CN111889873A

CN111889873A - Welding joint and welding method for friction stir welding of vacuum cavity

Info

Publication number: CN111889873A
Application number: CN202010597412.3A
Authority: CN
Inventors: 孟进
Original assignee: Shanghai Changqiao Vacuum System Manufacturing Co ltd
Current assignee: Shanghai Changqiao Vacuum System Manufacturing Co ltd
Priority date: 2020-06-28
Filing date: 2020-06-28
Publication date: 2020-11-06

Abstract

The invention relates to the technical field of friction stir welding, in particular to a welding head and a welding method for friction stir welding of a vacuum cavity. The device increases the friction contact area and the friction coefficient between the end face of the welding head and the workpiece to be welded by preheating the abrasive particles scattered on the abrasive particle part through arranging the preheating abrasive particle part on the welding head, and therefore, the speed of heat generation between the welding head and the workpiece can be accelerated, and meanwhile, the time of the workpiece reaching a thermoplastic state is shortened, so that the moving speed of the welding head on the workpiece can be accelerated, the welding speed is accelerated, and the welding efficiency is improved.

Description

Welding joint and welding method for friction stir welding of vacuum cavity

Technical Field

The invention relates to the technical field of friction stir welding, in particular to a welding joint and a welding method for friction stir welding of a vacuum cavity.

Background

Friction welding is a method in which the temperature of the welded portion of a workpiece is raised to a thermoplastic state by using heat generated by the mutual motion and friction between the end surfaces of the workpiece and the welded parts, and then two groups of workpieces are rapidly stirred and upset-forged into a whole by a stirring head, thereby completing welding. Friction welding can be used to join like or dissimilar materials including metals, partially metal matrix composites, ceramics and plastics. The heated area of the cavity is small when friction stir welding is carried out, so that the deformation of the cavity can be greatly reduced; the welding penetration is higher, the yield of products can be improved, and the external welding seam welded by friction stir welding is more attractive. Thus, in recent years, a method of welding a vacuum chamber by using friction stir welding has been increasingly used.

However, since the friction stir welding itself brings the workpiece into a thermoplastic state by heat generated by mutual friction between the respective members, it is necessary to rotate the welding torch quickly to generate frictional heat when welding, but it takes a long time to heat the workpiece to a thermoplastic state by only frictional heat generation, and thus the welding method of the conventional friction stir welding takes a long time to weld, resulting in low productivity.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a welding head and a welding method for friction stir welding of a vacuum cavity, which can quickly increase the temperature of the welding part of a welding workpiece, thereby improving the welding efficiency of the workpiece.

In order to achieve the above purpose, the invention provides the following technical scheme:

the welding head for friction stir welding of the vacuum cavity comprises a stirring head and a stirring needle, wherein the stirring needle is fixedly arranged on the end face of one side of the stirring head.

In the invention, further, a plurality of groups of accommodating grooves are formed along the axial direction of the stirring head, and the preheating abrasive particle parts are fixedly arranged in the plurality of groups of accommodating grooves in a penetrating manner.

In the invention, a pressing component is further arranged between the accommodating groove and the preheating abrasive particle part, and the pressing component applies pressure to the preheating abrasive particle part to enable the preheating abrasive particle part to be separated from the accommodating groove and freely slide downwards.

In the invention, the pressing assembly further comprises a pressing ring and a buffer part, the pressing ring is coaxially sleeved on the outer side wall of the stirring head, and the buffer part is connected between the pressing ring and the preheating abrasive particle part.

In the invention, further, the buffer part is provided with an elastic piece with deformation energy absorption.

In the invention, furthermore, a chamfer is arranged at the intersection of the containing groove and the bottom surface of the stirring head close to the stirring pin, so that friction particles can more easily enter a gap between the stirring head and a part to be welded.

In the invention, further, the preheating abrasive particle part comprises a raw lime grinding friction part and a reaction liquid accommodating part, and the raw lime grinding friction part and the reaction liquid accommodating part are arranged in the plurality of groups of accommodating grooves at intervals.

