An adaptive ear plate positioning mechanism for a welding connection arm tooling

Abstract

The utility model discloses a kind of self-adaptive ear plate positioning mechanisms for welding connecting arm tooling, including the datum positioning assembly and elastic clamping assembly of assembly in tooling support structure, datum positioning assembly contains the first mounting plate and the positioning boss fixed thereon of support structure through rotating shaft, and elastic clamping assembly contains the second mounting plate and the elastic compression member fixed thereon of support structure through rotating shaft. The mechanism provides stable datum by datum positioning assembly, and spring drive top rod telescopic of elastic compression member compensates ear plate thickness tolerance, solves the positioning gap caused by ear plate thickness tolerance of existing rigid positioning structure, welding displacement and clamping interference, prestress deformation problem, improves the reliability of ear plate positioning.

Description

Technical Field

[0001] This utility model relates to the field of mechanical processing equipment technology, and in particular to an adaptive ear plate positioning mechanism for welding connecting arm tooling. Background Technology

[0002] The connecting arm is a core load-bearing component of large machinery such as cranes, and its strength, rigidity, and the precision of key assembly parts directly determine the safety and stability of the entire machine. Currently, connecting arms are mostly manufactured using welding processes. Some connecting arms require two ear plates with bushing holes to be symmetrically welded onto the main rod, and subsequently rotated to connect with other components through the bushing holes. Therefore, the coaxiality of the bushing holes on the two ear plates must be strictly ensured during welding. To address this requirement, a utility model patent (authorization announcement number: CN 219426050 U) discloses a tooling for welding connecting arms. This tooling integrates a clamping mechanism, a coaxiality positioning mechanism, and an ear plate fixing mechanism onto the same worktable. The ear plate fixing mechanism includes a first mounting plate and a second mounting plate, both of which are equipped with positioning protrusions that can limit and fix the ear plates from the outer and inner sides, respectively, effectively ensuring the coaxiality of the bushing holes and improving welding efficiency, providing important technical support for the mass production of connecting arms.

[0003] In long-term mass production practice based on the aforementioned patented tooling, it was found that the rigid positioning structure of the original ear plate fixing mechanism has significant limitations: the positioning protrusions on the first and second mounting plates in the original mechanism are rigid structures of fixed size, and their spacing matches the design thickness of the ear plate. However, the ear plate to be welded inevitably has thickness tolerances during processing (e.g., an ear plate with a design thickness of 8mm may have an actual thickness that fluctuates between 7.5mm and 8.5mm). When the actual thickness of the ear plate is less than the nominal design value, a small gap will be generated between the ear plate and the positioning protrusion, causing the ear plate to easily shift due to vibration during welding, which will damage the coaxiality accuracy of the bushing hole. When the actual thickness of the ear plate is greater than the nominal design value, the ear plate cannot be smoothly installed between the positioning protrusions and must be forcibly pressed in by external force. This not only reduces the operating efficiency but also introduces prestress into the ear plate before welding. This prestress is released under the action of welding heat, which can easily cause welding deformation of the ear plate or the main rod of the connecting arm, further affecting the consistency of product quality. Therefore, how to solve the problem of adaptability of rigid positioning structure to ear plate thickness tolerance and improve positioning reliability and accuracy stability has become a key requirement for further optimization of existing tooling. Utility Model Content

[0004] The technical problem to be solved by this utility model is to address the poor adaptability of existing rigid positioning structures to ear plate thickness tolerance and the insufficient positioning reliability and accuracy stability, and to provide an adaptive ear plate positioning mechanism that can automatically compensate for ear plate thickness deviation.

[0005] The technical solution adopted by this utility model to solve its technical problem is: An adaptive ear plate positioning mechanism for a welding connecting arm tooling includes a reference positioning assembly and an elastic clamping assembly. Both the reference positioning assembly and the elastic clamping assembly are mounted on the support structure of the tooling. The reference positioning assembly includes a first mounting plate and a positioning protrusion. The first mounting plate is rotatably connected to the support structure via a rotating shaft, and the positioning protrusion is fixed to the side of the first mounting plate facing the ear plate. The elastic clamping assembly includes a second mounting plate and at least one elastic clamping member. The second mounting plate is rotatably connected to the support structure via a rotating shaft, and the elastic clamping member is fixed to the side of the second mounting plate facing the ear plate. The elastic clamping member includes a housing, a spring, and a push rod. The housing is a hollow structure with one open end. The spring is located inside the housing cavity. One end of the push rod extends into the housing cavity and abuts against the spring. The other end of the push rod extends out of the housing opening end, and the push rod can extend and retract along the housing axis.

