Internal spiral stirring friction material adding device with through wire feeding function

Abstract

The invention relates to the technical field of solid-phase additive manufacturing, in particular to an internal spiral friction stir additive device with a hollow wire feeding function, which comprises a support frame, a wire feeding device, a driving motor, a transmission device, a stirring shaft and a stirring head, the stirring shaft is freely and rotatably mounted on the support frame through a bearing, the driving motor is arranged on one side of the support frame, and the transmission device is arranged on the other side of the support frame. The driving motor is connected with the stirring shaft through the transmission device; the stirring head is mounted at the lower end of the stirring shaft; the stirring head comprises a sleeve-shaped stirring head body, a spiral feeding groove is formed in the inner wall of the stirring head body, an assembling through hole is formed in the stirring shaft, a mandrel is arranged in the assembling through hole, at least two vertically-through wire feeding channels are formed in the mandrel, and the lower ends of the wire feeding channels are located over the spiral feeding groove. A wire feeding device matched with the wire supply channel is arranged on the supporting frame above the mandrel, and a supply blocking column matched with the spiral supply groove is arranged in the center of the lower end of the mandrel. The problem that cut granular materials are blocked in the falling process in the material adding process is solved.

Description

Technical Field

[0001] The invention relates to the technical field of solid phase additive manufacturing, and in particular to an internal spiral friction stirring additive device with a central wire feeding. Background Art

[0002] Aluminum alloys are widely used in aerospace, transportation, automobiles and ships due to their low density, high strength, good electrical and thermal conductivity, and corrosion resistance. At present, aluminum alloy parts are developing in the direction of lightweight structure and composite performance. Traditional aluminum alloys use equal material manufacturing processes such as casting and forging, as well as subtractive manufacturing processes such as turning and milling to obtain the final required shape. However, when manufacturing complex parts, the use of equal material manufacturing processes requires the production of corresponding molds, and the use of subtractive manufacturing processes requires the continuous replacement of tools during the manufacturing process, which increases the manufacturing cost and time, and is difficult to adapt to the current development trend of the advanced manufacturing industry. In comparison, additive manufacturing is based on three-dimensional models and uses material accumulation to manufacture parts. It has a high degree of design freedom and provides a new method for free design and rapid manufacturing of complex lightweight aluminum alloy components. Depending on whether the material melts during the additive process, additive manufacturing is divided into two types: molten additive manufacturing and solid phase additive manufacturing. However, molten additive manufacturing melts the material at high temperature during the additive process, and the material melts and solidifies, making it easy for the molded parts to have defects such as pores and cracks.

[0003] Solid-phase additive manufacturing uses tools to apply pressure to the material, causing the material to undergo plastic deformation in the solid state, thus avoiding defects such as cracks and pores generated during the melt additive manufacturing process. Solid-phase additive manufacturing is divided into plate-based friction stir additive manufacturing, rod-based friction stir additive manufacturing, and wire-based friction stir additive manufacturing according to the state of the raw materials. Plate-based friction stir additive manufacturing uses a "solid shoulder + stirring needle" tool. The high-speed rotating shoulder generates friction heat and extrusion force, and the stirring needle stirs the welding interface to soften the material. The circumferential drive of the rotating tool and the extrusion of the shoulder promote the plastic flow of the softened material. During the advancement of the tool, the stirring needle mixes the material to form a dense weld, thereby achieving a solid-state connection. However, after each layer of welding is completed, the plate needs to be re-added, and then the plate needs to be tightened and the tool needs to be repositioned before the next layer of welding can be carried out. In addition, after the additive is completed, the flash needs to be removed and the surface needs to be processed, which has the disadvantages of complex procedures and low work efficiency. The friction stir additive manufacturing based on rods uses a "hollow shoulder + rod" tool. The rod passes through the hollow rotating shoulder under the push of high compressive axial force, and is plasticized by friction heating, thereby being deposited on the surface of the substrate. In the process of manufacturing large structural parts, due to the limited length, rods need to be added regularly, and continuous additive cannot be achieved, which reduces work efficiency. In response to this, the friction stir additive manufacturing technology based on wires came into being, using a wire reel to continuously provide wires to ensure the continuity of the additive process. However, the technology has not yet reached a mature stage. The existing friction stir additive manufacturing scheme based on wires has problems such as easy blockage of the tool or channel during the additive process and inability to perform composite additives of more than two materials. For example, the applicant's application for an invention patent for a variable radius wire cutting tool type hollow feeding wire friction stir additive equipment on August 23, 2024 was found to have defects such as uneven falling speed of additive particles in the blanking hole, easy blockage of the blanking channel by the cut additive particles, and poor additive quality during use. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies in the above-mentioned prior art and to provide an internal spiral friction stir additive device with center-through wire feeding.