Meanwhile, the invention also provides a friction stir welding method for the vacuum cavity, which is used for welding a welding seam formed between a first part to be welded and a second part to be welded and is characterized in that,

clamping a part to be welded, moving a first part to be welded and a second part to be welded, splicing the end parts to be combined of the first part to be welded and the second part to be welded to form a part to be welded, and clamping and fixing the first part to be welded and the second part to be welded;

providing a welding head, wherein the welding head comprises a stirring head and a stirring pin, the stirring pin is fixedly arranged on the end face of one side of the stirring head, and a plurality of groups of accommodating grooves are formed in the axial direction of the stirring head;

the installation preheats the grit portion, will preheat the grit portion and penetrate in the storage tank to guarantee to preheat the grit portion under natural state and can not take place relative displacement with the storage tank between.

And a welding step, namely installing the welding head provided with the preheated abrasive particle part on welding equipment, and guiding the welding head to move along the part to be welded for welding so as to form a welding seam.

In the present invention, further, the step of installing the preheated abrasive particle part includes the steps of:

selecting a preheating abrasive particle part corresponding to the accommodating groove;

and the preheating abrasive particle part penetrates into the accommodating groove, and the preheating abrasive particle part and the accommodating groove are connected and fixed in an interference fit manner.

In the invention, further, the finished welding line is subjected to grinding treatment, so that the flatness of the welding line is ensured.

Compared with the prior art, the invention has the beneficial effects that:

the device of the invention increases the friction contact area and the friction coefficient between the end surface of the welding head and the workpiece to be welded by arranging the preheating abrasive particle part on the welding head and preheating the abrasive particles scattered on the abrasive particle part, thereby accelerating the speed of generating heat between the welding head and the workpiece and simultaneously shortening the time when the workpiece reaches a thermoplastic state, thereby accelerating the moving speed of the welding head on the workpiece, accelerating the welding speed and improving the welding efficiency.

Drawings

Fig. 1 is a schematic view of the general structure of the welding head of the present invention.

Fig. 2 is a schematic view of the overall structure of the welding head of the present invention with a pressing assembly mounted thereon.

Fig. 3 is a schematic view of the overall exploded structure of the welding head of the present invention with a pressing assembly mounted thereon.

FIG. 4 is a schematic sectional view showing the structure of the preheated abrasive grains provided in the stirring head of the present invention in a state where the preheated abrasive grains are bonded to each other.

FIG. 5 is a schematic sectional view showing a configuration of a preheated abrasive grain part provided in a stirring head according to the present invention in a state where abrasive grains are packed in a single scattering container.

FIG. 6 is a schematic cross-sectional view of the preheated abrasive grain portion with a pressing member provided thereon.

Fig. 7 is a schematic view of the general structure of the welding head mounted to the welding apparatus in the present invention.

In the drawings: 1. a stirring head; 10. a containing groove; 11. a sweeping port; 12. a stirring pin; 2. preheating the abrasive particle part; 20. a leakage container; 21. a discharge spout; 30. a reaction solution accommodating part; 4. applying a pressure ring; 41. a support arm; 5. a buffer section; 61. a first part to be welded; 62. a second part to be welded; 7. welding seams; 8. and (4) welding equipment.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 to 7, a preferred embodiment of the present invention provides a welding head for friction stir welding of a vacuum chamber, including a stir head 1 and a stir pin 12, where the stir pin 12 is integrally fixed at an end surface of one side of the stir head 1 for contacting with a workpiece during welding, and the other side is fixedly installed in a welding head clamping portion of a welding machine, the stir head 1 is driven by the clamping portion to rotate around its own axis, the workpiece is heated to a thermoplastic state by rapid friction between the end surface of the stir head 1 and the surface of the workpiece during welding, and two groups of workpieces are fixedly connected into a whole by forging and pressing actions of the stir pin 12 and the stir head 1. The preheating abrasive particle part 2 is fixed on the stirring head 1, so that the friction coefficient and the contact area between the workpiece and the end surface of the friction head are increased by the falling friction particles when the preheating abrasive particle part 2 is scattered or rubbed with the surface of the workpiece, the speed of generating heat by friction is increased, and the workpiece can be rapidly heated to a thermoplastic state.