[0006] Preferably, there are two positioning protrusions, which are symmetrically distributed along the length of the first mounting plate. The center line connecting the two positioning protrusions is parallel to the axis of the ear plate, and the positioning protrusions are integrally formed with the first mounting plate.

[0007] Preferably, the outer wall of the housing is provided with external threads, and the second mounting plate is provided with a threaded hole on the side facing the ear plate. The housing is screwed into the second mounting plate through the cooperation of the external threads and the threaded hole.

[0008] Preferably, the second mounting plate has a positioning pin hole, and the support structure has a positioning hole corresponding to the positioning pin hole, with a positioning pin fitted inside the positioning pin hole; when the second mounting plate is flipped to a preset position, the positioning pin is inserted into the positioning pin hole and the positioning hole to lock the position of the second mounting plate.

[0009] Preferably, a wear-resistant pad is provided on the end face of the top rod extending out of the housing, and the wear-resistant pad is in contact with the inner surface of the ear plate.

[0010] Preferably, the tooling support structure is a third support column, and the rotation axis of the first mounting plate and the rotation axis of the second mounting plate are both assembled on the same third support column.

[0011] Preferably, the first mounting plate and the second mounting plate are installed at the same height on the third support, and the positioning protrusion of the first mounting plate and the elastic clamping member of the second mounting plate are arranged opposite each other in the horizontal direction.

[0012] Preferably, the third support is vertically fixed to the workbench of the tooling, and the workbench and the third support are fixedly connected.

[0013] The beneficial effects of this utility model include the following: 1. The first mounting plate of the reference positioning component is rotatably connected to the tooling support structure via a rotating shaft. The end face of the positioning protrusion facing the ear plate is set as a plane to provide a stable positioning reference. The second mounting plate of the elastic clamping component is rotatably connected to the support structure via a rotating shaft. The elastic clamping component drives the top rod to extend and retract along the axis of the housing through the spring in the inner cavity of the housing, so as to realize the elastic clamping of ear plates of different thicknesses. When the ear plate thickness is small, the spring pushes the top rod to extend and fill the positioning gap. When the thickness is large, the top rod is compressed and the spring is compressed to avoid forced clamping. This effectively solves the problems of positioning gap, welding displacement, clamping interference and prestress deformation caused by the ear plate thickness tolerance of the existing rigid positioning structure, and improves the reliability of ear plate positioning.

[0014] 2. By opening positioning pin holes in the second mounting plate and correspondingly opening positioning holes in the tooling support structure and fitting positioning pins, when the second mounting plate is flipped to the preset position, the positioning pins are inserted to lock its position, preventing the second mounting plate from rotating due to vibration during the welding process and causing the clamping force to fail; at the same time, the wear-resistant pad at the protruding end of the push rod fits against the inner surface of the ear plate to prevent the push rod from directly contacting and scratching the surface of the ear plate, effectively solving the problem that the existing rigid positioning structure is prone to loosening during the welding process and the ear plate surface is prone to damage, thus taking into account both positioning stability and ear plate processing quality. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the tooling structure used for welding connecting arms in the prior art. Figure 2 This is a schematic diagram of the adaptive ear plate positioning mechanism used for welding connecting arm tooling in Example 1; Figure 3 for Figure 1 Enlarged view of point a in the middle.

