Additive stirring head and additive device

Abstract

The present invention relates to the technical field of stir friction welding, and specifically to an additive stirring head and an additive device. The additive stirring head is particularly suitable for rod-shaped additive materials, and has an additive channel therein, the inner wall surface of the upper section of the additive channel encloses a polygonal channel, and the inner wall surface of the lower section of the additive channel gradually tilts outward and expands, so that the cross-sectional area of ​​the lower section of the additive channel in the direction extending toward the working end of the stirring head gradually increases, which can unload the tension force on the additive material at the outlet of the additive stirring head, so as to solve the problem of the heat-plasticized rod being blocked at the outlet of the stirring head; and the angle of the inner wall surface of the lower section of the additive channel tilting outward is specifically set, which can also constrain the rod at the outlet, and avoid the rod at the outlet from shaking due to the large outlet part, thereby improving the additive efficiency and additive quality.

Description

Technical Field

[0001] The invention relates to the technical field of friction stir welding, and in particular to an additive stirring head and an additive device. Background Art

[0002] Industrial development promotes the rapid advancement of the machining industry, but traditional technologies such as turning, milling, planing and grinding are not enough to meet industrial needs, and additive manufacturing has begun to emerge. As one of the solid-phase additive technologies, friction stir additive manufacturing generates heat through the friction of the stirring head to plasticize the additive material, which can quickly realize the manufacture of complex parts and has great engineering significance.

[0003] The rod is a conventional friction stir additive material. In the friction stir additive manufacturing process, the rod is placed in the additive channel. In order to continuously perform additive manufacturing, a conveying mechanism is required to continuously convey the rod. The rod can rotate with the stirring head for additive manufacturing. However, the heat-plasticized rod is prone to clogging at the outlet of the stirring head. Patent document US6543671B2 proposes a device and method for friction stir welding using a filler material, wherein the additive channel in the disclosed friction stir welding tool has a flared portion at the outlet. When the wire is fed through the additive channel, the wire contacts the flared portion, and the wire is damaged because it frictionally engages with the flared portion and disperses. The welding tool with the flared portion can solve the problem of easy clogging at the outlet of the stirring head to a certain extent. However, the welding tool with the flared portion disclosed in the patent document US6543671B2 is suitable for additive materials such as wires or powders. That is to say, the flared portion in the above patent document is set in such a way that the additive material is expected to produce axial deformation in the flared portion so as to disperse. However, for rod-shaped additive materials, if the flared portion is too large, the rod at the outlet will shake, thereby resulting in the defect of uneven additives. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the existing rod-shaped additive materials, such as the easy blockage of the stirring head outlet and the uneven additive during the stirring friction additive process, thereby providing an additive stirring head and an additive device.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0006] The present invention provides an additive stirring head, which has an additive channel therein, wherein the inner wall surface of the upper section of the additive channel forms a polygonal channel, and the inner wall surface of the lower section of the additive channel gradually tilts and expands outward, so that the cross-sectional area of ​​the lower section of the additive channel in the direction extending toward the working end of the stirring head gradually increases. The polygonal channel means that the cross section of the additive channel is a polygonal structure.

[0007] In the above-mentioned additive stirring head, the polygonal channel is a regular polygonal channel, that is, the cross section of the additive channel is a regular polygon. Preferably, the regular polygonal channel is a square channel.

[0008] In the above-mentioned additive stirring head, the angle α at which the inner wall surface of the lower section of the additive channel is inclined outwards satisfies the following conditions: Wherein, s is the stirring head speed, in rpm; v is the stirring head moving speed, in mm / min; h is the cone angle height, in mm; k is a constant, with a value of 0.1-1.5; △ is the compensation coefficient, with a value of 0.05-6.

[0009] Preferably, in the above-mentioned additive stirring head, the value range of the stirring head rotation speed s is 500-10000; the value range of the stirring head movement speed v is 100-5000; and the value range of the cone angle height is 10-100.

[0010] In the above-mentioned additive stirring head, the additive stirring head includes an insertion end, a mounting flange and a working end arranged in sequence; wherein the base of the insertion end has a positioning ring suitable for embedding into the tool handle, and the outer diameter of the positioning ring is larger than the outer diameter of the rest of the insertion end.

[0011] In the above-mentioned additive mixing head, the mounting flange has a plurality of bolt mounting holes, the axes of the bolt mounting holes are parallel to the axis of the additive channel, the bolt mounting holes are T-shaped holes, and the end with a larger diameter of the T-shaped hole is arranged toward the working end.

