Multi-point clamping welding jig for thin-wall part and multi-point clamping method

Abstract

The multi-point clamping welding jig for the thin-wall workpiece specifically comprises a side face multi-point clamping set and a plurality of top face pressing pieces, and the top face pressing pieces are used for being pressed on a plate body through long grooves; the top surface pressing piece comprises a first pressing part and a second pressing part, and the contact area of the first pressing part is larger than that of the second pressing part; and the rotating angle of the top surface pressing piece is adjustable, so that the first pressing part is closer to a next to-be-machined second machining position than the second pressing part. The top surface pressing piece is pressed on the plate body through the long groove, which means that the top pressing force is arranged near the core structure causing the thin-wall effect, so that groove edge sinking and elastic springback can be reduced in a targeted manner, and the defects of hole axis inclination, hole diameter enlargement and the like caused by the sinking and the elastic springback can be inhibited; and meanwhile, the position of the first pressing part is changed along with the machining sequence of the hole sites, so that indentation caused by bearing the maximum load for a long time at a certain position is avoided. Therefore, the local welding quality and the overall appearance quality of the thin-wall part can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of welding fixture structure technology for thin-walled parts, and in particular to a multi-point clamping welding fixture and multi-point clamping method for thin-walled parts. Background Technology

[0002] Thin-walled parts typically refer to plate or shell-type parts with relatively small wall thickness and weak overall rigidity. These parts are widely used in aerospace, precision machinery, and electronic equipment. Due to the limited structural strength of thin-walled parts, they are prone to deformation under cutting forces during machining processes such as milling, grooving, and drilling, which can affect the subsequent welding quality. Therefore, fixtures are usually required to reliably fix thin-walled parts during machining to ensure machining accuracy and structural stability.

[0003] In existing technologies, the thin wall of a type of thin-walled part originates from the wall thickness between the long groove and the hole, meaning the thin wall is created by the small distance between the long groove and the hole. For such thin-walled parts, the long groove and the hole are usually machined into shape by milling, drilling, or other methods after the thin-walled part is clamped. For existing fixtures, regardless of whether the hole or the long groove is machined first, the cutting force of the subsequent machining inevitably affects the hole or long groove formed earlier, thus affecting subsequent welding. For example, when machining a group of holes around a long groove, the axial and radial forces generated by drilling tend to concentrate on the thin wall adjacent to the long groove, causing the groove edge to sink or elastically rebound after unloading. This can lead to machining defects such as hole axis tilting and hole diameter enlargement, affecting the structural integrity of the thin-walled part and increasing the risk of breakage, resulting in a lack of effective positioning for subsequently welded parts. To overcome the above-mentioned technical problems, those skilled in the art mainly achieve this by increasing the clamping force of the fixture or increasing the number of clamping points. However, the above methods are prone to causing indentations or plastic deformation in other areas of the thin-walled part, affecting the overall appearance quality of the thin-walled part.

[0004] Therefore, when existing fixtures are applied to thin-walled parts that require multiple processing steps, they can easily lead to technical problems such as localized damage to the thin-walled parts and insufficient overall appearance quality, thus affecting the finished product quality of the thin-walled parts. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-point clamping welding fixture and multi-point clamping method for thin-walled parts, which solves the technical problems in the prior art where thin-walled parts that require multiple processing are prone to local damage and insufficient overall appearance quality before welding.

[0006] To achieve this objective, the present invention adopts the following technical solution: A multi-point clamping welding fixture for thin-walled parts is provided for clamping thin-walled parts, the thin-walled parts including a plate, the plate having a first machining position and a plurality of second machining positions arranged around the first machining position on the machining surface; the first machining position is used to machine a long groove, and the second machining positions are used to machine a first hole. The multi-point clamping welding fixture includes: Side multi-point clamping assembly, used to clamp the side of the plate at multiple points; The top surface multi-point clamping assembly includes multiple top surface clamping members, which are used to clamp onto the plate body through the long groove after the plate body is formed; The top surface clamping member includes a first clamping part and a second clamping part that respectively abut against the processing surface. The contact area of ​​the first clamping part is larger than that of the second clamping part. The rotation angle of the top surface clamping member is adjustable, so that the first clamping part is closer to the next processing position to be processed than the second clamping part.

[0007] Optionally, the top surface clamping member includes an integrally formed annular portion, the outer ring diameter of which is larger than the groove width of the long groove, and is stacked on top of the long groove; the inner ring of the annular portion is provided with a first clamping bolt, one end of which passes through the inner ring of the annular portion and is threaded to the frame, and the other end of which is pressed onto the annular portion; The annular portion includes an integrally formed first semi-annular portion and a second semi-annular portion; a load groove is provided on the second semi-annular portion, and the second semi-annular portion reduces the contact area through the load groove to form the second pressing portion; the first semi-annular portion forms the first pressing portion.

[0008] Optionally, the load groove is opened vertically and penetrates the second semi-ring portion; along the vertical direction, the outline of the load groove is arc-shaped, and the center of the outline of the load groove is located outside the ring portion, and the outline diameter of the load groove is larger than the outer ring diameter of the ring portion.

[0009] Optionally, the load groove is opened vertically and extends through the second semi-ring portion; along the vertical direction, the width of the load groove is smaller than the width of the long groove; along the vertical direction, when the width of the load groove coincides with the width of the long groove, the ring portion is symmetrically arranged with respect to the centerline of the long groove.

