A flexible friction stir welding device

Abstract

The invention discloses a flexible friction stir welding device, comprising a main shaft, a stirring head and a shoulder. The stirring head comprises a clamping part and a stirring needle. The clamping part is clamped at the end of the main shaft. The main shaft is coaxial with the stirring head. The flexible friction stir welding device also comprises a floating structure. The shoulder is fixedly installed on the floating structure. The stirring needle extends from the shoulder. The shoulder is provided with a pressing surface. The floating structure adjusts the axial position of the shoulder to adjust the distance from the pressing surface to the end of the stirring needle. When the device is in use, the shoulder only slides on the surface of the workpiece but does not rotate, so the problem of thinning of welding flash and weld is solved, and the weld surface is smooth without arc pattern. The heat input is only generated by the friction of the stirring needle, the amount of heat is small, the longitudinal temperature gradient of the weld is small, and the deformation of the workpiece is small. The axial position of the shoulder is adjustable, and the welding of workpieces of different thicknesses and different workpieces can be carried out without frequent replacement of stirring tools. The axial pressure of the shoulder can be controlled to achieve constant pressure welding, and the shoulder is kept tightly pressing the workpiece without overpressure.

Description

Technical Field

[0001] The invention relates to a welding device, in particular to a flexible friction stirring welding device. Background Art

[0002] Friction stir welding is an advanced solid-phase joining technology. The basic principle is to insert a high-speed rotating stirring tool into the weld and use the friction and stirring effect of the stirring tool to keep the weld material in a thermoplastic state. The stirring tool moves along the weld. Driven by the high-speed rotation of the stirring tool, the plastic material moves from front to back around the stirring tool. At the same time, the stirring tool forges the weld metal, and the materials are connected together under the combined action of heat and machinery.

[0003] The traditional friction stir welding shoulder rotates with the stirring needle, resulting in high friction heat, large heat input, and large longitudinal temperature gradient of the weld, which leads to large welding deformation. During the welding process, plastic metal materials easily overflow the weld area to form flash, resulting in weld thinning, and mechanical grinding is required to remove the flash after welding, which is time-consuming and labor-intensive, reducing production efficiency. The rotation of the shoulder in traditional friction stir welding will also cause "onion patterns" to form on the weld surface, which affects the joint performance and weld surface quality.

[0004] To solve these problems, only a non-rotating static shoulder friction stir welding tool can be used. The current conventional static shoulder friction stir welding tool has a complex structure, the shoulder is completely fixed, and when welding workpieces of different thicknesses or structures, the stirring tool needs to be replaced frequently, which is inefficient, single-function, and has a narrow scope of application. The shoulder cannot be adjusted during the welding process, resulting in an unadjustable welding pressure. When the workpiece is uneven and the thickness changes suddenly, overpressure and loose compression are prone to occur. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, one of the objectives of the present invention is to provide a flexible friction stir welding device in which the shaft shoulder can float axially and the shaft shoulder does not rotate during the welding process.

[0006] One of the purposes of the present invention is achieved by the following technical solution:

[0007] A flexible friction stir welding device comprises a main shaft, a stirring head and a shoulder, the stirring head comprises a clamping portion and a stirring needle, the clamping portion is clamped at the end of the main shaft, the main shaft is coaxial with the stirring head, the flexible friction stir welding device also comprises a floating structure, the shoulder is fixedly mounted on the floating structure, the stirring needle extends from the shoulder, the shoulder is provided with a pressing surface, and the floating structure adjusts the axial position of the shoulder to adjust the distance from the pressing surface to the end of the stirring needle.

[0008] Furthermore, the floating structure includes a cylinder and a piston rod, the piston rod is movably mounted on the cylinder, and the end of the piston rod is fixedly connected to the shaft shoulder.

[0009] Furthermore, the floating structure also includes an elastic member, which is sleeved on the piston rod, and two ends of the elastic member are respectively in contact with the piston rod and the bottom of the inner wall of the cylinder.

[0010] Furthermore, the elastic member is a spring.

[0011] Furthermore, the flexible friction stir welding device also includes a floating plate, the floating plate is fixedly connected to the piston rod, and the shoulder is fixed to the floating plate.

[0012] Furthermore, the flexible friction stir welding device further comprises a connecting block, and the shaft shoulder is fixedly connected to the floating plate via the connecting block.

