Disclosure of Invention
The invention aims to provide a method and technological equipment for playing a role in positioning, supporting and compressing a T-shaped joint during static shaft shoulder friction stir welding, which can meet the requirements of high-precision assembly, high-quality welding and nondestructive testing of the T-shaped joint and further can realize engineering application.
The scheme for solving the technical problem is that a stirring head structure suitable for static shaft shoulder friction stir welding of the T-shaped joint is designed, so that the stirring head is more suitable for the static shaft shoulder friction stir welding process of the T-shaped joint, a special welding clamping tool is designed, and the pre-welding assembly and welding quality are guaranteed.
The specific technical scheme is as follows: the utility model provides a static shaft shoulder friction stir welding device of T type joint, includes T type joint welding jig and the static shaft shoulder friction stir welding instrument of T type joint, its characterized in that, T type joint welding jig includes bed die subassembly and formpiston subassembly, and bed die subassembly and formpiston subassembly form vertically contained angle for place T type joint, and T type joint includes base plate and floor, base plate and floor mutually perpendicular, and the base plate of T type joint is fixed in on the bed die subassembly, and the floor is installed on the formpiston, and base plate and floor push up tightly along the welding direction, friction welding instrument includes stirring pin tail, stirring needle head and shaft shoulder sleeve head, and threaded connection is passed through at the rotation main shaft to stirring pin tail one end, and the other end is connected with the stirring needle head through connecting thread, and static shaft shoulder sleeve head keeps coaxial through bolted connection on the aircraft nose base of lathe and with the stirring needle.
In order to realize the high-quality static shoulder friction stir welding of the T-shaped joint (composed of the base plate and the ribbed plate), the joint surface of the base plate and the ribbed plate needs to be completely eliminated, and the defect similar to the incomplete penetration property is not allowed to exist, so the static shoulder friction stir welding of the T-shaped joint needs to be sequentially welded from two sides (as shown in figures 2 a-2 d). During single-side welding, the stirring pin profile needs to be ensured to exceed the thickness center line of the ribbed plate (as shown in figure 2a), and the cross section profile of the formed single welding seam can also exceed the thickness center line of the ribbed plate (as shown in figure 2 b). After the two sides are welded in sequence, the cross section profiles of the 2 welding seams are overlapped to a certain degree, and then the T-shaped joint is completely welded.
And (3) a nondestructive testing scheme: the nondestructive detection of the T-shaped joint is a difficult problem, firstly, the joint is not suitable for X-ray flaw detection, and moreover, only the surface quality of a welding seam can be detected by means of methods such as dye penetrant inspection. It is proposed herein to perform joint internal quality inspection from the back of the substrate of a T-joint using ultrasonic phased array inspection techniques, as shown in fig. 3.
In order to realize the friction stir welding of the T-shaped static shaft shoulder, the friction stir welding tool of the static shaft shoulder comprises a fixed support, a needle bearing, a combined stirring needle, a locking nut, a shaft shoulder, a central rotary power source and the like, and the specific connection relationship is as follows: the big end of the fixed support is connected with the static part of the friction stir welding equipment, but the big end of the fixed support is coaxial with the central rotation power source; 1 needle roller bearing is arranged in the fixed support, and the two are coaxially arranged; in order to prevent the lower end of the needle bearing from moving downwards, 1 locking nut is installed; the profiling static shaft shoulder is fixedly connected with the locking nut; one end of the combined stirring pin is connected with a central rotation power source, the middle part of the combined stirring pin is tightly matched with the needle bearing, and the lower end of the combined stirring pin penetrates through the static shaft shoulder. The functions of the various components are as follows:
a. fixing a support: the profiling static shaft shoulder is used for realizing no rotation in the welding process;
b. profiling static shaft shoulders: the angle between the left plane and the right plane is 90 degrees in order to imitate a T-shaped joint structure, the intersection of the two planes is in sharp transition, and theoretically, the intersection is a straight line. The plane with an included angle of 90 degrees and the sharp transition of the two surfaces mainly aim to keep the static shaft shoulder tightly attached to the T-shaped joint, seal the extrusion die and prevent plastic metal in the sealed extrusion die from overflowing in the welding process. In the actual welding process, in order to reduce the advancing resistance of the static shaft shoulder in the T-shaped joint welding process, the transition parts of two surfaces of the static shaft shoulder are designed to be in smooth transition, but the R angle is not required to be too large (below R1) so as not to damage the sealing effect.