As shown in fig. 1, a plurality of groups of accommodating grooves 10 are formed along the axial direction of the stirring head 1, and the preheating abrasive particle portions 2 are inserted into the plurality of groups of accommodating grooves 10. The circumferencial direction equipartition setting of stirring head 1 can be followed to the storage tank 10, it wears to establish in multiunit storage tank 10 to preheat 2 accessible interference fit of grit portion, the later stage rotates along with stirring head 1 together, and when preheating the initial condition of grit portion 2 just installing to the storage tank 10 in, the friction terminal surface of preheating grit portion 2 is higher than the friction terminal surface of stirring head 1, from this when carrying out welded initial condition, preheat grit portion 2 and carry out frictional contact with the work piece earlier, in order to provide more heat and preheat, make things convenient for going on of follow-up weldment, and should preheat the terminal surface of grit portion 2 and the terminal surface of stirring head 1 and can contact with the terminal surface of work piece jointly in subsequent welding, the friction granule that drops can be extruded to between work piece and the work piece in order to improve the thermogenic efficiency of friction. The preheating abrasive particle part 2 can be selected according to different welding workpieces to be welded, and it should be noted that the hardness of the friction particles of the preheating abrasive particle part 2 is smaller than the hardness of the surface of the workpiece and the end surface of the stirring head 1, so as to prevent the friction particles from increasing the abrasion of the workpiece and the stirring head 1.

As shown in fig. 4, the preheating abrasive particle portion 2 may be formed by bonding friction particles to one another to form the preheating abrasive particle portion 2 having the same shape and size as the receiving groove 10, and then the preheating abrasive particle portion 2 is inserted into the receiving groove 10, where the fitting between the preheating abrasive particle portion 2 and the receiving groove 10 is interference fit. The common friction particles comprise gypsum and talc, the particle diameter of the gypsum and the talc is 0.1-0.5 mm, and the hardness of the gypsum and the talc is far less than that of common metals to be welded (such as copper, iron, aluminum alloy and stainless steel), so that the friction particles can not scratch the surface of a workpiece to be welded during use. The preheating abrasive particle part 2 is added to the process of generating heat by friction with a workpiece together with the end surface of the stirring head 1 when the stirring head 1 is welded so as to improve the speed of generating heat by friction.

As shown in fig. 5, the pre-heating abrasive particle part 2 may be configured to pack the abrasive particles into a leakage container 20, the leakage container 20 is fixedly installed inside the receiving container 10, the leakage container 20 is provided with a plurality of sets of nozzles 21, the structure of the leakage container 20 is the same as that of an hourglass, but the leakage container 20 is configured to discharge the abrasive particles by using the combined action of centrifugal force and gravity. And the loading part of the leakage container 20 is bonded and fixed at a position close to the axis of the stirring head 1, wherein part of the leakage nozzles 21 are arranged along the axial direction of the stirring head 1 along the radial direction, and part of the leakage nozzles 21 are arranged along the axial direction of the stirring head 1, so that friction particles can uniformly leak from the leakage nozzles 21, and the friction particles are continuously supplied between the stirring head 1 and a workpiece in the welding process.

As shown in fig. 3 and 6, the receiving groove 10 is communicated with the circumferential wall surface of the stirring head 1, a pressing component is arranged between the receiving groove 10 and the preheating abrasive particle portion 2, the pressing component presses the workpiece close to the stirring head 1 in the axial direction of the stirring head, and the preheating abrasive particle portion 2 is formed by integrally bonding friction particles to the preheating abrasive particle portion 2 which is formed in the same shape and size as the receiving groove 10. The pressure applying part is used for applying pressure to the preheating abrasive particle part 2, so that the pressure of one end, which is in contact with the surface of the workpiece, of the preheating abrasive particle part 2 can be controlled, and the friction force between the preheating abrasive particle part 2 and the surface of the workpiece can be adjusted by adjusting the pressure test size of the pressure applying component, so that a better friction heating effect can be achieved.

