A method and device for realizing plate-tube connection by relying on radial flow of pipes

Abstract

The present invention discloses a method and apparatus for achieving plate-to-tube connection by relying on the radial flow of tubing, belonging to the technical field of material connection. Axial pressure applied to the non-connected end of the tubing causes radial flow of material at the connected end of the tubing. An annular groove is pre-machined at the plate to be connected, thereby forming an interface pressure and mechanical interlocking between the radially expanded portion of the tubing material and the plate to be connected. The present invention is applicable to connecting plates and tubing of different materials and wall thicknesses, and features low cost, high connection strength, good surface quality of the connection joint, and high processing efficiency, making it suitable for mass production.

Description

Technical Field

[0001] The invention belongs to the technical field of material connection, and in particular relates to a method and a device for realizing plate-tube connection by relying on radial flow of pipes. Background Art

[0002] Millions of parts are produced in the aerospace and automotive sectors, and the number and complexity of parts are increasing, including connections between parts made of different materials, which places ever-higher demands on lightweight and high-strength connections.

[0003] Mechanical components are typically connected using welding, bonding, and bolting. Fusion welding has low production efficiency and can leave welds that affect connection strength. Bonding, however, has low strength and is unsuitable for higher strength applications. Bolting, on the other hand, can easily loosen under alternating loads.

[0004] Furthermore, commercial demands for higher performance, higher productivity, and lower costs in material joining are becoming increasingly stringent, and there is a growing demand for joining components made of different materials to achieve lightweighting. However, traditional component joining methods are not well suited for joining components made of different materials. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a method and device for connecting plates and tubes by relying on radial flow of pipes, which can meet the connection requirements when the plates and tubes are made of different materials, and has low cost, high processing efficiency, simple operation, and is suitable for mass production.

[0006] The present invention is achieved through the following technical solutions:

[0007] The present invention discloses a method for achieving plate-tube connection by relying on radial flow of pipes, comprising:

[0008] S1: Processing an annular chamfer on the inner side of the end of the pipe to be connected; processing a circular hole at the position of the plate to be connected, and processing a plurality of annular grooves on the inner wall of the circular hole;

[0009] S2: Place the lower die in the restraining ring, and stack the plate and the annular pressing block on the lower die in sequence; place the end of the pipe to be connected downward into the receiving hole of the annular pressing block, and make the end of the pipe to be connected contact with the lower die; the upper die is a cylindrical boss structure, with the small diameter part as the core shaft and the large diameter part as the base; the core shaft of the upper die is inserted into the interior of the pipe and faces the through hole of the lower die, and the base of the upper die is in contact with the upper end of the pipe;

[0010] S3: Apply downward force to the annular pressing block to press the sheet material onto the lower die;

[0011] S4: The upper die moves downward, applying pressure to the upper end of the pipe, causing the end of the pipe to be connected to be squeezed and deformed. The deformed part flows radially, gradually filling the cavity formed by the annular pressing block, the plate, and the lower die.

[0012] S5: After the deformed portion of the pipe is completely connected with the several annular grooves on the inner wall of the circular hole of the plate, the upper die stops moving; the restraining ring, the upper die, the annular pressing block and the lower die are removed to obtain a connecting piece between the pipe and the plate.

[0013] Preferably, the wall thickness of the pipe is t1, the thickness of the plate is t2, r1≥t2; the radius of the annular chamfer processed on the inner side of the end of the pipe to be connected is r, The outer diameter of the pipe is D1, and the diameter of the circular hole processed at the plate to be connected is D. The bottom of the annular groove processed on the inner wall of the circular hole is a curved surface, the radius of the curved surface is r1, and there is a transition fillet between the annular groove and the inner wall of the circular hole, the radius of the transition fillet is r2.

[0014] Preferably, when the thickness of the plate is ≤3mm, the number of annular grooves processed on the inner wall of the circular hole of the plate is 1, and the annular grooves are symmetrical about the center line in the thickness direction of the plate; when the thickness of the plate is greater than 3mm, the number of annular grooves processed on the inner wall of the circular hole of the plate is greater than 1, and all annular grooves are evenly distributed along the axial direction of the circular hole.

[0015] Preferably, in S4, the speed of the downward movement of the upper mold is 0.1 to 0.5 mm / s.

