Plate-pipe plastic connecting device and method based on plate blanking-bending-flattening

Abstract

The invention belongs to the technical field of metal material plastic connection, and relates to a plate-pipe plastic connection device and method based on plate blanking-bending-flattening. The device comprises a plate pre-deformation mold and a flattening mold, the plate pre-deformation die comprises a blank holder, a female die, a punch and a male die. The punch and the male die are installed above the female die. The central axes of the annular ribs on the surface of the male die and the arc-shaped grooves in the female die coincide in the vertical direction; the flattening die comprises a supporting die and an extrusion die. A to-be-connected plate is placed between the blank holder and the female die, and the punch punches the joint of the to-be-connected plate to form a connecting hole; the annular rib pushes the plate to be bent into the arc-shaped groove, and pre-machining of the plate is completed; the pre-machined plate is sleeved with the pipe to be connected, and the pre-machined plate is arranged between the supporting die and the extrusion die; and the extrusion die extrudes the pre-machined plate, the plate is gradually flattened after being pressed, and the mechanical lock catch is formed. Machining of blanking, bending and flattening is achieved, and flexibility of the connection strength of the plate and the pipe is completed.

Description

Technical Field

[0001] The present invention belongs to the technical field of plastic connection of metal materials, and particularly relates to a plate-tube plastic connection device and method based on plate blanking-bending-flattening. Background Technique

[0002] In recent years, with the wide application of lightweight technologies in transportation tools such as automobiles and airplanes, and the continuous improvement of the requirements for the connection quality, reliability, and efficiency of metal tubes and plates in various industries, traditional metal tube and plate connection methods, such as welding, riveting, and gluing, have many drawbacks. During the welding process, high temperatures easily cause changes in the metallographic structure at the connection between the metal tube and the plate, leading to thermal deformation and making it difficult to ensure the dimensional accuracy of the connection part. Although riveting is relatively simple to operate, it requires pre-drilling holes in the metal tube and plate, which not only weakens the strength of the metal material but may also cause connection failure due to rivet loosening. Although gluing technology can avoid thermal deformation and hole-opening problems to a certain extent, the gluing strength is limited, and delamination is likely to occur under large loads or harsh environmental conditions, resulting in connection failure.

[0003] The plastic connection technology of plates has high connection strength and conforms to lightweight manufacturing. However, there is currently no complete set of plastic connection devices for plates that can complete the processing of blanking-bending-flattening together. Therefore, developing a new, efficient, and reliable metal plate-tube connection technology has become an urgent problem to be solved. Summary of the Invention

[0004] The purpose of the present invention is to provide a plate-tube plastic connection device and method based on plate blanking-bending-flattening, which realizes the processing of blanking-bending-flattening and completes the flexible connection strength between the plate and the tube.

[0005] The present invention is realized through the following technical solutions: The present invention discloses a plate-tube plastic connection device based on plate blanking-bending-flattening, which includes a plate pre-deformation die and a flattening die; The plate pre-deformation die includes a blank holder, a die, a punch, and a convex die; the punch and the convex die are installed above the die, and the punch is located inside the convex die; the processing surface of the convex die is provided with an annular rib, and an arc-shaped groove is prefabricated on the die. The central axes of the annular rib and the arc-shaped groove coincide vertically; During use, the plate to be connected is placed between the blank holder and the die, and the punch is used to punch the connection part of the plate to be connected to form a connection hole; The annular rib is used to push the plate into the arc-shaped groove to complete the pre-processing of the plate; The flattening die includes a support die and an extrusion die. There are mounting holes in the centers of the support die and the extrusion die for installing the tube to be connected; When performing the flattening process, the pre-processed sheet is sleeved with the pipe to be connected, and the pre-processed sheet is placed between the support die and the extrusion die; The extrusion die is used to extrude the pre-processed sheet. After being pressed, the pre-processed sheet is gradually flattened. The sheet contacts the pipe and they are mutually extruded to form a mechanical lock, completing the plastic connection between the pipe and the sheet.

