Arm vehicle connecting rod manufacturing method and tool thereof

Abstract

The invention discloses a method and a tool for manufacturing a boom connecting rod. The manufacturing method comprises the following steps: splicing and welding a rectangular tube part, splicing a connecting rod, welding a cylindrical shaft and a rectangular tube, and splicing and welding other parts. The tool comprises a controller, a tool body, a lifting device and positioning devices, the lifting device and the positioning devices are installed on the tool body, the positioning devices are installed at the two ends of the tool body respectively and are parallel to each other, the lifting device is arranged between the positioning devices, and the controller is in signal connection with the lifting device and the positioning devices respectively. By optimizing the splicing sequence, omitting the machining procedure, improving the production capacity, setting the post-welding shrinkage allowance and the welding current value, cooperating with segmented welding, reducing the welding deformation amount, improving the tool application universality through the lifting device and the positioning device, improving the overall precision and quality of the connecting rod by positioning all parts of the connecting rod, and improving the welding quality of the connecting rod. Precision is guaranteed and efficiency is improved.

Description

Technical Field

[0001] The invention relates to a boom car connecting rod manufacturing method and tooling thereof, belonging to the technical field of mechanical engineering. Background Art

[0002] The boom assembly of a boom truck is an indispensable and important part of modern mechanical equipment, mainly consisting of three parts: the boom, the connecting rod and the support. Due to its complex structure and large size, especially the length of the boom and the connecting rod, which are generally more than three meters, its manufacturing process faces many challenges.

[0003] First, due to the large size of each component of the boom assembly, the travel of ordinary machine tools is difficult to meet their processing needs. Therefore, in the manufacturing process, large-scale machining equipment is often required. These equipment are not only expensive to purchase, but also occupy a relatively large plant space, which directly affects the overall product cost and manufacturing efficiency. And the production capacity when using machining is often restricted by equipment conditions.

[0004] Secondly, during the manufacturing process of the connecting rod, manual splicing is usually used for assembly. During the splicing process, due to the limitations of manual operation, the position accuracy of each part of the connecting rod cannot be effectively guaranteed. Welding is an important process for connecting various parts, but due to the lack of precise positioning during the splicing process, the connecting rod will eventually have dimensional deviations.

[0005] In addition, during the welding process, there are many welds, which not only increases the complexity of the process, but also causes deformation of the connecting rod. Especially when welding the shafts at both ends, due to the thermal stress near the weld and the uneven cooling rate, the phenomenon of post-welding out-of-roundness is prone to occur. This out-of-round phenomenon seriously affects the subsequent assembly accuracy, resulting in reduced stability and reliability of the overall structure.

[0006] Finally, in the traditional manufacturing process, the design of tooling is often not compatible with products of different specifications. This means that tooling needs to be frequently switched during the production process, resulting in a waste of time and space. This not only reduces manufacturing efficiency, but also increases the labor intensity of operators, affecting the overall operating efficiency of the production line. Summary of the invention

[0007] Purpose of the invention: In view of the deficiencies in the prior art, the present invention provides a method for manufacturing a boom car connecting rod and its tooling. The present invention optimizes the assembly sequence, reserves a post-welding shrinkage margin and welding current value, and designs an adaptive tooling, thereby ensuring the connecting rod accuracy and improving production capacity.

[0008] Technical solution: A method for manufacturing a boom car connecting rod comprises the following steps: Welding of rectangular tube: weld the plate and rectangular tube together, and hoist the welded rectangular tube onto the fixture; Connecting rod assembly: vertically assemble the cylindrical shafts at both ends of the rectangular tube. After the assembly is completed, use the tooling to position the rectangular tube and the cylindrical shafts at both ends to keep the cylindrical shafts at both ends parallel. Welding of cylindrical shaft and rectangular tube: Set the post-weld shrinkage allowance of the cylindrical shaft and the welding current value, perform a first-stage segmental welding on the outer circle formed at the intersection of the cylindrical shaft and the rectangular tube, and perform a second-stage segmental welding after cooling; after completing the welding of the outer circle, perform full welding on the inner circle formed at the intersection of the cylindrical shaft and the rectangular tube to complete the welding of the cylindrical shaft and the rectangular tube; Welding of other parts: Welding of other parts is done to complete the manufacture of boom truck connecting rod.