[0012] In the above-mentioned additive mixing head, the mounting flange also has a plurality of positioning holes, and the positioning holes are suitable for installing positioning pins; the positioning holes are inverted T-shaped holes, and the end with a larger diameter of the inverted T-shaped hole is arranged toward the insertion end, and the end with a larger diameter of the inverted T-shaped hole is suitable for installing the positioning pin, and the end with a smaller diameter of the inverted T-shaped hole is a threaded hole.

[0013] The present invention also provides an additive device, which includes a main shaft, a tool handle and a stirring head, wherein the stirring head is the above-mentioned additive stirring head; the main shaft and the tool handle are provided with a conveying channel, and the conveying channel is connected to the additive channel of the stirring head and is coaxially arranged.

[0014] In the above-mentioned additive device, at least a part of the conveying channel is an irregular channel, wherein the irregular channel is a channel formed by the outer contour of a polygon intersecting with its concentric circles.

[0015] In the above-mentioned additive device, all of the conveying channels are the irregular channels; the polygon of the conveying channels is the same as and aligned with the polygon of the additive channels.

[0016] The above-mentioned additive device also includes an additive pushing system, which includes a push rod and a first linear drive structure. The starting end of the push rod is connected to the first linear drive structure, and the end of the push rod is suitable for being inserted into the additive channel to push the additive material under the drive of the first linear drive structure.

[0017] The above-mentioned material adding device further comprises a push rod assisting structure, which is movably sleeved on the push rod, and the push rod assisting structure is suitable for relative movement with the push rod in the axial direction of the push rod;

[0018] The push rod assisting structure comprises:

[0019] A bearing, wherein the bearing is sleeved on the push rod;

[0020] The second linear drive structure, the bearing is fixed to the movable end of the second linear drive structure through a bearing seat.

[0021] The above-mentioned additive device also includes a horizontally movable base and a frame, wherein the horizontally movable base is slidably connected to the frame via a guide rail; driven by a horizontal motor on the frame, the horizontally movable base drives the push rod and the first linear drive structure to move horizontally.

[0022] In the above-mentioned additive device, the stirring head is fixedly mounted on the tool handle by a plurality of bolts, and the positioning ring is embedded in the mounting hole of the tool handle, and a heat insulation sheet is provided between the mounting flange and the mounting end surface of the tool handle.

[0023] The technical solution of the present invention has the following advantages:

[0024] 1. The additive stirring head provided by the present invention is particularly suitable for rod-shaped additive materials, and has an additive channel therein. The inner wall surface of the upper section of the additive channel forms a polygonal channel, and the inner wall surface of the lower section of the additive channel gradually tilts outward and expands, so that the cross-sectional area of ​​the lower section of the additive channel in the direction extending toward the working end of the stirring head gradually increases, which can unload the tension force on the additive material at the outlet of the additive stirring head to solve the problem of the rod being blocked at the outlet of the stirring head due to heat plasticization. In addition, the outward tilt angle α of the inner wall surface of the lower section of the additive channel meets the following conditions: Among them, k takes a value of 0.1-1.5; △ takes a value of 0.05-6; the additive channel whose inner wall inclination angle of the lower section meets this condition can solve the blockage problem at the outlet of the mixing head while constraining the rod at the outlet, avoiding the outlet part from being too large and causing the rod at the outlet to shake, thereby improving the additive efficiency and additive quality. In addition, the relationship between the angle α and each parameter can be used in the actual production process to select a mixing head with a suitable inclination according to the process parameters, and determine the applicable process conditions according to the inclination of the mixing head, thereby providing convenient guidance for the selection and application of the mixing head, and preventing the mixing head from being blocked and the additive unevenness in the actual additive process.

[0025] 2. The additive stirring head provided by the present invention has a positioning ring suitable for embedding into the tool handle at the base of its insertion end. During installation, the positioning ring can be embedded in the mounting hole of the tool handle, so that the stirring head is connected in the mounting hole of the tool handle only by the positioning ring, which can reduce the contact area between the stirring head and the inner cavity of the tool handle, thereby reducing the heat transfer efficiency to avoid the tool handle from heating up too quickly; a plurality of bolt mounting holes are provided on the mounting flange, the axis of the bolt mounting hole is parallel to the axis of the additive channel, and the bolt mounting hole is a T-shaped hole, and the end with a larger diameter of the T-shaped hole is arranged toward the working end, so that the stirring head and the tool handle can be fixed by the mounting flange.

