and welding a plurality of structural segments of the super-long arm to obtain a segmented structure comprising at least a middle segment component and a rear fork component; (2) after the middle segment component is assembled and welded, automatically welding the external weld of the middle segment component by using a welding device to ensure the weld forming quality and the dimensional stability; (3) positioning the middle segment component and the rear fork component on an assembly tool to realize the overall connection of the structure by segmental assembly; and (4) adjusting the welding posture and the welding height according to the spatial position of the components during the welding process, so that the welding of the upper weld of the rear fork component is completed within a predetermined height range, thereby avoiding the overall lifting operation. The manufacturing method of the excavator super-long arm combines the segmental assembly and welding with the automatic welding of the welding device, and ensures the weld forming quality of the irregular surface and the welding strength.

Description

Technical Field

[0001] This invention belongs to the field of welding technology. Specifically, this invention relates to a method for manufacturing an extra-long boom for excavators. Background Technology

[0002] In engineering fields such as mining, water conservancy construction, and building construction, earthmoving is a core component. However, with the expansion of project scale and the increasing complexity of the working environment, higher demands are placed on the operating range, flexibility, and efficiency of excavating equipment. In particular, large-scale water conservancy and construction projects, such as river dredging and post-demolition debris clearing of high-rise buildings, require limited space or the avoidance of frequent equipment relocation to reduce construction costs and improve operational safety. Ordinary excavators, with their limited operating radius, are no longer sufficient to meet the demands of such long-distance, large-scale operations.

[0003] To address this issue, the ultra-long boom excavator was developed. This equipment, with a longer boom than ordinary excavators, can operate over greater distances, effectively reducing the number of mechanical relocations and significantly improving operational efficiency and adaptability in special working conditions, making it an indispensable key piece of equipment in these fields. However, the "long boom" structural characteristics of the ultra-long boom excavator present numerous technical challenges in its manufacturing process, particularly imposing stringent requirements on the precision and reliability of the production process. Among these, the lap welding process, as a core component affecting the structural strength, stability, and service life of the ultra-long boom, presents particularly significant technical difficulties.

[0004] In the welding process of components for ultra-long boom excavators, the irregular surfaces of some parts make it difficult to guarantee the welding quality of welds on these irregular surfaces using traditional integral lap welding techniques. This often results in defects such as poor weld formation, insufficient weld strength, porosity, or cracks, which in turn affect the mechanical and safety performance of the entire boom structure. Furthermore, improper welding process planning can lead to a chaotic welding sequence, making it difficult to control the overall dimensional accuracy of the ultra-long boom. Ultimately, this can cause the product to fail to meet design specifications, impacting the equipment's operational performance and market competitiveness. Therefore, overcoming the welding quality challenges of irregular surface welds in ultra-long boom excavators, optimizing the welding sequence, and ensuring overall dimensional accuracy have become critical technical issues that urgently need to be addressed in improving production processes in this field.

[0005] A method for manufacturing an extra-long excavator boom is provided, particularly concerning improving the welding quality of the extra-long boom product. Summary of the Invention

[0006] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides a method for manufacturing an extra-long excavator boom, with the purpose of improving the welding quality of the extra-long boom product.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: a method for manufacturing an extra-long excavator boom, comprising the following steps: (1) The multiple structural segments of the extra-long boom are welded together to form a segmented structure that includes at least the middle section and the rear fork. (2) After the middle section component is welded, the external weld of the middle section component is automatically welded using welding equipment to ensure the weld formation quality and dimensional stability. (3) The middle section component and the rear fork component are assembled and positioned on the welding fixture, and the overall structure is connected by segmented assembly; (4) During the welding process, adjust the welding posture and welding height according to the spatial position of the component so that the weld above the rear fork component is completed within the predetermined height range, thereby avoiding the overall lifting operation.

[0008] Each structural segment of the segmented lap welding is positioned by a special lap welding fixture, which includes multiple adjustable clamping points to control the spatial posture and axial alignment of each component during the welding process.

[0009] The welding equipment employs a multi-layer, multi-pass welding process for the external weld seams to reduce heat input concentration and welding stress.

[0010] The welding sequence is carried out sequentially from the middle section component to the rear fork component to disperse thermal stress and reduce the accumulation of welding deformation.

[0011] During the welding process, the temperature distribution in the weld area is monitored in real time using a measuring device, and the welding current and welding speed are dynamically adjusted based on the measurement results to control the weld cooling rate.