[0006] Furthermore, the radius of the annular rib is , ; The end face distance from the center of the annular rib to the outer cylindrical surface of the punch is , where .

[0007] Furthermore, the inner diameter of the connection hole of the sheet after blanking is , the outer diameter of the pipe is , where .

[0008] Furthermore, the wall thickness of the sheet is , ; the thickness of the pipe is , .

[0009] Furthermore, a blanking port is provided in the female die, and the blanking port has a tapered inclined surface, and the angle of the tapered inclined surface is .

[0010] Furthermore, a fillet is provided at the edge of the arc-shaped groove.

[0011] The present invention also discloses a sheet-pipe plastic connection method based on sheet blanking-bending-flattening, including the following steps: S1. Place the sheet to be connected between the blank holder and the female die, and install the punch and the male die directly above the sheet; S2. Keep the female die stationary, and the punch moves towards the sheet. The punch moves downward to punch a connection hole in the center of the sheet, completing the blanking; S3. The male die moves towards the sheet. The annular rib prefabricated on the processing surface of the male die pushes the sheet to bend into the arc-shaped groove prefabricated on the surface of the female die. The material around the connection hole punched on the sheet flows into the arc-shaped groove, and the size of the circular hole in the center of the sheet expands, completing the pre-processing of the sheet; S4. Sleeve the pre-processed sheet with the pipe to be connected, and place it between the support die and the extrusion die; S5. Keep the support die stationary, and the extrusion die moves towards the support die. The sheet is gradually flattened under pressure, the size of the circular hole in the center of the sheet gradually shrinks, the sheet contacts the pipe and they are mutually extruded to form a mechanical lock, completing the plastic connection between the pipe and the sheet.

[0012] Furthermore, the punch moves towards the sheet at a speed V1, .

[0013] Further, the punch moves towards the sheet at a speed V2. .

[0014] Further, the extrusion die moves towards the direction of the support die at a speed V3. .

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: The device for realizing the method for connecting a pipe and a sheet by using the plastic deformation of the pipe disclosed in the present invention includes a sheet pre-deformation die and a flattening die. By punching a connection hole on the surface of the sheet with a punch, and through the extrusion action of a concave die and a punch, the material around the connection hole of the sheet undergoes plastic deformation, expanding the inner diameter of the connection hole. Then, the extrusion die extrudes the pre-treated sheet, and the warped part around the round hole of the sheet is flattened under pressure, causing the connection hole to shrink, tightly clamping the pipe to be connected in the hole, generating a mechanical locking structure, and completing the plastic connection between the sheet and the pipe. The present invention punches and bends the sheet through the sheet pre-deformation die, and extrudes the sheet that has been pre-processed by the flattening die to complete the plastic connection between the sheet and the pipe. The die of the present invention has a simple structure, low processing cost, and short manufacturing cycle; it has a simple structure, reasonable design, convenient installation, good compatibility with conventional equipment, and is suitable for mass production.

[0016] Further, the blanking port of the concave die is a conical inclined surface. During the blanking process, after the material in the middle of the sheet fractures, it will slide down along the conical surface under its own gravity, facilitating the separation from the concave die.

[0017] Furthermore, a fillet is provided at the edge of the arc-shaped groove of the concave die to avoid damaging the surface of the sheet during the bending process of the sheet, and the through holes on the surface of the sheet are uniformly expanded.