[0010] Optionally, the top surface clamping member includes a first semi-ring portion and a second semi-ring portion that are separately disposed, and the first semi-ring portion and the second semi-ring portion are detachably connected; a first clamping bolt is provided through the inner ring surrounding the first semi-ring portion and the second semi-ring portion, one end of the first clamping bolt passing through the inner ring is threadedly connected to the frame, and the other end of the first clamping bolt is pressed onto the first semi-ring portion and the second semi-ring portion; Wherein, the first semi-ring portion is the first pressing portion, the second semi-ring portion is the second pressing portion, the inner diameter of the first semi-ring portion and the second semi-ring portion are the same, and the outer diameter of the first semi-ring portion is greater than the outer diameter of the second semi-ring portion.

[0011] Optionally, the side multi-point clamping assembly includes a plurality of side clamping members arranged around the plate body. The side clamping members include a side clamping positioning part fixed on the frame, a third clamping part slidably connected to the side clamping positioning part, and a locking part. The locking part is used to lock the side clamping positioning part and the third clamping part. The plurality of side-pressing positioning parts are arranged to form a positioning space, the positioning space is for the plate to be placed, and the third pressing part can slide along the direction of approaching or moving away from the positioning space.

[0012] Optionally, the third pressing part is provided with a sliding groove, the length of the sliding groove is arranged along the direction close to the positioning space; the locking part is a second pressing bolt, one end of the second pressing bolt passes through the sliding groove and is threaded to the frame, and the other end of the second pressing bolt is pressed on the top of the sliding groove.

[0013] Optionally, the side-pressure positioning part includes a first positioning block and a second positioning block arranged sequentially in a direction away from the positioning space. The first positioning block and the second positioning block are spaced apart to form a gap. The end of the first positioning block near the positioning space is used to abut against the plate. One end of the second clamping bolt passes through the slide groove and the gap in sequence and is threadedly connected to the frame.

[0014] Optionally, the third pressing part includes a first continuous part and a second continuous part that are sequentially arranged and integrally formed along a direction away from the positioning space; the groove is formed on the second continuous part; The first continuous portion includes a first surface connected to the second continuous portion and a second surface disposed away from the second continuous portion. The profile cross-section of the second surface is proportionally reduced relative to the profile cross-section of the first surface. The first continuous portion also includes a first continuous inclined surface connecting the first surface and the second surface. The joint edge of the first continuous inclined surface and the first surface is located on the surface of the second continuous portion where a groove is formed.

[0015] A multi-point clamping method for thin-walled parts, employing the multi-point clamping and welding fixture for thin-walled parts as described above, includes: The side of the plate is clamped by a multi-point clamping group, and a long groove is formed on the first station of the plate. The machined surface of the plate is pressed by a multi-point clamping assembly on the top surface; The first hole is machined sequentially at the second station of the plate; Before machining the Nth first hole, adjust the rotation angle of the top surface clamping part so that the first clamping part, which has a larger contact area with the plate, is closer to the second station corresponding to the Nth first hole than the second clamping part.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The multi-point clamping welding fixture and multi-point clamping method for thin-walled parts provided by this invention firstly clamps the side of the plate body through a side multi-point clamping group, providing a consistent positioning state for subsequent grooving and drilling; then, after the long groove is formed, a top multi-point clamping group is set, and the top clamping member is pressed onto the plate body through the long groove, so that the thin-walled band adjacent to the long groove receives continuous reverse support, avoiding the cutting force of subsequent processing from bending and crushing the groove edge as a "suspended thin beam". Therefore, it can specifically reduce the groove edge sinking and elastic rebound and suppress defects such as hole axis tilting and hole diameter enlargement caused by this, thereby providing a stable first hole and laying the foundation for subsequent welding. Meanwhile, the top clamping component is equipped with a first clamping part and a second clamping part that abut against the machined surface, with the contact area of ​​the first clamping part being larger than that of the second clamping part. When the position of the hole to be machined changes, rotating the clamping component allows the first clamping part with a larger contact area to be preferentially positioned above the long groove area adjacent to the hole position, reducing deformation and hole machining defects caused by local rigidity differences. At the same time, since the position of the first clamping part rotates with the hole machining sequence, the clamping load will not be concentrated on the same groove edge or the same contact point for a long time. This not only provides a larger support area to resist the instantaneous load of drilling when needed, but also avoids indentation or plastic deformation caused by a certain point bearing the maximum load for a long time through position shifting. Thus, it solves the problem of local vulnerability of thin-walled parts while taking into account the overall appearance quality. In summary, this solution can effectively improve the local welding quality and overall appearance quality of thin-walled parts that have undergone multiple processing steps. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0019] Figure 1 A schematic diagram of the overall structure of the multi-point clamping welding fixture for thin-walled parts provided in an embodiment of the present invention; Figure 2 A partial structural schematic diagram of the multi-point clamping welding fixture for thin-walled parts provided in an embodiment of the present invention; Figure 3 for Figure 2 A magnified schematic diagram of the structure at point A; Figure 4 A top view of the multi-point clamping welding fixture for thin-walled parts provided in an embodiment of the present invention; Figure 5 for Figure 4 A schematic diagram of the cross-sectional structure along point BB; Figure 6 This is a top view of the top surface clamping member in an embodiment of the present invention; Figure 7 This is a side view of the third pressing part in an embodiment of the present invention; Figure 8 This is a front view of the third pressing part in an embodiment of the present invention. Illustration: 100, plate; 110, machined surface; 111, long groove; 112, first hole; 200. Side multi-point clamping assembly; 201. Positioning space; 210. Side clamping component; 211. Side clamping positioning part; 2111. First positioning block; 2112. Second positioning block; 212. Third clamping part; 2121. Slide groove; 2122. First continuous part; 21221. First surface; 21222. Second surface; 21223. First continuous inclined surface; 21224. Second continuous inclined surface; 2123. Second continuous part; 213. Locking part; 300. Top surface multi-point clamping assembly; 310. Top surface clamping component; 311. First clamping part; 312. Second clamping part; 313. Load groove; 320. First clamping bolt; 400. Rack. Detailed Implementation

