Lateral alternative rod feeding component-adjustable friction stir additive manufacturing device and method

Abstract

In order to solve the problems that an existing friction stir additive manufacturing device is unsmooth or discontinuous in feeding, large in axial upsetting force, narrow in material application window and the like, the friction stir additive manufacturing device comprises an additive mechanism, a rod feeding mechanism, a conveying mechanism, a feeding mechanism and a supporting mechanism. The supporting mechanism is responsible for installation and position adjustment of other mechanisms, the feeding mechanism is responsible for ejecting out single bars in a stock bin and conveying the single bars to a conveying belt of the conveying mechanism, the conveying mechanism is responsible for conveying the bars into a bar conveying wheel of the bar conveying mechanism, and then the bars are conveyed to a feeding hole of the material adding mechanism through the bar conveying mechanism. The bar is sheared and plasticized in the material adding mechanism and moves to the bottom along the spiral cavity to be extruded out, and a deposition layer is formed. According to the invention, through an alternate continuous rod feeding mode, the additive manufacturing of the gradient composite material with adjustable light alloy components can be realized. The invention belongs to the technical field of solid phase additive manufacturing.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid-phase additive manufacturing, and in particular relates to a friction stir additive manufacturing device and method with adjustable lateral alternating rod feeding components. Background Art

[0002] Aerospace engineering materials often need to have a higher load-bearing capacity than ordinary mechanical engineering materials. In some extreme working conditions, such as supersonic flight, re-entry vehicles and propulsion systems, materials need to show excellent performance under harsh service conditions. Therefore, it is necessary to continuously develop more advanced new materials, and gradient materials as one of them have attracted much attention. Gradient materials are obtained by continuously changing the composition and structure of two materials so that their internal interface disappears, thereby obtaining a non-homogeneous material whose function gradually changes with the composition and structure changes, so as to reduce and overcome the performance mismatch factors at the joint. Lightweight alloy gradient materials achieve precise control of different physical or mechanical properties by regulating parameters such as the distribution and content of different components, which is of great significance for reducing the weight of structural parts in extreme working conditions such as aerospace.

[0003] In recent years, additive manufacturing has emerged as an innovative manufacturing method. The additive manufacturing process involves the accumulation and assembly of materials according to the component model layer by layer, which can achieve near-net forming of parts with complex geometric shapes, minimize material and energy consumption, and has unique advantages in the field of preparing gradient materials. Stir friction additive manufacturing technology is derived from stir friction welding. During the additive process, the material does not undergo melting and solidification but always remains in a solid state, which can avoid the problems of pores, cracks and element burnout that are prone to occur in the melting additive manufacturing method. In addition, the material undergoes strong plastic deformation to form a fine-grained structure, which is conducive to ensuring that the component has good mechanical properties. It has broad application prospects in the additive manufacturing of high-performance lightweight alloy components.

[0004] However, the existing friction stir additive manufacturing technology still has problems. According to the different forms of raw materials used, friction stir additive manufacturing technology can be divided into plate stacking, rod deposition and wire feeding. Plate stacking (FSAM) is based on the principle of friction stir lap welding, and there are overlap defects and mechanical treatment before each layer of overlap. The rod deposition method uses a coaxial rod feeding method to achieve a complex continuous feeding device, such as: CN118305418A, CN118305420A and other published patents, and there is a problem of temporary disappearance of the top forging force during material replacement, resulting in interface defects; in addition, for materials with lower strength, such as pure aluminum and aluminum-silicon aluminum alloys, under the action of a large axial force, the material is severely softened by heat, easy to expand and form an interference fit with the feeding mechanism, resulting in poor feeding and even material deposition. The wire feeding method adopts the side-axis wire feeding method, which is easy to achieve continuous feeding and has the conditions for realizing continuous additive manufacturing of large components. However, the wire used is often a commercial welding wire material suitable for melting welding or melting additive. There is no wire raw material specially developed for solid phase additive. For alloys with poor plasticity or light alloy composite materials with high volume fraction, the wire is difficult to bend and form, which limits its application and development. Summary of the invention

[0005] The present invention aims to solve the problems of the existing friction stir additive manufacturing device, such as poor or discontinuous material feeding, large axial upsetting force, and narrow material application window, and further proposes a friction stir additive manufacturing device and method with adjustable lateral alternating rod feeding composition.

