CN212264865U - Multi-shaft-shoulder double-telescopic friction stir welding stirring head - Google Patents

Abstract

The utility model relates to a double telescopic friction stir welding stirring head of multiaxis shoulder, including handle of a knife and tool bit, form the ascending first mounting hole of axial by the bottom surface of handle of a knife, the bottom surface of handle of a knife constitutes first shaft shoulder. The tool bit includes upper cutter head and lower cutter head, and the top surface of upper cutter head upwards extends axially and forms the last pin mixer that diameter reduces, goes up the pin mixer and can insert to establish telescopically and fix in first mounting hole, and the top surface of upper cutter head constitutes the upper shaft shoulder. An axially upward second mounting hole is formed by the bottom surface of the upper tool bit, and the bottom surface of the upper tool bit forms a second lower shaft shoulder. The utility model can weld the base metal with single thickness and double thickness at a single time; the distance between the corresponding shaft shoulders can be adjusted according to the different thicknesses of the base materials, the length of the corresponding stirring needle can be adjusted according to needs, the thickness of the different base materials is adapted, the welding quality is guaranteed, the stirring head is prevented from being replaced for multiple times, the operation is simpler and more convenient, and the working efficiency is improved.

Description

Multi-shaft-shoulder double-telescopic friction stir welding stirring head

Technical Field

The utility model relates to a friction stir welding technical field especially relates to a double telescopic friction stir welding stirring head of multiaxis shoulder.

Background

The friction stir welding is more and more widely applied to aluminum alloy and magnesium alloy, and the welding thickness of the aluminum alloy can be within the range of lmm to 75mm by the existing friction stir welding technology. In the welding process, the stirring pin rotating at a high speed extends into a butt joint gap of a workpiece, and the rotating stirring head and a shaft shoulder of the stirring head rub against the workpiece to generate heat, so that the material in front of the stirring head is subjected to strong plastic deformation, and along with the movement of the stirring head rotating at a high speed, the material subjected to high plastic deformation is gradually deposited behind the stirring head, and a friction stir welding seam is formed. Friction stir welding is not very demanding on equipment including the stir head, the workpiece, and the fixture used to hold the workpiece securely, the most basic requirements being rotational movement of the stir head and relative movement of the workpiece. However, the rigidity of the friction stir welding equipment plays a crucial role in the quality of a welding seam, the rigidity of the stirring head is generally required to be greater than that of a workpiece, and the material of the stirring head is usually made of a material with hardness far higher than that of the material to be welded, so that the abrasion of the stirring head can be reduced to the minimum in the welding process; meanwhile, the rigidity of the clamp is required to be larger than that of the workpiece, so that the workpiece is effectively fixed by the clamp in the rotating process of the stirring head; and the length of the stirring pin of the stirring head is smaller than the thickness of the workpiece, so that the clamp is prevented from being damaged by the stirring pin in the high-speed rotating process.

Wherein, the stirring head decides success or failure of friction stir welding, the reasonable design of stirring head shape is the key of obtaining good mechanical properties welding seam, and the stirring head that structural design is reasonable can obtain more reliable friction stir welding's welding seam. Successful design of the stir head allows for a wider range of friction stir welding applications, and in general, the stir head comprises two parts: a stirring pin and a shaft shoulder. The existing friction stir welding stirring head mainly comprises two types: the stirring head of the single-shaft shoulder single stirring pin and the stirring head of the double-shaft shoulder single stirring pin have the following disadvantages:

(1) the single-shaft-shoulder single stirring pin stirring head can only weld a single-layer-thickness base metal (namely a workpiece), the single-shaft-shoulder single stirring pin stirring head can also only weld a single-layer-thickness base metal, and the single-shaft-shoulder single stirring pin stirring head can not weld double-layer-thickness and multi-layer-thickness base metals. When the base materials with double thicknesses need to be welded, only one layer of base material can be welded first, and then the other layer of base material can be welded. However, the working efficiency is low; when one layer of base metal is welded, the other layer of base metal is deformed to the same extent, and then the other layer of base metal is welded, so that the forming effect is poor; in addition, when welding double-layer thickness's base metal, still need to ask double-layer thickness the same, if inequality, when welding the base metal of another layer thickness, still need change another specification and dimension's stirring head, the operation is comparatively loaded down with trivial details, influences work efficiency.

(2) The two stirring heads are mainly different in thickness of welding parent metal in use, the double-shaft-shoulder stirring head has certain requirements on the thickness of the welding parent metal, the thickness of the parent metal is required to be just equal to the distance between the double shaft shoulders, and if the two stirring heads are not matched, the stirring heads with other specifications and sizes need to be replaced; when the base material is thin, the extrusion of the double shaft shoulders can cause the deformation of the base material and further cause the quality deterioration of the welding seam, but the length of the stirring needle cannot be adjusted according to the thickness adaptability of the base material;

for a stirring head with a single shaft shoulder and a single stirring needle, only one shaft shoulder is provided, and the welding quality is poor when relatively thick base materials are welded; meanwhile, the length of the stirring needle cannot be adjusted adaptively according to different base material thicknesses, and only stirring heads with different specifications and sizes can be replaced, so that the operation is complex.