[0013] Furthermore, the shoulder is integral and the pressing surface is a plane.

[0014] Furthermore, the shoulder is split, the number of the pressing surfaces is multiple, and each of the pressing surfaces is a plane.

[0015] Furthermore, the distances between the plurality of pressing surfaces and the end of the stirring needle are different.

[0016] Furthermore, a gap is formed between the stirring head and the shaft shoulder.

[0017] Compared with the prior art, the flexible friction stir welding device of the present invention also includes a floating structure, the shoulder is fixedly installed on the floating structure, the stirring needle extends from the shoulder, the shoulder is provided with a pressing surface, and the floating structure drives the shoulder to move axially to adjust the distance from the pressing surface to the end of the stirring needle. Through the above design, when the flexible friction stir welding device is in use, the shoulder does not rotate, and the shoulder only slides on the surface of the workpiece, which solves the problem of thinning of welding flash welds, does not thin the workpiece, and the weld surface is smooth without arc lines; the heat input is only generated by the friction of the stirring needle, the amount of heat is small, the longitudinal temperature gradient of the weld is small, and the deformation of the workpiece is small; the axial position of the shoulder is adjustable, and there is no need to frequently replace the stirring tool, and welding of workpieces of different thicknesses and different workpieces can be carried out, which is efficient and has a wide range of applications; the axial pressure of the shoulder can be controlled to achieve constant pressure welding, and keep the shoulder tightly pressing the workpiece without over-pressing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A three-dimensional diagram of the flexible friction stir welding device of the present invention;

[0019] Figure 2 for Figure 1 A cross-sectional view of a state in which the pressing surface of the shoulder of the flexible friction stir welding device is flush;

[0020] Figure 3 for Figure 2 An enlarged view of the flexible friction stir welding device at position A;

[0021] Figure 4 for Figure 1 A cross-sectional view of a stirring head of a flexible friction stir welding device;

[0022] Figure 5 for Figure 1 A cross-sectional view of a state in which the pressing surface of a shoulder of a flexible friction stir welding device is staggered;

[0023] Figure 6 for Figure 5 Enlarged view of location B of the flexible friction stir welding device.

[0024] In the figure: 10, main shaft; 20, stirring head; 21, clamping part; 22, stirring needle; 30, shaft shoulder; 31, pressing surface; 40, floating plate; 50, connecting block; 60, floating structure; 61, cylinder; 610, chamber; 62, sealing ring; 63, piston rod; 64, elastic part. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may be another intermediate component through which it is fixed. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be another intermediate component at the same time. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be another intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0028] See also Figures 1 to 4 , a flexible friction stir welding device of the present invention includes a main shaft 10, a stirring head 20, a shoulder 30, a floating plate 40, a connecting block 50 and a floating structure 60.

[0029] The main shaft 10 provides power to drive the tool handle and the stirring head 20 to rotate.

[0030] The stirring head 20 includes a clamping portion 21 and a stirring pin 22. The clamping portion 21 is stepped. The clamping portion 21 and the stirring pin 22 are integrally formed. The stirring pin 22 generates heat by friction to plasticize the material to be welded and stirs the softened plastic material.

[0031] The shoulder 30 is provided with a pressing surface 31. The pressing surface 31 is a plane. In this embodiment, the shoulder 30 is an integrated structure, and the number of the pressing surface 31 is one. A through hole is provided in the middle of the pressing surface 31. When welding, the shoulder 30 presses the weld and slides on the surface to prevent the plastic material from overflowing.

[0032] The floating structure 60 includes a cylinder 61, a sealing ring 62, a piston rod 63 and an elastic member 64. The cylinder 61 is provided with a chamber 610. The piston rod 63 is movably installed in the chamber 610. The sealing ring 62 is located between the end of the piston rod 63 and the inner wall of the cylinder 61 to play a sealing role. The elastic member 64 is a spring, which is sleeved on the piston rod 63 and has two ends that respectively contact the end of the piston rod 63 and the bottom wall of the cylinder 61. The elastic member 64 provides a reaction force to push the piston rod 63 to move upward.

