A new energy automobile special-shaped pipe connecting structure and an inner high-pressure bulging device thereof

Abstract

The application relates to the technical field of automobile accessory manufacturing, and particularly discloses a new energy automobile special-shaped pipe connecting structure and an inner high-pressure bulging device thereof, which comprises a pipe blank and multiple groups of convex ribs arranged on the pipe blank, the pipe blank is a special-shaped pipe made through a one-time inner high-pressure bulging process, and one end of the pipe blank is arranged as a connecting section; the multiple groups of convex ribs are arranged at intervals along the axial direction of the connecting section, the convex height and the axial width of the multiple groups of convex ribs increase with the increase of the axial distance from the connecting section; the convex ribs close to the end face of the connecting section are arranged in a pointed top shape, and the convex ribs away from the end face of the connecting section are arranged in a circular arc top shape. The application has the effect of forming a more uniform and stable radial compression state in the whole connecting section, thereby avoiding the risk of seal failure and cooling liquid leakage caused by insufficient local contact pressure, and improving the long-term sealing reliability and use safety of the new energy automobile cooling liquid conveying pipeline connecting structure.

Description

Technical Field

[0001] This application relates to the field of automotive parts manufacturing technology, and in particular to a new energy vehicle irregular pipe connection structure and its internal high-pressure expansion device. Background Technology

[0002] Currently, with the rapid development of the new energy vehicle industry, the performance requirements of the power battery thermal management system, motor cooling system, and vehicle thermal management integrated system for coolant delivery pipelines are constantly increasing. To ensure that the engine maintains a suitable operating temperature under different operating conditions, coolant needs to circulate between the engine, water pump, radiator, heating system, and other thermal management components through coolant delivery pipelines. Due to factors such as the complex layout of the engine compartment, limited installation space, and differences in the interface positions of different components, coolant delivery pipelines are usually connected using metal profiled fittings with spatial bends or irregular cross-sections to meet the requirements of vehicle layout and fluid delivery.

[0003] In existing technologies, such shaped metal tubular fittings are typically manufactured using an internal high-pressure bulging process. This involves placing a metal tube blank within a mold cavity, applying a high-pressure medium to the tube, causing plastic deformation and forcing it to conform to the inner wall of the mold, thus forming the predetermined shaped structure. After the overall bulging is complete, to ensure a reliable connection with the rubber hose, annular ribs are usually formed at the fitting end using methods such as rolling, hydraulic bulging, or molding. During assembly, the hose is fitted onto the fitting end, and radial clamping force is applied using clamps to press the hose firmly against the fitting's outer wall and the rib position. The ribs provide axial restraint and sealing, preventing the hose from detaching and ensuring reliable sealing at the coolant connection point.

[0004] While existing technologies generally consider that rib dimensions meeting design requirements are sufficient to guarantee sealing performance, the sealing effect of hose connections actually depends not only on the height of the rib but also, and perhaps more importantly, on whether the hose can achieve a stable and uniform radial compression state throughout its circumference. During the high-pressure bulging process of the irregularly shaped tubing, its main body undergoes complex plastic deformation. The areas near the ends of the tubing experience varying degrees of axial tension, circumferential expansion, and wall thickness changes, altering the residual stress state and plastic distribution of the material in these areas. When ribs are subsequently machined at the ends, the material's response to plastic deformation differs across circumferential locations, easily leading to inconsistent rib heights in the circumferential direction. After subsequent hose assembly and clamping, the higher areas of the ribs are preferentially compressed, while the lower areas suffer insufficient compression, resulting in uneven stress distribution throughout the circumference. With long-term engine operation, coolant pressure fluctuations and repeated hot and cold cycles cause stress relaxation in the hose material. Areas with insufficient pressure easily form micro-leakage channels, ultimately leading to coolant leakage and affecting the sealing reliability and operational safety of the engine cooling system. Summary of the Invention

[0005] This application provides a new energy vehicle special-shaped pipe connection structure and its internal high-pressure expansion device. The special-shaped pipe connection structure of the vehicle adopts a pointed rib near the end face of the connection end and a rounded rib away from the end face of the connection end to cooperate, so that the hose can obtain reliable axial limit and initial positioning during the assembly process, and can form a more uniform and stable radial compression state throughout the connection section. This avoids the risk of sealing failure and coolant leakage due to insufficient local contact pressure, and improves the long-term sealing reliability and safety of the coolant delivery pipeline connection structure of the new energy vehicle.

[0006] Meanwhile, the high-pressure expansion device inside the special-shaped pipe of the new energy vehicle can differentiate the forming parameters of each rib according to the wall thickness at different positions of the connecting section, so that each area can obtain plastic deformation conditions that match its material state, avoid the phenomenon of insufficient forming of ribs in thin-walled areas and excessive forming of ribs in thick-walled areas due to differences in wall thickness, and improve the consistency of forming height, width and circumferential direction of each rib.

[0007] Firstly, this application provides a new energy vehicle irregular pipe fitting connection structure, which adopts the following technical solution: A connection structure for irregularly shaped pipe fittings in new energy vehicles, comprising: The tube blank is a special-shaped tube made by a single internal high-pressure bulging process, and one end of the tube blank is set as a connecting section. Multiple sets of annular ribs are provided on the outer peripheral surface of the connecting segment. The multiple sets of ribs are spaced apart along the axial direction of the connecting segment. The protrusion height and axial width of the multiple sets of ribs increase with the increase of the axial distance from the connecting segment. In the multiple sets of ribs, the ribs near the end face of the connecting segment are configured with pointed tops, while the ribs away from the end face of the connecting segment are configured with rounded tops.

[0008] By adopting the above technical solution, the multiple sets of ribs on the connecting section are set with gradually increasing height and width, and combined with pointed ribs and rounded ribs. This allows materials at different axial positions to form corresponding rib structures according to differences in plasticity, reducing the inconsistency in circumferential height caused by differences in material plasticity during the rib forming process. This results in a more uniform and stable radial compression state along the entire connecting section after assembly of the hose, ensuring axial anti-detachment capability while improving the sealing reliability of the coolant connection under long-term circulating conditions.

[0009] Optionally, the set of ribs closest to the end face of the connecting segment is designated as the first rib, which has a height H1 and an axial width W1; the set of ribs furthest from the end face of the connecting segment is designated as the Nth rib, which has a height Hn and an axial width Wn; wherein the heights of the first rib and the Nth rib satisfy 1.5≤Hn / H1≤3.5, and the widths of the first rib and the Nth rib satisfy 1.2≤Wn / W1≤2.8; the height increment between two adjacent sets of ribs is 0.2mm~0.6mm, and the width increment between two adjacent sets of ribs is 0.1mm~0.5mm.

[0010] By adopting the above technical solution, by limiting the height ratio, width ratio and incremental increment of each group of ribs, a continuous and gentle dimensional gradient is formed along the connection section by each group of ribs. This avoids insufficient compensation due to an excessively small gradient or excessive deformation of local materials due to an excessively large gradient. This allows each group of ribs to participate more evenly in the hose clamping process, improves the consistency of radial load distribution at the connection, and further improves sealing stability and connection reliability.

[0011] On the other hand, the internal high-pressure bulging device for connecting irregularly shaped pipe fittings in new energy vehicles provided in this application has the following technical solution: An internal high-pressure bulging device for connecting irregularly shaped pipe fittings in new energy vehicles includes: A machine base, wherein a controller is installed on the machine base; A mold closing mechanism, which is mounted on the machine base; A mold assembly includes an upper mold base, an upper mold core, a lower mold base, and a lower mold core. The upper mold base is disposed on the mold closing mechanism, and the lower mold base is disposed on the machine base. The upper mold core is disposed on the upper mold base, and the lower mold core is disposed on the lower mold base. The upper mold core is provided with an upper forming mold, and the lower mold base is provided with a lower forming mold. The mold closing mechanism is used to apply a downward clamping force to the upper mold core, thereby pressing the upper mold core and the lower mold core tightly together. When the upper mold core and the lower mold core are closed, they together form a cavity that matches the outer contour of the tube blank target. The lower forming mold includes a guide shaft, partitions, connecting plates, and support plates. A receiving groove is formed on the lower mold core. The guide shaft is fixed within the receiving groove. Multiple sets of partitions are arranged at intervals along the axial direction of the guide shaft within the receiving groove. Each set of partitions has a forming flange and a forming groove. Adjacent sets of partitions enclose a pre-forming cavity for bulging the rib. The connecting plate and the support plate are both disposed within the receiving groove. One side of the connecting plate is fixedly connected to the side of the partition away from the forming flange, and the other side of the connecting plate is connected to the support plate. Multiple sets of connecting plates and support plates are arranged, with their widths increasing linearly along the axial direction of the connecting section, from the tube blank end face away from the end face. In adjacent sets of support plates, the shorter set slides onto the longer set. The lower forming mold has the same characteristic features as the upper forming mold. An internal high-pressure filling mechanism is provided on the machine base and is used to inject high-pressure forming medium into the tube blank. A feeding mechanism is provided on the machine base, and the feeding mechanism is used to seal the end of the tube blank and apply axial feeding. A wall thickness detection mechanism is provided, which is mounted on the feeding mechanism and is used to detect the wall thickness of the connecting section. A spacing adjustment component is provided between two adjacent sets of partitions, which is electrically connected to the controller and is used to adjust the spacing between adjacent partitions. The controller controls the spacing adjustment component to adjust the volume of each pre-forming cavity based on the wall thickness data detected by the wall thickness detection mechanism, so as to form differentiated ribs in different wall thickness areas of the tube blank.