Therefore, the inventor provides a multi-shaft shoulder double telescopic friction stir welding stirring head by virtue of experience and practice of related industries for many years, so as to overcome the defects in the prior art.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a multi-shaft shoulder double telescopic stirring head for friction stir welding, which can weld the base metal with single-layer thickness and weld the base metal with double-layer thickness at a single time; the distance between the corresponding shaft shoulders can be adjusted according to the different thicknesses of the base materials, the length of the corresponding stirring needle can be adjusted according to needs, the thickness of the different base materials is adapted, the welding quality is guaranteed, the stirring head is prevented from being replaced for multiple times, the operation is simpler and more convenient, and the working efficiency is improved.

The utility model aims at realizing the stirring head of the multi-shaft shoulder double telescopic friction stir welding, which comprises a vertically arranged tool handle and a tool bit;

the bottom surface of the cutter handle faces the cutter head, an axially upward first mounting hole is formed in the bottom surface of the cutter handle, and a first lower shaft shoulder is formed in the bottom surface of the cutter handle; the cutter head comprises an upper cutter head and a lower cutter head, the top surface of the upper cutter head axially extends upwards to form an upper stirring pin with a reduced diameter, the upper stirring pin can be telescopically inserted and fixed in the first mounting hole, and the top surface of the upper cutter head forms an upper shaft shoulder; the bottom surface of the upper tool bit faces the lower tool bit, an axially upward second mounting hole is formed in the bottom surface of the upper tool bit, and a second lower shaft shoulder is formed in the bottom surface of the upper tool bit;

the top surface of the lower cutter head axially extends upwards to form a stepped shaft with a reduced diameter, the bottom surface of the lower cutter head axially extends downwards to form a first lower stirring pin with a reduced diameter, the stepped shaft can be telescopically inserted and fixed in the second mounting hole, and the bottom surface of the lower cutter head forms a third lower shaft shoulder; or

The lower tool bit is a second lower stirring pin, and the second lower stirring pin can be telescopically inserted and fixed in the second mounting hole.

In a preferred embodiment of the present invention, the first mounting hole is a circular hole, the hole wall of the first mounting hole is provided with an internal thread, at least two first inserting grooves are formed in the bottom surface of the tool holder at regular intervals along the circumferential direction of the first mounting hole, and the first inserting grooves are communicated with the first mounting hole; a first ejecting block is inserted into each first inserting groove, the inner wall of each first ejecting block is a cambered surface, an internal thread is arranged on the inner wall of each first ejecting block, the inner wall of each first ejecting block forms a part of the wall of the first mounting hole, and the upper stirring pin is in threaded connection with the wall of the first mounting hole; each first top block is fastened on the outer wall of the upper stirring pin through a first fastening piece.

The utility model discloses an among the preferred embodiment, first fastener is first holding screw, has seted up two at least first radial holes in the lateral wall circumference of handle of a knife, and the quantity in first radial hole is the same with the quantity in first inserting groove, every first holding screw radially insert establish corresponding first radial downthehole and with the pore wall threaded fixation in first radial hole, every first holding screw's medial extremity can support and lean on the outer wall at the first kicking block that corresponds.

In a preferred embodiment of the present invention, the second mounting hole is a circular hole, the hole wall of the second mounting hole is provided with an internal thread, at least two second inserting grooves are formed in the bottom surface of the upper tool bit at regular intervals along the circumferential direction of the second mounting hole, and the second inserting grooves are communicated with the second mounting hole; a second ejector block is inserted into each second inserting groove, the inner wall of each second ejector block is a cambered surface, an internal thread is arranged on the inner wall of each second ejector block, the inner wall of each second ejector block forms a part of the wall of the second mounting hole, and the stepped shaft or the second lower stirring pin is in threaded connection with the wall of the second mounting hole; each second top block is fastened on the outer wall of the stepped shaft or the second lower stirring pin through a second fastening piece.

The utility model discloses an among the preferred embodiment, the second fastener is the second holding screw, has seted up two at least second radial holes in the lateral wall circumference of last tool bit, and the quantity in second radial hole is the same with the quantity in second inserting groove, every second holding screw radially insert establish corresponding second radial hole and with the pore wall threaded fixation in second radial hole, every second holding screw's medial extremity can support and lean on the outer wall of the second kicking block that corresponds.

In a preferred embodiment of the present invention, the handle, the upper tool bit and the lower tool bit are cylindrical structures.

In a preferred embodiment of the present invention, the outer wall of the lower end of the first lower pin or the outer wall of the lower end of the second lower pin is a tapered surface.

In a preferred embodiment of the present invention, the included angle between the lower end conical surface of the first lower pin or the lower end conical surface of the second lower pin and the vertical surface is 25 to 30 °.

In a preferred embodiment of the present invention, the outer wall of the lower end of the handle is a tapered surface tapering downward.

The utility model discloses an among the preferred embodiment, the diameter of first shaft shoulder is 3.5 ~ 4.5 times of last pin diameter, and the diameter of handle of a knife is 5 ~ 6 times of last pin diameter.