[0020] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0021] In the description of this invention, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component positioned centrally in the connection.

[0022] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] Example 1: This invention provides a multi-point clamping welding fixture, specifically a multi-point clamping welding fixture for thin-walled parts. The multi-point clamping welding fixture provided in this embodiment is suitable for scenarios where other parts are welded into the holes after the thin-walled parts have been machined with holes and grooves. Thin-walled parts refer to metal parts with a high aspect ratio. For thin-walled parts, the formation of a thin-walled structure with a high aspect ratio can take the following forms: setting multiple spaced grooves, setting an array of hole structures, machining a group of holes around the long groove 111, etc. All of these will form a thin-walled structure (aspect ratio greater than 5) on the metal part. That is, when multiple milling and turning of holes and grooves are performed on the metal part, especially when the grooves are close to each other, the holes are close to each other, and the holes are close to the grooves, it is easy to form a thin-walled structure on the metal part. In this embodiment, the metal part is a thin-walled part.

[0024] like Figure 1 As shown, in this embodiment, taking a thin-walled part with a long groove 111 and a first hole 112 machined on a plate 100 as an example, the first hole 112 and the long groove 111 of the thin-walled part are used for positioning subsequent parts so that subsequent parts can be welded onto the thin-walled part. The thin-walled structure of the thin-walled part mainly refers to the narrow part between the long groove 111 and the first hole 112. The multi-point clamping welding fixture in this embodiment is described. In this embodiment, by improving the specific structure of the multi-point clamping welding fixture, the thin-walled part is less likely to be damaged locally when it is subjected to multiple milling and turning operations, that is, when machining holes and grooves, so as to ensure the subsequent welding quality and the overall appearance quality.

[0025] like Figures 1 to 3 As shown, the multi-point clamping welding fixture for thin-walled parts in this embodiment is used to clamp the thin-walled parts. The thin-walled parts include a plate 100. The processing surface 110 of the plate 100 is provided with a first processing position and a plurality of second processing positions arranged around the first processing position. The first processing position is used to process the long groove 111, and the second processing position is used to process the first hole 112.

[0026] The multi-point clamping welding fixture includes a side multi-point clamping group 200 and a top multi-point clamping group 300. The side multi-point clamping group 200 is used to clamp the sides of the plate 100 at multiple points, and the top multi-point clamping group 300 is used to clamp the top surface of the plate 100 at multiple points. In this embodiment, the top surface is the machining surface 110. First, after the long groove 111 is machined using the side multi-point clamping group 200, the top multi-point clamping group 300 is used for secondary clamping, forming multi-directional constraints on the frame 400, thereby significantly improving the overall clamping rigidity.

[0027] The top surface multi-point clamping assembly 300 includes multiple top surface clamping members 310. The top surface clamping members 310 are used to clamp onto the plate 100 through the long groove 111 after the plate 100 is formed. The top surface clamping members 310 include a first clamping part 311 and a second clamping part 312 that respectively abut against the processing surface 110. The contact area of ​​the first clamping part 311 is larger than the contact area of ​​the second clamping part 312. The rotation angle of the top surface clamping members 310 is adjustable, so that the first clamping part 311 is closer to the next processing position to be processed than the second clamping part 312. To facilitate understanding by those skilled in the art, the first clamping part 311 abuts against the machined surface 110 and is closer to the second machined position (first hole 112), which is equivalent to thickening the edge of the long groove 111. This makes the edge of the long groove 111 equivalent to a thicker structure under stress, effectively preventing the long groove 111 from collapsing, warping, or elastically rebounding during hole machining, thereby ensuring the dimensional stability of the groove shape and adjacent hole positions. Furthermore, the angle of the top surface clamping member 310 can be changed to alter its specific contact and support position with the long groove 111, allowing the clamping force to be distributed in different areas of the long groove 111. This enables flexible control of the stress state in the area where the long groove 111 is located, avoiding long-term pressure at a fixed position that could lead to localized plastic deformation or stress concentration. This prevents indentations or plastic deformation from appearing on the surface, ensuring the quality of the appearance.