[0005] To achieve the above purpose, the technical solution provided by the present invention is as follows: An internal spiral stir friction additive device with central wire feeding, comprising a support frame, a wire feeding device, a driving motor, a transmission device, a stirring shaft and a stirring head, the stirring shaft being freely rotatably installed on the support frame via a bearing, the driving motor being arranged on one side of the support frame, the driving motor being connected to the stirring shaft via the transmission device, and the stirring head being fixedly installed at the lower end of the stirring shaft; it is characterized in that: the stirring head comprises a sleeve-shaped stirring head body, a spiral feeding groove is arranged on the inner wall of the stirring head body, an assembly through hole is arranged in the stirring shaft, a core shaft is arranged in the assembly through hole, the upper end of the core shaft being fixedly connected to the support frame and the lower end of the core shaft being located on the upper side of the spiral feeding groove, at least two wire feeding channels which are connected from top to bottom and the lower end of which is located directly above the spiral feeding groove are arranged on the core shaft; a wire feeding device which cooperates with the wire feeding channel is arranged on the support frame above the core shaft, and a feeding stop column which cooperates with the spiral feeding groove is arranged at the center of the lower end of the core shaft.

[0006] The present invention is further improved, the core shaft is stepped, the core shaft includes an upper core shaft section, a middle core shaft section and a lower core shaft section, the upper core shaft section is fixedly connected to the support frame, the middle core shaft section passes through the assembly through hole to above the upper port of the spiral feed trough in the mixing head, the lower core shaft section is the feed baffle column, the lower core shaft section passes through the spiral feed trough part of the mixing head, and the lower end surface of the lower core shaft section is flush with the bottom surface of the mixing head.

[0007] The present invention is further improved, the through hole in the center of the stirring head body is a stepped hole with an upper diameter larger than a lower diameter, the lower end of the middle section of the mandrel is located in the upper part of the stepped hole, and the lower section of the mandrel is located in the lower part of the stepped hole. The operation is more stable and the additive effect is better.

[0008] The present invention is further improved, the spiral feed groove on the inner wall of the stirring head body is composed of double-line rectangular threads (that is, double-line rectangular threads are processed on the inner wall of the stirring head body, and the spiral feed groove is between adjacent threads), and the upper ends of the two threads are wire cutting blades. The lead of the double-line thread is 2 times the pitch, which alleviates the problem of easy blockage of continuous wire feeding at low speed corresponding to a higher wire feeding speed. On the cross section of the stirring head body part perpendicular to the axial direction, the proportion of the spiral feed groove to the entire circumference is greater than the proportion of the non-spiral groove to the entire circumference; the ratio of the tooth thickness to the pitch of the double-line rectangular thread described in the present invention is 1:2-3.5, and preferably, the ratio of the tooth thickness to the pitch of the double-line rectangular thread is 1:2.5-3; at low speed corresponding to a higher wire feeding speed, the spiral feed groove part accounts for a large proportion, the blockage time is short, and the fastest wire feeding speed is high.

[0009] The transmission device described in the present invention is a transmission belt or a transmission gear.

[0010] The wire feeding channel described in the present invention is cylindrical or square.

[0011] When the present invention is used, the driving motor drives the stirring shaft to rotate through the transmission device, and the stirring head rotates under the drive of the stirring shaft. The metal wire is transported by the wire feeding device through the wire feeding channel set inside the core shaft to the wire cutting blade of the spiral feeding groove of the stirring head. As the stirring head rotates, the wire in the wire feeding channel is sheared, and the sheared wire is in granular form, and falls along the spiral feeding groove to the additive working surface below the stirring head. Under the stirring friction between the stirring head and the additive working surface, plastic deformation occurs, and thus it is deposited on the additive surface. The present invention feeds wire through the wire feeding channel opened by the fixed core shaft, and cuts the wire through the upper port of the spiral feeding groove inside the high-speed rotating stirring head, which solves the problem of the granular material cut off in the process of falling and blocking the channel during the additive process; the spiral feeding groove is composed of a double-line rectangular thread, and the lead of the double-line thread is 2 times the pitch, which solves the problem of being unable to continuously feed wire at a low speed corresponding to a higher wire feeding speed; multiple wire feeding channels are set inside the core shaft, which can continuously transport different types of wires to meet the requirements of compound performance of additive manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0013] Figure 1 It is a structural schematic diagram of the present invention.