From the above, the multi-shoulder dual telescopic friction stir welding tool head of the present invention has two stirring pins, namely, an upper stirring pin and a first lower stirring pin or a second lower stirring pin, and the lower tool head can have two structures, wherein the first structure has the first lower stirring pin and a third lower shoulder, and can be used for welding a base metal with double-layer thickness; the stirring needle under the second kind of structure is a second, can be used for welding the base metal of individual thickness, consequently the utility model provides a stirring head is through the lower tool bit of changing different structures, and the single both can weld the base metal of individual thickness, also can weld the base metal of double thickness, uses more in a flexible way.

Meanwhile, the stirring head of the utility model is provided with a plurality of shaft shoulders, including an upper shaft shoulder, a first lower shaft shoulder, a second lower shaft shoulder and a third lower shaft shoulder, and the distance between the first lower shaft shoulder and the upper shaft shoulder can be adjusted by the telescopic upper stirring pin; lower tool bit can adjust the distance between the lower shaft shoulder and the third through flexible step shaft when adopting first kind of structure, can adjust the length that the tool bit stretches out the tool bit under the second through flexible second down the pin mixer when adopting second kind of structure down, and then adapt to the thickness and the size of different base metals, to the base metal of different thickness, need not change the pin mixer many times, only need through flexible adjustment alright satisfy the welding requirement, it is more nimble simple and convenient to operate, not only the work efficiency is improved, welding quality and shaping effect have still been improved.

Drawings

The drawings are only intended to illustrate and explain the present invention and do not limit the scope of the invention. Wherein:

FIG. 1: do the utility model provides a multiaxis shoulder dual telescopic friction stir welding tool bit's when tool bit adopts first structure schematic diagram one.

FIG. 2: do the utility model provides a structure explosion chart of multiaxis shoulder dual telescopic friction stir welding stirring head when tool bit adopts first structure.

FIG. 3: does the utility model provides a structural schematic diagram of handle of a knife.

FIG. 4: do the utility model provides a bottom view of handle of a knife.

FIG. 5: do the utility model provides a side view of handle of a knife.

FIG. 6: does the utility model provides a go up the structure schematic diagram of tool bit.

FIG. 7: do the utility model provides a top view of last tool bit.

FIG. 8: to the utility model provides a side view of last tool bit.

FIG. 9: do the utility model provides a structural schematic diagram two of multiaxis shoulder dual telescopic friction stir welding stirring head when tool bit adopts first structure.

FIG. 10: do the utility model provides a multiaxis shoulder dual telescopic friction stir welding tool bit's schematic structure when tool bit adopts the second kind of structure.

FIG. 11: for the utility model provides a multiaxis shoulder dual telescopic friction stir welding stirring head and cavity section bar complex schematic structure when tool bit adopts first structure.

FIG. 12: for the utility model provides a multiaxis shoulder dual telescopic friction stir welding stirring head and another structure sketch of cavity section bar complex when tool bit adopts first structure.

FIG. 13: do the utility model provides a multiaxis shoulder dual telescopic friction stir welding stirring head and single layer thickness's mother metal complex schematic structure when tool bit adopts the second kind of structure.

The reference numbers illustrate:

1. a knife handle; 11. a first mounting hole; 12. a first lower shoulder; 13. a first insertion groove; 14. a first radial bore; 15. a first top block; 16. a first set screw;

2. a cutter head;

21. an upper cutter head; 211. an upper stirring pin; 212. an upper shaft shoulder; 213. a second mounting hole; 214. a second lower shoulder; 215. a second insertion groove; 216. a second radial bore; 217. a second top block; 218. a second set screw;

22. a lower cutter head; 221. a stepped shaft; 222. a first lower pin; 223. a third lower shoulder; 224. a second lower pin;

3. a hollow cavity section bar;

4. a base material having a single-layer thickness.

Detailed Description

In order to clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in fig. 1 to 10, the present embodiment provides a multi-shoulder dual telescopic friction stir welding tool, which includes a tool shank 1 and a tool bit 2, which are vertically disposed. The bottom surface of the shank 1 faces the tool bit 2, an axially upward first mounting hole 11 is formed in the bottom surface of the shank 1, and a first lower shoulder 12 is formed in the bottom surface of the shank 1. The cutter head 2 comprises an upper cutter head 21 and a lower cutter head 22, the top surface of the upper cutter head 21 extends upwards and axially to form an upper stirring pin 211 with a reduced diameter, the upper stirring pin 211 can be telescopically inserted and fixed in the first mounting hole 11, and the top surface of the upper cutter head 21 forms an upper shaft shoulder 212. The bottom surface of the upper tool bit 21 faces the lower tool bit 22, and an axially upward second mounting hole 213 is formed by the bottom surface of the upper tool bit 21, the bottom surface of the upper tool bit 21 constituting a second lower shoulder 214.