[0028] As can be seen, the multi-point clamping welding fixture for thin-walled parts provided in this embodiment first uses the side multi-point clamping group 200 to clamp the side of the plate 100 at multiple points, so that the plate 100 obtains stable lateral positioning and anti-slip constraint during the machining datum establishment stage, thereby providing a consistent positioning state for subsequent grooving and drilling; then, after the long groove 111 is formed, the top multi-point clamping group 300 is activated, and the top clamping member 310 is pressed onto the plate 100 through the long groove 111. This means that the top clamping force is arranged near the core structure that causes the thin-wall effect, that is, above the long groove 111, so that the thin-walled band adjacent to the long groove 111 obtains continuous reverse support, avoiding the cutting force of subsequent machining from treating the groove edge as a "suspended thin beam" to bend and crush it. Therefore, it can specifically reduce the groove edge sinking and elastic rebound and suppress defects such as hole axis tilting and hole diameter enlargement caused by this. Meanwhile, the top clamping member 310 is provided with a first clamping part 311 and a second clamping part 312 that abut against the machining surface 110, and the contact area of ​​the first clamping part 311 is larger than that of the second clamping part 312. When the next hole position to be machined changes, by rotating the clamping member, the first clamping part 311 with a larger contact area can be preferentially arranged above the long groove 111 area adjacent to the hole position. This is equivalent to dynamically moving the stronger load-bearing capacity to the thin-walled band position that is most susceptible to drilling loads, so that each hole position is in a state of "key support" during machining. Under effective rigidity conditions, this solution reduces deformation and hole machining defects caused by localized rigidity differences at the source, ensuring subsequent welding quality. Simultaneously, because the position of the first clamping part 311 rotates according to the hole machining sequence, the clamping load will not be concentrated on the same groove edge or the same contact point for a long time. This provides a larger support area to resist instantaneous drilling loads when needed, and avoids indentation or plastic deformation caused by a single point bearing the maximum load for an extended period through positional shifting. Thus, it solves the problem of localized vulnerability in thin-walled parts while maintaining overall appearance quality. In summary, this solution effectively improves the localized welding quality and overall appearance quality of thin-walled parts that have undergone multiple machining processes.

[0029] As an optional implementation method, such as Figure 1 , Figures 4 to 6 As shown, the top surface clamping member 310 includes an integrally formed annular portion. The outer ring diameter of the annular portion is larger than the groove width wa of the long groove 111, and it is stacked above the long groove 111. A first clamping bolt 320 passes through the inner ring of the annular portion. One end of the first clamping bolt 320, passing through the inner ring of the annular portion, is threaded to the frame 400, and the other end of the first clamping bolt 320 is pressed onto the annular portion. The annular portion includes an integrally formed first half-ring portion and a second half-ring portion. A load groove 313 is formed on the second half-ring portion, which reduces the contact area to form a second clamping part 312. The first half-ring portion forms a first clamping part 311. It is understood that the forming method of the annular portion includes, but is not limited to, casting, CNC machining, etc., capable of forming a shape such as... Figure 6The circular portion shown can be used as a base, that is, the second half-ring portion can be formed into the second pressing portion 312 by passing through the load groove 313.

[0030] Specifically, such as Figure 5 and Figure 6 As shown, the vertical direction is perpendicular to the machining surface 110 and is also the downward pressing direction when the tool is machining the hole groove. The load groove 313 is opened in the vertical direction and penetrates the second half ring. In the vertical direction, the outline of the load groove 313 is arc-shaped, and the center of the outline of the load groove 313 is located outside the ring. The outline diameter of the load groove 313 is larger than the outer ring diameter of the ring.

[0031] In this embodiment, since the vertical direction is the main downward pressing direction of the tool during drilling, when the load groove 313 completely penetrates the second half-ring along this vertical direction, it is equivalent to forming a "force relief channel" on the second half-ring that is consistent with the direction of cutting load propagation. This reduces the cross-section of the local structure of the second half-ring when it is subjected to the vertical clamping force from the first clamping bolt 320, thereby exhibiting higher equivalent flexibility, that is, it is easier to undergo slight deformation, which increases the contact pressure per unit area and is significantly lower than the stiffness of the first half-ring. Meanwhile, the vertical profile of the load groove 313 is designed to be arc-shaped, with the center of the arc located outside the annular portion. The diameter of the arc is larger than the outer diameter of the annular portion. This profile means that the load groove 313 forms a large curvature groove that "opens outward," directly changing the stress flow direction of the second half-ring portion under load. Since the curvature center of the arc-shaped groove is located outside the clamping member, the material on both sides of the groove will shift outward along the bending radius when the vertical clamping force is introduced, resulting in the groove edge area exhibiting an "opening tendency" that opens outward. This is equivalent to: the lateral rigidity being weakened while the vertical compliance is further enhanced. As a result, when the second half-ring portion bears the vertical clamping load, it no longer forms a parallel "hard pressing surface" facing the machined surface 110, but rather a compliant contact surface achieved through flexible deformation, allowing the load to be transferred to the thin-walled structure more smoothly and avoiding the formation of unnecessary high-pressure marks or plastic indentations in non-critical areas.

[0032] Obviously, the load groove 313 can also adopt other contours, so that the contact area of ​​the second clamping part 312 on the machined surface 110 is smaller than the contact area of ​​the first clamping part 311 on the machined surface 110.