[0009] The preferred option is to switch the tooling to the lifting state, hoist the welded rectangular tube onto the tooling, and after completing the assembly of the cylindrical shaft and the rectangular tube, reset the tooling, and then position the rectangular tube and the cylindrical shafts at both ends.

[0010] Preferably, the welding of the outer circle is specifically as follows: firstly weld 3 / 4 of the outer circle, wait for it to cool, and then weld the remaining 1 / 4 of the outer circle to complete the welding of the outer circle.

[0011] Preferably, the connecting rod is a double rectangular tube structure. When the connecting rod is assembled, the side end face of one of the rectangular tubes is first positioned using a tool, and then the cylindrical shaft and the two rectangular tubes are assembled and positioned based on the rectangular tube to complete the assembly of the connecting rod.

[0012] Preferably, after the cylindrical shaft and the rectangular tube are welded, the ribs are assembled and welded between the double rectangular tubes in sequence, and the welding of the remaining parts is completed.

[0013] The present invention optimizes the assembly sequence and changes the original overall welding after one-time assembly to partial assembly, welding, overall assembly, and welding, thereby greatly reducing the number of welds of the connecting rod and preventing welding deformation. The post-welding shrinkage margin and welding current value of the cylindrical shaft are set to reduce the post-welding shrinkage of the cylindrical shaft. At the same time, the intersection of the cylindrical shaft and the rectangular tube is welded in sections to reduce the out-of-roundness of the cylindrical shaft after welding, thereby ensuring the overall accuracy of the connecting rod and eliminating subsequent machining procedures.

[0014] A tool for implementing a method for manufacturing a boom truck connecting rod comprises a controller, a tool body, and a lifting device and a positioning device installed on the tool body. The positioning devices are respectively installed at both ends of the tool body. The positioning devices are parallel to each other. The lifting device is arranged between the positioning devices. The controller is signal-connected to the lifting device and the positioning device respectively.

[0015] The present invention controls the lifting device through a controller to facilitate the assembly of the connecting rod and the cylindrical shaft, and uses a positioning device to position the cylindrical shaft to ensure the parallelism between the cylindrical shafts. The tooling optimizes the assembly sequence, and the original overall welding after one-time assembly is changed to partial assembly, welding, overall assembly, and welding, which greatly reduces the number of welds on the connecting rod and reduces welding deformation, achieves no processing after welding, cancels the machining process, and is applicable to products of different specifications, saving space while avoiding work efficiency delays caused by switching tooling.

[0016] Preferably, in order to facilitate the assembly of the cylindrical shaft and the rectangular tube, the lifting device includes a driving mechanism, a lifting part, and a supporting part which are connected in sequence, the supporting part is in contact with the rectangular tube, and the driving part is connected to the controller signal.

[0017] The cylindrical shaft and the rectangular tube are assembled on the top of the tooling body through the lifting device, which avoids the installation inconvenience caused by the positioning device. At the same time, there is no interference from other parts above, so the assembly can be completed more efficiently and avoid collision with other parts. At the same time, demoulding is convenient and quick.

[0018] Preferably, in order to adapt to connecting rods of different sizes, the positioning device is detachably mounted on the tooling body, the positioning device includes positioning mechanisms symmetrically arranged in groups along the length direction of the tooling body, the positioning mechanism includes a driving part and a telescopic part, one end of the telescopic part is connected to the driving part, and the other end is socketed with the axial end of the cylindrical shaft, the driving part is connected to the controller signal, and at least two groups of the positioning mechanisms are arranged.

[0019] The positioning mechanism can be installed according to the size of different connecting rods, or the installed positioning mechanism can be selected and used according to the specific size to realize the positioning of the cylindrical shaft. The telescopic part is controlled by the driving part to be connected with the shaft end of the cylindrical shaft. At the same time, in order to ensure the parallelism of the cylindrical shaft, the positioning mechanism is symmetrically arranged to prevent the deformation of the cylindrical shaft and difficulty in positioning during positioning.

