Plate-pipe connecting device and method based on connecting rod mechanism

Abstract

The invention belongs to the technical field of material connection, and discloses a plate-pipe connecting device and method based on a connecting rod mechanism. The device comprises a rotating shaft and a plurality of bulging mechanisms, wherein the rotating shaft drives the bulging mechanisms to rotate; each bulging mechanism comprises an upper connecting piece, a lower connecting piece, an upper connecting rod, a lower connecting rod, an extrusion die and an elastic body; the upper connecting piece and the lower connecting piece are connected to the rotating shaft; the upper connecting piece is hinged with the upper connecting rod which is hinged with the extrusion die; the lower connecting piece is hinged with the lower connecting rod which is hinged with the extrusion die to form a connecting rod mechanism; the elastomer is connected to the outer side of the extrusion die; two extrusion protrusions used for extruding a pipe blank are prefabricated on the outer side of the extrusion die. When the rotating shaft rotates along the axis of the rotating shaft, the upper connecting piece and the lower connecting piece are driven by the threads to move oppositely or reversely along the rotating shaft to drive the connecting rod assembly to be opened and closed, then the inner wall of the pipe blank is radially extruded by the extrusion die, the pipe blank is outwards expanded to form a firm mechanical lock catch with a plate, and the expansion connection process is completed.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of material connection, and particularly relates to a plate-pipe connecting device and method based on a connecting rod mechanism. BACKGROUND

[0002] Under the promotion of sustainable development strategy, lightweight mechanical structures have attracted widespread attention, and metal plate-pipe connecting structures are increasingly applied in the fields of automobiles, aerospace, chemical industry, medicine and the like, and play an important role in energy saving and emission reduction, cost reduction and the like. However, with the continuous development of lightweight mechanical structures, the traditional material connection method has been difficult to meet the processing and manufacturing of lightweight mechanical structures.

[0003] For example, aluminum alloy has high thermal conductivity, high melting point of surface oxide film, and large expansion coefficient, and the use of welding process will cause large welding deformation, thermal cracking and other problems. Magnesium alloy has active chemical properties, and under high-temperature welding environment, magnesium is easy to have a violent oxidation reaction with oxygen in the air, which has a safety hazard; bolt connection is not suitable for a vibration environment, and increases the manufacturing cost and the weight of the connecting piece; the hydraulic expansion equipment is complex, and the expansion cost is high. Plastic connection has been rapidly developed due to its environmental friendliness and high connection strength, but at present, the expander needs to be designed and manufactured for different shapes and sizes of the expanded piece during the expansion process, and the design and manufacturing process of these molds is complex, the cost is high, and the universality is poor. Therefore, a plate-pipe connecting method with high universality is urgently needed. SUMMARY

[0004] The present application aims to provide a plate-pipe connecting device and method based on a connecting rod mechanism, which solves various problems existing in the current plate-pipe connecting method.

[0005] The present application is achieved by the following technical solutions:

[0006] A plate-pipe connecting device based on a connecting rod mechanism, comprising a rotating shaft and a plurality of expansion mechanisms connected to the rotating shaft; the rotating shaft is used to drive the expansion mechanisms to rotate;

[0007] Each expansion mechanism comprises an upper connecting piece, a lower connecting piece, an upper connecting rod, a lower connecting rod, an extrusion die and an elastic body;

[0008] The upper connecting piece and the lower connecting piece are connected to the rotating shaft; the upper connecting piece is hinged to the upper connecting rod, and the upper connecting rod is hinged to the extrusion die; the lower connecting piece is hinged to the lower connecting rod, and the lower connecting rod is hinged to the extrusion die, forming a connecting rod mechanism;

[0009] The elastic body is connected to the outside of the extrusion die;

[0010] The outside of the extrusion die is preformed with two extrusion protrusions for extruding the pipe blank.

[0011] Further, the upper and lower ends of the rotating shaft are processed with threads in opposite directions, so that the upper and lower connecting pieces can move towards or away from each other when the rotating shaft rotates.

[0012] Further, the height of the elastic body is 1.2-1.5 times the height of the extrusion protrusion.