c. Needle roller bearing: during welding, the stirring pin rotates at high speed and bears the forward resistance opposite to the welding direction, and the profiling static shaft shoulder is hardly deformed, so that contact and frictional wear can occur at the matching surface of the stirring pin and the shaft shoulder, and even welding failure can be caused. In order to ensure the rotational stability of the stirring pin under a stress state, 1 needle bearing design is added, aiming at improving the high-speed rotational stability and rigidity of the stirring pin.
d. Locking the nut: the needle bearing is axially fixed and provides a connection feature for the stationary shoulder.
e. A central rotation power source: provides power for the high-speed rotation of the combined stirring pin.
f. A combined stirring pin: during the friction stir welding of the stationary shaft shoulder of the T-joint, the parent metal from the vertex of the intersecting line of the center hole of the stationary shaft shoulder to the two sides of the end of the shaft shoulder is positioned in the closed extrusion die until the half of the joint surface between the rib plate of the T-joint and the base plate, as shown in fig. 4.
The closed extrusion die from the vertex of the intersecting line of the shaft shoulder to the end part of the shaft shoulder has the largest volume, and in order to ensure that the plastic metal in the area flows sufficiently, the part of the stirring needle is recommended to be thicker, and a cylindrical thread is preferably adopted; for the closed extrusion die in the area below the shaft shoulder end, the occupied volume is slightly small, but the stirring needle is required to well penetrate through the workpiece until the stirring needle exceeds a half part of a joint surface between a T-shaped joint ribbed plate and a base plate, and a conical thread is preferably adopted. In order to increase the stirring capacity of the stirring pin for the plastic metal in the closed extrusion die, a plane structure is added on the cylindrical thread part and the conical thread part of the stirring pin at an interval of 120 degrees respectively. The utility model provides a stirring pin structure adopts split type structure, comprises stirring pin and clamping structure, and this is mainly in order to reduce the material volume and the manufacturing cost of stirring pin.
g. The static shaft shoulder of T type joint matches with the pin mixer:
the static shaft shoulder of T type joint and the probe clearance fit, be about 0.3mm, in order to further prevent that the fitting surface department of probe and shaft shoulder from taking place frictional wear among the welding process, welding fault appears even.
Because welding wires cannot be added in the welding process of the friction stir welding process, the assembly quality requirement before welding is high, and a special welding clamp is needed for assembly guarantee before welding. Based on the structural characteristics of the T-shaped joint and the high-quality assembly requirement before friction stir welding, the design idea of the welding fixture is as follows: the shaft shoulder does not rotate in the static shaft shoulder friction stir welding process of the T-shaped joint, and 2 planes with 90-degree included angles of the shaft shoulder are tightly attached and tightly press the base plate and the ribbed plate of the T-shaped joint, so that the area, close to a welding line, of the T-shaped joint does not need to be fixed, and only the ribbed plate and the far end of the base plate need to be fixed; after one side of the T-joint is welded, the test piece needs to be detached and the other side is welded. Therefore, the tool needs to be designed to be split, and is convenient to detach and install.
The invention has the beneficial effects that:
1) the method can effectively control the positioning and pressing state of the T-shaped joint rib plate and the base plate, and adjust the assembly state of the welded workpiece to be optimal;
2) the method is simple and clear, is easy to operate, and is convenient for observing and determining the assembly state;
3) the device is used for compressing the positioning support before the fillet weld of the T-shaped joint, is suitable for the static shaft shoulder friction stir welding with higher welding assembly precision requirement and realizes the near-gapless assembly;
4) the static shaft shoulder stirring head adopts a detachable structure of a needle head and a needle tail, so that different needle heads can be replaced when different parameters are welded, the production cost is greatly reduced, the production efficiency is effectively improved, the structure is simple, and the assembly is facilitated;
5) the clamping device is novel in structural design, wide in application range, concise in operation, high in precision and reliable in quality. The fastening device can be adjusted along with the thickness change of the base plate and the rib plate, the adaptability is strong, and the pre-welding assembly work of positioning, assembling and clamping products in a certain range is realized.