[0018] The plastic connection method of plate and pipe based on plate blanking-bending-flattening disclosed by the present invention processes the plate through a punch and a die. Through the extrusion of the die and the punch, the material around the connection hole of the plate flows, expanding the inner diameter of the connection hole. Then, the extrusion die extrudes the deformed plate, and the bent part of the plate is flattened under pressure, resulting in the shrinkage of the connection hole diameter, tightly clamping the pipe to be connected in the hole, generating a mechanical locking structure, and completing the plastic connection of the plate and the pipe. During the connection process of the present invention, the connection hole of the plate expands first and then shrinks, the plate firmly clamps the pipe, and the pipe undergoes local deformation, effectively avoiding the loosening phenomenon caused by the small interaction force between the plate and the pipe, and significantly improving the connection stability. The present invention can flexibly change the sizes of the annular ribs and arc grooves on the surfaces of the die and the punch according to the size parameters, material properties, and connection strength requirements of the plate-pipe, so as to accurately adapt to different application scenarios. In addition, this method does not require additional connection auxiliary parts, conforms to the concept of lightweight design, and at the same time realizes the flexible adjustment of the connection strength between the plate and the pipe. Therefore, the present invention is suitable for large-scale and automated production, can greatly improve production efficiency, and will not cause pollution to the environment during the production process, fully reflecting the development trend of green environmental protection.

[0019] Further, the plate and the pipe are plastic materials such as low-carbon steel, stainless steel, aluminum alloy, or magnesium alloy; the plastic bending of the plate is realized through the extrusion of the die and the punch, and the flattening necking of the plate and the connection with the pipe are realized through the extrusion of the extrusion die and the support die. To ensure reliable connection, the mechanical properties of the plate material need to be greater than or equal to those of the pipe. Description of the Drawings

[0020] Figure 1 is a schematic diagram of the layout of the plate pre-deformation die; Figure 2 is a schematic diagram of plate blanking; Figure 3 is a schematic diagram of plate pre-deformation; Figure 4 is a diagram of the flattened connection state; Figure 5 is a schematic diagram of the mechanical lock of the plate-pipe; Figure 6 is a diagram of the connection effect of the plate-pipe.

[0021] In the figure: 1, blank holder; 2, plate; 3, die; 31, arc groove; 4, punch; 5, punch; 51, annular rib; 6, support die; 7, extrusion die; 8, pipe. Detailed Embodiment

[0022] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following further detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments.

[0023] The components described and illustrated in the accompanying drawings and embodiments of the present invention can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present invention provided in the following drawings is not intended to limit the scope of the claimed present invention, but merely represents a selected embodiment of the present invention. Based on the accompanying drawings and embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present invention.

[0024] It should be noted that: the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, element, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to the process, element, method, article or device. In addition, the terms "lower" and "upper" are based on the orientation and positional relationship of the devices or components shown in the drawings, and are only for better describing the present invention, rather than requiring the devices, components or devices shown to have that specific orientation. Therefore, it cannot be understood as a limitation to the present invention.

[0025] The features and performance of the present invention are further described in detail below in conjunction with embodiments.

[0026] As Figure 1 shown, a specific set of devices for implementing the present invention is used as an example to specifically explain a method for plastic connection of a plate and a tube based on sheet metal blanking-bending-flattening of the present invention, which does not constitute a limitation to the present invention. The method of the present invention can be implemented using any existing device that can achieve its step-by-step functions.

[0027] The device includes a sheet metal pre-deformation die and a flattening die; as Figures 1 - 3 shown, the sheet metal pre-deformation die includes a blank holder 1, a die 3, a punch 4, and a punch 5; as Figure 4 and Figure 5 shown, the flattening die includes a support die 6 and an extrusion die 7.

[0028] As Figure 2As shown in the figure, the punch 4 and the convex die 5 are installed above the concave die 3, and the punch 4 is located inside the convex die 5; the corresponding positions of the concave die 3 and the punch 4 are provided with mating conical surfaces, the upper surface of the concave die 3 is provided with an arc groove 31, the edge of the arc groove 31 is provided with a fillet, and the lower surface of the convex die 5 is provided with an annular rib 51 with a semicircular cross-section, and the annular rib 51 is matched with the arc groove 31; the central connection hole of the support die 6 is matched with the size and shape of the pipe 8.

[0029] The sheet material 2 and the pipe 8 are plastic materials such as carbon steel, magnesium alloy or aluminum alloy.