[0014] Figure 2 It is a schematic cross-sectional structural diagram of the stirring head in the present invention.

[0015] Figure 3 It is a schematic diagram of the three-dimensional structure of the stirring head in the present invention.

[0016] Figure 4 It is a schematic diagram of the main structure of the stirring head in the present invention.

[0017] Figure 5 yes Figure 4 Schematic diagram of the BB cross-sectional structure. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0019] like Figure 1-Figure 5 The internal spiral stir friction additive device with central wire feeding shown in the figure comprises a support frame 1, a wire feeding device 2, a driving motor 3, a transmission device 5, a stirring shaft 7 and a stirring head 9. The stirring shaft 7 is freely rotatably installed in the middle of the support frame 1 via a bearing 6. The driving motor 3 is arranged on one side of the support frame 1. The driving motor 3 is connected to the stirring shaft via the transmission device 5 to drive it to rotate. Figure 1 It can be seen that the transmission device 5 in this embodiment is a transmission belt, that is, a driving transmission wheel and a driven transmission wheel are respectively provided on the output shaft of the driving motor 3 and the stirring shaft, and a transmission belt is provided between the driving transmission wheel and the driven transmission wheel. The stirring head 9 is fixedly mounted at the lower end of the stirring shaft 7; Figure 3 The stirring head shown in the figure is provided with a connecting seat 17 on the upper part of the stirring head 9, and a plurality of bolt holes 19 are processed on the connecting seat 17. The connecting seat 17 is connected to the lower end of the stirring shaft 7 through the bolts in the bolt holes 19. The stirring head 9 comprises a sleeve-shaped stirring head body, and a spiral feed groove 15 is provided on the inner wall of the stirring head body. The stirring shaft 7 is provided with an assembly through hole which penetrates from top to bottom, and a core shaft 8 is provided in the assembly through hole, the upper end of which is fixedly connected to the support frame 1 and the lower end of which is located on the upper side of the spiral feed groove 15. The core shaft 8, the stirring shaft 7 and the stirring head 9 are coaxial, and the core shaft 8 is provided with at least two wire supply channels which penetrate from top to bottom and the lower end of which is located above the upper port of the spiral feed groove 15; a variety of wire materials can be transported at the same time, and the gradient distribution of material organization and performance can be achieved by controlling the wire feeding rate and wire feeding time of different wire materials, thereby realizing the additive manufacturing of high-performance gradient materials. A wire feeding device 2 cooperating with the wire feeding channel is provided on the support frame 1 above the mandrel 8, and the wire feeding device can continuously feed the wire into the upper port of the spiral feeding groove 15 of the stirring head through the wire feeding channel. A feeding stop column is provided at the center of the lower end of the mandrel inside the wire feeding channel, which is located in the center of the inner wall of the stirring head body at the spiral feeding groove and cooperates with the inner wall of the stirring head body at the spiral feeding groove. In this embodiment, the mandrel 8 is stepped, and the mandrel includes an upper mandrel section 10, a middle mandrel section and a lower mandrel section 12; the upper mandrel section 10 is fixedly connected to the support frame 1, and the middle mandrel section passes through the assembly through hole until above the upper port of the spiral feeding groove in the stirring head, and the lower mandrel section 12 is the feeding stop column, and the lower mandrel section 12 passes through the spiral feeding groove part of the stirring head 9, and the lower end surface of the lower mandrel section 12 is flush with the bottom surface of the stirring head.

[0020] The present invention is further improved, the through hole in the center of the main body of the mixing head 9 is a stepped hole with an upper diameter larger than a lower diameter, the lower end of the middle section of the mandrel is located in the upper part of the stepped hole, and the lower section of the mandrel is located in the lower part of the stepped hole; the operation is smoother and the additive effect is better. The spiral feed groove on the inner wall of the mixing head main body is composed of a double-line rectangular thread, that is: a double-line rectangular thread is processed on the inner wall of the mixing head main body, and a spiral feed groove is provided between adjacent threads 16. A wire cutting blade 18 is provided at the upper end of the two threads 16; the upper front side surface of the thread 16 is inclined backward from top to bottom, and the upper edge of the upper front side surface of the thread 16 forms a wire cutting blade 18; when the mixing head rotates, the upper front side surface of the thread rotates from back to front. The lead of the double-line thread is 2 times the pitch, which alleviates the problem of easy blockage of continuous wire feeding at low speeds corresponding to higher wire feeding speeds; such as Figure 5As shown, in the cross section perpendicular to the axial direction of the middle part of the stirring head 9 (the part with the spiral feed groove), the proportion of the spiral feed groove to the entire circumference is greater than the proportion of the non-spiral groove to the entire circumference; at a low speed corresponding to a higher wire feeding speed, the spiral feed groove part accounts for a large proportion and the blocking time is short. Preferably, the ratio of the tooth thickness to the pitch of the double-line rectangular thread is 1:2.5-3; the wire feeding channel is cylindrical or square.