[0006] The technical solution adopted by the present invention to solve the above problems is:

[0007] The present invention includes an additive mechanism, a rod feeding mechanism, a conveying mechanism, a loading mechanism and a supporting mechanism. The additive mechanism, the rod feeding mechanism, the conveying mechanism and the loading mechanism are all connected to the supporting mechanism. The loading mechanism transports the rods in the silo to the rod feeding mechanism through the conveying mechanism, and the rod feeding mechanism transports them to the additive mechanism. The supporting mechanism includes a mounting plate, a supporting plate, an aluminum profile bracket and a crossbeam. One end of the crossbeam is connected to the additive mechanism through the mounting plate, and the other end is fixed to one end of the supporting plate. The other end of the supporting plate is fixedly connected to one end of the crossbeam close to the mounting plate through the aluminum profile bracket. The rod feeding mechanism, the conveying mechanism and the loading mechanism are all installed on the supporting plate.

[0008] Furthermore, the additive mechanism includes a screw, a sleeve, a dynamic shoulder tool holder, a static shoulder bracket and a static shoulder bracket end cover, the lower end of the static shoulder bracket and the upper end of the sleeve are connected through the bracket end cover, and the side wall of the sleeve is provided with a feeding hole; the dynamic shoulder tool holder is located in the static shoulder bracket, the upper end of the screw is connected to the dynamic shoulder tool holder, and the lower end is located in the sleeve, the lower outer side of the screw is provided with a screw ridge, and the bottom end of the screw is provided with a stirring pin.

[0009] Furthermore, the rod feeding mechanism includes a stepper motor, a motor gear, two rod feeding wheel gears, two rod feeding wheels, a limiting tube, a first clamping frame and a first spring knob. The stepper motor is installed on the support plate, and its output shaft is fixedly connected to the motor gear. The motor gear cooperates with the upper and lower rod feeding wheel gears for transmission respectively. A rod feeding wheel is installed on each rod feeding gear, and the rotation of the motor gear drives the rod feeding wheels installed on the upper and lower rod feeding wheel gears to rotate; the rod feeding wheel gear and the rod feeding wheel located at the upper part are connected to the support plate through the first clamping frame, and the first spring knob is provided on the first clamping frame, and a limiting tube is installed on the left side of the two rod feeding wheels.

[0010] Furthermore, a V-shaped groove is provided on the side of the rod feeding wheel to realize automatic centering of the rod, and a small groove needs to be etched on the contact surface to prevent slipping.

[0011] Furthermore, the conveying mechanism is mainly composed of two conveying wheels, two conveyor belts, a pressure wheel, a second clamping frame and a second spring knob. The two conveying wheels are respectively installed at both ends of the support plate, and the two conveying wheels are connected by two conveyor belts. The two conveyor belts are arranged side by side and have a gap. The two conveyor belts are installed side by side on the conveying wheels on both sides and are spaced a certain distance apart, so as to realize automatic centering of the rods. The pressure wheel is installed on the support plate adjacent to the first clamping frame through the second clamping frame. The distance between the pressure wheel and the conveyor belt is adjusted by adjusting the second spring knob on the second clamping frame. The conveying wheel gear is coaxially installed on the support plate with the conveying wheel located at the lower part of the pressure wheel, and the conveying wheel gear cooperates with the motor gear for transmission.

[0012] Furthermore, the feeding mechanism includes a swing cylinder, a cam, a top block, a top block connecting beam, a guide shaft, a guide block, a photoelectric sensor and a silo. The swing cylinder can rotate in an angle range of 0 to 90 degrees. The swing cylinder is connected to the cam. When the cylinder is deflated, it swings to 0 degrees, which corresponds to the cam's low point vertically upward. When the cylinder is inflated, it swings to 90 degrees, which corresponds to the cam's high point vertically upward. The two top blocks are connected to the support plate through a guide shaft and a guide shaft seat. The two top blocks are connected by a top block connecting beam. The top blocks on the left and right sides are connected by the top block connecting beam and can move synchronously. An adjustment block is designed at the contact position between the middle of the top block connecting beam and the cam to adjust the position of the top block. The two guide blocks are fixed on the support plate and each guide block is located on the outside of the top block. A limit baffle is installed at the contact position with the rod to adjust the position. The baffle is installed on the two guide blocks, which are located on the outside of the conveyor belt. The photoelectric sensor is installed on the baffle through a mounting frame. The silo is tilted on one side of the two top blocks and fixed to the support plate.

[0013] Furthermore, the swing cylinder has a rotation angle range of 0 to 90°. When the cam swings to the 0° position, the corresponding low point of the cam points vertically upward and contacts the adjusting block of the top block connecting beam. At this time, the top block is at the lowest position, and its upper surface slope is lower than the bottom plate of the silo; when the swing cylinder is inflated, the cam swings to the 90° position, and the corresponding high point of the cam points vertically upward and contacts the adjusting block of the top block connecting beam. At this time, the top block is at the highest position, and its upper surface slope is higher than the upper surface slope of the guide block.