[0020] Preferably, in order to realize the positioning of the rectangular tube, a positioning block can be detachably mounted on the tool body, and the end face of the positioning block contacts the side end face of the rectangular tube. Before the rectangular tube is hoisted onto the tool body, the positioning block is installed at the corresponding position of the tool body according to the size of the rectangular tube, and then after the rectangular tube is hoisted, the cylindrical shaft is installed, and the lifting device is reset, the side end face of the rectangular tube is closely contacted with the positioning block to realize the positioning of the rectangular tube.

[0021] Preferably, in order to realize the positioning of the cylindrical shaft, a cushion block can be detachably mounted on the tool body, and the cushion block contacts the bottom of the rectangular tube. If the cylindrical shaft and the positioning device cannot be sleeved when the rectangular tube is supported by the tool body after the lifting device is lowered and reset, a cushion block is added between the rectangular tube and the tool body to realize the sleeve connection between the cylindrical shaft and the positioning device, thereby realizing the positioning of the cylindrical shaft.

[0022] Beneficial effects: The present invention optimizes the assembly sequence, omits machining procedures, improves production capacity, sets post-weld shrinkage allowance and welding current value, and cooperates with segmented welding to reduce deformation during welding. At the same time, the lifting device and positioning device on the tooling are used to improve the wide applicability of the tooling, and by positioning the various parts of the connecting rod, the overall accuracy and quality of the connecting rod are improved, which not only ensures accuracy but also improves efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0024] Figure 1 It is a schematic diagram of the double rectangular tube tooling of the present invention; Figure 2 It is a schematic diagram of the integrated rectangular tube tooling of the present invention; Figure 3 It is the tooling structure diagram of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0026] In the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0027] 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.

[0028] A method for manufacturing a boom car connecting rod comprises the following steps: Welding of rectangular tube: weld the plate and rectangular tube together, and hoist the welded rectangular tube onto the fixture; Connecting rod assembly: vertically assemble the cylindrical shafts at both ends of the rectangular tube. After the assembly is completed, use the tooling to position the rectangular tube and the cylindrical shafts at both ends to keep the cylindrical shafts at both ends parallel. Welding of cylindrical shaft and rectangular tube: Set the post-weld shrinkage allowance of the cylindrical shaft and the welding current value, perform a first-stage segmental welding on the outer circle formed at the intersection of the cylindrical shaft and the rectangular tube, and perform a second-stage segmental welding after cooling; after completing the welding of the outer circle, perform full welding on the inner circle formed at the intersection of the cylindrical shaft and the rectangular tube to complete the welding of the cylindrical shaft and the rectangular tube; Welding of other parts: Welding of other parts is done to complete the manufacture of boom truck connecting rod.

[0029] In this embodiment, the post-welding shrinkage allowance of the cylindrical shaft is increased by 0.03-0.08 mm on the original tolerance of the cylindrical shaft diameter; the welding current is reduced to 180-190 A to reduce the welding heat input; After switching the tooling to the lifting state, hoist the welded rectangular tube onto the tooling. After completing the assembly of the cylindrical shaft and the rectangular tube, reset the tooling, and then position the rectangular tube and the cylindrical shafts at both ends.

[0030] The welding of the outer circle is specifically as follows: firstly weld 3 / 4 of the outer circle, wait for it to cool down, and then weld the remaining 1 / 4 of the outer circle to complete the welding of the outer circle.

[0031] like Figure 1 As shown, the connecting rod is a double rectangular tube structure, specifically including double rectangular tubes, a plate, a cylindrical shaft, and a rib plate. When assembling the connecting rod, first use a tool to position the side end face of one of the rectangular tubes, then use the rectangular tube as a reference to assemble and position the cylindrical shaft and the two rectangular tubes to complete the assembly of the connecting rod.

[0032] like Figure 2As shown, in this embodiment, this method is applicable not only to multi-rectangular tube structures, but also to integrated rectangular tubes, specifically including rectangular tubes, plates, cylindrical shafts, and other parts for strengthening and installation. When the connecting rod is assembled, the side end surface of the rectangular tube is positioned using a tool, and the cylindrical shaft and the rectangular tube are assembled and positioned to complete the assembly of the connecting rod.

[0033] After completing the welding of the cylindrical shaft and the rectangular tube, assemble and weld the ribs in sequence between the double rectangular tubes to complete the welding of the remaining parts.