[0012] By adopting the above technical solution, a wall thickness detection mechanism is set in the internal high-pressure bulging device, and the volume of each pre-forming cavity is adjusted in real time according to the wall thickness data of the connecting section obtained by detection. This allows different wall thickness areas to form rib sizes that match their material state, realizing the transformation of the rib forming process from fixed mold forming to adaptive differentiated forming. This effectively compensates for the wall thickness and plasticity differences of the connecting section caused by one internal high-pressure bulging, improves the forming consistency of each rib along the circumferential direction, reduces local insufficient compression after hose assembly from the source, and improves the long-term sealing performance of the connecting structure.

[0013] Optionally, the feeding mechanism includes a first push cylinder, a first punch, a second push cylinder, and a second punch. A first bracket is provided on one side of the lower die base. An angle deflection cylinder is fixed on the first bracket. The angle deflection cylinder is electrically connected to the controller. A deflection plate is fixed on the output end of the angle deflection cylinder. A first station and a second station are respectively provided on the deflection plate. The first station and the second station are symmetrically arranged along the deflection plate. The angle deflection cylinder drives the deflection plate to rotate, so that either the first station or the second station is aligned with the connecting section. The wall thickness detection mechanism is set on the second station, the first push cylinder is fixed on the first station, the first push cylinder is electrically connected to the controller, the output end of the first push cylinder can extend and retract along the axial direction of the connecting section, and the first punch is set on the output end of the first push cylinder; a second bracket is fixed on the other side of the lower mold base, the second push cylinder is fixed on the second bracket, the second push cylinder is electrically connected to the controller, and the second punch is fixed on the output end of the second push cylinder.

[0014] By adopting the above technical solution, and by setting up a switchable first station and second station, the wall thickness detection and internal high-pressure sealing feed can be completed in the same connecting section position. The deflection plate is used to realize the rapid switching between the detection station and the processing station. The detection and processing can be completed without repeatedly disassembling and assembling the tube blank, which improves the processing cycle of the equipment. At the same time, it avoids the positioning error caused by repeated positioning of the tube blank and improves the accuracy of subsequent rib processing.

[0015] Optionally, the wall thickness detection mechanism includes a telescopic drive, a plug-in cylinder, and a detection element. The telescopic drive is fixed on the second station and electrically connected to the controller. The plug-in cylinder is disposed on the output end of the telescopic drive and is telescopically mounted on the second station via the telescopic drive. The detection element is disposed on the plug-in cylinder and electrically connected to the controller. The detection element is used to measure the wall thickness of the connecting section. Multiple sets of detection elements are disposed on the plug-in cylinder, and the multiple sets of detection elements are evenly spaced along the circumference and axial direction of the plug-in cylinder. The coating element is used to spray coupling agent onto the inner wall of the connecting section before detection.

[0016] By adopting the above technical solution, multiple sets of detection elements are evenly distributed along the circumferential and axial directions on the outer periphery of the insertion cylinder, enabling simultaneous wall thickness detection at multiple locations on the inner wall of the connecting section. This provides more comprehensive and accurate wall thickness distribution data for the connecting section, offering a reliable data basis for the controller to adjust each pre-forming cavity and improving the control accuracy of the differentiated forming of the ribs.

[0017] Optionally, the wall thickness detection mechanism further includes a coating component, which includes a miniature injection pump, a coating seat, and a liquid storage box. The coating seat is fixed on the insertion cylinder and located at the end of the insertion cylinder away from the deflection plate. A liquid outlet is provided on the side of the coating seat facing away from the insertion cylinder. The miniature injection pump is fixed on the deflection plate and is electrically connected to the controller. The liquid storage box is disposed on the machine platform and is filled with coupling agent. The liquid storage box is connected to the input end of the miniature injection pump, and the output end of the injection pump is connected to the liquid outlet.

[0018] By adopting the above technical solution, a couplant is automatically sprayed onto the inner wall of the connecting section before testing, so that a stable acoustic coupling medium is formed between the test piece and the inner wall of the pipe, thereby improving the signal transmission quality of wall thickness detection, reducing detection errors caused by inconsistent coupling states, and improving the accuracy and repeatability of wall thickness detection results.

[0019] Optionally, a scraper is provided on the side of the coating seat away from the detection element, and the scraper is used to scrape the inner wall of the connecting section before the insertion of the plug-in cylinder.

[0020] By adopting the above technical solution and setting a scraper, the coupling agent remaining on the inner wall of the connecting section during the testing process can be removed simultaneously when the plug-in cylinder is withdrawn. This reduces the influence of the testing medium on the material flow state and forming stability during the subsequent internal high-pressure bulging process, enabling a residue-free connection between the wall thickness testing process and the internal high-pressure forming process. This improves the quality and processing consistency of the subsequent rib forming process, while reducing subsequent cleaning processes and increasing production efficiency.

[0021] Optionally, the spacing adjustment component includes a first oil box, a liquid injection pump, and a piston rod. The support plate has a first flow channel and a piston groove. The first flow channel communicates with the piston groove. One end of the piston rod is slidably disposed in the piston groove, and the other end of the piston rod is connected to the connecting plate on the adjacent side. The liquid injection pump is disposed on the lower mold base and is electrically connected to the controller. The first oil box is connected to the input end of the liquid injection pump, and the output end of the liquid injection pump is connected to the first flow channel. The liquid injection pump drives the piston rod to extend and retract by injecting hydraulic oil into the first flow channel, thereby driving the support plate to move on the guide shaft, and thus realizing the adjustment of the spacing between two adjacent sets of partitions.

[0022] By adopting the above technical solution, a spacing adjustment component is set up, which uses a liquid injection pump to drive a piston rod to move the corresponding support plate. This allows the spacing between adjacent partitions to be independently adjusted based on the wall thickness detection results at each position of the connecting section, thereby changing the volume of the corresponding pre-forming cavity without simultaneously changing the dimensions of other pre-forming cavities. In this way, during the local high-pressure bulging process, the material replenishment requirement of the corresponding pre-forming cavity can be increased separately for areas with thinner walls, while areas with thicker walls maintain their original forming state. This avoids changes in the forming parameters of other ribs due to overall linkage adjustment, ensuring that each position can be differentiated in forming control according to its own wall thickness.

[0023] Furthermore, different preformed cavities form different filling sequences under the action of differentiated volumes, allowing the material in the thick-walled area near the free end to continue migrating axially towards the thin-walled position near the irregularly shaped expansion area before the ribs are fully formed. This provides material replenishment to the thin-walled area and avoids the premature formation of the ribs at the free end, which would hinder the subsequent flow of material to the thin-walled area. This improves the material distribution balance among the ribs, ensuring that each position can form ribs with the required dimensions and rigidity. It also improves the forming consistency of the ribs along the circumferential direction, making the circumferential contact pressure more uniform after the hose is assembled, and reducing the risk of local seal failure and coolant leakage under long-term hot and cold cycles and pressure pulsation.

[0024] Optionally, the mold assembly further includes a lifting component, which includes a mounting post, an ejector pin, a clamping spring, and a pressure pump. The mounting post is fixed to one side of the partition plate. The mounting post has an installation cavity and a transition cavity inside. A connecting groove is formed on the inner wall of the transition cavity. The ejector pin is movably mounted on the mounting post through the transition cavity, with one end extending into the installation cavity and the other end extending out of the transition cavity. A sealing portion is fixed at the end of the ejector pin extending into the installation cavity, and a pushing portion is fixed at the other end. The sealing portion is slidably disposed within the installation cavity and has an overflow groove. A pressure pump is fixed on the inner wall of the installation cavity. The device includes an annular abutment portion that movably abuts against the sealing portion. The push portion is truncated cone-shaped. One end of the mounting post has a matching receiving groove. A clamping spring is sleeved on the ejector pin. One end of the clamping spring is connected to the sealing portion, and the other end is connected to the inner wall of the mounting cavity. The clamping spring allows the push portion to be flush with the inner wall of the mold cavity when not in operation. During the demolding stage, the ejector pin can extend out of the cavity surface to push out the formed tube. A pressure pump is connected to the mounting cavity and is used to inject lubricating oil, which then seeps through the connecting groove to the contact surface between the partition plate and the tube blank.

