Plate and pipe connecting method and device based on circumferential progressive extrusion deformation

Abstract

The invention belongs to the technical field of metal plastic connection, and relates to a plate and pipe connection method and device based on circumferential progressive extrusion deformation. The lower die, the plate and the upper die are sequentially sleeved outside the pipe from bottom to top; arranging an extrusion die on the pipe; a notch is prefabricated in the inner side face, close to the plate, of the upper-lower die to form a containing groove. Two annular bulges are prefabricated at the end part of the extrusion die; the extrusion die moves downwards along the center line of the pipe, the middle position of a groove of the extrusion die is flush with the middle position of the plate, and then the extrusion die moves in the radial direction of the pipe till the extrusion die is attached to the inner wall of one side of the pipe; the extrusion die moves circumferentially around the central axis of the pipe and moves outwards in the radial direction of the pipe according to a preset distance; in the moving process, the pipe is extruded to generate annular deformation protruding outwards; and the extrusion die stops radial motion and does circular motion around the central axis of the pipe. The problems that in the prior art, only the end of a pipe can be connected with a plate, and local breakage is prone to occurring are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of metal plastic connection, and in particular relates to a plate-tube connection method and device based on circumferential progressive extrusion deformation. Background Art

[0002] Plate-tube connectors are widely used in the fields of automobiles, chemicals, nuclear power, petroleum, etc. The strength and quality of their connections directly affect the overall performance and service life of the components. In the plate-tube connection process, compared with welding, mechanical connection methods do not require pre-welding treatment and post-welding inspection, and there will be no problem of structural changes after heating. They have the characteristics of fast, efficient connection, and high strength, making them an important connection method besides welding. Traditional mechanical connection methods, such as riveting and bolting, often require auxiliary parts, or are prone to problems such as loosening of connectors in the use environment, affecting the strength and reliability of the plate-tube connection.

[0003] In recent years, plate-tube plastic connection has attracted attention due to its high connection strength and green environmental protection characteristics. It utilizes the plastic deformation of metal materials to form a mechanical lock between the plate and the tube, thereby achieving plate-tube connection.

[0004] After searching, the patent document with application number 201811124324.0 discloses a method and device for plastic connection between metal pipes and plates, which realizes the connection between the plate and the pipe by opening a number of grooves on the inner wall of the pipe to be connected, and rolling the plastically deformed part of the plate flange into the annular groove of the pipe. However, for materials with poor plasticity such as titanium alloy and aluminum alloy, this method requires grooving inside the pipe, which will affect the strength of the pipe, and can only realize the connection between the end of the pipe and the plate. At the same time, it is easy to cause local rupture due to excessive deformation during the connection process. Therefore, it is urgent to develop a new method for connecting plates and pipes. Summary of the invention

[0005] The purpose of the present invention is to provide a plate-tube connection method and device based on circumferential progressive extrusion deformation, which solves the problem in the prior art that only the end of the tube can be connected to the plate and local rupture is prone to occur.

[0006] The present invention is achieved through the following technical solutions: The present invention discloses a plate-tube connection method based on circumferential progressive extrusion deformation, comprising the following steps: S1. Processing a circular hole at the position where the plate and tube are to be connected; Put the pipe on the center of the pad, and put the lower die, plate and upper die on the outside of the pipe from bottom to top in sequence; set the extrusion die above the pipe; A notch is prefabricated below one side of the upper die close to the outside of the pipe, and a notch is prefabricated above one side of the lower die close to the outside of the pipe, and the two notches form a receiving groove; Two annular protrusions are prefabricated at the end of the extrusion die, and the middle area between the two annular protrusions is a groove; S2. The extrusion die moves downward along the center line of the pipe, so that the middle position of the groove is flush with the middle position of the plate, and then moves along the radial direction of the pipe until the extrusion die fits against the inner wall of one side of the pipe; S3. The extrusion die makes a circular motion around the central axis of the pipe, and at the same time moves outward along the radial direction of the pipe according to a preset distance; during the compound motion of the extrusion die, the pipe is extruded to produce an outward protruding annular deformation; S4. After the annular deformation formed by the pipe meets the connection condition, the extrusion die stops the radial movement and makes a circular motion around the central axis of the pipe. After the deformation amounts generated by the annular deformation around the pipe are the same, the connection between the plate and the pipe is completed.