The top surface of the lower cutter head 22 axially extends upwards to form a stepped shaft 221 with a reduced diameter, the bottom surface of the lower cutter head 22 axially extends downwards to form a first lower stirring pin 222 with a reduced diameter, the stepped shaft 221 can be telescopically inserted and fixed in the second mounting hole 213, and the bottom surface of the lower cutter head 22 forms a third lower shaft shoulder 223; or

The lower cutter head 22 is a second lower pin 224, and the second lower pin 224 is telescopically inserted and fixed in the second mounting hole 213.

The lower tool bit 22 in this embodiment may have two structures, the first structure is shown in fig. 1 and fig. 2, and has a first lower pin 222 and a third lower shoulder 223, which are mainly used for welding a base material with a double-layer thickness, such as the cavity profile 3; second structure as shown in fig. 10, the entire lower tool tip 22 is a second lower pin 224, and is mainly used for welding a single-layer thickness of the base material 4. The lower cutter head 22 with the two structures can be replaced according to requirements when in use so as to meet different use requirements. In addition, the tool shank 1 is connected with a driving device during working so as to drive the tool shank 1 to rotate at a high speed.

Specifically, when the cavity profile 3, i.e., the base material with double thickness, needs to be welded, the lower tool bit 22 adopts the first structure, as shown in fig. 1, 9, 11 and 12, in which case the size of the stirring head is reasonably adjusted according to the distance L9 between the upper and lower inner side surfaces of the cavity profile 3, and there are several cases as follows:

in the first case: when the distance L9 between the upper and lower inner faces in the cavity profile 3 is length L3+ length L4, the upper shoulder 212 and the third lower shoulder 223 are in contact with the upper and lower inner faces of the cavity profile 3, respectively, as shown in fig. 11. At this time, according to the difference in thickness of the upper layer of the cavity profile 3, the first lower shoulder 12 may or may not be in contact with the upper surface of the cavity profile 3, and generally, in order to ensure the welding quality, when the thickness of the upper layer of the cavity profile 3 is thinner, only one surface of the upper layer of the cavity profile 3 needs to be in contact with the corresponding shoulder; when the thickness of the upper layer of the cavity section bar 3 is thicker, the upper surface and the lower surface of the upper layer of the cavity section bar 3 are required to be contacted with the corresponding shaft shoulders, so that whether the first lower shaft shoulder 12 is contacted with the upper surface of the cavity section bar 3 or not can be adjusted by the telescopic upper stirring pin 211 according to the specific thickness of the upper layer of the cavity section bar 3.

After adjustment, during welding, the tool shank 1 rotating at high speed drives the first lower shoulder 12, the upper pin 211, the upper shoulder 212, the third lower shoulder 223, and the first lower pin 222 to rotate together, and the upper pin 211 and the first lower pin 222 extend into the upper layer butt joint gap and the lower layer butt joint gap of the cavity profile 3, respectively. If the first lower shoulder 12 contacts with the upper surface of the cavity profile 3, the rotating upper pin 211, the first lower pin 222, the first lower shoulder 12, the upper shoulder 212 and the third lower shoulder 223 have two pins in total and three shoulders rub against the cavity profile 3 to generate heat; if the first lower shoulder 12 is not in contact with the upper surface of the cavity profile 3, the rotating upper pin 211, the first lower pin 222, the upper shoulder 212 and the third lower shoulder 223 share two pins and the two shoulders rub against the cavity profile 3 to generate heat. The material in front of the stirring head is enabled to generate strong plastic deformation, along with the movement of the stirring head rotating at a high speed, the 3 material of the cavity sectional material with the high-speed plastic deformation is gradually cooled and deposited behind the stirring head, so that an upper stirring friction welding seam and a lower stirring friction welding seam can be formed at one time through single welding, and the welding efficiency and the forming effect are improved.

In the second case: when the distance L9 between the upper and lower inner side surfaces in the cavity profile 3 is greater than the length L3+ the length L4, as shown in fig. 12, the first lower shoulder 12 and the third lower shoulder 223 are in contact with the upper surface and the lower inner side surface of the cavity profile 3, respectively (if the first lower shoulder 12 is not in contact with the upper surface of the cavity profile 3, it can be adjusted to be in contact by extending and retracting the upper pin 211), and the upper shoulder 212 is not in contact with the upper inner side surface of the cavity profile 3.

During welding, the tool shank 1 rotating at a high speed drives the first lower shoulder 12, the upper pin 211, the upper shoulder 212, the third lower shoulder 223 and the first lower pin 222 to rotate together, and the upper pin 211 and the first lower pin 222 respectively extend into the upper layer butt joint gap and the lower layer butt joint gap of the cavity profile 3. Rotatory last pin 211, first pin 222, first shoulder 12 and third shoulder 223 are total two pins and two shoulders and cavity section bar 3 friction production heat down for the preceding material of stirring head takes place strong plastic deformation, along with the removal of high-speed rotatory stirring head, high-speed plastic deformation's cavity section bar 3 material cools off the deposit gradually behind the stirring head, thereby can once only form upper and lower two friction stir welding welds through single welding, welded efficiency and shaping effect have been improved.