[0033] Furthermore, the load groove 313 is vertically oriented and extends through the second semi-ring portion; vertically, the width wb of the load groove 313 is less than the width wa of the long groove 111; vertically, when the width of the load groove 313 coincides with the width of the long groove 111, the annular portion is symmetrically arranged around the centerline of the long groove 111. It is understandable that since the width wb of the load groove 313 is less than the width wa of the long groove 111, the top surface clamping member 310 has an angle that causes the load groove 313 to coincide with the long groove 111. At this time, both sides of the annular portion contact the machining surface 110 with the same area, which is suitable for top surface clamping members 310 that are far from the next machining position (first hole 112) to be machined. When a certain second processing position is about to process the first hole 112, the nearest top surface clamping member 310 is rotated so that the nearest top surface clamping member 310 is positioned closer to the next second processing position than the second clamping member 312; the farthest top surface clamping member 310 is positioned so that the width of the load groove 313 coincides with the width of the long groove 111.

[0034] As another optional implementation, the top surface clamping member 310 includes a first semi-ring portion and a second semi-ring portion that are separately configured and detachably connected. The detachable connection method includes, but is not limited to, magnetic connection, bolt connection, etc., and this embodiment is not limited to these. A first clamping bolt 320 passes through the inner ring formed by the first and second semi-ring portions. One end of the first clamping bolt 320, passing through the inner ring, is threaded to the frame 400, and the other end of the first clamping bolt 320 is pressed onto the first and second semi-ring portions. The first semi-ring portion is the first clamping part 311, and the second semi-ring portion is the second clamping part 312. The inner diameters of the first and second semi-ring portions are the same, and the outer diameter of the first semi-ring portion is larger than that of the second semi-ring portion, providing the advantage of flexible size adjustment. Furthermore, each time the angle of the top surface clamping member 310 is adjusted, the first clamping bolt 320 needs to be loosened, allowing the stress on the thin-walled part to be released, further improving the forming quality of the thin-walled part.

[0035] Furthermore, such as Figures 1 to 3 As shown, the side multi-point clamping assembly 200 includes a plurality of side clamping members 210 arranged around the plate body 100. The side clamping member 210 includes a side clamping positioning part 211 fixed on the frame 400, a third clamping part 212 slidably connected to the side clamping positioning part 211, and a locking part 213. The locking part 213 is used to lock the side clamping positioning part 211 and the third clamping part 212. The plurality of side clamping positioning parts 211 surround to form a positioning space 201, the positioning space 201 for the plate body 100 to be placed, and the third clamping part 212 can slide in the direction of approaching or moving away from the positioning space 201.

[0036] Understandably, since the third clamping part 212 of the side clamping member 210 is slidably connected to the side clamping positioning part 211, the third clamping part 212 can move in the direction of approaching or moving away from the positioning space 201. This means that each side clamping point can be finely adjusted according to the actual size or local deformation of the plate 100, so that the clamping force no longer relies on the fixed pressure block to be applied hard, but automatically finds the contact position with the plate 100 through the sliding of the third clamping part 212, and then the locking part 213 locks its optimal force point. Therefore, this structure can enable multiple clamping points to achieve "independent contact + collective locking", so that the entire lateral load is automatically and evenly distributed among multiple clamping members, thereby significantly reducing the risk of indentation, local plastic deformation or side warping caused by single-point clamping to the thin-walled side.

[0037] Specifically, such as Figure 3 As shown, the third pressing part 212 is provided with a sliding groove 2121, and the length of the sliding groove 2121 is set along the direction close to the positioning space 201; the locking part 213 is a second pressing bolt, one end of the second pressing bolt passes through the sliding groove 2121 and is threadedly connected to the frame 400, and the other end of the second pressing bolt is pressed on the top of the sliding groove 2121.

[0038] Furthermore, the side-pressure positioning part 211 includes a first positioning block 2111 and a second positioning block 2112 arranged sequentially in a direction away from the positioning space 201. The first positioning block 2111 and the second positioning block 2112 are spaced apart to form a gap. The end of the first positioning block 2111 near the positioning space 201 is used to abut against the plate 100. One end of the second clamping bolt passes through the slide groove 2121 and the gap in sequence and is threadedly connected to the frame 400.

[0039] As a supplementary explanation, the first positioning block 2111 and the second positioning block 2112 can be pre-fixed to the frame 400 by means of bonding, welding or other methods. When the corresponding second clamping bolt is threaded in the frame 400, a semi-threaded hole can be opened on the edge of the first positioning block 2111 at the same time. The semi-threaded hole refers to the threaded hole whose axis coincides with the edge of the first positioning block 2111 when it is formed. Therefore, the threaded hole is set on the first positioning block 2111 in the form of a semi-threaded hole.

[0040] It should be noted that this solution sets the side pressure positioning part 211 as a structure in which the first positioning block 2111 and the second positioning block 2112 are arranged in sequence and spaced apart. By utilizing the gap formed between the two positioning blocks, the second clamping bolt can pass through the groove 2121 of the third clamping part 212 and continue to pass through the gap and make a direct threaded connection with the frame 400, thereby directly transmitting the locking force to the frame 400. Furthermore, the design of a semi-threaded hole on the edge of the first positioning block 2111 allows the thread of the second clamping bolt to partially contact the edge of the first positioning block 2111 when it enters the threaded hole of the frame 400 after passing through the gap, without forming a complete threaded hole inside the first positioning block 2111. This is equivalent to providing a "semi-enclosed guide seat" for the second clamping bolt. During the locking process, the first positioning block 2111 provides lateral guidance and initial positioning for the second clamping bolt, preventing the bolt from deviating or getting stuck in the groove 2121 and the gap. This ensures the bolt is stably connected in the threaded hole of the frame 400, improving the stability of the locking force transmission path. Moreover, the combination of the semi-threaded hole and the gap provides a "guiding but not load-bearing" effect, maintaining the long-term stability of the geometric accuracy of the end face used to abut against the plate 100, preventing cumulative dimensional deformation due to repeated locking.