[0013] Further, the included angle between the upper connecting rod and the rotating shaft or the included angle between the lower connecting rod and the rotating shaft is 30°-60°.

[0014] Further, the pipe blank is made of low-carbon steel, stainless steel, aluminum alloy or magnesium alloy, and the elastic body is made of polyurethane rubber.

[0015] Further, the number of connecting rod mechanisms is 2n, and n=1-4.

[0016] Further, the distance between the two extrusion protrusions is l2, and l2=t2+2(t1+c);

[0017] Wherein, t1 is the thickness of the pipe blank, t2 is the thickness of the plate 7; D is the diameter of the pipe blank; c is the compensation allowance, and the value range is 1-3 mm.

[0018] Further, the length of the upper connecting rod and the lower connecting rod is l1,

[0019] Wherein, D is the diameter of the pipe blank, e1 is the distance of the connecting rod hinge point from the axis of the rotating shaft, e2 is the radial distance between the center of the extrusion die hinge point and the extrusion die bulging point, and θ is the included angle between the connecting rod and the rotating shaft.

[0020] A plate-pipe connecting method based on a connecting rod mechanism, comprising the following steps:

[0021] S1, assembling and fixing the pipe blank and the plate to be connected;

[0022] S2, inserting the plate-pipe connecting device based on the connecting rod mechanism into the pipe blank at the bulging position, applying a driving torque W1 to the rotating shaft to make the rotating shaft rotate, the upper connecting piece and the lower connecting piece move towards each other along the rotating shaft, the upper connecting rod and the lower connecting rod push the extrusion die to expand outward, so that the elastic body contacts and extrudes the inner wall of the pipe blank to produce elastic deformation, the rotating shaft continues to rotate, the extrusion protrusion on the extrusion die extrudes the inner wall of the pipe blank to make the pipe blank plastically deform, and the pipe blank and the plate form a mechanical lock.

[0023] Further, after S2, a reverse driving torque W2 is applied to the rotating shaft to make the rotating shaft rotate in the opposite direction, the upper connecting piece and the lower connecting piece move away from each other along the rotating shaft, and the two connecting rods drive the extrusion die to fold inward until the elastic body restores its elastic deformation; and the plate-pipe connecting device is taken out.

[0024] The driving torques W1 and W2 are in opposite directions.

[0025] Compared with the prior art, the present application has the following beneficial technical effects:

[0026] The plate-pipe connecting method based on the connecting rod mechanism disclosed in the present application realizes the outward expansion of the connecting rod by controlling the opposite movement of the upper and lower connectors, and the extrusion die extrudes the inner wall of the pipe blank to produce local plastic deformation, thereby forming a mechanical locking structure of the pipe blank and the plate-pipe. The extrusion die in the present application is in a split form, and different sizes of connecting rods are replaced according to the size of the pipe diameter under the condition that the extrusion die remains unchanged, thereby controlling the bulging stroke of the extrusion die. Therefore, the present application can adapt to various plate-pipe bulging processes of different specifications, and a specific die does not need to be prepared for each size of plate-pipe, thereby embodying good compatibility and economy. In the connecting process, the pipe blank is locally deformed, and the overall deformation is small, so that the rupture phenomenon caused by low plasticity of the pipe blank can be avoided. In addition, according to the need of the plate-pipe connection strength, a plurality of bulging dies can be arranged to increase the plastic connection points and improve the plate-pipe connection reliability. Therefore, the method is not only suitable for the bulging of pipe fittings such as stainless steel with good plasticity, but also suitable for the bulging of pipe fittings such as aluminum alloy, magnesium alloy and titanium alloy with poor plasticity.

[0027] Further, the included angle θ between the connecting rod and the axis of the rotating shaft is recommended to be 30°-60°. If the included angle is too small, the radial force conversion efficiency is low, and the mechanism may be stuck due to friction. If the included angle is too large, the thrust demand will surge.

[0028] Further, the connecting rod mechanism adopts 2, 4, 6 or 8 even-numbered symmetrical connecting rods to ensure uniform circumferential force.