In addition, the stirring head in the embodiment has no special requirement on the plate thicknesses of the upper layer and the lower layer of the cavity profile 3, the thicknesses of the upper layer and the lower layer can be the same or different, the length L5 of the upper stirring pin 211 extending out of the tool holder 1 and the length L2 of the first lower stirring pin 222 during processing can be adjusted to meet the requirement, the purpose of forming an upper stirring friction welding seam and a lower stirring friction welding seam at one time through single welding can be achieved, and the forming effect is guaranteed.

When the base material 4 with a single thickness needs to be welded, the lower tool bit 22 has the second structure, as shown in fig. 10, in this case, since the upper probe 211 itself is relatively thin, in order to avoid the damage of the upper probe 211, the upper probe 211 generally needs to be completely retracted into the first mounting hole 11 first when in use, so that the first lower shoulder 12 and the upper shoulder 212 are completely attached to protect the upper probe 211. Meanwhile, according to the thickness of the base material, the length L8 of the second lower probe 224 extending out of the upper tool bit 21 can be adjusted by extending and retracting the second lower probe 224, so as to meet the welding requirements of base materials with different thicknesses.

During welding, as shown in fig. 13, the second lower shoulder 214 contacts the single-layer thickness base material 4, the entire tool bit 2 is rotated by the high-speed rotating tool shank 1, and the second lower pin 224 extends into the butt gap of the single-layer thickness base material 4. The rotating second lower pin 224 and the second lower shoulder 214 rub against the single-layer thickness base metal 4 to generate heat, so that the material in front of the pin is strongly plastically deformed, and the highly plastically deformed base metal material is gradually cooled and deposited at the back of the pin as the pin rotating at a high speed moves, thereby forming a single friction stir welding bead.

Of course, the first configuration of the lower tool tip 22 may be used to weld the base material 4 having a single thickness, in which case the upper probe 211 is first completely retracted into the first mounting hole 11. During welding, the third lower shoulder 223 contacts the single-layer thickness base material 4, and the first lower probe 222 extends into the butt seam of the single-layer thickness base material 4, thereby performing friction welding. However, in this case, since the length L2 of the first lower probe 222 is fixed and cannot be adjusted, the method can be applied only to a base material having a fixed thickness, and the application range is small.

Therefore, the multi-shoulder dual telescopic friction stir welding tool in the embodiment has two stirring pins, namely the upper stirring pin 211 and the first lower stirring pin 222 or the second lower stirring pin 224, and the lower tool bit 22 can have two structures, wherein the first structure has the first lower stirring pin 222 and the third lower shoulder 223 and can be used for welding a base material with double thicknesses; the second structure is a second lower pin 224, which can be used to weld the base material 4 with a single thickness, so the stirring head in this embodiment can weld the base material 4 with a single thickness or weld the base material with a double thickness by replacing the lower tool bit 22 with a different structure, and the use is more flexible.

Meanwhile, the stirring head in this embodiment has a plurality of shoulders, including an upper shoulder 212, a first lower shoulder 12, a second lower shoulder 214 and a third lower shoulder 223, and the distance between the first lower shoulder 12 and the upper shoulder 212 can be adjusted by extending and retracting the upper stirring pin 211; lower tool bit 22 can adjust the distance between last shaft shoulder 212 and the third lower shaft shoulder 223 through flexible step shaft 221 when adopting first kind of structure, can adjust the length L8 that the second lower pin 224 stretches out tool bit 21 through flexible second lower pin 224 when lower tool bit 22 adopts second kind of structure, and then adapt to the thickness and the size of different base metals, to the base metal of different thickness, need not change the pin for a plurality of times, only need through flexible adjustment alright satisfy the welding requirement, the operation is more nimble simple and convenient, not only the work efficiency is improved, welding quality and shaping effect have still been improved.

In a specific implementation manner, in order to facilitate the extension and the fixation of the upper stirring pin 211, as shown in fig. 1 to 5, the first mounting hole 11 is a circular hole, the hole wall of the first mounting hole 11 is provided with internal threads, at least two first insertion grooves 13 which are axially upward are formed in the bottom surface of the tool holder 1 along the circumferential direction of the first mounting hole 11 at uniform intervals, and the first insertion grooves 13 are communicated with the first mounting hole 11. A first ejector block 15 is inserted into each first insertion groove 13, the inner wall of each first ejector block 15 is an arc surface, an internal thread is arranged on the inner wall of each first ejector block 15, the inner wall of each first ejector block 15 forms a part of the hole wall of the first mounting hole 11, and the upper stirring pin 211 is in threaded connection with the hole wall of the first mounting hole 11. Each of the first top blocks 15 is fastened to the outer wall of the upper pin 211 by a first fastening member.

In detail, the first fastening member is a first set screw 16, at least two first radial holes 14 are formed in the circumferential direction of the side wall of the tool holder 1, the number of the first radial holes 14 is the same as that of the first insertion grooves 13, each first set screw 16 is radially inserted into the corresponding first radial hole 14 and is fixed to the hole wall of the first radial hole 14 in a threaded manner, and the inner side end of each first set screw 16 can abut against the outer wall of the corresponding first ejector block 15.