[0026] 3. In the additive device provided by the present invention, at least a portion of the conveying channel is an irregular channel, wherein the irregular channel is a channel formed by the outer contour of a polygon intersecting with its concentric circles; a partial polygonal contour is provided in the conveying channel, and the entire additive channel is a polygonal channel, and the polygons can be used for inserting and positioning prismatic additive materials to achieve stable conveying, and the conveying channel at the upper end also has a partial circular contour, and the circular contour can be used for inserting a cylindrical push rod to push the additive material downward to achieve additive conveying; the concentric circle where the circular contour is located intersects with the polygon, which can maximize the contact area between the push rod and the additive material in the channel, which can achieve stable conveying of the additive material on the one hand, and make the push rod as thick as possible on the other hand, thereby improving the strength of the push rod, preventing the push rod from bending during the pushing process, and further improving the stability of the entire additive device.

[0027] 4. The additive device provided by the present invention includes an additive pushing system, including a push rod and a first linear drive structure, the starting end of the push rod is connected to the first linear drive structure, and the end of the push rod is suitable for being inserted into a conveying channel under the drive of the first linear drive structure to push the additive material, thereby realizing the conveying of the additive material; it also includes a push rod supporting structure movably sleeved on the push rod, and the push rod supporting structure is suitable for relative movement with the push rod in the axial direction of the push rod to avoid shaking and bending of the push rod during the process of advancing the additive material, and prevent the push rod from breaking, so as to ensure the accurate and stable conveying of the rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 Schematic diagram of the additive stirring head provided in the embodiment of the present invention Figure 1 ;

[0030] Figure 2 Schematic diagram of the additive stirring head provided in the embodiment of the present invention Figure 2 ;

[0031] Figure 3 A cross-sectional view of an additive stirring head provided in an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of the structure of an additive device provided in an embodiment of the present invention;

[0033] Figure 5 A schematic diagram of the structure of an additive material pushing system provided in an embodiment of the present invention;

[0034] Figure 6 A schematic diagram of the structure of a horizontal movement system provided by an embodiment of the present invention;

[0035] Figure 7 A schematic diagram of the structure of a pressure sensor system provided by an embodiment of the present invention;

[0036] Figure 8 Schematic diagram of the support structure provided by the embodiment of the present invention Figure 1 ;

[0037] Fig. 9 Schematic diagram of the support structure provided by the embodiment of the present invention Figure 2 ;

[0038] Fig.10 A schematic diagram of the structure of a spindle system provided in an embodiment of the present invention;

[0039] Fig.11 A cross-sectional view of a delivery channel provided by an embodiment of the present invention;

[0040] Fig.12 A schematic structural diagram of a portion of a knife handle provided in an embodiment of the present invention.

[0041] Description of reference numerals:

[0042] 10-additive pushing system; 11-servo motor; 12-electric cylinder rod; 20-pressure sensor system; 21-pressure sensor; 22-end bearing; 23-end cover bearing; 30-assisting structure; 31-assisting motor; 32-bearing seat; 33-bearing; 34-vertical plate; 40-spindle system; 41-additive channel entrance; 410-conveying channel; 42-spindle; 43-tool handle; 44-belt; 45-drive shaft; 50-stirring head; 51-mounting flange; 510-additive channel; 510A-upper section of the additive channel; 510B-lower section of the additive channel; 511-bolt mounting hole; 512-positioning hole; 52-working end of the stirring head; 60-workbench; 70-horizontally movable base; 71-frame; 72-horizontal motor; 80-push rod; 90-CNC system; 100-air conditioning system. DETAILED DESCRIPTION

[0043] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] In the description of the present invention, it should be noted that the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. Example

[0046] like Figure 1-3 As shown, this embodiment provides an additive stirring head, which is particularly suitable for friction stir additive of rod materials. The stirring head 50 has an additive channel 510, and the inner wall surface of the upper section 510A of the additive channel is surrounded by a polygonal channel; wherein the polygonal channel means that the cross section of the additive channel is a polygonal structure; however, it is not limited to the method of the present invention, and the polygonal channel can be selected as a regular polygonal channel, through which prismatic additive materials can pass. In addition, as Figure 1 and 3As shown, the upper section of the additive channel is a square channel. The inner wall surface of the lower section 510B of the additive channel gradually tilts outward to expand, so that the cross-sectional area of ​​the lower section 510B of the additive channel in the direction extending toward the working end of the stirring head gradually increases, which can unload the tension force of the additive material at the outlet of the additive stirring head to solve the problem of blockage of the heated plasticized rod at the outlet of the stirring head.

[0047] In the above-mentioned additive stirring head, the inner wall surface of the lower section 510B of the additive channel is inclined outward at an angle α, and there are two cases for the angle α. One is that when the inner wall surface of the lower section 510B of the additive channel is a plane, the angle is the angle between the inner wall surface and the axis of the stirring head; the other is that when the inner wall surface of the lower section 510B of the additive channel is an arc surface, the angle is the angle between the tangent on the inner wall surface and the axis of the stirring head.