[0007] Furthermore, the extrusion die includes a connecting part and an extrusion end. The diameter of the extrusion end is larger than that of the connecting part, and a groove with a trapezoidal cross-section is machined on the outer circular surface of the extrusion end, so that annular protrusions are formed at both the upper end and the lower end of the extrusion end.

[0008] Furthermore, the pipe material is a plastic metal, and the extrusion die material is die steel.

[0009] Furthermore, the thickness of the pipe is t2, the thickness of the plate is t1, and t1 = (3 - 5)t2.

[0010] Furthermore, in S3, the extrusion die makes a circular motion around the central axis of the pipe at a constant angular velocity ω1, and at the same time moves outward along the radial direction of the pipe by a distance L at a speed V3; during the rotation of the extrusion die, the pipe is extruded to produce an outward protruding annular deformation; In S4, after the annular deformation formed by the pipe meets the connection condition, the extrusion die stops the radial movement and makes a circular motion around the central axis of the pipe at an angular velocity ω2; ω1 is 0.5 - 0.8 rad / s, and ω2 is 0.5 - 1 rad / s.

[0011] The present invention also discloses a plate-pipe connection device based on circumferential progressive extrusion deformation for realizing the plate-pipe connection method, including a lower die, an upper die, an extrusion die and a backing plate; a cylindrical protrusion structure is machined at the center above the backing plate for fixing the pipe; During use, the lower die, the plate, and the upper die are sleeved on the outside of the pipe in sequence from bottom to top; the extrusion die is placed inside the pipe to realize the circumferential extrusion of the pipe; A notch is prefabricated below the side of the upper die close to the outside of the pipe, and a notch is prefabricated above the side of the lower die close to the outside of the pipe. The two notches form a receiving groove; The extrusion die includes a connecting part and an extrusion end. The diameter of the extrusion end is larger than that of the connecting part. A groove with a trapezoidal cross-section is machined on the outer cylindrical surface of the extrusion end, so that annular protrusions are formed at both the upper end and the lower end of the extrusion end.

[0012] Furthermore, the width of the groove on the extrusion end is L2, and the dimension of L2 satisfies: t1 + t2 ≤ L2 ≤ t1 + 2t2; wherein, t1 is the thickness of the sheet material, and t2 is the thickness of the pipe material.

[0013] Furthermore, the horizontal distance between the outermost edge of the extrusion end and the bottom of the groove is L3, and L3 = (1 - 2)t2; t2 is the thickness of the pipe material.

[0014] Furthermore, the ends of the trapezoidal groove are all rounded.

[0015] Furthermore, the notches opened on the lower die and the upper die are rounded.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention discloses a method for connecting a plate and a pipe based on circumferential progressive extrusion deformation. A lower die, a sheet material, and an upper die are sequentially sleeved outside the pipe material; the upper die and the lower die have notches on the side close to the pipe material, which can leave space for the deformation of the pipe material, and the unnotched part can provide support during the deformation of the pipe material. The extrusion die includes a connecting part and an extrusion end. The diameter of the extrusion end is larger than that of the connecting part. A groove with a trapezoidal cross-section is machined on the outer cylindrical surface of the extrusion end, so that annular protrusions are formed at both the upper end and the lower end of the extrusion end. During the forming process, the extrusion die moves circumferentially around the central axis of the pipe material, and at the same time moves a certain distance outward in the radial direction. The circumferential extrusion of the pipe material is realized by the method of progressive extrusion forming to form a mechanical lock. The amount of deformation of the pipe material each time is small. In S3, the pipe material is extruded to generate an outward protruding annular deformation. At this time, the mechanical lock has been initially formed, but since the amount of deformation of the current annular deformation around the pipe material is inconsistent, this shape of the mechanical lock will affect the connection strength and quality. Therefore, in S4, by making the extrusion die move in a circular motion around the center line, the generated annular deformation is made more uniform, thereby improving the connection strength and stability.