[0033] When assembling the flexible friction stir welding device, the main shaft 10 passes through the floating structure 60, and the clamping portion 21 of the stirring head 20 is installed on the end of the main shaft 10. At this time, the axis of the stirring head 20 is the same as the axis of the main shaft 10. The end of the piston rod 63 of the floating structure 60 is fixedly connected to the floating plate 40. The shoulder 30 is fixedly connected to the floating plate 40 through the connecting block 50. At this time, a gap is formed between the stirring head 20 and the shoulder 30. The stirring needle 22 extends from the through hole of the shoulder 30, and the pressing surface 31 of the shoulder 30 forms a certain distance with the end of the stirring needle 22.

[0034] When the flexible friction stir welding device is used, the stirring needle 22 is inserted into the weld and rotated. The stirring needle 22 generates heat by friction with the workpiece to plasticize and connect the materials together. At the same time, the shoulder 30 is pressed tightly and slides on the weld surface. The pressing force of the shoulder 30 can be controlled by controlling the input pressure of the cylinder 61. By adjusting the compression amount of the elastic member 64, the axial position of the shoulder 30 can be adjusted arbitrarily, which can be applied to the welding of workpieces of different thicknesses. It has a wide range of applications and does not require frequent replacement of the stirring head 20.

[0035] The floating structure 60, the connecting block 50 and the shoulder 30 can also be split, so that the axial position of each part of the shoulder 30 can be controlled separately, and welds of different structural forms can be applied, such as butt welds, lap welds, welds of unequal thickness, etc. Figure 5 and Figure 6 As shown, the shoulder 30 is divided into multiple parts, each of which is provided with a pressing surface 31. The pressing surface 31 is a plane. Each part of the shoulder 30 is fixedly connected to a floating structure 60, and by adjusting the compression amount of the elastic member 64, the distances between the multiple pressing surfaces 31 and the end of the stirring needle 22 are different. Figure 5 and Figure 6 The shoulder 30 illustrated in the example is divided into two parts, and the number of the pressing surfaces 31 is two.

[0036] Through the above design, when the flexible friction stir welding device is used, the shoulder 30 does not rotate, and the shoulder 30 only slides on the surface of the workpiece, which solves the problem of thinning of the welding flash weld, does not thin the workpiece, and the weld surface is smooth without arc lines; the heat input is only generated by the friction of the stirring needle 22, the amount of heat is small, the longitudinal temperature gradient of the weld is small, and the deformation of the workpiece is small; the axial position of the shoulder 30 is adjustable, and there is no need to frequently replace the stirring tool, so that workpieces of different thicknesses and different workpieces can be welded, which is efficient and has a wide range of applications; the axial pressure of the shoulder 30 can be controlled to achieve constant pressure welding, and keep the shoulder 30 tightly pressing the workpiece without over-pressing.

[0037] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which are equivalent modifications and improvements made to the above embodiments based on the essential technology of the present invention, and all of them belong to the protection scope of the present invention.

Claims

1. A flexible friction stir welding device, comprising a main shaft, a stirring head and a shoulder, wherein the stirring head comprises a clamping portion and a stirring needle, wherein the clamping portion is clamped at the end of the main shaft, and the main shaft is coaxial with the stirring head, characterized in that: The flexible friction stir welding device further comprises a floating structure, the shaft shoulder is fixedly mounted on the floating structure, the stirring needle extends from the shaft shoulder, the shaft shoulder is provided with a pressing surface, and the floating structure adjusts the axial position of the shaft shoulder to adjust the distance from the pressing surface to the end of the stirring needle; The shoulder is split, the pressing surface is multiple, each pressing surface is a plane, and the distances between the multiple pressing surfaces and the end of the stirring needle are different; The floating structure comprises a cylinder and a piston rod, the piston rod is movably mounted on the cylinder, and the end of the piston rod is fixedly connected to the shaft shoulder; The flexible friction stir welding device also includes a floating plate and a connecting block. The floating plate is fixedly connected to the piston rod, and the shaft shoulder is fixedly connected to the floating plate through the connecting block.

2. The flexible friction stir welding device according to claim 1, characterized in that: The floating structure also includes an elastic member, which is sleeved on the piston rod, and two ends of the elastic member are respectively in contact with the piston rod and the bottom of the inner wall of the cylinder.

3. The flexible friction stir welding device according to claim 2, characterized in that: The elastic member is a spring.

4. The flexible friction stir welding device according to claim 1, characterized in that: A gap is formed between the stirring head and the shaft shoulder.

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