[0016] Reference numerals: 1. Third support column; 2. Coaxiality positioning mechanism; 3. Ear plate; 4. Reference positioning assembly; 41. First mounting plate; 42. Positioning protrusion; 5. Slot; 6. Elastic clamping assembly; 61. Second mounting plate; 7. Positioning hole; 8. Positioning pin; 9. Housing; 10. Spring; 11. Top rod. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, but these specific embodiments do not limit the scope of protection of the present invention in any way. Example

[0018] See Figure 2-3An adaptive ear plate positioning mechanism for welding connecting arm tooling is disclosed, which improves upon the ear plate fixing mechanism of the welding connecting arm tooling disclosed in the prior art utility model patent (CN 219426050 U). This adaptive ear plate positioning mechanism is mainly used for the positioning and clamping of two ear plates 3 with bushing holes during the welding process of connecting arms of large mechanical equipment such as cranes. By introducing an elastic compensation mechanism, it solves the problem of insufficient positioning reliability of the original rigid positioning structure when facing the thickness tolerance of the ear plates 3. It can automatically adapt to ear plates 3 of different thicknesses, achieving reliable positioning without gaps.

[0019] The adaptive ear plate positioning mechanism is integrated into the workbench of the original welding fixture and consists of two main parts: the reference positioning component 4 and the elastic clamping component 6. The reference positioning component 4 serves as the fixed positioning side, providing a uniform and stable positioning reference surface; the elastic clamping component 6 serves as the adaptive adjustment side, automatically compensating for the thickness tolerance of the ear plate 3 through the expansion and contraction characteristics of the elastic element.

[0020] The reference positioning assembly 4 includes a first mounting plate 41 and positioning protrusions 42. The first mounting plate 41 has a rectangular plate structure, and one side of it is rotatably connected to the third support column 1 of the original tooling via a rotating shaft, allowing it to be flipped around the rotating shaft for easy placement and removal of the ear plate 3. The first mounting plate 41 has multiple slots 5, the width of which is greater than the diameter of the coaxiality positioning mechanism 2 and the diameter of the connecting rod, to facilitate the smooth flipping of the first mounting plate 41. The positioning protrusions 42 are block structures, with two in total, symmetrically distributed along the length of the first mounting plate 41. The side of the positioning protrusions 42 facing the ear plate 3 is a plane, which serves as the positioning reference surface. It is integrally machined with the first mounting plate 41 to fit tightly against the outer surface of the ear plate 3, providing a fixed positioning reference. The center line connecting the two positioning protrusions 42 is parallel to the axis of the ear plate 3 to ensure a reasonable distribution of positioning force.

[0021] The elastic clamping assembly 6 includes a second mounting plate 61 and an elastic clamping element. The second mounting plate 61 also has a rectangular plate structure, and one side is rotatably connected to the third support column 1 of the original tooling via a rotating shaft. The rotation direction is the same as that of the first mounting plate 41. Both can be flipped to facilitate the clamping and removal of the ear plate 3. Similarly, the second mounting plate 61 is also provided with multiple slots 5, the width of which is greater than the diameter of the coaxiality positioning mechanism 2 and the diameter of the connecting rod, to facilitate the smooth flipping of the second mounting plate 61. The second mounting plate 61 has positioning pin holes, which correspond to the preset positioning holes 7 on the third support column 1. When the second mounting plate 61 is flipped to the preset clamping position, its angle can be locked by inserting positioning pins 8 to prevent rotation due to vibration during welding.

[0022] The elastic clamping component is a spring plunger, whose structure includes a housing 9, a spring 10, and a push rod 11. The housing 9 is a hollow cylindrical structure with one open end and external threads on its outer side wall. A threaded hole adapted to the external thread is correspondingly opened on the second mounting plate 61. The housing 9 is screwed into the threaded hole to achieve a detachable connection with the second mounting plate 61, which facilitates subsequent maintenance or replacement of the elastic clamping component. The spring 10 is built into the hollow cavity of the housing 9. One end of the push rod 11 extends into the inner cavity of the housing 9 and abuts against one end of the spring 10, while the other end extends out of the open end of the housing 9, forming a clamping end that can elastically expand and contract along the axial direction of the housing 9. A wear-resistant gasket is attached to the end face of the protruding end of the push rod 11 to prevent surface scratches caused by direct contact between the push rod 11 and the ear plate 3, and to enhance the fit between the push rod 11 and the inner side of the ear plate 3.