The first mounting hole 11 is preferably a blind hole, and certainly, a through hole may be used as needed, which is merely an example in this embodiment. In addition, in order to prevent the first top block 15 from rotating by itself to ensure that the upper pin 211 is effectively fixed, the first top block 15 is preferably a square block. The number of the first top blocks 15 is determined as needed, and for example, two first top blocks 15 are provided in the present embodiment. The first jacking blocks 15 and the first set screws 16 are uniformly arranged in the circumferential direction, so that the dynamic balance during working can be guaranteed, the damage to the upper stirring pin 211 is avoided, and the service life of the upper stirring pin is prolonged.

During installation, the first ejecting blocks 15 are firstly embedded in the corresponding first inserting grooves 13, then the upper stirring pin 211 is screwed into the first installation hole 11 through the threaded structure, and at the moment, the upper stirring pin 211 is not screwed tightly, so that the upper stirring pin 211 can stretch and contract to adjust the length L5 of the upper stirring pin extending out of the knife handle 1. Each first set screw 16 is then screwed radially into the corresponding first radial hole 14, at which time the first set screw 16 drives the corresponding first top block 15 to move radially, so that each first top block 15 is fastened to the outer wall of the upper stirring pin 211. And then the clamping action of each first ejector block 15 realizes the effective fixation of the upper stirring pin 211, and the idle rotation of the upper tool bit 21 is avoided in the process of high-speed rotation of the tool holder 1.

Thus, when the upper stirring pin 211 needs to be extended and retracted to adjust the extending length L5, the first set screws 16 are loosened, the screwing degree of the upper stirring pin 211 screwed into the first mounting hole 11 can be adjusted to a proper extension and retraction position, and then the first set screws 16 are fastened to fix the upper stirring pin 211 again. The whole upper stirring pin 211 is simple and convenient to stretch and fix.

Further, in order to facilitate the extension and the fixation of the lower tool bit 22, as shown in fig. 1, 2, 6, 7, 8 and 10, the second mounting hole 213 is a circular hole, the hole wall of the second mounting hole 213 is provided with internal threads, at least two second insertion grooves 215 are formed on the bottom surface of the upper tool bit 21 along the circumferential direction of the second mounting hole 213 at regular intervals in the axial direction, and the second insertion grooves 215 are communicated with the second mounting hole 213. A second top block 217 is inserted into each second insertion groove 215, the inner wall of each second top block 217 is an arc surface, an internal thread is arranged on the inner wall of each second top block 217, the inner wall of each second top block 217 forms a part of the hole wall of the second mounting hole 213, and the stepped shaft 221 or the second lower stirring pin 224 is in threaded connection with the hole wall of the second mounting hole 213. Each second top block 217 is fastened to the outer wall of the stepped shaft 221 or the second lower pin 224 by a second fastener.

In detail, the second fastening member is a second set screw 218, at least two second radial holes 216 are formed in the circumferential direction of the side wall of the upper tool bit 21, the number of the second radial holes 216 is the same as that of the second insertion grooves 215, each second set screw 218 is radially inserted into the corresponding second radial hole 216 and is fixed to the hole wall of the second radial hole 216 through threads, and the inner end of each second set screw 218 can abut against the outer wall of the corresponding second top block 217.

For convenience of installation, the first set screw 16 and the second set screw 218 are both generally straight fastening screws, but other types may be used as needed, and this embodiment is merely an example. The second mounting hole 213 is preferably a blind hole, but may be a through hole if necessary. In addition, in order to make the second top block 217 itself unable to rotate to ensure that the stepped shaft 221 or the second lower pin 224 is effectively fixed, the second top block 217 is preferably a square block. The number of the second top blocks 217 is determined according to the requirement, for example, two second top blocks 217 are provided in the present embodiment. The installation process for achieving the extension and the fixation of the entire lower tool bit 22 is similar to the installation process for achieving the extension and the fixation of the upper stirring pin 211, and is not described in detail herein. The lower tool bit 22 is effectively fixed through the clamping action of the second ejection blocks 217, and the situation that the stepped shaft 221 or the second lower stirring pin 224 idles in the process of high-speed rotation of the tool holder 1 is avoided. When the lower tool bit 22 needs to be replaced by the first structure or the second structure, the second set screw 218 is loosened, the structure of the lower tool bit 22 is replaced, and then the second set screw 218 is fastened, so that the tool is simple and convenient.

Of course, the way of extending and retracting and fixing the upper stirring pin 211 and the lower cutter head 22 can also adopt other structures according to needs, and this embodiment is only for illustration.

In practical applications, in order to reduce damage to the base material, the tool shank 1, the upper tool bit 21 and the lower tool bit 22 are all cylindrical structures.

In order to facilitate the extension of the first lower pin 222 or the second lower pin 224 into the butt weld of the base material, as shown in fig. 1 and 10, the outer wall of the lower end of the first lower pin 222 or the outer wall of the lower end of the second lower pin 224 is a tapered surface that tapers downward. Preferably, the included angle between the lower tapered surface of the first lower pin 222 or the lower tapered surface of the second lower pin 224 and the vertical surface is 25 to 30 °.