[0016] Preferably, in S4, before the upper die moves downward, the plasticity of the end of the pipe to be connected is improved.

[0017] The present invention discloses a device for realizing the above-mentioned method of achieving plate-tube connection by relying on radial flow of pipes, comprising an upper die, a constraint ring, an annular pressure block and a lower die; the upper die is a cylindrical boss structure, the small diameter portion is a core shaft, and the large diameter portion is a base; the constraint ring is sleeved on the outside of the annular pressure block and the lower die; a accommodating hole with a diameter not less than the outer diameter of the pipe is provided on the annular pressure block, and the upper die is placed in the accommodating hole; a through hole with a diameter not less than the outer diameter of the upper die core shaft is provided on the lower die.

[0018] Preferably, the upper mold core shaft is in clearance with the inner wall of the tube, and the height of the upper mold core shaft is not less than the length of the tube; the diameter of the upper mold base is equal to the outer diameter of the tube, and is in clearance with the inner wall of the accommodating hole on the annular pressing block.

[0019] Preferably, the core shaft of the upper die is clearance-matched with the inner wall of the through hole of the lower die.

[0020] Preferably, the inner wall and the bottom surface of the accommodating hole of the annular pressing block are provided with transition fillets.

[0021] Preferably, the inner diameter of the constraint ring is clearance-fitted with the outer diameter of the annular pressing block and the outer diameter of the lower die.

[0022] Compared with the prior art, the present invention has the following beneficial technical effects:

[0023] The present invention discloses a method for achieving plate-tube connection by relying on the radial flow of the pipe. The axial pressure applied to the upper end of the pipe causes the material at the connecting end of the pipe to flow radially. An annular groove is pre-machined at the position of the plate to be connected. The material flowing in the pipe enters the annular groove, and the radially expanded part of the pipe material forms an interface pressure and mechanical interlocking with the position of the plate to be connected. Compared with traditional fusion welding connections, the structural parts connected by the present invention have no welds and do not require complicated post-weld inspection procedures; compared with traditional bonding and bolt connection methods, the connection joints are stronger and more reliable; compared with traditional plastic connection methods, the joint position is transferred from the corner position to the plane area of the plate, and the corner is an integral structure. At the same time, severe plastic deformation occurs at the corner, similar to equal-diameter angular extrusion deformation, and the local grain structure is refined, which greatly improves the tensile strength of the corner deformation zone.

[0024] Furthermore, the setting of the dimensions at various locations can provide a better fulcrum for the radial flow of the material at the end of the pipe to be connected.

[0025] Furthermore, when the plate thickness is ≤3mm, the number of annular grooves machined into the inner wall of the plate's circular hole is one, preventing excessive grooves from affecting the plate's strength. Furthermore, the annular grooves are symmetrical about the plate's thickness centerline, ensuring uniform stress distribution in the connection structure. When the plate thickness is greater than 3mm, the plate has sufficient thickness, and the addition of multiple annular grooves can enhance the connection strength between the plate and the pipe.

[0026] Furthermore, before the upper die moves downward, the plasticity of the end of the pipe to be connected is improved, so that the connecting part of the pipe has better plastic deformation ability.

[0027] The device disclosed in the present invention for realizing the plate-tube connection method by relying on the radial flow of the tube has a simple structure, is well compatible with existing power equipment, has high processing efficiency, and can realize batch production.

[0028] Furthermore, the height of the upper die core shaft is not less than the length of the pipe, which can restrict the axial flow of the material at the non-connection end of the pipe and the radial flow of the material at the connection end.

[0029] Furthermore, the inner wall and bottom surface of the accommodating hole of the annular pressing block are provided with transition fillets, which also provide a good fulcrum for the radial flow of the material at the end of the pipe to be connected. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a main cross-sectional view of the plate and pipe to be connected after pretreatment of the present invention;

[0031] Figure 2 This is a main cross-sectional view of the device before connection installation of the present invention;

[0032] Figure 3 It is a main cross-sectional view of the device structure of the present invention when the axial extrusion portion of the pipe begins to expand radially after the accumulation of material at the corner of the annular pressing block is completed;

[0033] Figure 4 This is a main cross-sectional view of the device structure when the pipe is in radial flow;

[0034] Figure 5 This is a main cross-sectional view of the device structure when the pipe radially flows and the plate is connected;

[0035] Figure 6 This is a main cross-sectional view of the overall structure of the connecting piece obtained after a connection process of the present invention.