[0025] By adopting the above technical solution and setting up a lifting component that integrates lubrication and ejection functions, lubricating oil can be delivered to the contact area between the partition and the tube blank during the forming process, reducing the frictional resistance between the material and the mold, promoting the plastic flow of the material, and improving the forming quality of the ribs; during the demolding stage, the ejector pins automatically extend to push the tube away from the cavity, reducing demolding resistance and damage to the rib structure, improving the surface quality of the formed parts and the service life of the mold.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. By setting multiple sets of ribs with gradually varying axial height and width along the connecting section, and combining them with a wall thickness detection mechanism, spacing adjustment components, and adjustable pre-forming cavities, the forming parameters of each rib are differentiated according to the wall thickness at different locations of the connecting section. This allows each area to obtain plastic deformation conditions that match its material state, avoiding insufficient forming of ribs in thin-walled areas and excessive forming of ribs in thick-walled areas due to differences in wall thickness. This improves the consistency of the forming height, width, and circumferential direction of each rib, providing a consistent connection basis for subsequent hose sealing connections. 2. By adjusting the volume of each preformed cavity and ensuring that each preformed cavity can be adjusted independently without interfering with each other, the ribs at different positions are plastically formed sequentially according to the preset filling sequence, rather than competing for local materials at the same time. As a result, the material in the thick-walled area can continuously migrate axially towards the thin-walled position near the irregular bulging area, replenishing the material in the thin-walled area. At the same time, it avoids the ribs near the end face of the connecting section from forming too early and hindering the continued flow of subsequent materials, making full use of the original material reserves at the connecting end, improving the material distribution balance and the overall forming quality of each rib. 3. The use of a pointed rib near the end face of the connection and a rounded rib away from the end face of the connection allows the hose to achieve reliable axial limiting and initial positioning during assembly, while also forming a more uniform and stable radial compression state throughout the connection section. This avoids leakage channels caused by insufficient local contact pressure, reduces the risk of seal failure and coolant leakage under long-term hot and cold cycles and coolant pressure pulsation, and improves the long-term sealing reliability and operational safety of the coolant delivery pipeline connection structure in new energy vehicles. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the tube blank in the embodiments of this application.

[0028] Figure 2 This is a half-sectional schematic diagram of the protruding rib in the embodiment of this application.

[0029] Figure 3 This is a schematic diagram of the overall structure of the internal high-pressure expansion device in the embodiments of this application.

[0030] Figure 4 This is a schematic diagram of the overall structure of the mold assembly in the embodiments of this application.

[0031] Figure 5 This is a partial cross-sectional view of the lower mold core in an embodiment of this application.

[0032] Figure 6 This is a schematic diagram of the overall structure of the lower forming mold in an embodiment of this application.

[0033] Figure 7 This is a half-sectional structural diagram of the spacing adjustment component in the embodiments of this application.

[0034] Figure 8 This is a schematic diagram of the overall structure of the wall thickness detection mechanism in the embodiments of this application.

[0035] Figure 9 yes Figure 8 An enlarged schematic diagram of part A in the middle.

[0036] Reference numerals: 1. Tube blank; 11. Connecting section; 12. Raised rib; 121. First raised rib; 122. Nth raised rib; 2. Machine base; 21. Controller; 22. First support; 23. Second support; 3. Mold closing mechanism; 4. Mold assembly; 41. Upper mold base; 42. Upper mold core; 43. Lower mold base; 44. Lower mold core; 441. Receiving groove; 45. Upper forming mold; 46. Lower forming mold; 461. Guide shaft; 462. Partition plate; 4621. Forming flange; 4622. Forming groove; 463. Connecting plate; 464. Support plate; 4641. First flow channel; 4642. Piston groove; 47. Spacing adjustment component; 471. First oil box; 472. Injection pump; 473. Piston rod; 48. Elevating component; 481. Mounting column; 4811. Mounting cavity; 4812. Transition cavity; 4813. Connecting groove; 4814. Abutment part; 482. Ejector pin; 4821. Sealing part; 4822. Pushing part; 4823. Overflow groove; 483. Holding spring; 484. Pressure pump; 5. Internal high-pressure filling mechanism; 6. Feed mechanism; 61. First push cylinder; 62. First punch; 63. Second push cylinder; 64. Second punch; 65. Angle deflection cylinder; 66. Deflection plate; 661. First station; 662. Second station; 7. Wall thickness detection mechanism; 71. Telescopic drive component; 72. Insertion tube; 73. Detection component; 74. Coated component; 741. Miniature injection pump; 742. Coating seat; 7421. Liquid outlet; 743. Liquid storage box; 75. Scraper. Detailed Implementation

[0037] The following is in conjunction with the appendix Figure 1-9 This application will be described in further detail below.

[0038] This application discloses a connection structure for irregularly shaped pipe fittings in new energy vehicles.

[0039] Reference Figure 1 and Figure 2 A new energy vehicle special-shaped pipe connection structure includes a pipe blank 1 and multiple sets of protruding ribs 12 disposed at the end of the pipe blank 1. The pipe blank 1 is a special-shaped pipe made by a one-time internal high-pressure bulging process. One end of the pipe blank 1 is set as a connecting section 11. The special-shaped pipe is fixedly connected to the hose through the connecting section 11. Since the pipe blank 1 has undergone one-time internal high-pressure bulging process, its main body of the pipe blank 1 undergoes axial stretching and circumferential expansion during the internal high-pressure forming process. The residual stress state and plastic distribution of the end of the pipe blank 1 where the connecting section 11 is located and the adjacent area change, thereby forming an uneven wall thickness that gradually thins from the end face inward. The end wall thickness is significantly greater than the pipe body wall thickness away from the end.

[0040] The ribs 12 are provided on the outer circumferential surface of the connecting section 11, and multiple sets of ribs 12 are arranged at intervals along the axial direction of the connecting section 11, with each set of ribs 12 extending circumferentially; wherein, the protrusion height and axial width of the multiple sets of ribs 12 are differentiated according to the actual wall thickness of the tube blank 1 at their respective locations: In the relatively thin area of ​​the connecting section 11, the rib 12 has a first height and a first width, and the top of the rib 12 is set in an arc shape; in the area relatively close to the end face of the tube blank 1 and with a relatively thick wall, the rib 12 has a second height and a second width, the second height is less than the first height, the second width is less than the first width, and the top of the rib 12 at the corresponding position is set in a pointed shape.

[0041] Furthermore, along the axial direction of the connecting section 11, from the end face of the tube blank 1 to the direction away from the end face, the height and width of the rib 12 gradually increase, and the top shape gradually transitions from a pointed top to a rounded top.

[0042] In this embodiment, the tube blank 1 can be made of low-carbon steel, high-strength low-alloy steel, stainless steel, or aluminum alloy. The initial wall thickness of the tube blank 1 is 3mm to 4.5mm. After internal high-pressure forming, the wall thickness gradually decreases from t1 to t2, where t1 is 2.5mm to 5.5mm and t2 is 1.3mm to 3.2mm, and satisfies 1.5≤t1 / t2≤3.8. The wall thickness decreases monotonically along the axial direction, and the thinning rate gradually increases from the end face.

[0043] Furthermore, in some embodiments, the number of multiple sets of ribs 12 is 3 to 8, preferably 6. The rib 12 closest to the end face of the tube blank 1 is defined as the first rib 121, which has a height H1 and an axial width W1, and a pointed top; ribs 12 to ribs 122 are sequentially arranged along the direction away from the end face, wherein the rib 122 is the rib 12 furthest from the end face, having a height Hn and an axial width Wn, and a rounded top. The height and width of each rib 12 satisfy: 1.5 ≤ Hn / H1 ≤ 3.5, 1.2 ≤ Wn / W1 ≤ 2.8. The height increment of adjacent ribs 12 is 0.2 mm to 0.6 mm, and the width increment is 0.1 mm to 0.5 mm.

[0044] Furthermore, in some embodiments, the cross-sectional shape of the apex is an isosceles triangle or a sharp angle formed by the intersection of two symmetrical arcs, with the included angle α of the apex being 55° to 110°, and more preferably 65° to 95°.

[0045] In areas with relatively thin walls, the cross-section of the rib 12 is set as an isosceles trapezoidal top, and the two ends of the narrow side (upper base) of the isosceles trapezoid are smoothly transitioned to the two sides of the trapezoid through rounded corners.

[0046] Specifically, the width of the narrow side of the isosceles trapezoid is defined as Wt, the included angle between the two sides of the trapezoid (the vertex angle of the trapezoid) is γ, and the radius of the transition fillet at both ends of the narrow side is r.

[0047] Furthermore, the width of the narrow side Wt is 0.4mm to 2.2mm, the apex angle γ of the trapezoid is 100° to 135°, and the radius of the transition fillet r is 0.3mm to 1.8mm; Preferably, Wt is 0.6mm to 1.5mm, γ is 120°, and r is 0.5mm to 1.2mm.

[0048] The shape of the rib 12, which is "isosceles trapezoid + rounded corner transition", allows the rib 12 to form a surface contact sealing band through the narrow side plane when under pressure, while the rounded corner transition avoids stress concentration at right angles, making it particularly suitable for compensating for low stiffness and high deformation in thin-walled areas.

[0049] In the intermediate region (transition section) where the wall transitions from thick to thin, the top cross-sectional shape of the intermediate rib 12 gradually changes from a pointed top to an isosceles trapezoidal top. The transition characteristics are as follows: the top of the rib 12 gradually flattens to form a narrow side, while the radius of the fillet at the connection between the sidewall and the narrow side gradually increases from zero or a minimum value to r.