The subassembly of exerting pressure is including exerting pressure ring 4 and buffer 5, on the 1 lateral wall of stirring head is located to the coaxial line cover of pressure ring 4, buffer 5 pads are located and are exerted pressure ring 4 and preheat between grit portion 2, and the fixed multiunit support arm 41 that is equipped with on the ring 4 of exerting pressure, multiunit support arm 41 can extend to inside the storage tank 10 that corresponds to be connected with buffer 5 through support arm 41. Therefore, the preheated abrasive particle parts 2 can be pressed by the gravity of the pressing ring 4, a certain buffer space can be provided by the arranged buffer parts 5 so as to balance the stress condition of each preheated abrasive particle part 2, and the buffer parts 5 are arranged to be springs or rubber pads.

And a chamfer is arranged at the intersection of the bottom surface of the side, close to the stirring pin 12, of the containing groove 10 and the stirring head 1. The chamfer gradually decreases in size radially outward of the pin 1. Therefore, the sweeping opening 11 can be formed, and the falling friction particles can be completely collected into the sweeping path of the stirring head 1 through the arrangement, so that the friction efficiency is improved, and the friction particles are prevented from scattering to the outer side of the stirring head 1 and being incapable of being utilized.

As shown in fig. 5, the pre-heating abrasive particle part 2 includes a raw lime polishing friction part and a reaction liquid accommodating part 30, and the raw lime polishing friction part and the reaction liquid accommodating part 30 are disposed in the plurality of groups of accommodating grooves 10 at intervals. The preheating abrasive particle part 2 is provided with a friction part of the raw lime and a reaction liquid containing part 30, and water is filled in the reaction liquid containing part 30, so that in addition to increasing the friction coefficient of the quicklime to accelerate heat generation, the heat generated when the water is reflected by the quicklime can be used for further accelerating the heat generation, and the workpiece can be accelerated to reach a thermoplastic state.

The quicklime rubbing part may be provided in a form of loading quicklime abrasive grains into the leakage container 20, and the reaction liquid accommodating part 30 may be provided in a form of the leakage container 20 and may be filled with water.

As shown in fig. 7, a friction stir welding method for a vacuum chamber includes the steps of:

s1, moving the first part to be welded 61 and the second part to be welded 62 to enable the ends to be combined of the first part to be welded 61 and the second part to be welded 62 to be spliced with each other to form a part to be welded, and then clamping and fixing the first part to be welded 61 and the second part to be welded 62 through a clamp on a working table; the first part to be welded 61 and the second part to be welded 62 are two groups of workpieces to be welded.

S2, mounting and fixing the welding head on the welding head mounting part of the welding device 8; firstly, selecting a preheating abrasive particle part 2 corresponding to the shape and size of the accommodating groove 10;

then, the preheating abrasive particle part 2 penetrates into the accommodating groove 10, and the preheating abrasive particle part 2 and the accommodating groove 10 are fixedly connected through interference fit. The pressure applying component is added according to the processing requirement to apply pressure to the preheated abrasive particle part 2.

And S3, driving a welding arm on the welding equipment 8 through a movement track planning program which is pre-programmed on the controller, and driving the welding head to move along the part to be welded by the welding arm to weld so as to form a welding seam 7.

And (3) grinding the finished welding seam 7 by using a grinding wheel or a milling machine to remove friction particle waste residues on the surface of the welding seam and friction particles remained on the surface of the welding seam 7.

The above description is intended to describe in detail the preferred embodiments of the present invention, but the embodiments are not intended to limit the scope of the claims of the present invention, and all equivalent changes and modifications made within the technical spirit of the present invention should fall within the scope of the claims of the present invention.