[0023] Two elastic clamping components are provided, symmetrically distributed along the length of the second mounting plate 61, and the axes of the two elastic clamping components are collinear with the axes of the two positioning protrusions 42 on the first mounting plate 41. This one-to-one distribution ensures that the clamping force applied by the elastic clamping components is directly aligned with the positioning reference surface, thereby preventing positioning deviations caused by force offset of the ear plate 3.

[0024] The first mounting plate 41 and the second mounting plate 61 are rotatably connected to the same third support column 1 via rotating shafts. The two are mounted at the same height on the third support column 1 to ensure that the clamping direction of the ear plate 3 is horizontal and to prevent the ear plate 3 from tilting due to uneven force. The third support column 1 is vertically fixed on the worktable of the tooling. The worktable provides a stable bottom support for the entire mechanism to prevent the overall structure from shaking during clamping or welding.

[0025] When the ear plate 3 is in the positioning state, the positioning protrusion 42 of the first mounting plate 41 fits against the outer side of the ear plate 3, and the elastic clamping member of the second mounting plate 61 fits against the inner side of the ear plate 3, forming a double-sided clamping of the ear plate 3. The positioning pin 8 is inserted into the positioning pin hole of the second mounting plate 61 and the positioning hole 7 of the third support 1 to lock the position of the second mounting plate 61. At this time, the spring 10 of the elastic clamping member is in a moderately compressed state, continuously applying a clamping force towards the positioning protrusion 42 to the ear plate 3 to ensure that the ear plate 3 fits against the reference surface without gaps.

[0026] The working principle and method of the above-mentioned adaptive ear plate positioning mechanism for welding connecting arm tooling are as follows: The first step involves the operator placing the two ear plates 3 to be welded in their preset positions on the tooling workbench, with the outer surfaces of the ear plates 3 facing the positioning protrusions 42 of the first mounting plate 41. The first mounting plate 41 is then flipped over, ensuring the mating surfaces of the two positioning protrusions 42 are in close contact with the outer surfaces of the ear plates 3. The ear plates 3 are then gently pushed to confirm they are completely flush against the positioning protrusions 42 without significant movement or gaps, thus establishing the reference position of the ear plates 3.

[0027] In the second step, the operator slowly flips the second mounting plate 61 from its open position toward the ear plate 3, observing whether the push rod 11 of the elastic clamping member accurately contacts the inner surface of the ear plate 3. As the second mounting plate 61 continues to flip, the push rod 11 is gradually compressed by the ear plate 3, gradually compressing the spring 10 inside the housing 9, until the second mounting plate 61 flips to the preset clamping angle. At this point, the positioning pin hole on the second mounting plate 61 aligns with the positioning hole 7 of the third support column 1. During this process, the elastic force of the spring 10 gradually increases, pushing the ear plate 3 tightly toward the positioning protrusion 42, automatically filling the gap that may be caused by the thickness tolerance of the ear plate 3, and preventing forced compression due to the ear plate 3 being too thick, thus achieving adaptive clamping.

[0028] Third, after the positioning pin hole of the second mounting plate 61 is aligned with the positioning hole 7 of the third support column 1, insert the positioning pin 8 into the hole to completely lock the position of the second mounting plate 61. This is to prevent the second mounting plate 61 from rotating during the welding process, which would cause the clamping force to fail. After locking, gently shake the ear plate 3 to check whether the ear plate 3 is loose or displaced. At the same time, observe whether the top rod 11 of the elastic clamping member is still in contact with the inside of the ear plate 3 to ensure that the clamping force continues to act.

[0029] Fourth, after positioning, start the welding equipment to weld the ear plate 3 to the main rod of the connecting arm. During the welding process, since the ear plate 3 is clamped without gaps and the position of the second mounting plate 61 is locked, displacement of the ear plate 3 due to welding vibration can be effectively prevented, thus ensuring the coaxiality of the bushing holes of the two ear plates 3. After welding, first pull out the positioning pin 8, and flip the second mounting plate 61 away from the ear plate 3 to the open state. Then, depending on the position of the ear plate 3 after welding, if the first mounting plate 41 affects the removal of the ear plate 3, the first mounting plate 41 can also be flipped open. Finally, remove the welded connecting arm from the worktable to complete one positioning-welding process.