[0012] The welding height is adjusted by hoisting equipment. The welding height of the upper weld of the rear fork component is controlled within the range of 3500-4000 mm to meet the welding space requirements and reduce the risk of working at height.

[0013] After welding is completed, the dimensions of each weld are inspected and deformation is corrected to ensure that the total length error of the extra-long arm does not exceed ±2 mm as required by the design.

[0014] The welding fixture includes a base and a first positioning device, a first clamping device and a first supporting device disposed on the base. The first positioning device is configured to position the rear fork component, the first clamping device is configured to apply clamping force to the rear fork component, and the first supporting device is configured to provide support to the rear fork component.

[0015] The welding fixture further includes a second positioning device, a second support device, a second clamping device, and a third clamping device disposed on the base. The second positioning device is configured to position the middle section component, the second clamping device and the third clamping device are configured to apply clamping force to both ends of the middle section component, and the second support device is configured to provide support for the middle section component.

[0016] The welding fixture further includes a third positioning device, a fourth positioning device, a third support device, a fourth clamping device, and a fifth clamping device disposed on the base. The third and fourth positioning devices are configured to position the front component, the fourth and fifth clamping devices are configured to apply clamping force to the front component, and the third support device is configured to provide support for the front component.

[0017] The welds between the mid-section component and the rear fork component undergo non-destructive testing after welding, including ultrasonic testing or radiographic testing, to ensure the internal quality of the welds. The lap welding of the remaining components is performed after the main welds have cooled to room temperature to avoid structural deformation caused by the cumulative heat input.

[0018] The method for manufacturing an extra-long excavator boom according to the present invention has the following advantages and significant effects: (1) By combining segmented lap welding with automatic welding equipment, the forming quality and welding strength of irregular surface welds are guaranteed; (2) The welding height is controlled within the operable range to reduce the risk of working at height and improve the safety of the operation; (3) Achieve synergistic optimization of welding precision, structural strength and manufacturing safety, and significantly improve product consistency and assembly compatibility. Attached Figure Description

[0019] This manual includes the following figures, which illustrate the following: Figure 1 This is a structural diagram of an excavator's extra-long boom. Figure 2 This is a structural schematic diagram of the welding fixture; Figure 3 This is a top view of the welding fixture; Figure 4 This is a schematic diagram of the structure of the first positioning device; Figure 5 This is a structural schematic diagram of the first support device; The components in the diagram are labeled as follows: 1. Front section component; 2. Middle section component; 3. Rear fork component; 4. Base; 5. First positioning device; 6. First clamping device; 7. First support device; 8. Second positioning device; 9. Second support device; 10. Second clamping device; 11. Third clamping device; 12. Third positioning device; 13. Fourth positioning device; 14. Third support device; 15. Fourth clamping device; 16. Fifth clamping device; 17. Bracket; 18. First actuator; 19. First positioning pin. Detailed Implementation

[0020] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solutions of the present invention, and to facilitate its implementation.

[0021] like Figures 1 to 5 As shown in the figure, this embodiment of the invention provides a method for manufacturing an extra-long excavator boom, including the following steps: (1) The multiple structural segments of the long boom are welded together to form a segmented structure including at least the middle section component 2 and the rear fork component 3; (2) After the middle section component 2 is welded, the external weld of the middle section component 2 is automatically welded using welding equipment to ensure the weld formation quality and dimensional stability. (3) The middle section component 2 and the rear fork component 3 are assembled and positioned on the welding fixture, and the overall structure is connected by segmented assembly; (4) During the welding process, adjust the welding posture and welding height according to the spatial position of the component so that the weld above the rear fork component 3 is completed within the predetermined height range, thereby avoiding the overall lifting operation; (5) Optimize the welding sequence and welding parameters according to the stress distribution and heat input characteristics of each weld to control welding deformation and dimensional shrinkage; (6) After the main weld is completed, the remaining parts are lap welded and welded to complete the overall forming of the super long arm.

[0022] Specifically, in the embodiments of the present invention, such as Figure 1 As shown, the excavator's extra-long boom is mainly composed of a front section component 1, a middle section component 2, and a rear fork component 3. The excavator's extra-long boom includes three structural sections, namely the front section component 1, the middle section component 2, and the rear fork component 3. The middle section component 2 is located between the front section component 1 and the rear fork component 3, and both ends of the middle section component 2 need to be welded to the front section component 1 and the rear fork component 3, respectively.