[0017] During the forming process, different connection situations can be adapted by controlling the shape parameters and motion parameters of the extrusion die; the present invention can effectively improve the stress state of the metal pipe material during the plastic connection process of the pipe and the plate. On this basis, a mechanical lock is formed, which has high connection strength and can realize the rapid and efficient connection of different sheet materials and any position at the end or middle of the pipe material.

[0018] Further, ω1 is 0.5 - 0.8 rad / s, and ω2 is 0.5 - 1 rad / s. If the angular velocity of the extrusion die is too small, the forming efficiency is low; if the angular velocity is too large, the deformation of the local action area of the tube blank is insufficient.

[0019] Further, the thickness t2 of the pipe should be 2 - 5 mm, and the thickness t1 of the plate = 3 - 5t2. The greater the wall thickness of the pipe, the greater the extrusion force required to form the mechanical lock; if the pipe thickness is too small, the strength of the formed metal lock is insufficient.

[0020] The device for realizing the method of connecting a plate and a pipe by relying on the plastic deformation of the pipe disclosed in the present invention has a simple structure, is easy to operate, has good compatibility with conventional equipment, and is suitable for mass production.

[0021] Further, the width L2 of the groove under the extrusion die is sized such that: t1 + t2 ≤ L2 ≤ t1 + 2t2, to prevent the pipe from being cut by the extrusion die during deformation.

[0022] Further, the horizontal distance L3 between the extrusion end of the extrusion die and the bottom of the groove is L3 = 1 - 2t2. If the distance is too small, the deformation of the tube blank is insufficient and not enough connection strength can be provided; if the distance is too large, the strength of the extrusion end of the extrusion die is insufficient.

[0023] Further, the end of the extrusion head of the extrusion die is rounded, which can effectively reduce the extrusion force and improve the surface quality of the blank after processing.

[0024] Further, the notches of the upper die and the lower die are rounded, which is beneficial to the metal flow of the pipe and reduces stress concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of the overall structure of the present invention; Figure 2 is a partial enlarged view of the connection part Figure 3 is a schematic diagram of the progressive deformation of the pipe metal of the present invention Figure 4 is a schematic diagram of the mechanical lock formed by the plate - pipe connection Wherein, 1, pipe; 2, extrusion die; 3, upper die; 4, plate; 5, lower die; 6, backing plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following further detailed description is given in conjunction with the 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.

[0027] 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 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 fall within the protection scope of the present invention.

[0028] It should be noted that the term "comprising", "including" or any other variant 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 expressly listed, or also includes elements inherent in the process, element, method, article or device. In addition, the terms "horizontal" and "vertical" 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 shown devices, components or equipment to have this specific orientation. Therefore, it cannot be understood as a limitation to the present invention.

[0029] The features and performance of the present invention will be further described in detail below in conjunction with embodiments.

[0030] As Figure 1 shown, to implement a plate-tube connection device based on circumferential progressive extrusion deformation of the present invention, taking this as an example, a plate-tube connection method based on circumferential progressive extrusion deformation of the present invention will be specifically explained, 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.

[0031] As Figure 1 shown, a plate-tube connection device based on circumferential progressive extrusion deformation disclosed by the present invention includes: a pipe 1, an extrusion die 2, an upper die 3, a plate 4, a lower die 5, and a backing plate 6. The backing plate 6 is fixed on the workbench of the machine tool, and the pipe 1 is fixed at the cylindrical protrusion structure of the backing plate 6; the lower die 5, the plate 4, and the upper die 3 are sequentially sleeved on the outside of the pipe 1 from bottom to top, and the extrusion die 2 is fixed on the numerical control machine tool.