[0029] Further, when the material plasticity is poor, the compensation allowance c is taken as the upper limit (2-3 mm) to avoid the edge cracking of the pipe blank caused by the short buffer section. When the compensation allowance c is taken as the lower limit (1-2 mm) in the low-pressure and low-sealing requirement scene.

[0030] Further, the pipe blank can be low-carbon steel, stainless steel, aluminum alloy or magnesium alloy, and the application range is wide. The rotating shaft and the nut are made of high-strength steel to avoid plastic deformation. The elastomer is made of polyurethane rubber, which has high strength and elasticity and can generate sufficient friction force with the inner surface of the pipe blank.

[0031] The device for realizing the above-mentioned plate-pipe connection method by using the plastic deformation of the pipe blank is simple in structure, reasonable in design, convenient to install, good in universality, and free of auxiliary parts such as rivets and bolts in the connection process, and is suitable for mass production. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a schematic diagram of the overall structure of the present application;

[0033] Figure 2 is a state diagram of the extrusion die and the pipe blank during extrusion;

[0034] Figure 3 is a schematic diagram of a long connecting rod matched with large-sized plate pipe expansion;

[0035] Figure 4 is a schematic diagram of a top view structure of four connecting rod mechanisms;

[0036] Figure 5 is a schematic diagram of mechanical locking after pipe plate expansion; wherein, Fig. a is a schematic diagram of a cross section of a pipe blank at the locking position; Fig. b is a schematic diagram of formed pipe plate connection;

[0037] Figure 6 is a schematic diagram of a top view structure of six connecting rod mechanisms;

[0038] Figure 7 is a schematic diagram of a rotating shaft and connecting rod arrangement.

[0039] In the figure: 1, rotating shaft; 2, upper connecting piece; 3, upper connecting rod; 4, lower connecting rod; 5, lower connecting piece; 6, elastic body; 7, plate material; 8, extrusion die; 9, elastic body; 10, pipe blank. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the present application more clear and obvious, the following further describes in detail in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application, that is, the described examples are only a part of the examples of the present application, but not all examples.

[0041] The components described and shown in the drawings and examples of the present application can be arranged and designed in various different configurations, therefore, the detailed description of the embodiments of the present application provided in the following drawings is not intended to limit the scope of the claimed present application, but only represents a selected embodiment of the present application. Based on the drawings and examples of the present application, all other examples obtained by those skilled in the art without making creative efforts are within the scope of protection of the present application.

[0042] It should be noted that the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, element, method, article or equipment including a series of elements includes not only those elements, but also other elements not explicitly listed, or further includes the elements inherent in the process, element, method, article or equipment. In addition, the terms "horizontal", "vertical" are based on the orientation and position relationship of the devices or components shown in the drawings, and are only used to better describe the present application, and are not required to have the specific orientation of the devices, components or equipment shown, and therefore cannot be understood as a limitation on the present application.

[0043] As Figure 1A specific device is used to explain the plate-pipe connecting method based on the connecting rod mechanism, which does not limit the present application, and the method can be realized by using any existing device which can realize the step-by-step function.

[0044] The application discloses a plate-pipe connecting device based on a connecting rod mechanism, which comprises a rotating shaft 1 and a plurality of bulging mechanisms connected to the rotating shaft 1, each of the bulging mechanisms comprises an upper connecting piece 2, a lower connecting piece 5, an upper connecting rod 3, a lower connecting rod 4, an extrusion die 8 and an elastic body 9, the upper connecting piece 2 and the lower connecting piece 5 are connected to the rotating shaft 1, the upper connecting piece 2 is hinged to the upper connecting rod 3, the upper connecting rod 3 is hinged to the extrusion die 8, the lower connecting piece 5 is hinged to the lower connecting rod 4, the lower connecting rod 4 is hinged to the extrusion die 8, the outer side of the extrusion die 8 is connected to the elastic body 9, and the outer side of the extrusion die 8 is preformed with two extrusion protrusions for extruding a pipe blank 10, and the rotating shaft 1 drives the bulging mechanism to rotate relatively around an axis.

[0045] The features and performances of the present application are further explained in detail in combination with the embodiments.