[0041] Furthermore, such as Figures 1 to 3 , Figure 7 , Figure 8 As shown, the third pressing part 212 includes a first continuous part 2122 and a second continuous part 2123 that are sequentially arranged and integrally formed along the direction away from the positioning space 201; a groove 2121 is formed on the second continuous part 2123; the first continuous part 2122 includes a first surface 21221 that is connected to the second continuous part 2123 and a second surface 21222 that is disposed away from the second continuous part 2123. The outline cross section of the second surface 21222 is proportionally reduced relative to the outline cross section of the first surface 21221. The first continuous part 2122 also includes a first continuous inclined surface 21223 that connects the first surface 21221 and the second surface 21222. The joint edge of the first continuous inclined surface 21223 and the first surface 21221 is located on the surface of the second continuous part 2123 where the groove 2121 is formed.

[0042] Furthermore, the first continuous portion 2122 also includes a second continuous inclined surface 21224 connecting the first surface 21221 and the second surface 21222, with the joint edge of the second continuous inclined surface 21224 and the first surface 21221 located on the side surface of the second continuous portion 2123. Meanwhile, the bottom surface of the first continuous portion 2122 and the bottom surface of the second continuous portion 2123 are coplanar.

[0043] Understandably, since the second surface 21222 of the first continuous portion 2122 is proportionally reduced in size relative to the first surface 21221, the entire first continuous portion 2122 presents a trapezoidal shape that gradually narrows outward from the second continuous portion 2123, reducing the area of ​​the end face in contact with the plate 100. More importantly, the proportional reduction makes the first continuous portion 2122 obtain a more compliant force-bearing characteristic at the end near the plate 100. For example, when the third pressing portion 212 pushes the plate 100 to be positioned laterally, this reduced end will not produce a "forced push" like the overall thick block, but can adhere with a more appropriate pressure, achieving a stable clamping effect without damaging the thin-walled part. Specifically, the first continuous inclined surface 21223 and the second continuous inclined surface 21224 provided on the first continuous part 2122 are not simple chamfers, but are respectively arranged on the front and rear surfaces of the second continuous part 2123 in two different directions, so that the connection between the first continuous part 2122 and the second continuous part 2123 is not abrupt at a right angle, but forms a continuous curved surface that gradually transitions from two directions. This double inclined surface structure significantly reduces the structural stress concentration at the junction of the two continuous parts, making the force transmitted from the second continuous part 2123 where the groove 2121 is located to the first continuous part 2122 more uniform and smooth. The inclined surface guides the force line to be naturally dispersed, avoiding the formation of sharp boundaries that could cause fatigue cracks or local deformation in the first continuous part 2122 during repeated locking or processing vibrations, so that the first continuous part 2122 obtains a more compliant force-bearing characteristic at the end near the plate 100. In particular, the joint edge of the first continuous inclined surface 21223 is located on the side with the groove 2121, so that the inclined surface can directly receive the force flow from the groove 2121 area and guide the bolt tension near the groove 2121 naturally and evenly to the entire third clamping part 212, thereby improving the continuity of force flow of the entire component.

[0044] Example 2: This embodiment also provides a multi-point clamping method for thin-walled parts, using the multi-point clamping welding fixture for thin-walled parts in Embodiment 1, including: Step S1: The side of the plate 100 is clamped by the side multi-point clamping group 200, and the long groove 111 is formed on the first station of the plate 100. Step S2: Press the machined surface 110 of the plate 100 with the multi-point clamping assembly 300 on the top surface; Step S3: Machin the first hole 112 sequentially at the second station of plate 100; Step S4: After all the first holes 112 have been machined, insert and weld the parts to be welded onto the first holes 112 in sequence. Before machining the Nth first hole 112, adjust the rotation angle of the top surface clamping member 310 so that the first clamping part 311, which has a larger contact area with the plate 100, is closer to the second station corresponding to the Nth first hole 112 than the second clamping part 312. N is less than or equal to M, where N is the order of the first holes 112 and M is the total number of first holes 112.

[0045] Furthermore, when the long groove 111 is formed on the first station of the plate 100, the third clamping part 212 does not contact the plate 100; when the first hole 112 is formed on the second station of the plate 100, the third clamping part 212 contacts the plate 100. Specifically, when machining the long groove 111 at the first station of the plate 100, the third clamping part 212 does not contact the plate 100. This avoids the formation of prestress or uneven lateral force at the location to be machined into a groove or in the area adjacent to the groove, preventing the plate 100 from experiencing slight lateral bending or warping of the machined surface 110 due to lateral pressure interference during the milling of the long groove 111. After the long groove 111 is machined, when machining the first hole 112 at the second station, the third clamping part 212 is designed to contact the plate 100, forming lateral support compensation for the plate 100. This clamping force and the top clamping part 310 form a coordinated constraint in both vertical and horizontal directions, giving the plate 100 additional lateral resistance to deformation during drilling. This effectively counteracts the effects of the radial force of the tool, cutting vibration, and local thermal stress on the thin-walled band during drilling, preventing the hole from becoming eccentrically enlarged due to the weakening of the groove edge, and preventing the hole axis from tilting or the hole opening from drifting due to the springback of the thin wall.