[0048] As mentioned above, the angle at which the inner wall of the lower section 510B of the additive channel is tilted outward increases, which can unload the tension force on the additive material at the outlet of the additive stirring head; and, in order to avoid the expansion portion of the lower section 510B of the additive channel being too large, which will cause the rod-shaped additive material to shake, thereby causing the defect of uneven additive, in the above-mentioned additive stirring head, the angle α at which the inner wall of the lower section 510B of the additive channel is tilted outward also needs to be limited to a certain range. The tension force is related to the friction between the additive material at the outlet and the inner wall of the stirring head. The friction is affected by the temperature of the stirring head at the outlet and is positively correlated with the temperature. Among them, the stirring head rotation speed s is positively correlated with the temperature; the faster the stirring head movement speed v, the less likely it is that the temperature at the working end of the stirring head will accumulate. Therefore, the stirring head movement speed v and the temperature are inversely proportional; in addition, the vertical height of the lower section 510B of the additive channel, that is, the cone angle height h, is inversely proportional to the angle α.

[0049] Combining the influence of the above process parameters on the outward tilt angle α of the inner wall surface of the lower section 510B of the additive channel, and fitting through actual stirring head data and actual parameters, the following relationship between the outward tilt angle α of the inner wall surface of the lower section 510B of the additive channel and various parameters is obtained: In the formula, s is the stirring head speed, in rpm; v is the stirring head movement speed, in mm / min; h is the cone angle height, in mm; k is a constant, with a value of 0.1-1.5; △ is a compensation coefficient, with a value of 0.05-6; wherein each parameter s, v and h takes an actual value. Preferably, the stirring head speed s ranges from 500 to 10000; the stirring head movement speed v ranges from 100 to 5000; and the cone angle height ranges from 10 to 100. The additive channel whose inner wall inclination angle α of the lower section of the additive channel meets this condition can not only solve the blockage problem at the stirring head outlet, but also constrain the rods at the outlet to avoid the outlet part being too large and causing the rods at the outlet to shake, thereby improving the additive efficiency and additive quality. The relationship between the angle α and various parameters can be used to select a stirring head with a suitable inclination angle according to the process parameters during actual production and use, and to determine the applicable process conditions according to the inclination angle of the stirring head, thereby providing convenient guidance for the selection and application of the stirring head and preventing the stirring head from being blocked and unevenly added during the actual additive process.

[0050] Preferably, in this embodiment, s is selected as 1000, v is selected as 100, H is selected as 10, k is 1.5, △ is 0.5, and according to the above relationship, α is equal to 2. Under the above process parameters, a stirring head with an inner wall surface of the lower section 510B of the additive channel inclined outward at an angle α of 2 degrees is selected. This can effectively solve the defects of the existing rod-shaped additive materials, such as easy clogging of the stirring head outlet and uneven additive during the stir friction additive process.

[0051] The additive stirring head provided in this embodiment includes an insertion end, a mounting flange 51 and a working end 52 of the stirring head, wherein the insertion end is suitable for being inserted into the mounting hole of the tool handle during installation, and the base of the insertion end has a positioning ring 501 suitable for being embedded in the tool handle, and the positioning ring 501 plays a role of abutting and positioning in the mounting hole of the tool handle, that is, in the mounting hole of the tool handle, the insertion end is in contact with the tool handle only through the positioning ring 501, so as to reduce the contact area between the stirring head and the inner cavity of the tool handle, thereby reducing the heat transfer efficiency and reducing the excessive transfer of heat to the tool handle, so as to avoid the tool handle from heating up too quickly; in addition, in order to realize that the stirring head can be fixedly installed at the end of the tool handle, the mounting flange 51 has a plurality of bolt mounting holes 511, and the axis of the bolt mounting hole 511 is parallel to the axis of the additive channel, that is, when the stirring head is installed, the bolt mounting hole 511 is directly opposite to the mounting end face of the tool handle; further, the bolt mounting hole is a T-shaped hole, and the end with a larger diameter of the T-shaped hole is arranged toward the working end to facilitate the screwing in of the bolt.

[0052] The additive stirring head provided in this embodiment can be installed with a positioning ring 501 embedded in the mounting hole of the tool handle, so that the stirring head is connected in the mounting hole of the tool handle only through the positioning ring, which can reduce the contact area between the stirring head and the inner cavity of the tool handle, thereby reducing the heat transfer efficiency to avoid the tool handle from heating up too quickly; a plurality of bolt mounting holes are provided on the mounting flange, the axes of the bolt mounting holes are parallel to the axes of the additive channel, and the bolt mounting holes are T-shaped holes, and the end with a larger diameter of the T-shaped hole is arranged toward the working end, so that the stirring head can be fixed to the tool handle through the mounting flange.