[0046] Embodiment 1

[0047] As shown in Figure 1 and Figure 4 , the application discloses a plate-pipe connecting device based on a connecting rod mechanism, which comprises a rotating shaft 1 and four connecting rod mechanisms connected to the rotating shaft 1, each of the connecting rod mechanisms comprises an upper connecting piece 2, a lower connecting piece 5, an upper connecting rod 3, a lower connecting rod 4 and an extrusion die 8, the upper connecting piece 2 and the lower connecting piece 5 are connected to the rotating shaft 1, the upper connecting piece 2 is hinged to the upper connecting rod 3, the upper connecting rod 3 is hinged to the extrusion die 8, the lower connecting piece 5 is hinged to the lower connecting rod 4, the lower connecting rod 4 is hinged to the extrusion die 8, the outer side of the extrusion die 8 is connected to the elastic body 9, and the outer side of the extrusion die 8 is preformed with two extrusion protrusions for extruding a pipe blank 10, and the rotating shaft 1 drives the connecting rod mechanism to rotate relatively around an axis.

[0048] When the number of the connecting rod mechanisms is four, four mechanical locks can be formed as shown in Figure 5 a and b of the drawings.

[0049] Embodiment 2

[0050] In a more preferable embodiment of the present application, the connecting rod of different sizes can be replaced to control the bulging stroke of the extrusion die 8 according to the diameter of the plate-pipe to be connected without changing the extrusion die 8, as shown in Figure 4 .

[0051] Embodiment 3

[0052] As shown in Figure 1 and Figure 6As shown, the present invention discloses a plate-tube connection device based on a connecting rod mechanism, comprising a rotating shaft 1 and six connecting rod mechanisms connected to the rotating shaft 1, wherein the six connecting rod mechanisms are evenly arranged along the circumferential direction.

[0053] like Figure 1 As shown, each connecting rod mechanism includes an upper connecting member 2, a lower connecting member 5, an upper connecting rod 3, a lower connecting rod 4 and an extrusion die 8. The upper connecting member 2 and the lower connecting member 5 are connected to the rotating shaft 1; the upper connecting member 2 is hinged to the upper connecting rod 3, and the upper connecting rod 3 is hinged to the extrusion die 8; the lower connecting member 5 is hinged to the lower connecting rod 4, and the lower connecting rod 4 is hinged to the extrusion die 8. The outside of the extrusion die 8 is connected to an elastomer 9, and the outside of the extrusion die 8 is prefabricated with two extrusion protrusions for extruding the tube blank 10. The rotating shaft 1 drives the connecting rod mechanism to rotate relative to the axis.

[0054] When the number of the connecting rod mechanisms is 6, 6 mechanical locks can be formed.

[0055] In a preferred embodiment of the present invention, there are good lubrication conditions between the rotating shaft 1 and the upper connecting member 2 and the lower connecting member 5.

[0056] Not limited to the above embodiment, the number of the link mechanisms is 2n, where n=1-4.

[0057] In actual application scenarios, a nut stopper or other travel limiting device may be added to control the expansion stroke and prevent the tube blank 10 from cracking.

[0058] Based on the above device, the specific processing steps of the present invention are:

[0059] S1: According to the structure and size of the tube blank 10 and the plate 7 to be connected, an extrusion die 8 with an elastic body 9 is processed, a rotating shaft 1 with oppositely rotating threads at the upper and lower ends, and an upper connecting piece 2 and a lower connecting piece 5 that match the threads of the rotating shaft 1 are processed; the tube blank 10 and the plate 7 to be connected are assembled and fixed; the upper connecting piece 2 and the lower connecting piece 5 are screwed into the upper and lower ends of the rotating shaft respectively; the upper connecting rod 3 is hinged to the upper connecting piece 2, the lower connecting rod 4 is hinged to the lower connecting piece 5, and the other end is hinged to the die to form a connecting rod mechanism, such as Figure 1 .