[0046] As another alternative implementation, when the long groove 111 is formed at the first station of the plate 100, the third pressing part 212 can be brought into contact with the plate 100.

[0047] In this embodiment, the top surface clamping member 310 is an integrally formed ring portion, and the outer ring diameter of the ring portion is greater than the groove width wa of the long groove 111; the load groove 313 is opened vertically and penetrates the second half ring portion; in the vertical direction, the groove width wb of the load groove 313 is less than the groove width wa of the long groove 111; there are three top surface clamping members 310, which are respectively located at one end, the middle and the other end of the long groove 111; the first hole 112 to be formed has the following conditions: a) it is located between two top surface clamping members 310; b) there is a top surface clamping member 310 on only one side; Before machining the Nth first hole 112, determine the positional relationship between the Nth first hole 112 and the top surface clamping part 310; When the Nth first hole 112 is located between two top surface clamping members 310, the angles of the corresponding two top surface clamping members 310 are adjusted so that the first clamping part 311 of the corresponding two top surface clamping members 310 faces the Nth first hole 112; the angles of the remaining top surface clamping members 310 are adjusted so that the top surface clamping members 310 are set so that the width of the load groove 313 coincides with the width of the long groove 111. Specifically, when machining the Nth first hole 112, the axial and radial forces of the cutting tool are concentrated on the thin-walled portion adjacent to the long groove 111. At this time, the two top-face clamping members 310 simultaneously form a symmetrical clamping from both sides with the first clamping parts 311, so that the thin-walled portion is no longer "suspended beam-shaped" but forms a stable clamping reaction frame on both sides of the Nth first hole 112. This suppresses potential defects such as outward expansion, sinking, local buckling, and elastic rebound after unloading of the thin-walled structure, keeping the hole axis vertical and non-skewed, ensuring that the hole diameter does not enlarge and the roundness of the hole opening is not distorted. The other first clamping parts 311, through maximizing the contact area, fully spread the allocated clamping force along the direction of the long groove 111, preventing the plate 100 from warping as a whole or bulging at the distal end when subjected to force near the Nth first hole 112.

[0048] When the Nth first hole 112 has a top surface clamping member 310 on only one side, adjust the angle of all the top surface clamping members 310 so that the top surface clamping members 310 are set so that the width of the load groove 313 coincides with the width of the long groove 111. Specifically, the above configuration allows the long groove 111 to unfold into a continuous "top pressure beam," ensuring that the thin-walled bands on both sides of the long groove 111 receive uniform and continuous pressure support from above during the machining of the Nth first hole 112. Since all the top surface clamping members 310 are adjusted to a "groove width overlap" posture, it is equivalent to fixing the clamping position of each top surface clamping member 310 on the long groove 111 in a state of symmetry with the centerline of the long groove 111 as the axis of symmetry, and the clamping force is evenly distributed along the direction of the long groove 111. For thin-walled parts, this "full-length symmetrical arrangement" of the clamping state along the direction of the long groove 111 can compensate for the geometric asymmetry of local clamping points with overall symmetrical stiffness in such special end- and unilateral clamping positions; this means that even if the axial and radial forces generated during machining are concentrated on one side, the long groove 111 as a whole will not be bent or folded on one side under the clamping of the wide-face clamping bands on both sides, the hole axis will not be severely tilted, and the thin wall near the hole opening will not collapse or spring back due to unilateral loss of support.

[0049] In summary, the multi-point clamping method in this embodiment achieves dynamic reinforcement support for thin-walled parts through the linkage control of processing sequence and clamping posture, thereby achieving high dimensional stability and high appearance quality of thin-walled parts in multiple processing operations, and thus ensuring the subsequent welding quality.

[0050] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-point clamping welding fixture for thin-walled parts, characterized in that, For clamping thin-walled parts, the thin-walled parts include a plate (100), and a first machining position and a plurality of second machining positions arranged around the first machining position are provided on the machining surface (110) of the plate (100); the first machining position is used to machine a long groove (111), and the second machining positions are used to machine a first hole (112). The multi-point clamping welding fixture includes: Side multi-point clamping assembly (200) for clamping the side of the plate (100) at multiple points; The top surface multi-point clamping assembly (300) includes multiple top surface clamping members (310), which are used to clamp onto the plate (100) through the long groove (111) after the plate (100) is formed; The top surface clamping member (310) includes a first clamping part (311) and a second clamping part (312) that respectively abut against the processing surface (110). The contact area of ​​the first clamping part (311) is larger than the contact area of ​​the second clamping part (312). The rotation angle of the top surface clamping member (310) is adjustable, so that the first clamping part (311) is closer to the next processing position to be processed than the second clamping part (312).