[0053] Optionally, in the above-mentioned additive stirring head, the insertion end, the mounting flange 51 and the working end 52 can be integrally formed.

[0054] In the above-mentioned additive stirring head, the outer diameter of the positioning ring 501 is larger than the outer diameter of the remaining part of the insertion end, so that in the tool handle, the stirring head is in contact with the tool handle only through the positioning ring 501.

[0055] Optionally, in the above-mentioned additive stirring head, the mounting flange 51 further has a plurality of positioning holes 512, and the positioning holes 512 are suitable for installing positioning pins. The positioning holes 512 can be inserted with positioning pins to achieve positioning when the stirring head is installed, so as to ensure that the cross-sections of the additive channels in the stirring head and the tool handle structure are aligned and connected.

[0056] As a preferred embodiment, in the above-mentioned additive stirring head, the positioning hole 512 is an inverted T-shaped hole, the end of the inverted T-shaped hole with a larger diameter is arranged toward the insertion end 52, and the end of the inverted T-shaped hole with a larger diameter is suitable for installing the positioning pin, and the end of the inverted T-shaped hole with a smaller diameter is a threaded hole. Since the positioning pin will be clamped in the positioning hole 512 after the stirring head is installed, the threaded hole can be used to screw in a bolt or screw from the reverse side to push out the positioning pin, thereby facilitating the disassembly of the stirring head.

[0057] Optionally, in the above-mentioned additive mixing head, the positioning holes 512 and the bolt mounting holes 511 are both set to four, and are arranged in sequence and spaced around each other.

[0058] Optionally, in order to facilitate precise positioning, in the above-mentioned additive stirring head, the positioning hole 512 is located on the extension line of the diagonal line of the cross section of the additive channel 510 .

[0059] When using the additive stirring head provided in this embodiment, at least two positioning pins can be first inserted into the positioning holes 512, and then the protruding ends of the positioning pins are inserted into the positioning holes corresponding to the mounting ends of the tool handle to achieve circumferential positioning; at the same time, the insertion end 52 is inserted into the mounting hole of the tool handle, and the positioning in the mounting hole is achieved by the positioning ring 501 of the insertion end; then the stirring head is fixed by bolts; wherein a mica sheet for heat insulation can be arranged between the mounting flange 51 and the mounting end of the tool handle to further suppress the heat of the stirring head from being transferred toward the tool handle, thereby increasing the service life of the tool handle. Example

[0060] like Figure 4-12 As shown, this embodiment provides an additive device, including a spindle system 40, a stirring head 50 and a workbench 60. When working, the spindle system 40 drives the stirring head 50 to rotate, thereby realizing additive manufacturing on the workbench 60, and the stirring head 50 is the stirring head provided in Example 1; the spindle system 40 includes a spindle 42 and a tool handle 43 installed on the spindle, and the spindle is driven to rotate by a driving shaft 45 of a spindle motor (not shown) through a belt 44 or a gear; a stirring head 50 is installed at the working end of the tool handle 43, wherein the spindle 42, the tool handle 43 and the stirring head 50 can be installed in a known manner, and the spindle 42, the tool handle 43 and the stirring head 50 have a conveying channel and an additive channel that are interconnected, and the top of the conveying channel has an additive channel inlet 41.

[0061] The additive device provided in this embodiment, when additive manufacturing is required, inserts the rod to be added, such as an aluminum rod, from the additive channel entrance 41 into the conveying channel and the additive channel, and is pushed downward by the additive propulsion system described below to perform additive manufacturing, and the additive propulsion system can be prevented from rotating with the rod.

[0062] The material-additive device provided in this embodiment has a spindle system, which is a belt or gear transmission structure, and the spindle is driven to rotate by a motor. In order to prevent the spindle bearing and other structures from being burned under the high-speed rotation and high temperature below, the spindle needs to be equipped with a cooling system. The cooling system can be a water-cooling structure, and the spindle is cooled by a water cooler cooling liquid. It can also be oil-cooled, and the water cooler is replaced with a hydraulic system to cool the spindle. In addition, the material-additive device provided in this embodiment can also include a numerical control system 90 and an air conditioning system 100.