[0034] By optimizing the assembly sequence, the original overall welding after one-time assembly is changed to partial assembly, welding, overall assembly, and welding, which greatly reduces the number of welds on the connecting rod and prevents welding deformation. The post-weld shrinkage allowance and welding current value of the cylindrical shaft are set to reduce the post-weld shrinkage of the cylindrical shaft. At the same time, the junction of the cylindrical shaft and the rectangular tube is welded in sections to reduce the out-of-roundness of the cylindrical shaft after welding, thereby ensuring the overall accuracy of the connecting rod and eliminating subsequent machining steps.

[0035] like Figure 3 As shown, a tool for realizing a method for manufacturing a boom truck connecting rod comprises a controller, a tool body 1, and a lifting device 2 and a positioning device 3 installed on the tool body 1. The positioning devices 3 are respectively installed at both ends of the tool body 1. The positioning devices 3 are parallel to each other. The lifting device 2 is arranged between the positioning devices 3. The controller is signal-connected to the lifting device 2 and the positioning device 3 respectively.

[0036] The lifting device 2 is controlled by the controller to facilitate the assembly of the rectangular tube and the cylindrical shaft, and the positioning device 3 is used to position the cylindrical shaft to ensure the parallelism between the cylindrical shafts. The assembly sequence is optimized by this tooling, and the original overall assembly and welding after one-time molding is changed to partial assembly, welding, overall assembly, and welding, which greatly reduces the number of welds on the connecting rod, reduces welding deformation, realizes no processing after welding, cancels the machining process, and can be applied to products of different specifications, saving space while avoiding the work efficiency delayed by switching tooling. The lifting device 2 and the positioning device 3 in this embodiment are both hydraulically driven.

[0037] In order to facilitate the assembly of the cylindrical shaft and the rectangular tube, the lifting device 2 includes a driving mechanism, a lifting part 21, and a supporting part 22 which are connected in sequence. The supporting part 22 is in contact with the rectangular tube, and the driving mechanism is connected to the controller signal.

[0038] The cylindrical shaft and the rectangular tube are assembled on the top of the tooling body 1 by the lifting device 2, avoiding the installation inconvenience caused by the positioning device 3. At the same time, there is no interference from other parts above, so the assembly can be completed more efficiently, avoiding collision with other parts, and demoulding is convenient and quick.

[0039] In order to adapt to connecting rods of different sizes, the positioning device 3 is detachably installed with the tool body 1. The positioning device 3 includes positioning mechanisms symmetrically arranged in groups along the length direction of the tool body 1. The positioning mechanism includes a driving part and a telescopic part 31. One end of the telescopic part 31 is connected to the driving part, and the other end is sleeved with the shaft end of the cylindrical shaft. The driving part is connected to the controller signal. At least two groups of the positioning mechanism are provided. The telescopic part 31 can be adaptively replaced according to different diameters of the shaft end of the cylindrical shaft.

[0040] The positioning mechanism can be installed according to the size of different connecting rods, or the installed positioning mechanism can be selected and used according to the specific size to realize the positioning of the cylindrical shaft. The telescopic part 31 is controlled by the driving part to be sleeved with the axial end of the cylindrical shaft. At the same time, in order to ensure the parallelism of the cylindrical shaft, the positioning mechanism is symmetrically arranged to prevent the deformation of the cylindrical shaft and difficulty in positioning during positioning.

[0041] In order to realize the positioning of the rectangular tube, a positioning block 4 is detachably mounted on the tool body 1, and the end surface of the positioning block 4 contacts the side end surface of the rectangular tube.

[0042] Before the rectangular tube is hoisted onto the tooling body 1, the positioning block 4 is installed at the corresponding position of the tooling body 1 according to the size of the rectangular tube. Then, after the rectangular tube is hoisted and the cylindrical shaft is installed, the lifting device 2 is reset and the side end face of the rectangular tube is brought into close contact with the positioning block 4 to achieve the positioning of the rectangular tube.

[0043] In order to realize the positioning of the cylindrical shaft, a cushion block 5 is detachably mounted on the tool body 1 , and the cushion block 5 is in contact with the bottom of the rectangular tube.