6) The device has flexible structural design, adopts a split type female die and a split type male die, greatly improves the product adaptability, improves the product manufacturing process, reduces the labor intensity of spaceworkers, and improves the labor productivity and the safe production level.
7) Compared with the traditional fusion welding, the product welded by the device has the advantages of high joint quality, small deformation, few defects, greenness, no pollution and the like. The successful application of the device has very important significance for optimizing the welding process of the T-shaped joint fillet weld, improving the welding quality of products and reducing the environmental pollution.
Detailed Description
A static shaft shoulder friction stir welding device for a T-shaped joint mainly comprises a female die assembly, a male die assembly, a jacking assembly, a pressing assembly and a stirring head, and specifically comprises a connecting plate 1, a first base plate 2, a second base plate 3, a baffle 4, a female die 5, a jacking assembly 6, a pressing assembly 7, a male die 8, a rotating main shaft 9 and a stirring head 10, wherein the specific structure is shown in figure 5. A base plate 1-1 of a T-shaped joint is placed on a female die assembly, a female die and a male die are connected and fastened into a whole, the base plate 1-1 is clamped by the female die and the male die, a rib plate 1-2 is installed on a positioning plate of the male die, the rib plate 1-2 and the base plate 1-1 are pressed and pressed tightly through a pressing assembly and a pressing assembly, the base plate 1-1 and the rib plate 1-2 are pressed and pressed tightly along the welding direction through baffles at two ends of the female die and the male die, and assembling, positioning and clamping before welding of a static shaft shoulder are achieved.
The device is used for compressing the positioning support before welding the fillet weld 1-3 of the T-shaped joint, is suitable for welding and assembling with higher precision requirement, and realizes the static shaft shoulder friction stir welding of near zero clearance assembly.
The female die assembly is a reference for assembling and positioning a T-shaped joint base plate 1-1 to realize the full positioning and clamping of the base plate 1-1 on a female die, the cross section of the female die assembly is in an equilateral right-angled triangle structure, two acute angles of the triangle are chamfered, the bevel edge position is the positioning and mounting position of the base plate 1-1, the female die assembly mainly comprises a long strip-shaped steel plate, a top plate 5-1, a first vertical plate I5-2 with three uniformly distributed and supplemented square lightening holes, an inclined plate 5-3 with mounting threaded holes, a rib 5-4 which is in a triangle structure and has a triangular heavier hole in the center, a bottom plate 5-5 and a second vertical plate I5-6 which are connected in an angle welding manner, one end of the inclined plate 5-3 is provided with a sinking platform structure for positioning a first cushion plate 2 which is subsequently mounted on the surface of the inclined plate, and the other end of the inclined plate 5-3 is provided with a mounting threaded hole structure for mounting a puller assembly 6 and a pressing assembly 7, two side surfaces of the inclined plate 5-3 are provided with mounting threaded hole structures for connecting the plate 1, the connecting plate 1 realizes the connecting and clamping effects of the female die assembly and the male die assembly, in order to effectively realize the fastening and connection of the female die assembly and the male die assembly, the second vertical plate I5-6 is provided with threaded connecting holes and positioning pin holes, one positioning pin hole in the middle of the two threaded holes is a group, and the three groups are uniformly distributed on the second vertical plate I5-6. As shown in fig. 6 and 10.
The male die assembly is a reference for assembling and positioning the T-shaped joint rib plate 1-2 to realize the full-positioning clamping of the rib plate 1-2 on the female die, and the cross section of the male die assembly is formed by the combination of two right-angle sides and a rectangle. The vertical plate mainly comprises a first flat plate 8-1, a second flat plate 8-6, a first vertical plate II 8-2, a second vertical plate II 8-5, a first right-angle plate 8-3 and a second right-angle plate 8-4. The first flat plate 8-1 and the second flat plate 8-6 are placed in parallel, the first vertical plate II 8-2 and the second vertical plate II 8-5 are placed in parallel and are vertically arranged and connected with the second flat plate 8-6, and the first right-angle plate 8-3 and the second right-angle plate 8-4 are connected in a right-angle shape, wherein the second right-angle plate 8-4 is connected with the second flat plate 8-6, and the first right-angle plate 8-3 is connected with the first flat plate 8-1. U-shaped lightening holes are uniformly distributed in the first vertical plate II 8-2, reinforcing ribs 8-7 are connected in the male die to improve the rigidity of the whole male die, a mounting hole is processed at one end of the first right-angle plate 8-3 to mount the jacking component 6, the pressing component 7 and the second base plate 3, the rib plate 1-2 is mounted on the first right-angle plate 8-3, threaded connecting holes are formed in two sides of the second right-angle plate 8-4 and used for connecting the connecting plate 1 with the female die component, threaded connecting holes and positioning pin holes are formed in the second vertical plate II 8-5, one positioning pin hole in the middle of each threaded hole is a group, the three groups are uniformly distributed in the second vertical plate II 8-5, and the female die component and the male die component are reinforced to be connected and fastened. Specifically, as shown in fig. 7 and 11.
