Stirring friction additive manufacturing machine based on powder

Abstract

The utility model discloses a powder-based stirring friction additive manufacturing machine which comprises a sleeve and a screw shaft located in the sleeve, a fixed shaft shoulder is formed at the lower end of the sleeve, the screw shaft comprises a rod body and a screw blade formed on the outer circumferential surface of the rod body, and a screw channel is formed between the screw shaft and the inner wall of the sleeve. A movable shaft shoulder is arranged at the lower end of the spiral shaft, a stirring head is arranged on the lower side of the movable shaft shoulder, and a cutter handle is formed at the top of the rod body; the lower surface of the movable shaft shoulder downwards exceeds the lower end face of the fixed shaft shoulder; a feeding barrel is installed on the side wall of the sleeve, a spiral conveyor is installed in the feeding barrel, a motor is connected to the end, away from the sleeve, of the spiral conveyor, a stock bin is installed on the upper side of the feeding barrel, and the stock bin is communicated with an inner cavity of the feeding barrel. The powder in the stock bin can be pushed by the spiral conveyor to uniformly enter the sleeve, the rotating speed of the spiral conveyor can be adjusted according to different material amounts, the powder is stably fed into the sleeve, and normal and continuous production is guaranteed.

Description

Technical Field

[0001] This utility model relates to a powder-based stirring friction additive manufacturing machine. Background Technology

[0002] Friction stir welding technology can be broadly categorized into powder, granules, rods, wires, and plates, depending on the form of the raw materials used. When using powder as the raw material, the stationary and rotating parts of the friction stir additive manufacturing equipment need to be connected to the fixed part and drive mechanism of the machining equipment, respectively, in order for the friction stir additive manufacturing equipment to operate. Furthermore, the powder needs to be fed into the gap between the stationary and rotating parts and conveyed downwards using a spiral groove. However, since the rotating part needs to be connected to the drive mechanism of the machining equipment, it is impossible to set up a hopper for holding the powder. The powder can only be added directly into the spiral groove through an external pipe, which makes the addition of powder susceptible to interference from other external factors, causing interruptions and affecting the continuous operation of production. Utility Model Content

[0003] To address the problem in existing technologies where the addition of powder is easily interrupted by external factors, this application proposes a powder-based friction stir additive manufacturing machine, which includes a sleeve and a helical shaft located inside the sleeve. The lower end of the sleeve is formed as a fixed shoulder. The helical shaft includes a rod extending downward in a vertical direction and helical blades formed on the outer circumferential surface of the rod. A helical channel is formed between the helical shaft and the inner wall of the sleeve. A movable shoulder is provided at the lower end of the helical shaft, and a stirring head is provided on the lower side of the movable shoulder. A knife handle is formed at the top of the rod. In the vertical direction, the lower surface of the movable shoulder extends downward beyond the lower end face of the fixed shoulder.

[0004] A feed cylinder is installed on the side wall of the sleeve, and a screw conveyor is installed inside the feed cylinder. A motor is connected to the end of the screw conveyor away from the sleeve, and a hopper is installed on the upper side of the feed cylinder, which is connected to the inner cavity of the feed cylinder.

[0005] When this embodiment is working, the screw shaft and the sleeve are first connected to the drive part and the fixed part of the machining equipment, respectively. Then, the powder is introduced into the hopper, the motor is started, and the powder in the hopper is sent into the screw channel in the sleeve through the screw conveyor. The screw shaft is rotated to press the stirring head into the workpiece. Under the push of the screw shaft, the powder moves downward and is discharged. Then, under the pressure of the moving shaft shoulder, it is stirred and welded with the surface layer of the workpiece to continuously form an additive layer. The lower end face of the fixed shaft shoulder smooths the surface layer of the additive workpiece.

[0006] In this application, a feed cylinder, a screw conveyor, and a hopper are installed on the side wall of the sleeve. The powder in the hopper can be evenly fed into the sleeve under the push of the screw conveyor, and the speed of the screw conveyor can be adjusted according to the different amounts of material used, so as to stably feed the powder into the sleeve and ensure the normal and continuous operation of production.

[0007] Furthermore, in order to make full use of the spiral blades on the spiral shaft and improve the uniformity of powder conveying, the outlet of the feed cylinder is positioned directly above the spiral blades in the vertical direction.

[0008] Furthermore, to prevent bridging of powder materials in the silo, a silo wall vibrator is installed on the outer wall of the silo.

[0009] Furthermore, to ensure the powder in the feed cylinder moves smoothly downwards and enters the sleeve, the feed cylinder is tilted upwards, with an angle of 5-10° between its central axis and the horizontal plane. However, the tilt of the feed cylinder should not be too large, as an excessively large tilt makes it difficult to install the hopper.