[0060] S2: Insert the device into the position to be expanded in the tube blank 10, drive the rotating shaft 1 to rotate, and the upper connecting piece 2 and the lower connecting piece 5 move toward each other along the rotating shaft 1, so that the upper connecting rod 3 and the lower connecting rod 4 push the extrusion die 8 to expand outward, and the elastic body 9 contacts and extrudes the inner wall of the tube blank 10 to produce elastic deformation. The rotating shaft 1 continues to rotate, and the protrusion on the extrusion die 8 squeezes the inner wall of the tube blank 10, so that the outer wall of the tube blank 10 produces outward plastic deformation. The upper and lower deformed protrusions clamp the plate 7, and the tube blank 10 and the plate 7 are formed as shown in the figure. Figure 2 Mechanical latch shown.

[0061] S3: apply reverse driving force to the rotating shaft 1 to make the rotating shaft 1 rotate reversely, the upper connecting piece 2 and the lower connecting piece 5 move in opposite directions along the rotating shaft 1, the upper connecting rod 3 and the lower connecting rod 4 drive the extrusion die 8 to close, as shown in Figure 3 the elastic body 9 restores the elastic deformation, no longer contacts the inner wall of the pipe blank 10, the taking-out device is completed, and the pipe blank 10 is expanded and connected with the plate 7.

[0062] In a preferred embodiment of the present application, the pipe blank 10 is made of low-carbon steel, stainless steel, aluminum alloy or magnesium alloy, and the elastic body 9 is polyurethane rubber, and the rotating shaft and the nut are made of high-strength steel.

[0063] In a preferred embodiment of the present application, the height h1 of the elastic body 9 is 1.2-1.5 times the height h2 of the extrusion protrusion, and when expanding, the elastic body 9 is in contact with the inner wall of the pipe blank 10 first, and the friction generated when the elastic body 9 is in contact with the inner wall of the pipe blank 10 can overcome the friction between the rotating shaft 1 and the connecting piece screw pair, so as to prevent the connecting piece from rotating together with the rotating shaft 1.

[0064] As shown in Figure 7 , the height of the extrusion protrusion is h2, and the distance between the two extrusion protrusions is l2, l2=t2+2(t1+c);

[0065] Wherein, t1 is the thickness of the pipe blank 10, t2 is the thickness of the plate; D is the diameter of the pipe blank 10; c is the compensation allowance, and the value range is 1-3mm.

[0066] The length of the upper connecting rod 3 and the lower connecting rod 4 is l1,

[0067] Wherein, D is the diameter of the pipe blank 10, e1 is the distance between the connecting rod hinge point and the axis of the rotating shaft 1, e2 is the radial distance between the hinge point center of the extrusion die 8 and the bulging point of the extrusion die 8, and θ is the angle between the connecting rod and the rotating shaft 1.

[0068] The features and performances of the present application are further described in detail in combination with a specific embodiment.

[0069] The material of the pipe blank 10 is 6061T6 aluminum alloy, the diameter D is 30mm, and the wall thickness t1 is 2mm; the plate 7 is made of 304 stainless steel, and the thickness t2 is 5mm.

[0070] The height h2 of the extrusion protrusion is 3mm, and the distance l2 is 11mm.

[0071] The diameter d of the rotating shaft 1 is 5mm, the upper and lower ends of the rotating shaft 1 are respectively machined with trapezoidal threads with opposite rotation directions, the thread angle α is 30°, and the thread length l3 is 30mm.

[0072] In a preferred embodiment of the present application, the size of the connecting rod matches the inner diameter of the pipe blank 10, and the length l1 is 10mm; the angle θ between the connecting rod and the rotating shaft 1 is 30°-60°, as shown inFigure 7 are shown.

[0073] Finally, it should be noted that the above examples are merely intended to illustrate the technical solutions of the present application but not to limit the same. Although the present application has been described in detail with reference to the above examples, those of ordinary skill in the art should understand that the specific implementation of the present application can be modified or equivalently replaced without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered within the protection scope of the claims of the present application.