[0032] The extrusion die 2 makes a circumferential movement under the control of the machine tool, and at the same time has a certain displacement distance in the radial direction. This displacement distance is determined by the connection requirements of the connecting piece. If the connection strength requirement is high, the radial distance can be appropriately extended. The extrusion die 2 uses the method of progressive extrusion forming to achieve the circumferential extrusion of the pipe.

[0033] Specifically, the extrusion die 2 includes a connecting part and an extrusion end. The diameter of the extrusion end is larger than that of the connecting part. A groove with a trapezoidal cross-section is machined on the outer cylindrical surface of the extrusion end, so that an annular protrusion is formed at both the upper end and the lower end of the extrusion end. The annular protrusion is used to extrude the pipe 1 during the rotation of the extrusion die 2.

[0034] The ends of the trapezoidal grooves are all rounded.

[0035] In a preferred embodiment of the present invention, as Figure 2 shown, the groove width of the extrusion die 2 is L2, and the dimension of L2 satisfies: t1 + t2 ≤ L2 ≤ t1 + 2t2. Wherein, t1 is the thickness of the plate 4, and t2 is the thickness of the pipe 2.

[0036] In a preferred embodiment of the present invention, as Figure 1 and Figure 2 shown, a notch is opened below the surface of the upper die 3 close to the outer side of the pipe 1, and a notch is opened above the surface of the lower die 5 close to the outer side of the pipe 1. The two notches form a receiving groove.

[0037] In a preferred embodiment of the present invention, the notches opened on the upper die 3 and the lower die 5 are all rounded. When the pipe 1 is extruded, an arc-shaped lock is obtained. A right-angle design is easily broken by extrusion.

[0038] In a preferred embodiment of the present invention, the horizontal distance between the outermost edge of the extrusion end of the extrusion die 2 and the bottom of the groove is L3, and L3 = (1 - 2)t2, where t2 is the thickness of the pipe 2.

[0039] A method for connecting a plate and a pipe based on circumferential progressive extrusion deformation of the present invention includes: S1: At the plate-pipe connection position, a circular hole with a diameter of D is processed on the plate 4. The spacer 6 is fixed, and the pipe 1 is sleeved on the central cylindrical protrusion structure of the spacer 6. The lower die 5, the plate 4, and the upper die 3 are sequentially sleeved on the outside of the pipe 1 from bottom to top; S2: The extrusion die 2 moves downward along the center line of the pipe 1 at a speed of V1, so that the middle position of the groove below the extrusion die 2 is flush with the middle position of the plate 4, and then moves along the radial direction of the pipe 1 at a speed of V2 until the extrusion die 2 fits against the inner wall of the pipe 1; S3: As Figure 3 shown, the extrusion die 2 makes a circular motion around the central axis of the pipe 1 at a constant angular velocity ω1, and at the same time moves a distance L along the radial direction at a speed of V3. During the rotation of the extrusion die 2, the pipe 1 generates an outward protruding annular deformation due to extrusion.

[0040] S4: After the deformation formed on the pipe 1 meets the connection condition, the extrusion die 2 stops moving radially and makes a circular motion around the central axis of the pipe 1 at an angular velocity 2; because the amount of deformation of the currently generated annular deformation is inconsistent around the pipe, the position with a small amount of deformation will affect the overall connection strength; by making the extrusion die 2 make a circular motion around the center line of the pipe 1, the amount of deformation of the generated annular deformation is made consistent around the pipe, improving the connection strength and stability.

[0041] S5: After the connection is completed, the extrusion die 2 withdraws from the pipe-sheet connection position, moves out from inside the pipe 1, removes the upper die 3, and takes out the pipe-sheet connector.

[0042] Specifically, the specific process of S3 is as follows: As Figure 3 shown, in the initial state, the extrusion die 2 is in close contact with the inner wall of the pipe 1. Subsequently, the extrusion die 2 rotates 540° around the central axis of the pipe 1 at an angular velocity ω1, and at the same time moves outward a distance L in the radial direction of the pipe at a constant speed V3. During the movement of the extrusion die 2, the extrusion die 2 continuously extrudes the pipe 1, and the pipe 1 generates an annular protrusion outward.