[0050] Furthermore, in some embodiments, the axial spacing d between two adjacent sets of ribs 12 is 5.5mm to 10mm, and this spacing can remain consistent along the axial direction or gradually increase. The circumferential extension form of the ribs 12 can be a full-circumferential closed-loop rib, a partially arc-shaped rib 12, or a discontinuously distributed tooth, selected according to the requirements of connection sealing and anti-rotation.

[0051] Furthermore, in some embodiments, the outer diameter D of the connecting segment 11 is in the range of 20mm to 80mm, and the total length L of the connecting segment 11 is 25mm to 80mm. The radial protrusion height of the ribs 12 (relative to the outer circumferential surface of the connecting segment 11) is between 1.8mm and 5mm, wherein the height H1 of the first rib 121 is preferably 2mm, and the height Hn of the Nth rib 122 is preferably 5mm.

[0052] The higher and wider design of the arc-shaped rib 12 in the thin-walled region effectively compensates for the decrease in local stiffness and insufficient sealing contact stress caused by thinning and plastic deformation, increasing the average contact pressure in the contact area by 25% to 55% during connection. The lower and narrower design of the pointed rib 12 in the thick-walled region reduces excessive compression on the high-stiffness, high-residual-stress area, lowering the risk of microcracks in this area due to local overload. Finite element simulation and physical testing show that, after mating with the corresponding standard connector and undergoing press-fitting or roll-forming connection, the connection section 11 can simultaneously meet the following performance requirements: The sealing performance is within the temperature range of -40℃ to 120℃. The connection can withstand an internal liquid or gas pressure of not less than 60% of the yield strength of the pipe material without leakage. For typical high-strength steel pipes, the internal pressure sealing limit is not less than 35MPa. Pull-out resistance: The axial static load pull-out force is not less than 80% of the theoretical tensile load of the minimum cross-section of the pipe. Under dynamic vibration conditions (frequency 10Hz~200Hz, acceleration 3g), after 10... 6 After the second cycle, there was no obvious loosening of the connection or weakening of the seal.

[0053] This application also discloses an internal high-pressure bulging device for connecting irregularly shaped pipe fittings in new energy vehicles, referring to... Figure 3 The internal high-pressure bulging device includes a machine base 2, a mold closing mechanism 3, a mold assembly 4, an internal high-pressure liquid filling mechanism 5, a feeding mechanism 6, and a wall thickness detection mechanism 7. The machine base 2 serves as the mounting base for the entire internal high-pressure bulging device. The mold closing mechanism 3 is mounted on the machine base 2, and the mold assembly 4 is mounted on the mold closing mechanism 3. The internal high-pressure liquid filling mechanism 5 and the feeding mechanism 6 are both mounted on the machine base 2. The mold assembly 4 is supported above the internal high-pressure liquid filling mechanism 5 and the feeding mechanism 6 via the mold closing mechanism 3. The internal high-pressure liquid filling mechanism 5 is located on one side of the feeding mechanism 6, and the feeding mechanism 6 is located between the mold closing mechanism 3 and the internal high-pressure liquid filling mechanism 5. The wall thickness detection mechanism 7 is mounted on the feeding mechanism 6.

[0054] Among them, the mold closing mechanism 3 is used to support the mold and apply the mold closing force, the mold assembly 4 is used to provide a cavity to accommodate the tube blank 1 to be processed, the internal high pressure liquid filling mechanism 5 is used to provide ultra-high pressure forming liquid to the inside of the tube blank 1, the feeding mechanism 6 is used to seal the end of the tube blank 1 and provide axial feeding as needed, and the wall thickness detection mechanism 7 is used to detect the wall thickness of the tube blank 1 to be processed.

[0055] Reference Figure 3 In this embodiment, a controller 21 is fixedly mounted on the machine base 2. The mold closing mechanism 3 includes a column, an upper crossbeam, a sliding seat, and a mold closing drive component. The column is fixedly mounted on the machine base 2, and the sliding seat slides through the column. There are four sets of columns on the machine base 2, and the four sets of columns are located at the four corners of the sliding seat. The upper crossbeam is fixedly mounted on the end of the column away from the machine base 2. The sliding seat is slidably mounted on the machine base 2 through the column, and the upper crossbeam is mounted on the sliding seat through the column. The mold closing drive component is fixedly mounted on the upper crossbeam. The mold closing drive component can be configured as a hydraulic cylinder. The mold closing drive component is electrically connected to the controller 21. The output end of the mold closing drive component is fixedly connected to the side of the sliding seat away from the machine base 2. The mold closing drive component can drive the sliding seat to reciprocate along the column in the vertical direction.

[0056] Reference Figure 4 , Figure 5 and Figure 6In this embodiment, the mold assembly 4 includes an upper mold base 41, an upper mold core 42, a lower mold base 43, a lower mold core 44, an upper forming mold 45, a lower forming mold 46, and a lifting member 48. The upper mold base 41 is fixedly mounted on the sliding seat facing the machine base 2. The upper mold core 42 is fixedly embedded in the upper mold base 41. The lower mold base 43 is fixedly mounted on the machine base 2. The lower mold core 44 is fixedly embedded in the lower mold base 43. The upper mold core 42 has a first cavity, and the lower mold core 44 has a second cavity. After the mold is closed, the first cavity and the second cavity together form a cavity that matches the outer contour of the target tube blank 1 to be formed.

[0057] The lower forming mold 46 is mounted on the lower mold core 43. The lower forming mold 46 includes a guide shaft 461, a partition plate 462, a connecting plate 463, a spacing adjustment component 47, a support plate 464, and a return spring. The lower mold core 43 has a receiving groove 441 on the side near the connecting section 11. The guide shaft 461 is fixed in the receiving groove 441. The axis of the guide shaft 461 is parallel to the axis of the connecting section 11. The partition plate 462 is a rectangular plate. A semi-circular through hole is opened on the long side of the partition plate 462. An inwardly protruding annular forming flange 4621 is provided in the middle area of ​​the inner wall of the through hole. The cross-sectional profile of the flange matches the concave shape between two adjacent sets of ribs 12. An inwardly recessed annular forming grooves 4622 are provided at both ends of the inner wall of the through hole. The cross-sectional profile of the groove matches the shape of the rib 12.

[0058] The connecting plate 463 is also provided with a rectangular plate. The connecting plate 463 is fixed on the side of the partition 462 away from the side with the through hole. The connecting plate 463 and the partition 462 have the same thickness. The connecting plate 463 is slidably inserted on the guide shaft 461. The connecting plate 463 is slidably disposed in the receiving groove 441 through the guide shaft 461. The support plate 464 is slidably disposed in the receiving groove 441. The support plate 464 is fixedly connected to the side of the connecting plate 463 away from the partition 462. The partition 462, the connecting plate 463 and the support plate 464 are combined to form an "L" shape.

[0059] In this embodiment, multiple sets of partition plates 462, connecting plates 463, and support plates 464 are arranged at intervals along the axial direction of the connecting section 11. The width of the multiple sets of connecting plates 463 and support plates 464 increases linearly along the axial direction of the connecting section 11 and from the end face of the tube blank 1 away from the end face. In two adjacent sets of support plates 464, the set of support plates 464 with shorter width is slidably arranged on the set of support plates 464 with longer width.

[0060] The spacing adjustment component 47 includes a first oil box 471, an injection pump 472, and a piston rod 473. The first oil box 471 is mounted on the machine base 2 and is filled with hydraulic oil. The injection pump 472 is fixed on the lower mold base 43 and is connected to the first oil box 471. The injection pump 472 is electrically connected to the controller 21. The support plate 464 has a first flow channel 4641 and a piston groove 4642 respectively. The first flow channel 4641 is connected to the piston groove 4642. One end of the piston rod 473 is slidably mounted in the piston groove 4642, and the other end of the piston rod 473 is fixedly connected to a set of connecting plates 463 facing the piston groove 4642. The injection pump 472 drives the piston rod 473 to extend and retract by injecting hydraulic oil into the first flow channel 4641.

[0061] In this embodiment, each set of support plates 464 has multiple sets of piston grooves 4642 along its own length, and each set of piston grooves 4642 is provided with a set of piston rods 473. The spacing adjustment member 47 provided can drive the multiple sets of partitions 462 to move closer or further away from each other. When the multiple sets of partitions 462 are stacked together, the forming flange 4621 and the forming groove 4622 of the adjacent partition 462 together enclose an annular cavity for forming a single complete rib 12. In addition, a set of limiting blocks are provided on the outermost of each of the two axial ends of the guide shaft 461. When the axial compression reaches the preset stroke, the outermost partition 462 abuts against the corresponding limiting block, preventing the module from moving further, thereby precisely controlling the final length and wave pitch of the connecting structure on the tube blank 1.

[0062] A clearance groove is provided through the center of the connecting plate 463. A guide rod is fixed in the receiving groove 441. A limiting block is slidably connected to the guide rod. The guide rod and the clearance groove are coaxially arranged. A return spring is sleeved on the guide rod. One end of the return spring is fixedly connected to a set of limiting blocks at one end of the guide rod, and the other end of the return spring is fixedly connected to a set of limiting blocks at the other end of the guide rod.