The pressing component 7 and the jacking component 6 realize the pressing and jacking fixation of one side of the base plate 1-1 and the ribbed plate 1-2. The pressing component 7 consists of a stud 7-1, a pressing plate 7-2 and a supporting nail 7-3, one end of the stud 7-1 is connected with a first straight angle plate 8-3 or an inclined plate 5-3 by adopting a threaded structure, a reverse fastening nut is used for preventing looseness, and the supporting nail 7-3 adjusts the supporting length to realize the pressing of the pressing plate 7-2 with different thicknesses. The jacking component 6 consists of a jacking nail 6-1, a base 6-2 and a jacking block 6-3, the base 6-2 is connected with a first straight angle plate 8-3 or an inclined plate 5-3 in a threaded manner to take root, the jacking block 6-3 is pushed by the jacking nail 6-1 in a telescopic manner to realize jacking of the rib plate 1-2 and the side surface of the base plate 1-1 and eliminate the gap of a contact surface, and the assembling requirement before welding of static shaft shoulder friction stir welding is met, and the specific structure is shown in a figure 8 and a figure 9.
The stirring head assembly 10 is a stirring head for realizing static shaft shoulder stirring friction welding, a rotary stirring needle of the assembly is connected to a rotary main shaft 9, and a static shaft shoulder sleeve head 10-6 is connected to a machine head base of machine tool equipment. The device mainly comprises a stirring pin tail 10-1, a stirring pin head 10-3, a T-shaped profiling static shaft shoulder 10-2, a tightly-supported connecting threaded sleeve 10-4, a high-speed rotary needle bearing 10-5 and a static shaft shoulder sleeve head 10-6. One end of a stirring needle tail 10-1 is connected with a rotating main shaft 9 through a thread, the other end of the stirring needle tail is connected with a stirring needle head 10-3 through a connecting thread, a static shaft shoulder sleeve head 10-6 is connected with a machine head base of a machine tool through a bolt and is coaxial with the stirring needle, in order to prevent the stirring needle head 10-3 from interfering and clamping with a T-shaped profiling static shaft shoulder 10-2 in the welding process, a needle bearing 10-5 is arranged between the stirring needle tail 10-1 and the static shaft shoulder sleeve head 10-6 to ensure that the stirring needle tail and the static shaft shoulder sleeve head are coaxial and do not interfere with each other, one end of the needle bearing 10-5 is limited through a shaft shoulder at one end of the static shaft shoulder sleeve head 10-6, the other end of the needle bearing is connected with the static shaft shoulder sleeve head 10-6 through a thread on the outer surface of a jacking connecting screw sleeve 10-4, a threaded hole is processed on one end surface of the jacking connecting screw sleeve 10-4 to realize that the T-shaped profiling static shaft shoulder 10-2 is connected into a whole through the bolt, meanwhile, the stirring needle head 10-3 and the T-shaped profiling static shaft shoulder 10-2 can be ensured to be coaxial, when the rotating main shaft 9 rotates, the stirring needle head 10-3 rotates to realize the transmission of the rotating motion, the T-shaped profiling static shaft shoulder 10-2 is connected to a machine head base of equipment machine tool equipment and does not rotate, and when the welding motion is carried out, the T-shaped profiling static shaft shoulder 10-2 and the rotating stirring needle head 10-3 move together to realize the motion of a welding track. The specific structure is shown in fig. 12.
The present invention has not been described in detail as is known to those skilled in the art.