[0043] The movement of the extrusion die 2 is a compound movement, including a circular movement around the center line of the pipe 1 and a radial movement in the radial direction.

[0044] In a preferred embodiment of the present invention, ω1 is 0.5 - 0.8 rad / s, and ω2 is 0.5 - 1 rad / s.

[0045] In a preferred embodiment of the present invention, the material of the pipe 1 is usually a plastic metal such as titanium alloy, aluminum alloy, magnesium alloy, etc., and the extrusion die 2 is made of die steel.

[0046] In a preferred embodiment of the present invention, the thickness t2 of the pipe 1 should be 2 - 5 mm, and the thickness t1 of the plate 4 = (3 - 5)t2.

[0047] The following takes a specific example to further explain the present invention.

[0048] 1) As Figure 1 、 Figure 2 shown, the material of the pipe 1 is 6061 aluminum alloy, the diameter of the hole opened on the pipe 1 is D = 60 mm, and the wall thickness t2 of the pipe 1 = 5 mm; the material of the extrusion die 2 is H13 die steel, and the parameters of the extrusion die 2 are L2 = 21 mm, L3 = 10 mm, L4 = 8 mm; the thickness t1 of the plate 4 = 15 mm. A circular hole with a diameter of D = 60 mm is processed on the plate 4. The backing plate 6 is fixed on the machine tool workbench, the pipe 1 is sleeved on the central cylindrical protrusion structure of the backing plate 6, and the lower die 5, the plate 4, and the upper die 3 are sequentially sleeved outside the pipe; 2) As Figure 1 shown, the extrusion die 2 is fixed on the machine tool and moves downward along the center line of the pipe 1 at a speed V1 = 4 mm / s, so that the middle position of the lower groove of the extrusion die 2 is flush with the middle position of the plate 4, and then moves along the radial direction of the pipe 1 at a speed V2 = 2 mm / s until the extrusion die 2 is in contact with the inner wall of the pipe 1; 3) As Figure 2 、 Figure 3As shown, the extrusion die 2 makes a circular motion around the central axis of the pipe 1 at 1 = 0.6 rad / s, and at the same time moves a distance L = 6 mm in the radial direction at a speed V3 = 0.4 mm / s. During the rotation of the extrusion die 2, the pipe 1 generates an outward protruding annular deformation due to extrusion. After the extrusion die rotates 1.5 turns, the deformation formed by the pipe 1 meets the connection condition. The extrusion die 2 stops the radial movement and makes a circular motion around the central axis of the pipe 1 at an angular velocity 2 = 1 rad / s; 4) After the extrusion die rotates one turn at 2, the plate 4 and the pipe 1 are completely connected. The extrusion die 2 withdraws from the plate-pipe connection position, moves out from the inside of the pipe 1, removes the upper die 3, and takes out the plate-pipe connector, forming a Figure 4 mechanical lock as shown.

[0049] Specifically, as Figure 4 shown, the pipe 1 is extruded, and annular protrusions are generated on both the upper and lower sides of the plate 4 respectively. The plate 4 is clamped between the annular protrusions, and a mechanical lock is formed.

[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 modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered by the protection scope of the claims of the present invention.

Claims

1. A method for connecting a plate and a pipe based on circumferential progressive extrusion deformation, characterized in that It includes the following steps: S1. A circular hole is machined at the position of the pipe-to-plate connection of the plate (4). The pipe (1) is sleeved at the center of the backing plate (6), and the lower die (5), the plate (4) and the upper die (3) are sequentially sleeved outside the pipe (1) from bottom to top; an extrusion die (2) is arranged above the pipe (1). Among them, a notch is prefabricated below the surface of the upper die (3) close to the outer side of the pipe (1), and a notch is prefabricated above the surface of the lower die (5) close to the outer side of the pipe (1), and the two notches form a receiving groove. Two annular protrusions are prefabricated at the end of the extrusion die (2), and the middle area between the two annular protrusions is a groove. S2. The extrusion die (2) moves downward along the center line of the pipe (1) so that the middle position of the groove is flush with the middle position of the plate (4), and then moves along the radial direction of the pipe (1) until the extrusion die (2) fits against the inner wall of one side of the pipe (1). S3. The extrusion die (2) makes a circular motion around the central axis of the pipe (1), and at the same time moves outward along the radial direction of the pipe (1) by a preset distance; during the combined motion of the extrusion die (2), the pipe (1) is extruded to generate an outward protruding annular deformation. S4. After the annular deformation formed by the pipe (1) meets the connection condition, the extrusion die (2) stops the radial movement and makes a circular motion around the central axis of the pipe (1). After the deformation amounts generated by the annular deformation around the pipe are the same, the pipe-to-plate connection is completed.