[0010] Furthermore, to ensure that the powder falls evenly onto the workpiece, the inner wall of the lower end of the sleeve expands radially outward to form a discharge chamber, and the upper end of the moving shoulder is accommodated in the discharge chamber. This design enables a cylindrical annular gap to be formed between the discharge chamber and the moving shoulder. The powder in this annular gap is no longer agitated by the spiral blades and fills the entire annular gap, thus allowing it to be evenly dispersed onto the workpiece.

[0011] Furthermore, in order to expand the width that the friction stir additive manufacturing machine can form during operation, the moving shoulder is formed by the outer peripheral surface of the screw shaft protruding radially outward, and the moving shoulder extends into the discharge chamber.

[0012] Furthermore, to prevent powder from overflowing from the gap between the moving shaft shoulder and the workpiece, an anti-overflow plate is provided on the outer surface of the sleeve. This anti-overflow plate is detachably installed on the sleeve, and its position can be adjusted vertically. The anti-overflow plate is located on the downstream side of the sleeve. In this application, the side of the friction stir additive manufacturing machine facing the direction of movement during operation is referred to as the downstream side. When the friction stir additive manufacturing machine is working, the powder on the downstream side has not yet formed an additive layer and is still in powder form, which is easy to diffuse outward, causing material loss. The anti-overflow plate can effectively reduce the amount of material loss. When the friction stir additive manufacturing machine is working, the height of the anti-overflow plate needs to be adjusted according to the thickness of the powder on the workpiece surface to avoid affecting the normal operation of the friction stir additive manufacturing machine.

[0013] Specifically, to facilitate the connection between the fixed part and the drive mechanism of the machining equipment, a tool holder is formed at the top of the rod, and a connecting flange is installed on the outer circumferential surface of the sleeve. The tool holder is used to connect to the drive mechanism of the machining equipment, and the connecting flange is used to connect to the fixed part of the machining equipment. Attached Figure Description

[0014] Figure 1 This is a structural schematic diagram of one embodiment of the present invention. Detailed Implementation

[0015] See Figure 1 A powder-based friction stir additive manufacturing machine includes a sleeve 10 and a helical shaft 20 located within the sleeve 10. The sleeve 10 and the helical shaft 20 are coaxially mounted. The lower end of the sleeve forms a fixed shoulder 11. The helical shaft 20 includes a rod 21 extending downward in a vertical direction and helical blades 22 formed on the outer circumferential surface of the rod. A helical channel 23 is formed between the helical shaft 20 and the inner wall of the sleeve. A movable shoulder 25 is provided at the lower end of the helical shaft, and a stirring head 26 is provided on the lower side of the movable shoulder. For easy stirring, a downwardly protruding stirring needle 27 is provided on the lower surface of the stirring head 26. A tool holder 24 is formed at the top of the rod. In this embodiment, the tool holder has a square cross-section and is used to connect to a drive mechanism on a machining equipment. In the vertical direction, the lower surface 251 of the movable shoulder 25 extends downward beyond the lower end face 12 of the fixed shoulder 11.

[0016] The inner wall of the lower end of the sleeve expands radially outward to form a discharge cavity 13. The moving shoulder is formed by the outer peripheral surface of the screw shaft protruding radially outward. The moving shoulder extends into the discharge cavity, and in the height direction, the upper end of the moving shoulder is accommodated in the discharge cavity to form a cylindrical discharge channel between the moving shoulder and the inner wall of the discharge chamber, thereby expanding the processing width of the working surface.

[0017] A feed cylinder 31 is installed on the side wall of the sleeve. In this embodiment, the outlet of the feed cylinder is directly opposite the upper part of the spiral blade in the height direction.

[0018] A screw conveyor 32 is installed inside the feed cylinder 31. A motor 37 is connected to the end of the screw conveyor away from the sleeve. A hopper 33 is installed on the upper side of the feed cylinder 31, and the hopper 33 is connected to the inner cavity of the feed cylinder 31. A flat flange 35 is welded to the end of the feed cylinder away from the sleeve. A blind flange 36 is detachably bolted to the flat flange. The motor is fixedly mounted on the blind flange. The output shaft of the motor freely passes through the shaft hole on the blind flange and is connected to the connecting shaft of the screw conveyor via a coupling. To maintain a seal, a sealing ring is installed in the shaft hole. To prevent bridging of the powder in the hopper, a hopper wall vibrator 34 is installed on the outer wall of the hopper.