[0063] The lifting component 48 includes a mounting post 481, a ejector pin 482, a clamping spring 483, a pressure pump 484, and a second oil box. The mounting post 481 is cylindrical and fixed to the side of the partition plate 462 facing the end of the tube blank 1. The mounting post 481 has a mounting cavity 4811 and a transition cavity 4812, which communicate with each other. One end of the ejector pin 482 is fixed with a sealing part 4821, and the other end of the ejector pin 482 is fixed with a top... The push part 4822 and the ejector pin 482 are provided with a sealing part 4821 at one end, which extends into the mounting cavity 4811. The sealing part 4821 is slidably disposed in the mounting cavity 4811. The shape of the sealing part 4821 is adapted to the shape of the inner cavity of the mounting cavity 4811. An overflow groove 4823 is provided through the sealing part 4821. Multiple sets of overflow grooves 4823 are provided on the sealing part 4821. The multiple sets of overflow grooves 4823 are arranged in a circle with the axis of the ejector pin 482 as the center.

[0064] An abutment ring is fixedly installed inside the mounting cavity 4811. The abutment ring is located on the side of the sealing part 4821 opposite to the ejector pin 482, and the abutment ring movably abuts against the sealing part 4821. The ejector pin 482 is slidably disposed in the transition cavity 4812. A connecting groove 4813 is provided on the inner wall of the transition cavity 4812, and the connecting groove 4813 communicates with the mounting cavity 4811. The mounting cavity 4811 can communicate with the mold cavity through the connecting groove 4813. The push part 4822 is configured as a frustoconical shape. A receiving groove is provided at the end of the mounting post 481 opposite to the mounting cavity 4811. The shape of the push part 4822 is adapted to the receiving groove. The side of the push part 4822 opposite to the sealing part 4821 is flush with the inner wall of the mold cavity.

[0065] The clamping spring 483 is disposed in the mounting cavity 4811 and is sleeved on the ejector pin 482. One end of the clamping spring 483 is fixedly connected to the sealing part 4821, and the other end of the clamping spring 483 is fixedly connected to the inner wall of the mounting cavity 4811.

[0066] Both the pressure pump 484 and the second oil box are mounted on the machine base 2. The pressure pump 484 is electrically connected to the controller 21 and is connected to the second oil box, which is filled with lubricating oil. An oil delivery pipe is fixed to the output end of the pressure pump 484, and the pressure pump 484 is connected to the mounting cavity 4811 through the oil delivery pipe. The pressure pump 484 injects low-pressure lubricating oil into the mounting cavity 4811. The lubricating oil seeps out through the connecting groove 4813 to the contact area between the partition plate 462 and the tube blank 1, forming a lubricating film before the mold closes to reduce the axial flow resistance of the material.

[0067] In this embodiment, the upper forming mold 45 and the lower forming mold 46 have the same feature settings. At the same time, each set of partitions 462 is provided with a set of mounting posts 481, and a clearance groove is also provided on the side of an adjacent set of partitions 462 facing the mounting posts 481. The clearance groove can ensure that multiple sets of partitions 462 can be tightly stacked together.

[0068] Reference Figure 3 In this embodiment, the internal high-pressure filling mechanism 5 includes a booster and a low-pressure unit. The booster generates and delivers the high-pressure forming medium, while the low-pressure unit rapidly fills the cavity with liquid before forming begins to form a low-pressure forming medium. The booster includes a booster cylinder, a high-pressure control valve assembly, and a pressure sensor. The booster cylinder is composed of a large-area low-pressure piston and a small-area high-pressure plunger connected in series, thereby forming a low-pressure drive chamber and a high-pressure output chamber. The low-pressure drive chamber is connected to the booster control circuit via a pipeline and receives pressurized oil supplied by the hydraulic pump assembly. The outlet of the high-pressure output chamber is connected to the inlet of a high-pressure control valve assembly via a high-pressure pipeline.

[0069] The high-pressure control valve assembly includes at least a check valve and a relief valve. Its outlet is connected to a pre-machined liquid channel within the upper forming mold 45 or lower forming mold 46 via a high-pressure rigid pipe or high-pressure flexible pipe. The internal high-pressure liquid medium channel ultimately leads to the inner wall of the cavity, allowing the pressurizing medium to be injected into the tube blank 1. Driven by the low-pressure piston, the high-pressure plunger amplifies the pressure by a factor of its area ratio, raising the forming liquid pressure in the high-pressure output chamber to the required internal high pressure. A pressure sensor is installed on the high-pressure pipeline and feeds back the pressure signal to the electronic control unit in real time to form a closed-loop pressure control.

[0070] The low-pressure filling system includes a filling pump, a filling valve, and filling pipelines. The outlet of the filling valve is connected to pre-machined injection holes in the upper forming mold 45 and the lower forming mold 46. The injection holes are connected to the mold cavity. The filling valve can be a two-position two-way solenoid valve. It opens during the filling stage and reliably closes during the pressurization stage to isolate the low-pressure circuit. The filling pump is usually a low-pressure, high-flow-rate vane pump. The inlet of the filling pump is connected to a liquid tank located on one side of the machine base 2. During the filling stage, the controller 21 opens the filling valve while simultaneously venting the gas in the mold cavity and the blank 1 to ensure complete liquid filling.

[0071] The above content is well known to those skilled in the art, and will not be elaborated further here.

[0072] Reference Figure 3 and Figure 8In this embodiment, the feeding device is disposed on the left and right sides of the mold closing mechanism 3. The feeding mechanism 6 includes a first push cylinder 61, a first punch 62, a second push cylinder 63, and a second punch 64. A first bracket 22 is disposed on one side of the lower mold base 43 in the width direction. An angle deflection cylinder 65 is fixed on the first bracket 22. The angle deflection cylinder 65 is electrically connected to the controller 21. A deflection plate 66 is fixed on the output end of the angle deflection cylinder 65. The output end of the angle deflection cylinder 65 coincides with the center position of the deflection plate 66. One side of the length direction of the deflection plate 66 is set as the first station 661, and the other side of the deflection plate 66 is set as the second station 662. The first station 661 and the second station 662 are selectively matched with the connecting end under the action of the angle deflection cylinder 65.

[0073] A second bracket 23 is fixed on one side of the lower mold base 43 along its length. A first push cylinder 61 is fixed on the first station 661. The first push cylinder 61 is a hydraulic cylinder and is electrically connected to the controller 21. The output end of the first push cylinder 61 can extend and retract along the axial direction of the connecting section 11. A first punch 62 is installed on the output end of the first push cylinder 61. A second push cylinder 63 is fixed on the second bracket 23 and is also electrically connected to the controller 21. A second punch 64 is fixed on the output end of the second push cylinder 63.

[0074] The outer periphery of the front end of the first punch 62 and the second punch 64 is adapted to the inner diameter of the connecting section 11, and several sealing grooves are opened on the outer peripheral surfaces of the first punch 62 and the second punch 64, and sealing rings are installed in the sealing grooves. When the tube blank 1 is placed in the cavity of the lower forming mold 46 and the mold is closed, the first push cylinder 61 and the second push cylinder 63 respectively drive the corresponding punches to feed towards each other, so that the first punch 62 and the second punch 64 are respectively inserted into the two ends of the tube blank 1 to achieve axial sealing at the ends. At the same time, a liquid medium channel is opened inside the second punch 64 along its own axial direction. This channel is used to inject high-pressure expansion liquid medium into the tube blank 1 and is connected to the booster.

[0075] During the forming process, the first pusher cylinder 61 and the second pusher cylinder 63 can apply axial thrust to the end of the tube blank 1 according to a preset displacement or force control curve to replenish material and prevent excessive wall thickness reduction. Each pusher cylinder is equipped with a displacement sensor and a pressure sensor, and the feedback signals are incorporated into the control loop of the electronic control unit.

[0076] Reference Figure 8 and Figure 9In this embodiment, the wall thickness detection mechanism 7 includes a plug-in cylinder 72, a detection element 73, a coating element 74, and a telescopic drive element 71. The plug-in cylinder 72 is disposed on the second station 662, and the length of the plug-in cylinder 72 is greater than the length of the connecting section 11. The detection element 73 is configured as an ultrasonic probe and is electrically connected to the controller 21. The detection element 73 is fixedly inserted into the plug-in cylinder 72, and multiple sets of detection elements 73 are evenly spaced on the plug-in cylinder 72. At the same time, the controller 21 establishes the effective volume of each preformed cavity according to the correspondence between the wall thickness at each detection position and the size of the target rib 12, and calculates the initial position of the partition 462.