Claims

1. A plate-tube connection device based on a connecting rod mechanism, characterized in that: It comprises a rotating shaft (1) and a plurality of bulging mechanisms connected to the rotating shaft (1); the rotating shaft (1) is used to drive the bulging mechanisms to rotate; Each bulging mechanism comprises an upper connecting piece (2), a lower connecting piece (5), an upper connecting rod (3), a lower connecting rod (4), an extrusion die (8) and an elastic body (9); The upper connecting member (2) and the lower connecting member (5) are connected to the rotating shaft (1); the upper connecting member (2) is hinged to the upper connecting rod (3), and the upper connecting rod (3) is hinged to the extrusion die (8); the lower connecting member (5) is hinged to the lower connecting rod (4), and the lower connecting rod (4) is hinged to the extrusion die (8), forming a connecting rod mechanism; The elastic body (9) is connected to the outside of the extrusion die (8); Two extrusion protrusions for extruding the tube blank (10) are prefabricated on the outer side of the extrusion die (8).

2. A plate-tube connection device based on a connecting rod mechanism according to claim 1, characterized in that: The upper and lower ends of the rotating shaft (1) are processed with threads with opposite rotation directions, which can enable the upper connecting member (2) and the lower connecting member (5) to move towards or away from each other when the rotating shaft (1) rotates.

3. The plate-tube connection device based on a connecting rod mechanism according to claim 1, characterized in that: The height of the elastic body (9) is 1.2 to 1.5 times the height of the extrusion protrusion.

4. The plate-tube connection device based on a connecting rod mechanism according to claim 1, characterized in that: The angle between the upper connecting rod (3) and the rotating shaft (1) or the angle between the lower connecting rod (4) and the rotating shaft (1) is 30°-60°.

5. The plate-tube connection device based on a connecting rod mechanism according to claim 1, characterized in that: The tube blank is low carbon steel, stainless steel, aluminum alloy or magnesium alloy, and the elastomer is polyurethane rubber.

6. The plate-tube connection device based on a connecting rod mechanism according to claim 1, characterized in that: The number of connecting rod mechanisms is 2n, where n=1-4.

7. The plate-tube connection device based on a connecting rod mechanism according to claim 1, characterized in that: The distance between the two extrusion protrusions is l2, l2 = t2 + 2 (t1 + c); Wherein, t1 is the thickness of the tube blank (10), t2 is the thickness of the plate 7; D is the diameter of the tube blank (10); and c is the compensation margin, which has a value range of 1 to 3 mm.

8. The plate-tube connection device based on a connecting rod mechanism according to claim 1, characterized in that: The lengths of the upper connecting rod (3) and the lower connecting rod (4) are both l1. Wherein, D is the diameter of the tube (10), e1 is the distance of the connecting rod hinge point from the axis of the rotating shaft (1), e2 is the radial distance between the center of the hinge point of the extrusion die (8) and the bulging point of the extrusion die (8), and θ is the angle between the connecting rod and the rotating shaft (1).

9. A plate-tube connection method based on a connecting rod mechanism, characterized in that: The following steps are involved: S1, assembling and fixing the tube blank (10) and the plate (7) to be connected; S2. Insert the plate-tube connecting device based on the connecting rod mechanism into the position to be expanded in the tube blank (10), apply a driving torque W1 to the rotating shaft (1) to rotate the rotating shaft (1), and the upper connecting member (2) and the lower connecting member (5) move toward each other along the rotating shaft (1). The upper connecting rod (3) and the lower connecting rod (4) push the extrusion die (8) to expand outward, so that the elastomer (9) contacts and extrude the inner wall of the tube blank (10) to produce elastic deformation. The rotating shaft (1) continues to rotate, and the extrusion protrusion on the extrusion die (8) extrude the inner wall of the tube blank (10) to plastically deform the tube blank (1), and the tube blank (10) and the plate (7) form a mechanical lock.

10. A plate-tube connection method based on a connecting rod mechanism according to claim 9, characterized in that: After S2, a reverse driving torque W2 is applied to the rotating shaft (1) to cause the rotating shaft (1) to rotate in the reverse direction, and the upper connecting member (2) and the lower connecting member (5) move in opposite directions along the rotating shaft (1). The two connecting rods drive the extrusion die (8) to retract inward until the elastic body (9) recovers its elastic deformation; and the plate-tube connecting device is removed; The driving torques W1 and W2 are in opposite directions.

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