Generally, for easier welding, the diameter D3 of the first lower shoulder 12 is smaller than the diameter D4 of the tool holder 1, so that the outer wall of the lower end of the tool holder 1 is a tapered surface tapering downward as shown in fig. 1 to 3.

The dimensions of the components of the entire stir head are designed according to actual conditions, and the degree of extension and contraction of the upper pin 211, the stepped shaft 221, and the second lower pin 224 is adaptively adjusted according to the thickness and the dimensions of the actual base material, and generally, in order to ensure the welding quality, as shown in fig. 9, the dimensions are designed or adjusted as follows:

the length L1 in the vertical direction corresponding to the lower tapered surface of the first lower probe 222 or the lower tapered surface of the second lower probe 224 corresponds to the length of the tapered surface that serves as a butt gap for guiding the probe into the base material, and the length L1 is set to 0.2 to 0.3 times the thickness of the plate at the position to be welded in the base material in order to provide a better guiding function.

When the lower tool bit 22 adopts the first structure, for the length L2 of the first lower probe 222, the length L2 is slightly smaller than the thickness of the welded base metal during design, and is not much smaller than the welded base metal, the weld forming effect is better when the length L2 is 0.8-0.9 times of the thickness of the plate at the required welding position in the base metal, and if the length L2 is too small than the welded base metal, the welding crack is easily caused. When the lower tool bit 22 has the second structure, as shown in fig. 10, the length L8 of the second lower pin 224 extending out of the upper tool bit 21 is 0.8 to 0.9 times of the thickness of the plate at the desired welding position in the base material, and the specific length L8 can be achieved by telescopically adjusting the second lower pin 224.

When the lower cutter head 22 adopts the first structure, the length L3 is not less than 1 to 2 times of the plate thickness and the length L4 is 1 to 3 times of the plate thickness in design for the length L3 of the middle portion of the lower cutter head 22 (i.e., the length of the portion of the lower cutter head 22 between the stepped shaft 221 and the first lower pins 222) and the length L4 of the lower portion of the upper cutter head 21 (i.e., the length of the portion of the upper cutter head 21 below the upper pins 211). The upper shoulder 212 may or may not contact the upper inner side of the welded cavity profile 3 according to actual welding requirements. Therefore, the length L3+ L4 may be equal to the distance L9 between the upper and lower inner sides of the cavity profile 3 to be welded, according to welding needs. The distance between the upper shoulder 212 and the third lower shoulder 223 can be realized by the stepped shaft 221 of the telescopic lower cutter head 22, so that the distance is equal to or less than the distance L9 between the upper inner side surface and the lower inner side surface of the cavity profile 3, thereby meeting the welding requirements of parent materials with different sizes.

For the length L5 of the upper probe 211 extending out of the shank 1 (i.e., the distance between the first lower shoulder 12 and the upper shoulder 212), the length L5 can be adjusted by extending and retracting the upper probe 211 so that the first lower shoulder 12 contacts or does not contact the upper surface of the cavity profile 3, depending on the thickness of the cavity profile 3 to be welded.

The maximum length L6+ L7 that the upper probe 211 can extend and contract is generally 2 to 5 times the thickness of the plate material as long as L6, and the length L6 is not too large, and the size of the length L6 can be appropriately adjusted according to actual needs.

The width of the welding seam is not too large in actual welding, the high plastic deformation of the base metal has certain influence on the strength of the base metal, the diameter of the stirring pin and the diameter of the shaft shoulder determine the width of the plastic deformation of the butt joint seam of the base metal, and the width of the welding seam is at least equal to the thickness of the wood to be welded. Therefore, in order to ensure the quality of the welding seam, when the lower cutter head 22 adopts the first structure, the diameter D1 of the first lower stirring pin 222 is 1-2 times of the thickness of the plate. When the lower cutter head 22 adopts the second structure, the diameter of the second lower stirring pin 224 is preferably 1-2 times of the thickness of the plate.

When the lower tool tip 22 has the first structure, the diameter D2 of the lower tool tip 22 (i.e., the diameter of the portion of the lower tool tip 22 between the stepped shaft 221 and the first lower pin 222) determines the contact range of the third lower shoulder 223 with the base metal, and the diameter D2 is 2.5 to 3.5 times the diameter D1 in order to improve the reliability of the weld.

In addition, in order to ensure the welding effect, the diameter D3 of the first lower shaft shoulder 12 is 3.5-4.5 times of the diameter of the upper stirring pin 211, and the diameter D4 of the knife handle 1 is 5-6 times of the diameter of the upper stirring pin 211.

Of course, the sizes of the components of the stirring head can be selected according to actual needs, and this embodiment is only for illustration. In addition, the material of the whole stirring head is preferably tool steel so as to meet the requirement of hardness.

In conclusion, the stirring head in the embodiment improves the welding efficiency of single-layer and double-layer plates, and compared with the welding of a single-layer stirring head, the welding efficiency is improved by nearly one time. The stirring head has four shaft shoulders, and the shaft shoulders matched with the section bar are flexibly selected for friction stir welding in the welding process. Simultaneously this kind of stirring head can also weld the cavity double-deck plate that the scope is a little bigger, and this stirring head can also turn into single shoulder stirring head at last, and nimble change shaft shoulder makes the welding scope grow of stirring head.