[0077] The coating component 74 includes a miniature injection pump 741, a coating seat 742, and a reservoir 743. The miniature injection pump 741 is fixedly mounted on the deflection plate 66 and is electrically connected to the controller 21. The coating seat 742 is annular and is fixedly sleeved on the outer peripheral wall of the insertion cylinder 72. The coating seat 742 is located at the end of the insertion cylinder 72 away from the deflection plate 66. The side of the coating seat 742 facing away from the insertion cylinder 72 is adapted to the inner wall of the connecting section 11, and the side of the coating seat 742 facing away from the insertion cylinder 72 is slidably connected to the inner wall of the connecting section 11. The coating seat 742 has multiple sets of outlets 7421 for spraying coupling agent, and the multiple sets of outlets 7421 are arranged at equal intervals. A connecting pipe is fixedly mounted on the output end of the miniature injection pump 741, and the miniature injection pump 741 is connected to the coating seat 742 through the connecting pipe.

[0078] The liquid storage box 743 is fixed on the machine base 2. The liquid storage box 743 is located on one side of the first support 22. The liquid storage box 743 is connected to the input end of the micro injection pump 741. The liquid storage box 743 is filled with coupling agent.

[0079] Furthermore, a scraper 75 is provided on the side of the coating seat 742 away from the deflection plate 66. The scraper 75 is configured as a trumpet-shaped cylinder. The scraper 75 is fixedly sleeved on the end of the insertion cylinder 72 away from the deflection plate 66. The side of the scraper 75 away from the insertion cylinder 72 slides against the inner wall of the connecting section 11.

[0080] The telescopic drive component 71 is fixed on the deflection plate 66. The telescopic drive component 71 can be configured as a cylinder. The telescopic drive component 71 is electrically connected to the controller 21. The telescopic drive component 71 is fixedly connected to the end of the insertion tube 72 near the deflection plate 66. The telescopic drive component 71 can drive the insertion tube 72 to reciprocate and insert along the axis of the connecting section 11.

[0081] More specifically, during the connection structure construction, the tube blank 1, which has undergone internal high-pressure expansion, is first placed in the second cavity of the lower mold core 44. Then, the controller 21 controls the angle deflection cylinder 65 to drive the deflection plate 66 to rotate, so that the second station 662 is aligned with the connection section 11. The telescopic drive component 71 drives the insertion tube 72 to insert into the connection section 11. The scraper 75 will abut against the inner wall of the connection section 11. As the insertion tube 72 goes deeper, the scraper 75 will deflect towards the deflection plate 66. At the same time, the scraper 75 will scrape the inner wall at the corresponding position on the insertion path. Simultaneously, the coating seat 742 will also apply coupling agent to the scraped inner wall.

[0082] After the insert sleeve 72 is inserted into place, the controller 21 can detect the wall thickness of the connecting section 11 through multiple sets of detection components 73. After the wall thickness detection mechanism 7 completes the detection, the controller 21 pre-calculates the initial spacing of the corresponding partition 462 based on the wall thickness data at each axial position, and drives the spacing adjustment component 47 to complete the position setting of the partition 462 before the mold closes. The partition 462 is locked in the target position before entering the formal forming stage, and remains fixed during the subsequent internal high-pressure forming process.

[0083] Specifically, during the overall internal high-pressure bulging process, due to the significant plastic deformation in the irregularly shaped section of the tube blank 1, the material of the tube blank 1 flows axially towards the bulging region, resulting in a non-uniform wall thickness distribution at the connecting end along the axial direction. Typically, the wall thickness is relatively thicker near the free end, while the wall thickness gradually decreases towards the irregularly shaped bulging region. If the same size rib 12 is subsequently used for local internal high-pressure forming, the thinner wall area will have insufficient material for plastic flow, resulting in rib 12 with lower height, width, and local stiffness than the thicker wall area. This ultimately leads to uneven contact pressure distribution after hose assembly, making it prone to sealing failure under long-term thermal cycling and pressure pulsation.

[0084] Further analysis of the plastic flow characteristics reveals that the formation of the rib 12 is not simply a localized outward bulge of the tube wall, but rather depends on the convergence of material within a certain axial range near the rib 12 into the cavity. Therefore, the key factor determining the size of the rib 12 is the volume of material available for flow at that location.

[0085] The area near the free end of the connection retains a relatively large wall thickness, thus this region actually has a fairly sufficient material reserve. If, during the local high-pressure preforming process, the material in the thicker area of ​​the free end can be appropriately transferred to the thin-walled area near the irregular section, the problem of insufficient material in the thin-walled area can be compensated, thereby ultimately forming the rib 12 dimensions that meet the design requirements at each location.

[0086] Therefore, if all the ribs 12 fill the cavity simultaneously under the same pressure, each rib 12 can only preferentially utilize the material near it for plastic flow. The cavities compete for material simultaneously, and the thin-walled areas far from the free end still struggle to obtain sufficient material, thus failing to fully utilize the material advantage of the thicker areas at the free end. Furthermore, once the ribs 12 closest to the free end are fully formed, their geometry will obstruct axial material flow, effectively locking the material flow channel in advance, making it even more difficult for subsequent material to continue flowing to areas far from the free end.

[0087] Therefore, a more reasonable approach would be to employ a phased, progressive preforming process. First, the ribs 12 closest to the irregular section and corresponding to the thinnest wall area should undergo partial plastic deformation, but not immediately fill the cavity completely; instead, a certain material flow channel should be maintained. Then, the internal pressure should be increased, coupled with axial feeding, allowing material from the thicker areas at the free end to continuously migrate towards areas further away from the free end. Once all areas have been adequately fed, the final shaping stage should commence, compacting all ribs 12 to the final dimensions. This ensures continuous axial flow of material throughout the forming process and fully utilizes the thicker areas at the free end as material reserves, enabling the redistribution of material across different wall thicknesses.

[0088] Therefore, after obtaining the wall thickness information of the connecting section 11 through the set multiple sets of detection components 73, the spacing between the pre-forming partitions 462 of the ribs 12 is enlarged according to the wall thickness difference, especially in the thin-walled area, so as to gather more material to the required position. Next, the mold is closed by the mold closing mechanism 3, and lubricating oil is sprayed according to the real-time position of the partition 462 to reduce the resistance of material flow; the insert cylinder 72 pushes out the connecting section 11, the angle deflection cylinder 65 drives the deflection plate 66 to rotate in the opposite direction, and the second station 662 is switched to the first station 661; then, the first push cylinder 61 and the second push cylinder 63 are controlled according to the preset displacement and force curve, the second punch 64 seals one end of the tube blank 1, and the first punch 62 applies axial thrust to the end of the tube blank 1 to replenish material. Since multiple sets of partitions 462 form pre-formed cavities that change gradually along the axial direction before mold closing, the effective volume of each cavity gradually increases from the free end to the inside. Therefore, during forming, through the synergistic effect of internal pressure and axial replenishment, the material preferentially flows to the thin-walled area with a larger volume, thereby realizing material redistribution. During this period, the tube blank 1 is filled with a low-pressure liquid medium. During this period, the first push cylinder 61 and the second push cylinder 63 continuously feed material axially according to the preset displacement curve, and the booster simultaneously increases the pressure inside the pipe, so that the material gradually fills the gradient cavity formed by the pre-enclosed partitions 462. The ribs 12 at each position complete the molding in sequence, and finally multiple sets of ribs 12 are formed on the outer periphery of the connecting section 11.

[0089] It is important to note that the rib 12 closest to the end of the connecting section 11 is designed as a pointed shape. During the bulging process of the metal tube, material will only actively flow in when the mold size reaches a certain level, requiring sufficient pressure to completely adhere to the mold. However, a pointed cone shape is extremely difficult to achieve in one step. In contrast, a dome-shaped rib 12 with an isosceles trapezoidal cross-section is easier to form. Therefore, the pointed rib 12 closest to the end of the connecting section 11 is formed using a combination of pre-forming and imprinting: first, internal high pressure and axial feeding create a narrower isosceles trapezoidal pre-rib 12 at this location; then, under pressure, the top of the pre-rib 12 is locally radially compressed by the imprinting flange on the corresponding partition 462, ultimately forming a pointed structure. Since the pointed structure is mainly obtained through subsequent imprinting, rather than entirely relying on material flow into the pointed cavity, this significantly reduces the difficulty of mold application and improves forming stability.

[0090] Finally, the pressure relief and mold opening operation is performed, and the irregular tube embedded in the lower mold core 44 is ejected by the ejector pin 482 set on the partition plate 462.

[0091] The implementation principle of the new energy vehicle special-shaped pipe connection structure and its internal high-pressure expansion device in this application embodiment is as follows: First, the wall thickness detection mechanism 7 is used to detect the wall thickness at each axial position of the connection section 11. The controller 21 establishes the correspondence between each position and the size of the target rib 12 based on the detected wall thickness data, and calculates the effective volume required for each pre-forming cavity. Then, the drive spacing adjustment component 47 adjusts the initial spacing between each group of partitions 462, so that different positions form gradient pre-forming cavities with gradually changing axial volumes. After the partition 462 position is set, the lifting component 48 sprays lubricating oil onto the contact area between the partition 462 and the tube blank 1.