[0036] In the figure: 1 is the upper die, 2 is the pipe, 3 is the restraining ring, 4 is the annular pressing block, 5 is the plate, and 6 is the lower die. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, which are intended to explain the present invention rather than to limit it.

[0038] like Figure 2 , is a set of specific devices for realizing the method of the present invention for realizing plate-tube connection by relying on radial flow of pipes. This example is used to specifically explain the method of the present invention for realizing plate-tube connection by relying on radial flow of pipes, which does not constitute a limitation of the present invention. The method of the present invention can be realized by using any existing device that can realize its step-by-step functions.

[0039] The device includes an upper mold 1, a constraint ring 3, an annular pressure block 4 and a lower mold 6; the upper mold 1 is a cylindrical boss structure, the small diameter part is the core shaft, and the large diameter part is the base; the constraint ring 3 is sleeved on the outside of the annular pressure block 4 and the lower mold 6; the annular pressure block 4 is provided with a accommodating hole with a diameter not less than the outer diameter of the pipe 2, and the upper mold 1 is placed in the accommodating hole; the lower mold 6 is provided with a through hole with a diameter not less than the outer diameter of the core shaft of the upper mold 1.

[0040] In a preferred embodiment of the present invention, the core shaft of the upper mold 1 is clearance-matched with the inner wall of the tube 2, and the height of the core shaft of the upper mold 1 is not less than the length of the tube 2; the diameter of the base of the upper mold 1 is equal to the outer diameter of the tube 2, and is clearance-matched with the inner wall of the accommodating hole on the annular pressing block 4.

[0041] In a preferred embodiment of the present invention, the core shaft of the upper die 1 is clearance-matched with the inner wall of the through hole of the lower die 6 .

[0042] In a preferred embodiment of the present invention, the inner wall and the bottom surface of the accommodating hole of the annular pressing block 4 are provided with transition fillets.

[0043] In a preferred embodiment of the present invention, the inner diameter of the restraining ring 3 is clearance-fitted with the outer diameters of the annular pressing block 4 and the lower die 6 .

[0044] The method for realizing plate-tube connection by using the above-mentioned device and relying on radial flow of the tube includes:

[0045] S1: Processing an annular chamfer on the inner side of the end of the pipe 2 to be connected; processing a circular hole at the position of the plate 5 to be connected, and processing a plurality of annular grooves on the inner wall of the circular hole;

[0046] S2: Place the lower die 6 in the restraining ring 3, and stack the plate 5 and the annular pressing block 4 on the lower die 6 in sequence; place the end of the pipe 2 to be connected downward into the receiving hole of the annular pressing block 4, and make the end of the pipe 2 to be connected contact with the lower die 6; the upper die 1 is a cylindrical boss structure, with the small diameter part as the core shaft and the large diameter part as the base; the core shaft of the upper die 1 is inserted into the interior of the pipe 2 and faces the through hole on the lower die 6, and the base of the upper die 1 is in contact with the upper end of the pipe 2;

[0047] S3: Apply downward force to the annular pressing block 4 to press the plate 5 onto the lower die 6;

[0048] S4: The upper die 1 moves downward, applying pressure to the upper end of the tube 2. The end of the tube 2 to be connected is squeezed and deformed. The deformed part flows radially, gradually filling the cavity formed by the annular binder 4, the plate 5 and the lower die 6.

[0049] S5: After the deformed portion of the tube 2 is completely connected with the several annular grooves on the inner wall of the circular hole of the plate 5, the upper die 1 stops moving; the restraining ring 3, the upper die 1, the annular pressing block 4 and the lower die 6 are removed to obtain a connecting piece between the tube 2 and the plate 5.

[0050] In a preferred embodiment of the present invention, the wall thickness of the pipe 2 is t1, the thickness of the plate 5 is t2, t1≥t2; the annular chamfer radius processed on the inner side of the end of the pipe 2 to be connected is r, The outer diameter of the pipe 2 is D1, and the diameter of the circular hole processed in the plate 5 to be connected is D. The bottom of the annular groove processed on the inner wall of the circular hole is a curved surface, the radius of the curved surface is r1, and there is a transition fillet between the annular groove and the inner wall of the circular hole, the radius of the transition fillet is r2.