Claims

1. The utility model provides a soldered connection for friction stir welding of vacuum chamber body, includes stirring head (1) and stirring needle (12), stirring needle (12) are fixed to be set up in stirring head (1) side end face department, its characterized in that, be equipped with on stirring head (1) and preheat grit portion (2), it includes multiunit friction granule to preheat grit portion (2), the hardness of friction granule is less than the hardness of waiting to weld the part.

2. The welding head for friction stir welding of a vacuum chamber according to claim 1, wherein a plurality of groups of holding grooves (10) are formed along the axial direction of the welding head (1), and the preheating abrasive grain parts (2) are fixedly arranged in the plurality of groups of holding grooves (10) in a penetrating manner.

3. A welding head for friction stir welding of a vacuum chamber according to claim 2, characterized in that a pressure applying assembly is arranged between the receiving groove (10) and the preheated abrasive particle portion (2), said pressure applying assembly applying pressure to the preheated abrasive particle portion (2) so that the preheated abrasive particle portion (2) can slide freely downwards out of the receiving groove (10).

4. A welding head for friction stir welding of a vacuum chamber according to claim 3, characterized in that said pressing assembly comprises a pressing ring (4) and a buffer (5), said pressing ring (4) is coaxially sleeved on the outer sidewall of the stirring head (1), said buffer (5) is connected between the pressing ring (4) and the pre-heated abrasive particle portion (2).

5. A welding head for friction stir welding of a vacuum chamber according to claim 4, characterized in that said buffer (5) is provided as an elastic member having deformation absorption.

6. A welding head for friction stir welding of a vacuum chamber according to claim 2, characterized in that the intersection of the receiving groove (10) and the bottom surface of the stirring head (1) on the side close to the stirring pin (12) is chamfered to make it easier for friction particles to enter the gap between the stirring head (1) and the part to be welded.

7. A welding head for friction stir welding of vacuum chambers according to claim 2 or 3, characterized in that the pre-heated abrasive grain portion (2) comprises a raw lime grinding friction portion and a reaction liquid receiving portion (30), the raw lime grinding friction portion and the reaction liquid receiving portion (30) being arranged at intervals in a plurality of groups of receiving grooves (10).

8. A friction stir welding method for a vacuum chamber for welding a weld (7) formed between a first part to be welded (61) and a second part to be welded (62), characterized in that,

clamping a part to be welded, moving a first part (61) to be welded and a second part (62) to be welded, splicing the ends to be combined of the first part (61) to be welded and the second part (62) to be welded to form a part to be welded, and clamping and fixing the first part (61) to be welded and the second part (62) to be welded;

providing a welding head, wherein the welding head comprises a stirring head (1) and a stirring pin (12), the stirring pin (12) is fixedly arranged on the end face of one side of the stirring head (1), and a plurality of groups of accommodating grooves (10) are formed in the axial direction of the stirring head (1);

the preheating abrasive particle part (2) is installed, the preheating abrasive particle part (2) penetrates into the accommodating groove (10), and the preheating abrasive particle part (2) is ensured not to be displaced relative to the accommodating groove (10) in a natural state.

And a welding step of mounting the welding head provided with the preheating abrasive particle part (10) on a welding device (8) and guiding the welding head to move along the part to be welded for welding so as to form a welding seam (7).

9. A weld head for friction stir welding of a vacuum chamber according to claim 8, wherein said mounting of the preheated abrasive grain portion comprises the steps of:

selecting a preheating abrasive particle part (2) corresponding to the accommodating groove (10);

the preheating abrasive particle part (2) penetrates into the accommodating groove (10), and the preheating abrasive particle part (2) is fixedly connected with the accommodating groove (10) through interference fit.

10. A friction stir welding method for a vacuum chamber according to claim 9, characterized in that the finished weld seam (7) is ground flat to ensure flatness at the weld seam (7).