[0023] In this embodiment of the invention, each structural segment of the segmented lap welding is positioned by a special lap welding fixture, which includes multiple adjustable clamping points to control the spatial posture and axial alignment of each component during the welding process.

[0024] In step (2), after the middle section component 2 is welded, a welding device is used to perform multi-layer and multi-pass welding on the external weld, and the welding heat input is controlled not to exceed the preset threshold in order to obtain a uniform weld appearance and weld penetration depth.

[0025] In step (3), after the front part 1, the middle part 2 and the rear fork part 3 are welded together, a special welding fixture is used for positioning. The welding fixture is equipped with adjustable clamping points to ensure the posture accuracy and axis alignment of each part. The positioning and clamping of the front part 1, the middle part 2 and the rear fork part 3 are achieved through the welding fixture.

[0026] In this embodiment of the invention, the external weld seam welded by the welding equipment adopts a multi-layer, multi-pass welding process to reduce the heat input concentration and welding stress.

[0027] In this embodiment of the invention, the welding sequence is carried out sequentially from the middle section component 2 to the rear fork component 3 in order to disperse thermal stress and reduce the accumulation of welding deformation.

[0028] In this embodiment of the invention, the temperature distribution in the weld area is monitored in real time during the welding process using a measuring device, and the welding current and welding speed are dynamically adjusted based on the measurement results to control the weld cooling rate.

[0029] In this embodiment of the invention, in step (4) above, the welding height is adjusted by a hoisting device. The welding height of the upper weld of the rear fork component 3 is controlled within the range of 3500 to 4000 mm, preferably controlled at about 3885 mm, so that the whole structure does not need to be hoisted to 10529 mm, in order to meet the welding space requirements of the weld and reduce the risk of climbing operations, and reduce the risk of hoisting and time consumption.

[0030] In step (5) above, welding is performed segment by segment in the order from the front part to the rear fork part 3, so that the thermal stress is released along the arm body direction and deformation is prevented from accumulating; at the same time, the welding speed, current and welding angle are adjusted according to the weld position.

[0031] In step (5) above, the welding sequence and parameters are adjusted during welding to control product deformation. The welding sequence is as follows: use the reverse method to perform staggered welding, welding from the small end of the fork component to the large end, and welding in the order of root pass - fill pass - cover pass. And control the current, voltage, gas flow rate and wire feed speed according to the standard requirements of the work instruction.

[0032] In step (6) above, after the main weld is completed, the remaining parts are lap-welded, and ultrasonic or radiographic testing is performed on the weld to confirm that there are no defects such as pores or cracks inside the weld.

[0033] In this embodiment of the invention, after welding is completed, the dimensions of each weld are inspected and the deformation is corrected. For example, the total length dimension is re-measured using laser ranging or coordinate measuring machine to ensure that the error of the total length dimension of the extra-long arm does not exceed ±2 mm as required by the design.

[0034] In embodiments of the present invention, such as Figures 1 to 5 As shown, the welding fixture includes a base 4 and a first positioning device 5, a first clamping device 6, and a first support device 7 disposed on the base 4. The first positioning device 5 is configured to position the rear fork component 3, the first clamping device 6 is configured to apply clamping force to the rear fork component 3, and the first support device 7 is configured to provide support for the rear fork component 3. The first positioning device 5 is disposed at the bottom of the base 4, and the base 4 has a through hole for the rear fork component 3 to pass through. The first positioning device 5 positions the rear fork component 3 at one end along its length, and the other end of the rear fork component 3 needs to be welded to the middle section component 2. Two first clamping devices 6 are provided, and the two first clamping devices 6 clamp the rear fork component 3 at the other end of the rear fork component 3, with the rear fork component 3 located between the two first clamping devices 6. The length direction of the base 4 is parallel to a first direction. The two first clamping devices 6 are on the same straight line parallel to a second direction, both of which are horizontal and perpendicular.