[0044] If the cylindrical shaft and the positioning device 3 cannot be sleeved together when the rectangular tube is supported by the tooling body 1 after the lifting device 2 is lowered and reset, a cushion block 5 is added between the rectangular tube and the tooling body 1 to achieve the sleeve connection between the cylindrical shaft and the positioning device 3 and realize the positioning of the cylindrical shaft.

[0045] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0046] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for manufacturing a boom car connecting rod, characterized in that: The following steps are involved: Welding of rectangular tube: weld the plate and rectangular tube together, and hoist the welded rectangular tube onto the fixture; Connecting rod assembly: vertically assemble the cylindrical shafts at both ends of the rectangular tube. After the assembly is completed, use the tooling to position the rectangular tube and the cylindrical shafts at both ends to keep the cylindrical shafts at both ends parallel. Welding of cylindrical shaft and rectangular tube: Set the post-weld shrinkage allowance of the cylindrical shaft and the welding current value, perform a first-stage segmental welding on the outer circle formed at the intersection of the cylindrical shaft and the rectangular tube, and perform a second-stage segmental welding after cooling; after completing the welding of the outer circle, perform full welding on the inner circle formed at the intersection of the cylindrical shaft and the rectangular tube to complete the welding of the cylindrical shaft and the rectangular tube; Welding of other parts: Welding of other parts is done to complete the manufacture of boom truck connecting rod.

2. The method for manufacturing a boom car connecting rod according to claim 1, characterized in that: After switching the tooling to the lifting state, hoist the welded rectangular tube onto the tooling. After completing the assembly of the cylindrical shaft and the rectangular tube, reset the tooling, and then position the rectangular tube and the cylindrical shafts at both ends.

3. The method for manufacturing a boom car connecting rod according to claim 2, characterized in that: The welding of the outer circle is specifically as follows: firstly weld 3 / 4 of the outer circle, wait for it to cool down, and then weld the remaining 1 / 4 of the outer circle to complete the welding of the outer circle.

4. The method for manufacturing a boom car connecting rod according to claim 3, characterized in that: The connecting rod is a double rectangular tube structure. When assembling the connecting rod, first use the tooling to position the side end face of one of the rectangular tubes, and then use the rectangular tube as a reference to assemble and position the cylindrical shaft and the two rectangular tubes to complete the assembly of the connecting rod.

5. The method for manufacturing a boom car connecting rod according to claim 4, characterized in that: After completing the welding of the cylindrical shaft and the rectangular tube, assemble and weld the ribs in sequence between the double rectangular tubes to complete the welding of the remaining parts.

6. A tool for implementing the boom car connecting rod manufacturing method according to claim 2, characterized in that: The invention comprises a controller, a tool body (1), and a lifting device (2) and a positioning device (3) mounted on the tool body (1); the positioning devices (3) are respectively mounted at two ends of the tool body (1); the positioning devices (3) are parallel to each other; the lifting device (2) is arranged between the positioning devices (3); and the controller is signal-connected to the lifting device (2) and the positioning device (3).

7. The tooling for the boom car connecting rod manufacturing method according to claim 6, characterized in that: The lifting device (2) comprises a driving mechanism, a lifting part (21), and a supporting part (22) which are connected in sequence, the supporting part (22) is in contact with the rectangular tube, and the driving mechanism is connected to a controller signal.

8. The tooling for the boom car connecting rod manufacturing method according to claim 6, characterized in that: The positioning device (3) is detachably mounted on the tool body (1), and comprises positioning mechanisms symmetrically arranged in groups along the length direction of the tool body (1). The positioning mechanisms comprise a driving portion and a telescopic portion (31), one end of the telescopic portion (31) is connected to the driving portion, and the other end is sleeved with the shaft end of the cylindrical shaft. The driving portion is connected to a controller signal, and at least two groups of the positioning mechanisms are provided.

9. The tooling for the method for manufacturing the boom car connecting rod according to claim 6, characterized in that: A positioning block (4) is also detachably mounted on the tool body (1), and an end surface of the positioning block (4) contacts a side end surface of the rectangular tube.

10. The tooling for the boom car connecting rod manufacturing method according to claim 6, characterized in that: A cushion block (5) is also detachably mounted on the tool body (1), and the cushion block (5) is in contact with the bottom of the rectangular tube.

Images