The above are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention. Any person skilled in the art should also realize that such equivalent changes and modifications can be made without departing from the spirit and principles of the present invention.

Claims (10)

1. A multi-shaft-shoulder double telescopic friction stir welding stirring head is characterized by comprising a vertically arranged tool shank and a tool bit;

the bottom surface of the knife handle faces the knife head, a first mounting hole which is upward in the axial direction is formed in the bottom surface of the knife handle, and a first lower shaft shoulder is formed in the bottom surface of the knife handle; the cutter head comprises an upper cutter head and a lower cutter head, the top surface of the upper cutter head axially extends upwards to form an upper stirring pin with a reduced diameter, the upper stirring pin can be telescopically inserted and fixed in the first mounting hole, and the top surface of the upper cutter head forms an upper shaft shoulder; the bottom surface of the upper cutter head faces the lower cutter head, an axially upward second mounting hole is formed in the bottom surface of the upper cutter head, and a second lower shaft shoulder is formed in the bottom surface of the upper cutter head;

the top surface of the lower cutter head axially extends upwards to form a stepped shaft with a reduced diameter, the bottom surface of the lower cutter head axially extends downwards to form a first lower stirring pin with a reduced diameter, the stepped shaft can be telescopically inserted and fixed in the second mounting hole, and the bottom surface of the lower cutter head forms a third lower shaft shoulder; or

The lower tool bit is a second lower stirring pin, and the second lower stirring pin can be telescopically inserted and fixed in the second mounting hole.

2. The multi-shoulder dual telescopic friction stir welding tool of claim 1,

the first mounting hole is a circular hole, internal threads are arranged on the wall of the first mounting hole, at least two first inserting grooves which are axially upward are formed in the bottom surface of the cutter handle at uniform intervals along the circumferential direction of the first mounting hole, and the first inserting grooves are communicated with the first mounting hole;

a first ejector block is inserted into each first insertion groove, the inner wall of each first ejector block is a cambered surface, an internal thread is arranged on the inner wall of each first ejector block, the inner wall of each first ejector block forms a part of the wall of the first mounting hole, and the upper stirring pin is in threaded connection with the wall of the first mounting hole; each first top block is fastened on the outer wall of the upper stirring pin through a first fastening piece.

3. The multi-shoulder dual telescopic friction stir welding tool of claim 2,

the first fastening piece is a first set screw, at least two first radial holes are formed in the circumferential direction of the side wall of the cutter handle, the number of the first radial holes is equal to that of the first inserting grooves, each first set screw is radially inserted into the corresponding first radial hole and is in threaded fixation with the hole wall of the first radial hole, and the inner side end of each first set screw can abut against the outer wall of the corresponding first ejector block.

4. The multi-shoulder dual telescopic friction stir welding tool of claim 2,

the second mounting hole is a circular hole, the hole wall of the second mounting hole is provided with internal threads, at least two second inserting grooves which are upward in the axial direction are uniformly formed in the bottom surface of the upper tool bit at intervals along the circumferential direction of the second mounting hole, and the second inserting grooves are communicated with the second mounting hole;

a second ejector block is inserted into each second inserting groove, the inner wall of each second ejector block is a cambered surface, an internal thread is arranged on the inner wall of each second ejector block, the inner wall of each second ejector block forms a part of the wall of the second mounting hole, and the stepped shaft or the second lower stirring pin is in threaded connection with the wall of the second mounting hole; each second top block is fastened on the outer wall of the stepped shaft or the second lower stirring pin through a second fastening piece.

5. The multi-shoulder dual telescopic friction stir welding tool of claim 4,

the second fastening piece is a second set screw, at least two second radial holes are formed in the circumferential direction of the side wall of the upper tool bit, the number of the second radial holes is equal to that of the second inserting grooves, each second set screw is radially inserted into the corresponding second radial hole and is in threaded fixation with the hole wall of the second radial hole, and the inner side end of each second set screw can abut against the outer wall of the corresponding second ejector block.

6. The multi-shoulder dual telescopic friction stir welding tool of claim 1,

the handle of a knife, go up the tool bit with lower tool bit is the cylinder structure.

7. The multi-shoulder dual telescopic friction stir welding tool of claim 6,

the outer wall of the lower end of the first lower stirring pin or the outer wall of the lower end of the second lower stirring pin is a conical surface which is gradually reduced downwards.

8. The multi-shoulder dual telescopic friction stir welding tool of claim 7,

the included angle between the lower end conical surface of the first lower stirring pin or the lower end conical surface of the second lower stirring pin and the vertical surface is 25-30 degrees.

9. The multi-shoulder dual telescopic friction stir welding tool of claim 6,

the outer wall of the lower end of the knife handle is a conical surface which is gradually reduced downwards.

10. The multi-shoulder dual telescopic friction stir welding tool of claim 6,

the diameter of the first lower shaft shoulder is 3.5-4.5 times of the diameter of the upper stirring needle, and the diameter of the cutter handle is 5-6 times of the diameter of the upper stirring needle.

Images