[0021] When the present invention is used, the driving motor drives the stirring shaft to rotate through the transmission device, and the stirring head rotates under the drive of the stirring shaft. The metal wire is transported by the wire feeding device through the wire feeding channel set inside the core shaft to the wire cutting blade of the spiral feeding groove of the stirring head. As the stirring head rotates, the wire in the wire feeding channel is sheared, and the sheared wire is in granular form, and falls along the spiral feeding groove to the additive working surface below the stirring head. Under the stirring friction between the stirring head and the additive working surface, plastic deformation occurs, and thus it is deposited on the additive surface. The present invention feeds wire through the wire feeding channel opened by the fixed core shaft, and cuts the wire through the upper port of the spiral feeding groove inside the high-speed rotating stirring head, which solves the problem of the granular material cut off in the process of falling and blocking the channel during the additive process; the spiral feeding groove is composed of a double-line rectangular thread, and the lead of the double-line thread is 2 times the pitch, which solves the problem of being unable to continuously feed wire at a low speed corresponding to a higher wire feeding speed; multiple wire feeding channels are set inside the core shaft, which can continuously transport different types of wires to meet the requirements of compound performance of additive manufacturing.

Claims

1. An internal spiral friction stir additive device with a central wire feed, comprising a support frame, a wire feeder, a drive motor, a transmission device, a stirring shaft and a stirring head, wherein the stirring shaft is rotatably mounted on the support frame via a bearing, the drive motor is arranged on one side of the support frame, the drive motor is connected to the stirring shaft via the transmission device, and the stirring head is fixedly mounted at the lower end of the stirring shaft; characterized in that: The stirring head comprises a sleeve-shaped stirring head body, a spiral feed groove is provided on the inner wall of the stirring head body, an assembly through hole is provided in the stirring shaft, a core shaft is provided in the assembly through hole, the upper end of which is fixedly connected to the support frame and the lower end of which is located on the upper side of the spiral feed groove, the core shaft is provided with at least two wire supply channels which pass through from top to bottom and the lower end of which is located directly above the spiral feed groove; a wire feeding device which cooperates with the wire supply channel is provided on the support frame above the core shaft, and a feed stop column which cooperates with the spiral feed groove is provided at the center of the lower end of the core shaft.

2. The internal spiral friction stir additive device with center-through wire feeding according to claim 1, characterized in that: The core shaft is stepped, and the core shaft includes an upper section, a middle section and a lower section. The upper section of the core shaft is fixedly connected to the support frame, the middle section of the core shaft passes through the assembly through hole to the top of the spiral feed groove in the mixing head, and the lower section of the core shaft is the feed baffle column. The lower section of the core shaft passes through the spiral feed groove part of the mixing head, and the lower end surface of the lower section of the core shaft is flush with the bottom surface of the mixing head.

3. The internal spiral friction stir additive device with center-through wire feeding according to claim 1, characterized in that: The through hole in the center of the stirring head body is a stepped hole with an upper diameter larger than a lower diameter, the lower end of the middle section of the mandrel is located in the upper part of the stepped hole, and the lower section of the mandrel is located in the lower part of the stepped hole.

4. The internal spiral friction stir additive device with center-through wire feeding according to claim 1, characterized in that: The transmission device is a transmission belt or a transmission gear.

5. The internal spiral friction stir additive device with center-through wire feeding according to claim 1, characterized in that: The wire feeding channel is cylindrical or square.

6. The internal spiral friction stir additive device with central wire feeding according to claim 1, characterized in that: The spiral feed groove on the inner wall of the stirring head body is composed of double-line rectangular threads, and the upper ends of the two threads are provided with cutting blades.

7. The internal spiral friction stir additive device with center-through wire feeding according to claim 6, characterized in that: The ratio of the tooth thickness to the pitch of the double-line rectangular thread described in the present invention is 1:2.5-3.

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