[0030] Throughout the positioning process, the fixed reference surface provided by the reference positioning component 4, combined with the elastic compensation characteristics of the elastic clamping component 6, enables adaptive positioning of ear plates 3 with different thicknesses. When the actual thickness of the ear plate 3 is less than the design value, the spring 10 pushes the push rod 11 to extend, filling the gap and maintaining the clamping force; when the actual thickness of the ear plate 3 is greater than the design value, the push rod 11 is compressed by the spring 10, avoiding the introduction of prestress through forced clamping. This ensures both the reliability and accuracy of positioning and simplifies the operation process, significantly improving welding efficiency and product quality consistency.

[0031] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any innovative improvements or substitutions based on this utility model should fall within the scope of the claims of this utility model. Furthermore, the parameters, materials, and processes mentioned in the above embodiments are not unique. Without departing from the technical essence of this utility model, those skilled in the art can make various alternative choices, and these alternative solutions should also be considered to fall within the scope of protection of this utility model.

Claims

1. An adaptive ear plate positioning mechanism for a welding connecting arm tooling, characterized in that, The fixture includes a reference positioning assembly and an elastic clamping assembly. Both the reference positioning assembly and the elastic clamping assembly are mounted on the support structure of the tooling. The reference positioning assembly includes a first mounting plate and a positioning protrusion. The first mounting plate is rotatably connected to the support structure via a rotating shaft, and the positioning protrusion is fixed to the side of the first mounting plate facing the ear plate. The elastic clamping assembly includes a second mounting plate and at least one elastic clamping member. The second mounting plate is rotatably connected to the support structure via a rotating shaft, and the elastic clamping member is fixed to the side of the second mounting plate facing the ear plate. The elastic clamping member includes a housing, a spring, and a push rod. The housing is a hollow structure with one open end. The spring is located inside the housing cavity. One end of the push rod extends into the housing cavity and abuts against the spring. The other end of the push rod extends out of the housing opening end. The push rod can extend and retract along the housing axis.

2. The adaptive ear plate positioning mechanism for welding connecting arm tooling according to claim 1, characterized in that, The positioning protrusion is provided in two parts, which are symmetrically distributed along the length of the first mounting plate. The center line connecting the two positioning protrusions is parallel to the axis of the ear plate, and the positioning protrusion is integrally formed with the first mounting plate.

3. The adaptive ear plate positioning mechanism for welding connecting arm tooling according to claim 1, characterized in that, The outer wall of the housing is provided with external threads, and the second mounting plate has a threaded hole on the side facing the ear plate. The housing is screwed into the second mounting plate through the cooperation of the external threads and the threaded hole.

4. The adaptive ear plate positioning mechanism for welding connecting arm tooling according to claim 1, characterized in that, The second mounting plate has a positioning pin hole, and the support structure has a positioning hole corresponding to the positioning pin hole. A positioning pin is fitted into the positioning pin hole. When the second mounting plate is flipped to a preset position, the positioning pin is inserted into the positioning pin hole and the positioning hole to lock the position of the second mounting plate.

5. The adaptive ear plate positioning mechanism for welding connecting arm tooling according to claim 1, characterized in that, A gasket is provided on one end face of the top rod extending out of the housing, and the gasket is in contact with the inner surface of the ear plate.

6. The adaptive ear plate positioning mechanism for welding connecting arm tooling according to claim 1, characterized in that, The tooling is supported by a third support column, and the rotation axis of the first mounting plate and the rotation axis of the second mounting plate are both mounted on the same third support column.

7. The adaptive ear plate positioning mechanism for welding connecting arm tooling according to claim 6, characterized in that, The first mounting plate and the second mounting plate are installed at the same height on the third support column, and the positioning protrusion of the first mounting plate and the elastic clamping member of the second mounting plate are arranged opposite each other in the horizontal direction.

8. The adaptive ear plate positioning mechanism for welding connecting arm tooling according to claim 6, characterized in that, The third support column is vertically fixed to the workbench of the tooling, and the workbench is fixedly connected to the third support column.

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