[0063] The additive device provided in this embodiment has a conveying channel and an additive channel that are interconnected in the spindle 42, the tool handle 43 and the stirring head 50, a conveying channel 410 in the spindle and the tool handle, and an additive channel 510 in the stirring head, wherein the conveying channel is connected to the additive channel of the stirring head and is coaxially arranged; at least a portion of the conveying channel 410 is an irregular channel, wherein the irregular channel is a channel formed by the outer contour of a regular polygon intersecting with its concentric circles; the additive channel is a regular polygon channel. However, this does not limit the implementation mode of the present invention, and the regular polygon is a regular quadrilateral. Among them, the channel formed by the outer contour of a regular polygon intersecting with its concentric circles means that the cross section of the channel is the outer contour of a regular polygon intersecting with its concentric circles, that is, the angles of each regular polygon are evenly distributed on the circumference of its concentric circles.

[0064] The additive device provided in this embodiment has a channel including a coaxially arranged conveying channel and an additive channel; the conveying channel is located in the main shaft and the tool handle, and at least a part of it is an irregular channel, wherein the irregular channel is a channel formed by the outer contour of a regular polygon intersecting with its concentric circles; the additive channel is located in the stirring head, and it is a regular polygon channel. A partial regular polygonal contour is provided in the conveying channel, and the additive channel is entirely a regular polygonal channel. The regular polygon can be used for inserting and positioning regular prism-shaped additive materials to achieve stable conveying, and the conveying channel at the upper end also has a partial circular contour, and the circular contour can be used for inserting a cylindrical push rod to push the additive material downward to achieve the conveying of the additive material; the concentric circle where the circular contour is located intersects with the regular polygon, which can maximize the contact area between the push rod and the additive material in the channel, on the one hand, can achieve stable conveying of the additive material, and on the other hand, can make the push rod as thick as possible, thereby improving the strength of the push rod, preventing the push rod from bending during the pushing process, and further improving the stability of the entire additive device.

[0065] In addition, as a replaceable embodiment, the additive channel 510 in the mixing head may be partially a regular polygonal channel, which is the part connected to the conveying channel 410, that is, the upper section of the additive channel 510 is a regular polygonal channel; wherein, the lower section of the additive channel can be set as a conical channel with a flared opening.

[0066] Preferably, in the above-mentioned additive device, all of the conveying channels 410 are irregular channels; the regular polygons of the conveying channels 410 are identical to and aligned with the regular polygons of the additive channels 510 .

[0067] The additive device provided in this embodiment also includes an additive propulsion system 10, which also includes a push rod 80 and a first linear drive structure, wherein the starting end of the push rod 80 is connected to the first linear drive structure, and the end of the push rod 80 is suitable for being driven by the first linear drive structure to be inserted into the conveying channel of the stir friction welding tool to push the additive material; wherein the starting end of the push rod refers to the top end of the push rod 80, and the end of the push rod refers to the bottom end of the push rod 80. Specifically, the first linear drive structure can be set as an electric cylinder, and the electric cylinder includes a servo motor 11 and an electric cylinder rod 12, and the electric cylinder rod 12 is connected to the starting end of the push rod 80 as the movable end of the electric cylinder.

[0068] The push rod 80 is preferably a cylindrical push rod, which is made of ejector material. Because the push rod 80 will rotate with the rotation of the main shaft in the conveying channel, the use of a cylindrical push rod can avoid the centrifugal force generated by the push rod during the rotation process to a certain extent. However, the cylindrical material used in industry will have a certain error. Therefore, shaking will inevitably occur during the rotation process. In addition, the advancement of the push rod needs to bear a large pressure. When the shaking occurs, the push rod will bend or break when pressure is applied. The material-adding device provided in this embodiment also includes a push rod assisting structure 30, which is movably sleeved on the push rod 80. The push rod assisting structure 30 is suitable for relative movement with the push rod in the axial direction of the push rod to avoid shaking and bending of the push rod during the advancement of the material-adding process, and prevent the push rod from breaking, so as to ensure the accurate and stable delivery of the rod.

[0069] In addition, in the above-mentioned material adding device, the cross section of the push rod is adapted to the outer contour of the concentric circle so as to be able to be inserted into the conveying channel closely against the wall of the conveying channel.

[0070] In the above-mentioned additive device, the push rod assisting structure 30 includes a bearing 33 and a second linear drive structure, the bearing 33 is sleeved on the push rod 80, and the bearing 33 is fixed to the movable end of the second linear drive structure through a bearing seat 32. Specifically, the second linear drive structure includes an assisting motor 31, a screw and a slide seat, the screw is connected to the driving end of the assisting motor 31, and the slide seat is slidably matched with the screw; wherein the bearing seat 32 is connected to the screw through a slide seat. The pushing system is responsible for pushing the raw material rod into the main shaft, while preventing the system from rotating with the rod. This part is composed of a servo motor and an electric cylinder rod. The servo motor rotates and converts the rotational force into a thrust for the electric cylinder rod to move downward through a screw mechanism.