2. The tube-sheet connection method according to claim 1, wherein The extrusion die (2) includes a connecting part and an extrusion end. The diameter of the extrusion end is larger than that of the connecting part, and a groove with a trapezoidal cross-section is machined on the outer circular surface of the extrusion end, so that annular protrusions are formed at both the upper end and the lower end of the extrusion end.

3. The tube - plate connection method according to claim 1, wherein, The material of the pipe (1) is a plastic metal, and the material of the extrusion die (2) is die steel.

4. The tube-sheet connection method according to claim 1, wherein The thickness of the pipe (1) is t2, and the thickness of the plate (4) is t1, and t1 = (3 - 5)t2.

5. The tube-sheet connection method according to claim 1, characterized in that, In S3, the extrusion die (2) makes a circular motion around the central axis of the pipe (1) at a constant angular velocity ω1, and at the same time moves outward along the radial direction of the pipe (1) by a distance L at a speed V3; during the rotation of the extrusion die (2), the pipe (1) is extruded to generate an outward protruding annular deformation. In S4, after the annular deformation formed by the pipe (1) meets the connection condition, the extrusion die (2) stops the radial movement and makes a circular motion around the central axis of the pipe (1) at an angular velocity ω2. ω1 is 0.5 - 0.8 rad / s, and ω2 is 0.5 - 1 rad / s.

6. A tube - sheet connection device based on circumferential progressive extrusion deformation for implementing the tube - sheet connection method according to any one of claims 1 to 5, characterized in that, It includes a lower die (5), an upper die (3), an extrusion die (2) and a backing plate (6); a cylindrical protrusion structure is machined at the center above the backing plate (6) for fixing the pipe (1). During use, the lower die (5), the plate (4) and the upper die (3) are sequentially sleeved outside the pipe (1) from bottom to top; the extrusion die (2) is placed inside the pipe (1) to realize the circumferential extrusion of the pipe (1). A notch is prefabricated below the surface of the upper die (3) close to the outer side of the pipe (1), and a notch is prefabricated above the surface of the lower die (5) close to the outer side of the pipe (1), and the two notches form a receiving groove. The extrusion die (2) includes a connecting part and an extrusion end part. The diameter of the extrusion end part is larger than that of the connecting part. A groove with a trapezoidal cross-section is machined on the outer cylindrical surface of the extrusion end part, so that annular protrusions are formed at both the upper end and the lower end of the extrusion end part.

7. The tube - plate connection device based on circumferential progressive extrusion deformation according to claim 6, wherein, The width of the groove on the extrusion end part is L2, and the dimension of L2 satisfies: t1 + t2 ≤ L2 ≤ t1 + 2t2; wherein, t1 is the thickness of the sheet material (4), and t2 is the thickness of the pipe (2).

8. The tube-sheet connection device based on circumferential progressive extrusion deformation according to claim 6, wherein, The horizontal distance between the outermost edge of the extrusion end part and the bottom of the groove is L3, and L3 = (1 - 2)t2; t2 is the thickness of the pipe (2).

9. The tube-sheet connection device based on circumferential progressive extrusion deformation according to claim 6, characterized in that, The ends of the trapezoidal groove are all rounded.

10. The tube-plate connection device based on circumferential progressive extrusion deformation according to claim 6, characterized in that, The notch formed by the lower die (5) and the upper die (3) is rounded.

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