[0019] To ensure the powder in the feed cylinder smoothly enters the sleeve, the feed cylinder is tilted upwards. Specifically, in this embodiment, the angle between the central axis of the feed cylinder and the horizontal plane is 8°. It can be understood that in other embodiments, the angle between the central axis of the feed cylinder and the horizontal plane can also be 5°, 7°, 9° or 10°. The tilt angle of the feed cylinder should not be too large, as an excessively large tilt makes it inconvenient to install the hopper.

[0020] To prevent powder from overflowing from the gap between the moving shaft shoulder and the workpiece, an anti-overflow plate 51 is provided on the outer surface of the sleeve 10. An elongated hole 52 is formed vertically on the anti-overflow plate 51, and an adjusting screw 53 passes through this hole and is screwed onto the sleeve. When the height of the anti-overflow plate needs to be adjusted, the adjusting screw is loosened to adjust the height, and then tightened again. The anti-overflow plate 51 is specifically installed on the downstream side of the sleeve. The side of the friction stir additive manufacturing machine facing the direction of movement during operation is called the downstream side. In the attached diagram, arrow X indicates the direction of movement of the friction stir additive manufacturing machine during operation.

[0021] To facilitate the installation of the friction stir additive manufacturing machine on the fixed part of machining equipment such as friction stir welding machine, CNC milling machine, and CNC machining center, a connecting flange 28 is installed on the outer circumferential surface of the sleeve, and a flange hole 29 is provided on the connecting flange.

[0022] When this embodiment is in operation, the tool holder and connecting flange 28 are first connected to the drive part and the fixed part of the machining equipment, respectively. Then, the powder is introduced into the hopper, the motor 37 is started, and the powder in the hopper is fed into the spiral channel in the sleeve through the screw conveyor 32. The screw shaft is rotated, and the stirring head 26 is pressed into the workpiece 71. Under the push of the screw shaft, the powder moves downward and is discharged. Then, under the pressure of the moving shaft shoulder, it is stirred and welded with the surface layer of the workpiece 71 to continuously form the additive layer 72. The lower end face 12 of the fixed shaft shoulder 11 smooths the surface layer of the additive workpiece.

Claims

1. A powder-based friction additive manufacturing machine, characterized in that, The device includes a sleeve and a helical shaft located inside the sleeve. The lower end of the sleeve is formed as a fixed shoulder. The helical shaft includes a rod extending downward in a vertical direction and helical blades formed on the outer circumferential surface of the rod. A helical channel is formed between the helical shaft and the inner wall of the sleeve. A movable shoulder is provided at the lower end of the helical shaft, and a stirring head is provided on the lower side of the movable shoulder. A knife handle is formed at the top of the rod. In the vertical direction, the lower surface of the movable shoulder extends downward beyond the lower end face of the fixed shoulder. A feed cylinder is installed on the side wall of the sleeve, and a screw conveyor is installed inside the feed cylinder. A motor is connected to the end of the screw conveyor away from the sleeve, and a hopper is installed on the upper side of the feed cylinder, which is connected to the inner cavity of the feed cylinder.

2. The friction stir additive manufacturing machine according to claim 1, characterized in that, In the vertical direction, the outlet of the feed cylinder is directly opposite the upper part of the spiral blade.

3. The friction stir additive manufacturing machine according to claim 1, characterized in that, A silo wall vibrator is installed on the outer wall of the silo.

4. The friction stir additive manufacturing machine according to claim 1, characterized in that, The feed cylinder is tilted upwards, and the angle between the central axis of the feed cylinder and the horizontal plane is 5-10°.

5. The friction stir additive manufacturing machine according to claim 1, characterized in that, The inner wall of the lower end of the sleeve expands radially outward to form a discharge cavity, and the upper end of the moving shaft shoulder is accommodated in the discharge cavity.

6. The friction stir additive manufacturing machine according to claim 5, characterized in that, The moving shoulder is formed by the radial outward protrusion of the outer circumferential surface of the screw shaft, and the moving shoulder extends into the discharge chamber.

7. The friction stir additive manufacturing machine according to claim 1, characterized in that, An anti-overflow plate is provided on the outer side of the sleeve. The anti-overflow plate is detachably installed on the sleeve, and its position can be adjusted in the vertical direction. The anti-overflow plate is located on the downstream side of the sleeve.

8. The friction stir additive manufacturing machine according to claim 1, characterized in that, A tool holder is formed at the top of the rod, and a connecting flange is installed on the outer circumferential surface of the sleeve. The tool holder is used to connect to the drive mechanism of the machining equipment, and the connecting flange is used to connect to the fixed part of the machining equipment.

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