[0071] Since the first linear drive structure provides a large downward pressure on the push rod 80, the push rod will inevitably bend, and since the starting end of the push rod 80 is connected and fixed to the first linear drive structure, and the end of the push rod 80 is inserted into the conveying channel, it can also be equivalent to the end of the push rod being fixed in the axial direction. The two ends of the push rod are fixed, so the position where the push rod is bent by force generally occurs in the middle of the distance from the outside of the conveying channel to its starting end. Therefore, preferably, in the above-mentioned additive pushing system, as the push rod 80 is pushed forward, the bearing 33 is always located in the middle of the push rod outside the conveying channel under the drive of the second linear drive structure, further avoiding the bending of the push rod. In order to ensure that the bearing 33 can always be in the middle of the outside of the conveying channel during the additive manufacturing process, the speed of the downward movement of the bearing can be selected to be half of the pushing speed of the push rod. In addition, as an alternative embodiment, the assisting motor 31 that provides power to the bearing can be communicatively connected to the servo motor 11 that provides power to the push rod; according to the signal of the servo motor 11, the assisting motor 31 can adjust the rotation speed in real time so that the downward movement speed of the bearing is always half of the propulsion speed of the push rod, so as to ensure that the bearing is always in the middle of the push rod outside the conveying channel.

[0072] Optionally, the material adding device further comprises a vertical plate 34 , and the first linear drive structure and the second linear drive structure are both fixed on the vertical plate 34 .

[0073] Optionally, in the above-mentioned additive device, the movable end of the electric cylinder is provided with a pressure sensor system 20, and the pressure sensor system 20 includes a pressure sensor 21, an end bearing 22 and an end cover bearing 23 arranged in sequence, the end bearing 22 is fixedly arranged at the bottom of the pressure sensor 21, and the end cover bearing 23 is rotatably assembled at the bottom of the end bearing 22; wherein the end cover bearing 23 is a seated end cover bearing, the beginning of the push rod 80 is inserted into the shaft seat of the end cover bearing, and the end bearing plays the role of assembling and supporting the end cover bearing to ensure that there is sufficient thrust on the push rod and prevent the movable end of the electric cylinder from rotating, thereby ensuring the stability of the electric cylinder. The pressure sensor senses the pressure applied by the push rod to the raw material and realizes closed-loop control of the pressure through the PID adjustment of the PLC. The pressure system adds a feedback mechanism through the pressure sensor, and ensures the additive pressure through the servo motor torque determination and the pressure sensor dual feedback mechanism. The pressure feedback mechanism is established by the pressure sensor to ensure the accuracy of the pressure.

[0074] The above-mentioned additive device further includes a horizontal movable base 70 and a frame 71, wherein the horizontal movable base 70 is slidably connected to the frame 71 via a guide rail; the additive propulsion system 10 is fixed on the horizontal movable base 70, and driven by the horizontal motor 72 on the frame 71, the horizontal movable base 70 drives the push rod 80 and the first linear drive structure to move horizontally. The horizontal movable base drives the push rod and the first linear drive structure to move horizontally, so that when the additive material is assembled in the additive channel, the push rod can avoid the entrance of the additive channel, and after the additive material is assembled, the push rod is driven to reset to the entrance of the additive channel, so as to facilitate the smooth operation of the entire additive material assembly process.

[0075] When the additive device provided in this embodiment is in use, the additive raw material is placed at the entrance of the additive channel below the push rod, the main shaft rotates and moves along the Z-axis direction, and stops moving when the stirring head is 0.1-5mm away from the substrate; in particular, it can reach the position first and then rotate.

[0076] The push rod pushes the material downward and applies pressure, and the spindle moves according to the original path, and the material is deposited on the substrate. As the spindle is fixed, the raw material is continuously consumed and shortened, and the push rod also moves downward. At this time, the supporting mechanism also moves with the push rod downward, so that the supporting mechanism is always in the center of the push rod. In particular, this device can replace the pressure sensor with displacement control, that is, the push rod moves downward 0.1-100mm per minute.

[0077] In the additive device provided in this embodiment, the end of the push rod of the additive pushing system is suitable for being inserted into the conveying channel of the friction stir welding tool to push the additive material under the drive of the first linear driving structure.

[0078] In the additive device provided in this embodiment, the stirring head is fixedly mounted on the tool handle by multiple bolts, and the positioning ring is embedded in the mounting hole of the tool handle, and a heat insulation sheet is provided between the mounting flange and the mounting end surface of the tool handle. Preferably, in the additive device, the heat insulation sheet is a mica sheet.