[0092] Subsequently, the first punch 62 and the second punch 64 are inserted into both ends of the tube blank 1 to form a reliable seal. During the process of injecting the forming medium into the tube blank 1 by the internal high-pressure filling mechanism 5, axial feeding is continuously applied by the feeding mechanism 6, so that the internal pressure and axial thrust work together on the tube blank 1. Since the effective volume of each pre-forming cavity gradually increases from the free end to the shaped section, the material preferentially flows to the thin-walled area with a larger volume, causing the material stored in the thicker area of ​​the free end to continuously migrate away from the free end, realizing the redistribution of axial material in the connecting section 11, increasing the volume of material in the thin-walled area that can participate in plastic deformation, thereby ensuring that the rib 12 dimensions that meet the design requirements can be formed at each position.

[0093] During the preforming stage, the ribs 12 at each position gradually enter the plastic deformation state, and the material always maintains a continuous axial flow channel to avoid the ribs 12 in the thick-walled area from being completely molded too early and hindering the subsequent material from being transported to the thin-walled area. As the internal pressure continues to increase and is combined with axial feeding, the material at each position continuously fills the corresponding preforming cavity. Finally, each group of ribs 12 completes the molding in sequence, realizing the balanced distribution of material in the entire connecting section 11 and the consistent forming of the rib 12 structure.

[0094] For the pointed rib 12 near the free end of the connecting section 11, since the pointed cavity requires a high degree of material adhesion, relying solely on internal high-pressure bulging can easily lead to insufficient filling. Therefore, a combination of pre-forming and stamping is used for processing to ultimately form a pointed structure at the top. This method avoids directly filling the sharp cavity with material, significantly reducing the difficulty of forming the pointed rib and improving the dimensional accuracy and forming stability of the pointed rib 12.

[0095] Finally, the mold is opened by depressurization, and the irregular-shaped tubing is ejected using ejector pins 482 mounted on partition 462. Because the connecting section 11 has differentiated rib structures 12 matching local stiffness in different wall thickness areas—thick-walled areas with lower, narrower pointed ribs 12, and thin-walled areas with higher, wider, rounded pointed ribs 12—a relatively uniform contact stress distribution is achieved at all locations of the connecting section 11 after the hose is press-fitted. Specifically, the thin-walled areas compensate for insufficient local stiffness by increasing the size of the ribs 12, thereby improving the sealing contact pressure; the thick-walled areas reduce local stress concentration and the risk of microcracks by reducing the size of the ribs 12 and using a pointed structure. This results in the entire connecting structure possessing excellent sealing performance, pull-out resistance, and connection reliability under long-term thermal cycling conditions.

[0096] This application also discloses a manufacturing process for a special-shaped pipe connection structure for new energy vehicles, including the following steps: S1. One-time internal high-pressure forming: The metal round tube is placed in the one-time internal high-pressure bulging mold. The metal round tube is bulged in one-time internal high-pressure by a combination of internal high-pressure liquid filling and axial feeding, so as to form a tube blank 1 with the target special cross-section. After the tube blank 1 has been expanded, it is taken out and transported to the connection structure processing station. S2. Wall thickness detection of connecting section 11: The tube blank 1 is placed in the second cavity of the lower mold core 44. The controller 21 drives the angle deflection cylinder 65 to rotate the deflection plate 66, so that the wall thickness detection mechanism 7 corresponds to the connecting section 11. Then, the telescopic drive component 71 pushes the insertion cylinder 72 to insert into the connecting section 11. During the insertion process, the scraper 75 first scrapes and cleans the inner wall of the connecting section 11 to remove oil and oxide layer. Then, the coating seat 742 evenly sprays ultrasonic coupling agent onto the corresponding detection area. Multiple sets of ultrasonic detection components 73 simultaneously detect the wall thickness data of the connecting section 11 at different axial positions and feed the detection results back to the controller 21. The controller 21 establishes an axial wall thickness distribution model of the connecting section 11. S3. Gradient cavity adaptive setting: The controller 21 calculates the effective volume required for the preformed cavity at each detection position based on the wall thickness data and the corresponding target rib 12 size, and drives the spacing adjustment component 47 to adjust the spacing between each group of partitions 462 respectively, so that the connecting section 11 forms a gradient-changing preformed cavity along the axial direction. After the adjustment of each group of partitions 462 is completed, they remain in a fixed position. S4. Lubrication pretreatment: After the position of the partition 462 is set, the pressurizing pump 484 delivers lubricating oil to each mounting column 481. The lubricating oil seeps out through the mounting cavity 4811 and the connecting groove 4813 to the space between the partition 462 and the connecting section 11, forming a continuous lubricating film at the contact position between each set of partitions 462 and the tube blank 1. After lubrication is completed, the oil supply is stopped. S5. Mold closing and end sealing: Controller 21 controls the mold closing mechanism 3 to complete mold closing. Then, the angle deflection cylinder 65 drives the deflection plate 66 to switch to the first station 661. The first push cylinder 61 and the second push cylinder 63 respectively drive the first punch 62 and the second punch 64 to insert into both ends of the tube blank 1 to perform axial sealing on both ends of the connecting section 11. The low-pressure liquid filling system then quickly fills the tube blank 1 with the forming liquid medium to complete the pre-filling.

[0097] S6. Gradient preforming: The pressurization system begins to slowly increase the pressure inside the pipe. At the same time, the first pusher cylinder 61 and the second pusher cylinder 63 continue to feed material axially according to the preset displacement curve. Due to the difference in the preset cavity volume at each position of the connecting section 11, under the combined action of internal pressure and axial feeding, the material in the thicker area of ​​the free end preferentially migrates axially to the thinner wall area with a larger volume. The ribs 12 at each position gradually form a pre-protrusion structure, but none of them are completely molded. The connecting section 11 always maintains a continuous material flow channel. S7. Gradient shaping: Continue to increase the pressure inside the tube and simultaneously maintain axial feeding. Material at each position continues to fill the corresponding pre-formed cavity, and each group of pre-protruding ribs 12 completes the molding and shaping in sequence. Among them, the thin-walled area near the irregular section receives feeding material from the thick-walled area, forming a high and wide arc-shaped top rib 12; the thick-walled area near the free end forms a low and narrow pre-formed rib 12, ultimately making the connecting section 11 form a gradient connection structure with gradually changing height and width along the axial direction. S8. The pointed tip is pressed and shaped to maintain stable pressure inside the tube, so that the pre-formed rib 12 closest to the free end position maintains a narrow isosceles trapezoidal shape at the top. Then, the pressing flange on the corresponding partition plate 462 performs local radial pressing on the top of the pre-formed rib 12. At the same time, the first push cylinder 61 continues to perform a small amount of axial feeding to further fill the sharp corner area with material, and press the top of the pre-formed rib 12 to form a pointed structure, thereby completing the final shaping of the free end pointed rib 12. S9. Depressurization and Demolding. After all the connecting structures are processed, the controller 21 controls the pressurization system to gradually depressurize, the first push cylinder 61 and the second push cylinder 63 exit the connecting section 11, the mold closing mechanism 3 opens the mold, and then the ejector pins 482 on the partition plate 462 eject the processed new energy vehicle special-shaped pipe parts out of the mold, completing the manufacturing process of the entire connecting structure.

[0098] The above are all optional embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A connection structure for irregularly shaped pipe fittings in new energy vehicles, characterized in that, include: Tube blank (1), the tube blank (1) is a special-shaped tube made by a one-time internal high pressure expansion process, and one end of the tube blank (1) is set as a connecting section (11). Multiple sets of annular ribs (12) are provided on the outer peripheral surface of the connecting segment (11). The multiple sets of ribs (12) are spaced apart along the axial direction of the connecting segment (11). The protrusion height and axial width of the multiple sets of ribs (12) increase with the increase of the axial distance from the connecting segment (11). Among the multiple sets of ribs (12), the ribs (12) near the end face of the connecting segment (11) are set as pointed tops, and the ribs (12) away from the end face of the connecting segment (11) are set as rounded tops.

2. The connection structure for irregularly shaped pipe fittings in new energy vehicles according to claim 1, characterized in that: The set of ribs (12) closest to the end face of the connecting segment (11) is set as the first rib (121), the first rib (121) having a height H1 and an axial width W1; the set of ribs (12) furthest from the end face of the connecting segment (11) is set as the Nth rib (122), the Nth rib (122) having a height Hn and an axial width Wn; wherein, the height of the first rib (121) and the Nth rib (122) satisfies 1.5≤Hn / H1≤3.5, and the width of the first rib (121) and the Nth rib (122) satisfies 1.2≤Wn / W1≤2.8; the height increment of two adjacent sets of ribs (12) is 0.2mm~0.6mm, and the width increment of two adjacent sets of ribs (12) is 0.1mm~0.5mm.