[0035] In embodiments of the present invention, such as Figure 2 and Figure 4 As shown, the first positioning device 5 includes a support 17, a first positioning pin 19, and a first actuator 18. The first actuator 18 is connected to the first positioning pin 19 and is mounted on the base 4. The first actuator 18 controls the first positioning pin 19 to move linearly. The direction of movement of the first positioning pin 19 is parallel to the second direction. By controlling the movement of the first positioning pin 19, the first actuator 18 can insert the first positioning pin 19 into the positioning hole at the end of the rear fork component 3 and control the first positioning pin 19 to move out of the positioning hole. The support 17 is fixedly mounted on the base 4. The support 17 provides support for the rear fork component 3 below its end and carries the rear fork component 3. The support 17 is provided with a positioning groove for the rear fork component 3 to be inserted. The support 17 is located below the through hole on the base 4. After the rear fork component 3 is inserted into the positioning groove, the first positioning pin 19 and the positioning hole at the end of the rear fork component 3 are coaxial. In the next step, the first actuator 18 can control the first positioning pin 19 to move, so that the first positioning pin 19 is inserted into the positioning hole at the end of the rear fork component 3, thereby achieving accurate positioning of the rear fork component 3.

[0036] In this embodiment of the invention, since the first positioning device 5 is located at the bottom of the base 4, a pressure sensor is provided on the support 17. The pressure sensor and the first actuator 18 are electrically connected to the control system to realize automated control, saving time and effort. In the above step (3), when the pressure sensor on the support 17 contacts the rear fork component 3, the pressure sensor is triggered, and then the pressure sensor sends a signal to the control system. The control system sends a signal to the first actuator 18, and then the control system sends a command to the controller. Then the first actuator 18 controls the first positioning pin 19 to move, so that the first positioning pin 19 is inserted into the positioning hole at the end of the rear fork component 3, completing the accurate positioning of the rear fork component 3. The rear fork component 3 can also rotate up and down around the axis of the first positioning pin 19.

[0037] In embodiments of the present invention, such as Figure 2 and Figure 5 As shown, the first support device 7 is fixedly mounted on the top surface of the base 4. The first support device 7 is located between the two first clamping devices 6, and provides support for the rear fork component 3 below its end. After the first positioning pin 19 is inserted into the positioning hole at the end of the rear fork component 3, the rear fork component 3 can be rotated downwards to make it contact the lower first support device 7, ensuring that the height position of the end of the rear fork component 3 is accurate. Then, the first clamping device 6 clamps the middle rear fork component 3.

[0038] like Figures 1 to 3As shown, the welding fixture also includes a second positioning device 8, a second support device 9, a second clamping device 10, and a third clamping device 11 mounted on the base 4. The second positioning device 8 is configured to position the middle section component 2. The second clamping device 10 and the third clamping device 11 are configured to apply clamping force to both ends of the middle section component 2, respectively. The second support device 9 is configured to provide support for the middle section component 2. The second positioning device 8, the second clamping device 10, and the third clamping device 11 are mounted on the top surface of the base 4. Two second clamping devices 10 are provided, clamping the middle section component 2 at one end, with the middle section component 2 located between the two second clamping devices 10. Two third clamping devices 11 are provided, clamping the middle section component 2 at the other end, with the middle section component 2 located between the two third clamping devices 11. Two second clamping devices 10 are positioned on the same straight line parallel to the second direction, and two third clamping devices 11 are also positioned on the same straight line parallel to the second direction. Two second positioning devices 8 are provided, positioned on the same straight line parallel to the second direction. Each second positioning device 8 is located between one second clamping device 10 and one third clamping device 11, with the second clamping device 10 and the first clamping device 6 arranged adjacent to each other. The positions of the second clamping devices 10 and 11 on the base 4 are adjustable, allowing for adjustment of the clamping position as needed. The second positioning device 8 includes a second positioning pin and a second actuator. The second actuator is connected to the second positioning pin and is positioned on the base 4. The second actuator controls the linear movement of the second positioning pin, with the movement direction parallel to the second direction. By controlling the movement of the second positioning pin, the second positioning pin is inserted into the positioning hole on the middle section component 2, and the second positioning pin is moved out of the positioning hole.