[0030] Generally, the thickness of the sheet material 2 is , and the wall thickness of the pipe 8 is . When the wall thickness of the pipe 8 is too large and the thickness of the sheet material 2 is too small, it is difficult to flatten the sheet material 2 and make the material of the pipe 8 flow, resulting in connection failure; when the thickness of the sheet material 2 is too large, the extrusion surface of the sheet material 2 on the pipe 8 increases, increasing the difficulty of necking of the pipe 8; when the wall thickness of the pipe 8 is too small, the surface of the pipe 8 is prone to cracking.

[0031] In a preferred embodiment of the present invention, as Figure 1 shown, the radius of the annular rib 51 on the lower surface of the convex die 4 is , and the end face distance from the center of the annular rib 51 to the outer circular surface of the punch 4 is , where .

[0032] Preferably, a blanking port is provided in the concave die 3, and the conical inclined surface of the blanking port is . During the blanking process, after the material in the middle of the sheet material 2 breaks, it will slide down along the conical surface under the action of its own gravity, which is convenient for separating from the concave die 3.

[0033] Furthermore, the diameter D of the punch 4 is 0.85 to 0.95 times the outer diameter d of the pipe 8. When the original through-hole diameter of the sheet material 2 is too small and the outer diameter of the pipe 8 is too large, the pipe will deform too much when the sheet material 2 unfolds, resulting in wrinkling and cracking of the pipe 8; when the original through-hole diameter of the sheet material 2 is too large, the diameter reduction amount of the pipe 8 after connection is small, and the connection strength is low or even unable to connect.

[0034] Furthermore, the wall thickness of the sheet material is , and the thickness of the pipe is . A sheet-pipe plastic connection method based on sheet blanking-bending-unfolding of the present invention specifically comprises the following steps: S1: Place the sheet material 2 to be connected between the blank holder 1 and the concave die 3, and install the punch 4 and the convex die 5 above the sheet material 2; S2: Keep the concave die 3 stationary, and the punch 4 moves downward at a speed , and punch a round hole with a diameter of D in the center of the sheet material 2; S3: The punch 5 moves downward at a speed of The annular rib 51 with a prefabricated cross-sectional radius of on its lower surface pushes the sheet 2 to bend into the arc-shaped groove 31 prefabricated on the surface of the die 3. The material around the circular hole of the sheet 2 flows into the arc-shaped groove 31, and the size of the central circular hole of the sheet 2 expands, completing the preprocessing of the sheet 2; S4: The preprocessed sheet 2 is sleeved with the pipe 8 to be connected and placed between the support die 6 and the extrusion die 7; S5: The support die 6 remains stationary, and the extrusion die 7 moves upward at a speed of The sheet 2 is gradually flattened under pressure. The size of the central circular hole of the sheet 2 shrinks. The sheet 2 contacts the pipe 8 and is mutually extruded to form a mechanical lock, completing the plastic connection between the pipe 8 and the sheet 2.

[0035] Furthermore, , this speed is the punching speed of the sheet 2 and can be adjusted according to the material and thickness of the sheet 2. For thinner sheets 2, the speed can be appropriately faster; for thicker or harder sheets 2, the speed should be slower to prevent damage to the die. A suitable speed can obtain a good circular hole wall surface.

[0036] Furthermore, , this speed is the bending speed of the sheet 2, mainly to push the material around the through hole of the sheet 2 downward. During the pushing process, the sheet 2 is bent and deformed to achieve the expansion of the hole diameter. A suitable speed can save time and accurately control its position.

[0037] Furthermore, , this speed is the speed at which the extrusion die pushes the sheet 2 to flatten, mainly to flatten the pre-deformed sheet 2, so that the through hole size shrinks, and the end face of the sheet 2 extrudes and pushes the plastic flow of the material of the pipe 8 during the shrinkage of the hole diameter. When the speed is too high, the plastic deformation of the material is uneven, and a large friction is generated at the contact surface between the sheet 2 and the pipe 8, resulting in poor connection joint quality. When the speed is too low, the connection time is prolonged.