[0051] In a preferred embodiment of the present invention, when the thickness t2 of the plate 5 is ≤ 3 mm, the number of annular grooves processed on the inner wall of the circular hole of the plate 5 is 1, and the annular grooves are symmetrical about the center line of the thickness direction of the plate 5; when the thickness t2 of the plate 5 is greater than 3 mm, the number of annular grooves processed on the inner wall of the circular hole of the plate 5 is greater than 1, and all annular grooves are evenly distributed along the axial direction of the circular hole.

[0052] In a preferred embodiment of the present invention, in S4, the speed of the downward movement of the upper mold 1 is 0.1-0.5 mm / s.

[0053] In a preferred embodiment of the present invention, in S4, before the upper mold 1 moves downward, the plasticity of the end of the pipe 2 to be connected is improved, such as by using electromagnetic induction heating.

[0054] The present invention will be further explained below with a specific example:

[0055] like Figure 1 The thickness of pipe 2 is t1=6mm, the thickness of plate 5 is t2=4mm, t1>t2, and a circular chamfer with a radius of r is processed on the connecting port of pipe 2. The outer diameter of pipe 2 is D1, and a circular hole with a diameter of D is processed at the connecting position of plate 5. An annular groove is processed on the inside of the circular hole, and the annular radius is r1. The radius between the annular groove and the circular hole wall is r2.

[0056] Take r = 2t1 / 5 = 2.4mm, Take r1=t2 / 6=0.7mm, r2=r1 / 2=0.35mm.

[0057] The number of annular grooves in the circular hole wall of plate 5 is 2 and is evenly distributed along the axial direction of the circular hole.

[0058] like Figure 2 , place the lower die 6 in the restraint ring 3, stack the preformed plate 5 and the annular pressing block 4 on the lower die 6 in sequence, place the processed end of the preformed tube 2 in the annular pressing block 4 so that it is in direct contact with the lower die 6, and completely pass the core shaft part of the upper die 1 through the tube 2; the height of the core shaft part of the upper die 1 is equal to the height of the tube 2.

[0059] The end of the pipe 2 to be connected is subjected to electromagnetic induction heating to improve its plastic deformation ability. Figure 3 The upper die 1 descends at a speed of 0.5 mm / s, and the non-connected end of the tube 2 is subjected to axial extrusion. Material accumulates at the corner of the annular pressing block 4, and the material accumulation at the corner begins to flow radially. The material flow rate on the side of the tube 2 with annular chamfer is slightly slower than that on the unprocessed side.

[0060] like Figure 4The upper die 1 passes through the inner hole of the lower die 6 and continues to move downward. The non-connected end of the tube 2 continues to be squeezed axially, and the material accumulated at the corner continues to flow radially. The material flow rate tends to be stable, and the material flow degree on the side of the tube 2 with annular chamfer is approximately equal to that on the unprocessed side.

[0061] like Figure 5 , the upper die 1 continues to move downward, and the radially expanded portion of the connecting end of the tube 2 completes the connection with the annular groove in the circular hole wall at the connecting position of the plate 5.

[0062] Remove the restraining ring 3, the upper die 1, the annular pressing block 4 and the lower die 6, grind the connection parts, and complete the connection between the pipe 2 and the plate 5.

[0063] like Figure 6 For the connection piece obtained after the connection is completed, the radial flow part of the pipe and the position to be connected of the plate form a large interface pressure and mechanical interlocking, and the connection strength is high.

[0064] It should be noted that the present invention is not limited to the above-mentioned embodiments, and any obvious improvements or changes to the above-mentioned embodiments made by those skilled in the art will not exceed the concept of the present invention and the scope of protection of the appended claims.