2. The multi-point clamping welding fixture for thin-walled parts according to claim 1, characterized in that, The top surface clamping member (310) includes an integrally formed circular ring portion. The outer ring diameter of the circular ring portion is larger than the groove width of the long groove (111) and is stacked on top of the long groove (111). The inner ring of the circular ring portion is provided with a first clamping bolt (320). One end of the first clamping bolt (320) passes through the inner ring of the circular ring portion and is threadedly connected to the frame (400). The other end of the first clamping bolt (320) is pressed onto the circular ring portion. The annular portion includes an integrally formed first semi-annular portion and a second semi-annular portion; a load groove (313) is provided on the second semi-annular portion, and the second semi-annular portion reduces the contact area through the load groove (313) to form the second pressing portion (312); the first semi-annular portion forms the first pressing portion (311).

3. The multi-point clamping welding fixture for thin-walled parts according to claim 2, characterized in that, The load groove (313) is opened in the vertical direction and passes through the second semi-ring portion; along the vertical direction, the outline of the load groove (313) is arc-shaped, and the center of the outline of the load groove (313) is located outside the ring portion, and the outline diameter of the load groove (313) is larger than the outer ring diameter of the ring portion.

4. The multi-point clamping welding fixture for thin-walled parts according to claim 2, characterized in that, The load groove (313) is opened vertically and passes through the second semi-ring portion; along the vertical direction, the width of the load groove (313) is smaller than the width of the long groove (111); along the vertical direction, when the width of the load groove (313) coincides with the width of the long groove (111), the ring portion is symmetrically arranged with respect to the centerline of the long groove (111).

5. A multi-point clamping welding fixture for thin-walled parts according to claim 1, characterized in that, The top surface clamping member (310) includes a first half-ring portion and a second half-ring portion that are separately arranged. The first half-ring portion and the second half-ring portion are detachably connected. The inner ring surrounding the first half-ring portion and the second half-ring portion is provided with a first clamping bolt (320). One end of the first clamping bolt (320) passing through the inner ring is threadedly connected to the frame (400), and the other end of the first clamping bolt (320) is pressed onto the first half-ring portion and the second half-ring portion. The first half-ring portion is a first pressing portion (311), and the second half-ring portion is a second pressing portion (312). The inner diameters of the first half-ring portion and the second half-ring portion are the same, and the outer diameter of the first half-ring portion is greater than the outer diameter of the second half-ring portion.

6. The multi-point clamping welding fixture for thin-walled parts according to claim 1, characterized in that, The side multi-point clamping assembly (200) includes a plurality of side clamping members (210) arranged around the plate body (100). The side clamping member (210) includes a side clamping positioning part (211) fixed on the frame (400), a third clamping part (212) slidably connected to the side clamping positioning part (211), and a locking part (213). The locking part (213) is used to lock the side clamping positioning part (211) and the third clamping part (212). The plurality of side-pressing positioning parts (211) are arranged to form a positioning space (201), the positioning space (201) is for the plate (100) to be placed, and the third pressing part (212) can slide in the direction of approaching or moving away from the positioning space (201).

7. A multi-point clamping welding fixture for thin-walled parts according to claim 6, characterized in that, The third pressing part (212) is provided with a sliding groove (2121), and the length of the sliding groove (2121) is arranged in the direction close to the positioning space (201); the locking part (213) is a second pressing bolt, one end of the second pressing bolt passes through the sliding groove (2121) and is threadedly connected to the frame (400), and the other end of the second pressing bolt is pressed on the top of the sliding groove (2121).

8. A multi-point clamping welding fixture for thin-walled parts according to claim 7, characterized in that, The side-pressure positioning part (211) includes a first positioning block (2111) and a second positioning block (2112) arranged sequentially in a direction away from the positioning space (201). The first positioning block (2111) and the second positioning block (2112) are spaced apart to form a gap. The end of the first positioning block (2111) near the positioning space (201) is used to abut against the plate (100). One end of the second clamping bolt passes through the slide groove (2121) and the gap in sequence and is threadedly connected to the frame (400).

9. A multi-point clamping welding fixture for thin-walled parts according to claim 7, characterized in that, The third pressing part (212) includes a first continuous part (2122) and a second continuous part (2123) that are sequentially arranged and integrally formed along a direction away from the positioning space (201); the groove (2121) is formed on the second continuous part (2123); The first continuous portion (2122) includes a first surface (21221) connected to the second continuous portion (2123) and a second surface (21222) disposed away from the second continuous portion (2123). The profile cross-section of the second surface (21222) is proportionally reduced relative to the profile cross-section of the first surface (21221). The first continuous portion (2122) also includes a first continuous inclined surface (21223) connecting the first surface (21221) and the second surface (21222). The joint edge of the first continuous inclined surface (21223) and the first surface (21221) is located on the surface of the second continuous portion (2123) where the groove (2121) is provided.

10. A multi-point clamping method for thin-walled parts, characterized in that, The multi-point clamping welding fixture for thin-walled parts as described in any one of claims 1-9 includes: The side of the plate is clamped by a multi-point clamping group, and a long groove is formed on the first station of the plate. The machined surface of the plate is pressed by a multi-point clamping assembly on the top surface; The first hole is machined sequentially at the second station of the plate; Before machining the Nth first hole, adjust the rotation angle of the top surface clamping part so that the first clamping part, which has a larger contact area with the plate, is closer to the second station corresponding to the Nth first hole than the second clamping part.

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