[0038] The following is a specific embodiment to further explain and illustrate the present invention: As Figure 1 shown, the sheet 2 with a thickness of is placed on the die 3, the blank holder 1 is installed and fixed, and the punch 4 and the punch 5 with a diameter of are installed in place.

[0039] As Figure 2 shown, the punch 4 moves downward at a speed of to punch the sheet to obtain a through hole.

[0040] As Figure 3As shown, the punch 5 is at a speed The downward movement pushes the plate 2 to bend, and the material around the circular hole of the plate flows into the arc groove 31, and the diameter of the circular hole of the plate expands.

[0041] like Figure 4 As shown, the wall thickness , outer diameter The pipe 8 is fixedly placed in the circular hole of the supporting die 6, the pre-deformed sheet is mounted on the pipe 8, and then the extrusion die 7 is extruded at a speed of Move upward to push the plate 2 to flatten. After the plate 2 is completely flattened, the extrusion die 7 stops moving and takes out the plate 2. Figure 6 The connecting piece between the plate 2 and the pipe 8 shown completes the plastic connection between the metal pipe 8 and the plate 2.

[0042] like Figure 5 The figure shows a schematic diagram of the plate 2 being flattened and the aperture being shrunk to tighten the pipe 8.

[0043] like Figure 6 , which is the effect diagram after the plate 2 and the pipe 8 are connected.

[0044] Furthermore, the cross-sectional radius of the annular rib on the lower surface of the punch is ,in , the distance between the annular rib and the end face of the circular hole is l , when the cross-sectional radius If the cross-sectional radius is too small, the plate deformation is small, and the plate hole expansion ∆ is insufficient, which affects the subsequent plate-tube connection quality; when the cross-sectional radius is too large, the plate hole expansion ∆ is too large, which can easily lead to thinning and cracking of the hole wall, affecting the subsequent plate and pipe connection quality.

[0045] The plate 2 of the present invention undergoes a series of plastic deformations such as punching, bending and flattening, and is squeezed against the tube 8 to form a mechanical lock. This connection method can provide strong connection strength and stability, ensuring a reliable connection between the tube 8 and the plate 2. Compared with some traditional connection methods, such as welding, riveting, etc., it is less likely to loosen or fall off when subjected to large external forces.

[0046] The device can be applied to the connection of plates 2 and pipes 8 of different materials and specifications. For plates 2 of different thicknesses, precise control of blanking and bending can be achieved by adjusting the parameters of components such as the punch, the punch and the die; for pipes 8 of different diameters and materials, a good connection with the plate 2 can be achieved by replacing the plate pre-deformation die and the flattening die of the corresponding size and adjusting the extrusion parameters, which has high flexibility.

[0047] Since processing is carried out using a mold, the dimensional accuracy and shape consistency of each connection part can be guaranteed, thus improving the stability of the connection quality. The mold has high processing accuracy and good repeatability, which can effectively reduce connection quality problems caused by human factors or unstable processing techniques, such as loose connections and irregular buckle shapes, and is conducive to the control and improvement of product quality.

[0048] During the process of blanking - bending - flattening of the sheet 2, plastic deformation of the sheet 2 mainly occurs, and less material is wasted. Compared with some connection methods that require a large amount of cutting or material consumption, this device can make better use of the material of the sheet 2, reduce the material cost, and at the same time reduce the generation of waste materials, meeting the requirements of energy conservation and environmental protection.