Claims

1. A method for achieving plate-tube connection by relying on radial flow of pipes, characterized in that: include: S1: Processing an annular chamfer on the inner side of the end of the pipe (2) to be connected; processing a circular hole at the position of the plate (5) to be connected, and processing a plurality of annular grooves on the inner wall of the circular hole; S2: Place the lower die (6) in the restraining ring (3), and stack the plate (5) and the annular pressing block (4) on the lower die (6) in sequence; place the end of the pipe (2) to be connected downwardly into the receiving hole of the annular pressing block (4), and make the end of the pipe (2) to be connected contact with the lower die (6); the upper die (1) is a cylindrical boss structure, the small diameter part is the core shaft, and the large diameter part is the base; the core shaft of the upper die (1) is inserted into the inside of the pipe (2) and faces the through hole on the lower die (6), and the base of the upper die (1) is in contact with the upper end of the pipe (2); S3: applying downward force to the annular pressing block (4) to press the plate (5) onto the lower die (6); S4: the upper die (1) moves downward, exerting pressure on the upper end of the tube (2), causing the end of the tube (2) to be connected to be deformed by extrusion, and the deformed portion flows radially, gradually filling the cavity formed by the annular pressing block (4), the plate (5) and the lower die (6); S5: After the deformed portion of the pipe (2) is completely connected with the several annular grooves on the inner wall of the circular hole of the plate (5), the upper die (1) stops moving; the restraining ring (3), the upper die (1), the annular pressing block (4) and the lower die (6) are removed to obtain a connecting piece of the pipe (2) and the plate (5).

2. The method for achieving plate-tube connection by relying on radial flow of pipes according to claim 1, characterized in that: The wall thickness of the pipe (2) is t1, and the thickness of the plate (5) is , The radius of the annular chamfer processed on the inner side of the end of the pipe (2) to be connected is r, ; The outer diameter of the pipe (2) is , the diameter of the circular hole processed in the plate (5) to be connected is D, The bottom of the annular groove processed on the inner wall of the circular hole is a curved surface, the radius of the curved surface is, the transition fillet between the annular groove and the inner wall of the circular hole is, the radius of the transition fillet is r2, , .

3. The method for achieving plate-tube connection by relying on radial flow of pipes according to claim 1, characterized in that: When the thickness of the plate (5) is ≤3 mm, the number of annular grooves machined on the inner wall of the circular hole of the plate (5) is 1, and the annular grooves are symmetrical about the center line of the thickness direction of the plate (5); when the thickness of the plate (5) is greater than 3 mm, the number of annular grooves machined on the inner wall of the circular hole of the plate (5) is greater than 1, and all the annular grooves are evenly distributed along the axial direction of the circular hole.

4. The method for achieving plate-tube connection by relying on radial flow of pipes according to claim 1, characterized in that: In S4, the speed of the downward movement of the upper die (1) is 0.1~0.5mm / s.

5. The method for achieving plate-tube connection by relying on radial flow of pipes according to claim 1, characterized in that: In S4, before the upper die (1) moves downward, the plasticity of the end of the pipe (2) to be connected is increased.

6. A device for realizing the method of connecting plates and tubes by relying on radial flow of tubes as described in any one of claims 1 to 5, characterized in that: The invention comprises an upper die (1), a restraining ring (3), an annular pressing block (4) and a lower die (6); the upper die (1) is a cylindrical boss structure, the small diameter portion is a core shaft, and the large diameter portion is a base; the restraining ring (3) is sleeved on the outside of the annular pressing block (4) and the lower die (6); the annular pressing block (4) is provided with a receiving hole with a diameter not less than the outer diameter of the pipe (2), and the upper die (1) is placed in the receiving hole; the lower die (6) is provided with a through hole with a diameter not less than the outer diameter of the core shaft of the upper die (1).

7. The device according to claim 6, characterized in that The core shaft of the upper die (1) is clearance-matched with the inner wall of the tube (2), and the height of the core shaft of the upper die (1) is not less than the length of the tube (2); the diameter of the base of the upper die (1) is equal to the outer diameter of the tube (2), and is clearance-matched with the inner wall of the accommodating hole on the annular pressing block (4).

8. The device according to claim 6, characterized in that The core shaft of the upper die (1) and the inner wall of the through hole of the lower die (6) are clearance-matched.

9. The device according to claim 6, characterized in that The inner wall and bottom surface of the accommodating hole of the annular pressing block (4) are provided with transition fillets.

10. The device according to claim 6, characterized in that The inner diameter of the restraining ring (3) is clearance-fitted with the outer diameter of the annular pressing block (4) and the outer diameter of the lower die (6).

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