[0039] like Figures 1 to 3As shown, the welding fixture also includes a third positioning device 12, a fourth positioning device 13, a third support device 14, a fourth clamping device 15, and a fifth clamping device 16 disposed on the base 4. The third positioning device 12 and the fourth positioning device 13 are configured to position the front component 1, the fourth clamping device 15 and the fifth clamping device 16 are configured to apply clamping force to the front component 1, and the third support device 14 is configured to provide support for the front component 1. The third positioning device 12, the fourth positioning device 13, the third support device 14, the fourth clamping device 15, and the fifth clamping device 16 are located on the top surface of the base 4. Two fourth clamping devices 15 are provided, and the two fourth clamping devices 15 clamp the front component 1 at one end, with the front component 1 located between the two fourth clamping devices 15. Four fifth clamping devices 16 are provided, clamping the front section component 1 at the other end. The four fifth clamping devices 16 are arranged in pairs facing each other, with the front section component 1 located between the two rows of fifth clamping devices 16. Two fourth clamping devices 15 are located on the same straight line parallel to the second direction, and the two opposing fifth clamping devices 16 are also located on the same straight line parallel to the second direction. Two third positioning devices 12 are provided, located on the same straight line parallel to the second direction. Each third positioning device 12 is located between one fourth clamping device 15 and one fifth clamping device 16, with the fourth clamping device 15 and the third clamping device 11 arranged adjacent to each other. Two fourth positioning devices 13 are provided, located on the same straight line parallel to the second direction, with the fifth clamping device 16 located between the third positioning device 12 and the fourth positioning device 13. The positions of the fourth clamping devices 15 and the fifth clamping devices 16 on the base 4 are adjustable, allowing for adjustment of the clamping position as needed.

[0040] The welds between the mid-section component 2 and the rear fork component 3 undergo non-destructive testing after welding, including ultrasonic testing or radiographic testing, to ensure the internal quality of the welds. The lap welding of the remaining components is performed after the main welds have cooled to room temperature to avoid structural deformation caused by the cumulative heat input.

[0041] The above-described implementation method can significantly improve the production safety and manufacturing precision of excavator booms while ensuring structural strength and weld reliability, and also improve welding efficiency. It is applicable to the production and manufacturing of various types of boom excavators.

[0042] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A method for manufacturing an extra-long excavator boom, characterized in that, Includes the following steps: (1) The multiple structural segments of the extra-long boom are welded together to form a segmented structure that includes at least the middle section and the rear fork. (2) After the middle section components are welded together, the external welds of the middle section components are automatically welded using welding equipment; (3) The middle section component and the rear fork component are assembled and positioned on the welding fixture, and the overall structure is connected by segmented assembly; (4) During the welding process, adjust the welding posture and welding height according to the spatial position of the component so that the weld above the rear fork component is completed within the predetermined height range.

2. The manufacturing method according to claim 1, characterized in that, Each structural segment of the segmented lap welding is positioned by a special lap welding fixture, which includes multiple adjustable clamping points to control the spatial posture and axial alignment of each component during the welding process.

3. The manufacturing method according to claim 1 or 2, characterized in that, The welding equipment employs a multi-layer, multi-pass welding process for the external weld seams to reduce heat input concentration and welding stress.

4. The manufacturing method according to any one of claims 1 to 3, characterized in that, The welding sequence is carried out sequentially from the middle section component to the rear fork component to disperse thermal stress and reduce the accumulation of welding deformation.

5. The manufacturing method according to any one of claims 1 to 4, characterized in that, During the welding process, the temperature distribution in the weld area is monitored in real time using a measuring device, and the welding current and welding speed are dynamically adjusted based on the measurement results to control the weld cooling rate.

6. The manufacturing method according to any one of claims 1 to 5, characterized in that, The welding height is adjusted by hoisting equipment. The welding height of the upper weld of the rear fork component is controlled within the range of 3500-4000 mm to meet the welding space requirements and reduce the risk of working at height.

7. The manufacturing method according to any one of claims 1 to 6, characterized in that, After welding is completed, the dimensions of each weld are inspected and deformation is corrected to ensure that the total length error of the extra-long arm does not exceed ±2 mm as required by the design.

8. The manufacturing method according to any one of claims 1 to 7, characterized in that, The welding fixture includes a base and a first positioning device, a first clamping device and a first supporting device disposed on the base. The first positioning device is configured to position the rear fork component, the first clamping device is configured to apply clamping force to the rear fork component, and the first supporting device is configured to provide support to the rear fork component.

9. The manufacturing method according to claim 8, characterized in that, The welding fixture further includes a second positioning device, a second support device, a second clamping device, and a third clamping device disposed on the base. The second positioning device is configured to position the middle section component, the second clamping device and the third clamping device are configured to apply clamping force to both ends of the middle section component, and the second support device is configured to provide support for the middle section component.

10. The manufacturing method according to claim 9, characterized in that, The welding fixture further includes a third positioning device, a fourth positioning device, a third support device, a fourth clamping device, and a fifth clamping device disposed on the base. The third and fourth positioning devices are configured to position the front component, the fourth and fifth clamping devices are configured to apply clamping force to the front component, and the third support device is configured to provide support for the front component.

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