[0079] In the additive device provided in this embodiment, the stirring head is positioned in the mounting hole of the tool handle through a positioning ring at the insertion end, and a heat insulation sheet is provided between the mounting flange and the mounting end of the tool handle. Through the synergistic effect of the above two methods of reducing the heat transfer area and using the heat insulation sheet to limit heat conduction, the heat of the stirring head is further prevented from being transferred toward the tool handle, which can increase the service life of the tool handle and thus improve the stability of the additive device.

[0080] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. An additive stirring head having an additive channel therein, characterized in that: The inner wall surface of the upper section of the additive channel forms a polygonal channel, the additive channel is connected to the conveying channel, at least a part of the conveying channel is an irregular channel, wherein the irregular channel is a channel formed by the outer contour of the polygon intersecting with its concentric circle; the inner wall surface of the lower section of the additive channel gradually tilts outward to expand so that the cross-sectional area of ​​the lower section of the additive channel in the direction extending toward the working end of the stirring head gradually increases; The additive stirring head comprises an insertion end, a mounting flange and a working end which are arranged in sequence; wherein the base of the insertion end has a positioning ring which is suitable for embedding into the tool handle, and the outer diameter of the positioning ring is larger than the outer diameter of the rest of the insertion end; The angle α at which the inner wall of the lower section of the additive channel is inclined outwards satisfies the following conditions: Wherein, s is the stirring head speed, unit rpm; v is the stirring head moving speed, unit mm / min; h is the cone angle height, unit mm; k is a constant, the value is 0.1-1.5; △ is the compensation coefficient, the value is 0.05-6.

2. The additive stirring head according to claim 1, characterized in that: The polygonal channel is a regular polygonal channel.

3. The additive stirring head according to claim 2, characterized in that: The regular polygonal channel is a square channel.

4. The additive stirring head according to claim 1, characterized in that: The value range of the stirring head rotation speed s is 500-10000; the value range of the stirring head movement speed v is 100-5000; the value range of the cone angle height is 10-100.

5. The additive stirring head according to claim 1, characterized in that: The mounting flange is provided with a plurality of bolt mounting holes, the axes of the bolt mounting holes are parallel to the axis of the additive channel, the bolt mounting holes are T-shaped holes, and the end of the T-shaped hole with a larger diameter is arranged toward the working end.

6. The additive stirring head according to claim 5, characterized in that: The mounting flange also has a plurality of positioning holes, and the positioning holes are suitable for installing positioning pins; the positioning holes are inverted T-shaped holes, and the end with a larger diameter of the inverted T-shaped hole is arranged toward the insertion end, and the end with a larger diameter of the inverted T-shaped hole is suitable for installing the positioning pin, and the end with a smaller diameter of the inverted T-shaped hole is a threaded hole.

7. An additive device, characterized in that: It comprises a main shaft, a tool handle and a stirring head, wherein the stirring head is the additive stirring head according to any one of claims 1 to 6; the main shaft and the tool handle are provided with a conveying channel, and the conveying channel is connected to the additive channel of the stirring head and is coaxially arranged.

8. The additive device according to claim 7, characterized in that: The entirety of the transport channel is the irregular channel; the polygon of the transport channel is identical to and aligned with the polygon of the additive channel.

9. The additive device according to claim 8, characterized in that: It also includes an additive pushing system, which includes a push rod and a first linear drive structure. The starting end of the push rod is connected to the first linear drive structure, and the end of the push rod is suitable for being inserted into the additive channel to push the additive material under the drive of the first linear drive structure.

10. The additive device according to claim 9, characterized in that: It also includes a push rod assisting structure, which is movably sleeved on the push rod, and the push rod assisting structure is suitable for relative movement with the push rod in the axial direction of the push rod; The push rod assisting structure comprises: A bearing, wherein the bearing is sleeved on the push rod; The second linear drive structure, the bearing is fixed to the movable end of the second linear drive structure through a bearing seat.

11. The additive device according to claim 10, characterized in that: It also includes a horizontal movable base and a frame, wherein the horizontal movable base is slidably connected to the frame via a guide rail; driven by a horizontal motor on the frame, the horizontal movable base drives the push rod and the first linear drive structure to move horizontally.

12. The additive device according to claim 7, characterized in that: The stirring head is fixedly mounted on the tool handle by a plurality of bolts, and the positioning ring is embedded in the mounting hole of the tool handle. A heat insulating sheet is provided between the mounting flange and the mounting end surface of the tool handle.

Images