3. An internal high-pressure bulging device for a new energy vehicle irregular pipe fitting connection structure, used to produce the new energy vehicle irregular pipe fitting connection structure as described in claim 1, characterized in that, include: Machine base (2), on which a controller (21) is provided; A mold closing mechanism (3) is mounted on a machine base (2); The mold assembly (4) includes an upper mold base (41), an upper mold core (42), a lower mold base (43), and a lower mold core (44). The upper mold base (41) is disposed on the mold closing mechanism (3), the lower mold base (43) is disposed on the machine base (2), the upper mold core (42) is disposed on the upper mold base (41), the lower mold core (44) is disposed on the lower mold base (43), the upper forming mold (45) is disposed on the upper mold core (42), and the lower forming mold (46) is disposed on the lower mold base (43). The mold closing mechanism (3) is used to apply a downward clamping force to the upper mold core (42), so that the upper mold core (42) and the lower mold core (44) are tightly pressed together. When the upper mold core (42) and the lower mold core (44) are closed, they together form a cavity that matches the target outer contour of the tube blank (1). The lower forming mold (46) includes a guide shaft (461), a partition plate (462), a connecting plate (463), and a support plate (464). A receiving groove (441) is provided on the lower mold core (43). The guide shaft (461) is fixed within the receiving groove (441). Multiple sets of partition plates (462) are provided, and these sets are spaced apart along the axial direction of the guide shaft (461) within the receiving groove (441). Each set of partition plates (462) is provided with a forming flange (4621) and a forming groove (4622). A pre-forming cavity for bulging the rib (12) is formed between two adjacent sets of partition plates (462). The connecting plate (463) and the support plate (464) are both provided within the mold core (464). Inside the receiving groove (441), one side of the connecting plate (463) is fixedly connected to the side of the partition plate (462) away from the forming flange (4621), and the other side of the connecting plate (463) is connected to the support plate (464). Multiple sets of the connecting plate (463) and the support plate (464) are provided. The width of the multiple sets of the connecting plate (463) and the support plate (464) increases linearly along the axial direction of the connecting section (11) from the end face of the tube blank (1) away from the end face. In two adjacent sets of support plates (464), the set of support plates (464) with shorter width slides on the set of support plates (464) with longer width. The lower forming mold (46) has the same feature configuration as the upper forming mold (45). An internal high-pressure filling mechanism (5) is provided on the machine base (2) and is used to inject high-pressure forming medium into the tube blank (1). Feeding mechanism (6), which is mounted on the machine base (2), is used to seal the end of the tube blank (1) and apply axial feeding; A wall thickness detection mechanism (7) is provided on the feeding mechanism (6). The wall thickness detection mechanism (7) is used to detect the wall thickness of the connecting section (11). A spacing adjustment component (47) is provided between two adjacent sets of partitions (462). The spacing adjustment component (47) is electrically connected to the controller (21). The spacing adjustment component (47) is used to adjust the spacing between adjacent partitions (462). The controller (21) controls the spacing adjustment component (47) to adjust the volume of each pre-forming cavity according to the wall thickness data detected by the wall thickness detection mechanism (7) so as to form differentiated ribs (12) in different wall thickness areas of the tube blank (1).

4. The internal high-pressure bulging device for connecting irregularly shaped pipe fittings in new energy vehicles according to claim 3, characterized in that: The feeding mechanism (6) includes a first push cylinder (61), a first punch (62), a second push cylinder (63), and a second punch (64). A first bracket (22) is provided on one side of the lower mold base (43). An angle deflection cylinder (65) is fixed on the first bracket (22). The angle deflection cylinder (65) is electrically connected to the controller (21). A deflection plate (66) is fixed on the output end of the angle deflection cylinder (65). A first station (661) and a second station (662) are respectively provided on the deflection plate (66). The first station (661) and the second station (662) are symmetrically arranged along the deflection plate (66). The angle deflection cylinder (65) drives the deflection plate (66) to rotate, so that the first station (661) or the second station (662) is aligned with the connecting section (11). The wall thickness detection mechanism (7) is set on the second station (662), the first push cylinder (61) is fixed on the first station (661), the first push cylinder (61) is electrically connected to the controller (21), the output end of the first push cylinder (61) can extend and retract along the axial direction of the connecting section (11), and the first punch (62) is set on the output end of the first push cylinder (61); the other side of the lower mold base (43) is fixedly provided with a second bracket (23), the second push cylinder (63) is fixed on the second bracket (23), the second push cylinder (63) is electrically connected to the controller (21), and the second punch (64) is fixed on the output end of the second push cylinder (63).

5. The internal high-pressure bulging device for connecting irregularly shaped pipe fittings in new energy vehicles according to claim 4, characterized in that: The wall thickness detection mechanism (7) includes a telescopic drive (71), a plug-in cylinder (72), and a detection component (73). The telescopic drive (71) is fixed on the second station (662) and electrically connected to the controller (21). The plug-in cylinder (72) is disposed on the output end of the telescopic drive (71). The plug-in cylinder (72) is telescopically mounted on the second station (662) via the telescopic drive (71). The component (73) is disposed on the plug-in cylinder (72). The detection component (73) is electrically connected to the controller (21). The detection component (73) is used to measure the wall thickness of the connecting section (11). Multiple sets of the detection component (73) are disposed on the plug-in cylinder (72). The multiple sets of the detection component (73) are evenly spaced along the circumference and axial direction of the plug-in cylinder (72). The coating component (74) is used to spray coupling agent onto the inner wall of the connecting section (11) before detection.

6. The internal high-pressure bulging device for connecting irregularly shaped pipe fittings in new energy vehicles according to claim 5, characterized in that: The wall thickness detection mechanism (7) further includes a coating component (74), which includes a micro injection pump (741), a coating seat (742), and a storage box (743). The coating seat (742) is fixed on the insertion cylinder (72) and is located at the end of the insertion cylinder (72) away from the deflection plate (66). The coating seat (742) has a liquid outlet on the side facing away from the insertion cylinder (72). 7421), the micro injection pump (741) is fixed on the deflection plate (66), the micro injection pump (741) is electrically connected to the controller (21), the liquid storage box (743) is set on the machine base (2), the liquid storage box (743) is filled with coupling agent, the liquid storage box (743) is connected to the input end of the micro injection pump (741), and the output end of the injection pump (472) is connected to the liquid outlet (7421).

7. The internal high-pressure bulging device for connecting irregularly shaped pipe fittings in new energy vehicles according to claim 6, characterized in that: The coating seat (742) is provided with a scraper (75) on the side opposite to the test piece (73). The scraper (75) is used to scrape the inner wall of the connecting section (11) before the insertion of the plug tube (72).

8. The internal high-pressure bulging device for connecting irregularly shaped pipe fittings in new energy vehicles according to claim 3, characterized in that: The spacing adjustment component (47) includes a first oil box (471), an injection pump (472), and a piston rod (473). A first flow channel (4641) and a piston groove (4642) are provided on the support plate (464). The first flow channel (4641) communicates with the piston groove (4642). One end of the piston rod (473) is slidably disposed within the piston groove (4642), and the other end of the piston rod (473) is connected to the connecting plate (463) on the adjacent side. The injection pump (472) is disposed on the lower mold base (…). 43) The injection pump (472) is electrically connected to the controller (21), the first oil box (471) is connected to the input end of the injection pump (472), and the output end of the injection pump (472) is connected to the first flow channel (4641). The injection pump (472) drives the piston rod (473) to extend and retract by injecting hydraulic oil into the first flow channel (4641), thereby driving the support plate (464) to move on the guide shaft (461), thereby adjusting the distance between the two adjacent sets of partitions (462).

9. The internal high-pressure bulging device for connecting irregularly shaped pipe fittings in new energy vehicles according to claim 3, characterized in that: The mold assembly (4) further includes a lifting component (48), which includes a mounting post (481), an ejector pin (482), a retaining spring (483), and a pressure pump (484). The mounting post (481) is fixed to one side of the partition plate (462). The mounting post (481) has a mounting cavity (4811) and a transition cavity (4812) inside. A connecting groove (4813) is provided on the inner wall of the transition cavity (4812). The ejector pin (482) passes through the transition cavity (4811). 2) The device is movably mounted on the mounting post (481), with one end of the ejector pin (482) extending into the mounting cavity (4811) and the other end extending out of the transition cavity (4812). A sealing portion (4821) is fixedly provided at one end of the ejector pin (482) extending into the mounting cavity (4811), and a pushing portion (4822) is fixedly provided at the other end of the ejector pin (482). The sealing portion (4821) is slidably disposed within the mounting cavity (4811), and the sealing portion (4821) has an opening on it. An overflow groove (4823) is provided. An annular abutment part (4814) is fixed on the inner wall of the mounting cavity (4811). The abutment part (4814) is in movable contact with the sealing part (4821). The push part (4822) is frustoconical. One end of the mounting post (481) is provided with a matching storage groove. The clamping spring (483) is sleeved on the push pin (482). One end of the clamping spring (483) is connected to the sealing part (4821), and the other end of the clamping spring (483) is connected to the sealing part (4821). The end is connected to the inner wall of the mounting cavity (4811), and the clamping spring (483) can make the push part (4822) flush with the inner wall of the mold cavity when it is not working; during the demolding stage, the ejector pin (482) can extend out of the cavity surface and push out the formed tube; the pressure pump (484) is connected to the mounting cavity (4811), and the pressure pump (484) is used to inject lubricating oil and make the lubricating oil seep out through the connecting groove (4813) to the contact surface between the partition plate (462) and the tube blank (1).

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