[0049] The entire connection process does not involve pollutants such as smoke and waste gas generated during welding, nor does it require the use of materials such as chemical adhesives that may pollute the environment. Therefore, the impact on the environment is small, which is conducive to realizing green production.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific implementation manners of the present invention, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A plate-tube plastic connection device based on sheet blanking-bending-flattening, characterized in that It includes a sheet pre-deformation die and a flattening die; The sheet pre-deformation die includes a blank holder (1), a female die (3), a punch (4) and a male die (5); the punch (4) and the male die (5) are installed above the female die (3), and the punch (4) is located inside the male die (5); an annular rib (51) is provided on the machining surface of the male die (5), and an arc-shaped groove (31) is prefabricated on the female die (3), and the central axes of the annular rib (51) and the arc-shaped groove (31) coincide vertically; During use, the sheet to be connected (2) is placed between the blank holder (1) and the female die (3), and the punch (4) is used to punch the connection part of the sheet to be connected (2) to form a connection hole; The annular rib (51) is used to push the sheet (2) to bend into the arc-shaped groove (31) to complete the pre-processing of the sheet (2); The flattening die includes a support die (6) and an extrusion die (7), and there are installation holes in the centers of the support die (6) and the extrusion die (7) for installing the pipe (8) to be connected; During the flattening process, the pre-processed sheet (2) is sleeved with the pipe (8) to be connected, and the pre-processed sheet (2) is placed between the support die (6) and the extrusion die (7); The extrusion die (7) is used to extrude the pre-processed sheet (2). After being pressed, the pre-processed sheet (2) gradually flattens, and the sheet (2) contacts and squeezes the pipe (8) to form a mechanical lock, completing the plastic connection between the pipe (8) and the sheet (2).

2. The plate-tube plastic connection device based on sheet blanking-bending-flattening according to claim 1, wherein, The radius of the annular rib (51) is , ; The end face distance from the center of the annular rib (51) to the outer cylindrical surface of the punch (4) is , where .

3. A sheet-tube plastic connection device based on sheet blanking-bending-flattening according to claim 1, characterized in that The inner diameter of the connecting hole of the sheet material (2) after blanking is , the outer diameter of the pipe (8) is , where .

4. A plate-tube plastic connection device based on sheet blanking-bending-flattening according to claim 1, characterized in that, The wall thickness of the plate (2) is , ; the thickness of the pipe (8) is , .

5. A plate-tube plastic connection device based on sheet blanking-bending-flattening according to claim 1, characterized in that, The die cavity (3) is provided with a blanking opening, and the blanking opening has a conical inclined surface, and the angle of the conical inclined surface is .

6. A plate-tube plastic connection device based on plate blanking-bending-flattening according to claim 1, characterized in that, The edge of the arc-shaped groove (31) is provided with a fillet.

7. A plastic connection method for plate and tube based on plate blanking-bending-flattening, characterized in that, It includes the following steps: S1. Place the sheet to be connected (2) between the blank holder (1) and the female die (3), and install the punch (4) and the male die (5) directly above the sheet (2); S2. Keep the female die (3) stationary, and the punch (4) moves towards the sheet (2). The punch (4) moves downward to punch a connection hole in the center of the sheet (2) to complete punching; S3. The male die (5) moves towards the sheet (2). The annular rib (51) prefabricated on the machining surface of the male die (5) pushes the sheet (2) to bend into the arc-shaped groove (31) prefabricated on the surface of the female die (3). The material around the connection hole punched on the sheet (2) flows into the arc-shaped groove (31), and the size of the circular hole in the center of the sheet (2) expands to complete the pre-processing of the sheet (2); S4. Sleeve the pre-processed sheet (2) with the pipe (8) to be connected and place it between the support die (6) and the extrusion die (7); S5. Keep the support die (6) stationary, and the extrusion die (7) moves towards the support die (6). After being pressed, the sheet (2) gradually flattens, the size of the circular hole in the center of the sheet (2) gradually shrinks, and the sheet (2) contacts and squeezes the pipe (8) to form a mechanical lock, completing the plastic connection between the pipe (8) and the sheet (2).

8. A sheet-tube plastic connection method based on sheet blanking-bending-flattening according to claim 7, characterized in that The punch (4) moves towards the sheet (2) at a speed V1, .

9. A method for plastic connection of a plate and a pipe based on plate blanking-bending-flattening according to claim 7, characterized in that, The punch (5) moves towards the sheet (2) at a speed V2, .

10. A sheet-tube plastic connection method based on sheet blanking-bending-flattening according to claim 7, characterized in that, The extrusion die (7) moves in the direction of the support die (6) at a speed V3, .

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