[0014] A friction stir additive manufacturing method with adjustable composition and lateral alternating rod feeding, the method comprising the following steps:

[0015] Step 1: According to the size of the bar material, design the dimensions of the screw and sleeve to ensure that the bar can pass through the feeding hole into the spiral cavity and be cut into material particles of appropriate size;

[0016] Step 2: Install the static shoulder bracket on the mounting ring at the lower end of the mounting plate, install the screw on the dynamic shoulder handle, and install the sleeve on the static shoulder bracket. Adjust the installation position of the screw and the sleeve to ensure that they have a certain degree of coaxiality. The side wall of the screw should maintain a certain gap with the inner wall of the sleeve to prevent the two from wearing during rotation. In addition, the bottom surface of the screw and the bottom surface of the sleeve are in the same plane, and the stirring needle is fully extended to ensure that the stirring needle has sufficient effect on the extruded material, which is conducive to enhancing the interlayer bonding.

[0017] Step 3: Select a suitable rod feeding wheel according to the rod size, install the rod feeding mechanism on the support plate, and rotate the first spring knob of the first clamping frame to adjust the gap between the upper and lower rod feeding wheels to prevent the rod from slipping during the feeding process;

[0018] Step 4: Select appropriate conveying wheels, pressure wheels and conveyor belts according to the size of the rods, install the conveying mechanism on the support plate, adjust the tension of the conveyor belt by adjusting the installation position of the distal conveying wheel, rotate the second spring knob of the second clamping frame to adjust the gap between the proximal conveying wheel and the pressure wheel, and ensure that the rods can pass through the proximal conveying wheel and the pressure wheel on the conveyor belt and enter between the upper and lower rod feeding wheels;

[0019] Step 5: Install the feeding mechanism on the support plate, design a suitable cam according to the relative positions of the top block, the silo bottom plate and the guide block, so that the 0° and 90° of the swing cylinder correspond to the low point and high point of the cam edge respectively. When the top block connecting beam adjustment block contacts the cam low point, the top surface of the top block is below the silo bottom plate, and when the top block connecting beam adjustment block contacts the cam high point, the top surface of the top block is above the upper surface of the guide block.

[0020] Step 6: Adjust the installation position of the photoelectric sensor so that the laser emitted by the transmitter passes through the gap between the two conveyor belts and enters the receiver; when the receiver is not sensitive to light, the swing cylinder is inflated and swung to 90°, the high point of the cam contacts the adjustment block, and the top block rises; when the receiver is sensitive to light, the swing cylinder is deflated and swung to 0°, the low point of the cam contacts the adjustment block, and the top block descends; adjust the left and right positions of the photoelectric sensor so that the next bar slides onto the conveyor belt through the guide block and just connects with the previous bar;

[0021] Step 7: Connect the mounting plate of the support mechanism to the friction stir welding machine, adjust the mounting position of the support plate of the support mechanism to keep a certain distance and inclination angle from the main shaft of the welding machine, and insert the limiting tube into the feeding hole of the sleeve so that the rod can pass through the feeding wheel and the limiting tube and then pass through the feeding hole of the additive mechanism in a straight line;

[0022] Step 8: According to the size and shape of the additive component, design a reasonable additive path and select appropriate process parameters; install the substrate on the tooling platform and clamp it with a fixture, set the coordinate origin, write the additive program, and prepare for additive;

[0023] Step 9: During additive manufacturing, the screw rotates at high speed, and the stirring needle at the bottom penetrates into the substrate. After reaching the predetermined depth, the stepper motor is started, and the rod is fed into the rod feeding wheel by the conveyor belt and continues to be transported into the additive mechanism. The rod is sheared and plasticized by the additive mechanism, and is continuously extruded from the bottom and deposited on the substrate. At this time, the welding machine is started to feed, and the additive process is carried out stably.

[0024] Step 10: When the additive mechanism traverses a layer of the path and needs to proceed to the next layer, the screw and sleeve are lifted up to a layer height, and then the welder continues to feed, and the additive process continues to proceed steadily on the previous deposition layer;

[0025] Step 11: After the additive process is completed, the screw and the sleeve are lifted upward, and the rod feeding mechanism, the transmission mechanism and the feeding mechanism are closed at the same time. The screw is kept rotating for a period of time and then stopped to squeeze out the remaining material in the spiral cavity to obtain the additive component.

[0026] The beneficial effects of the present invention are:

[0027] 1. The present invention can solve the problems of poor or discontinuous feeding, large axial upsetting force, narrow material application window, etc. in the existing friction stir additive manufacturing method. At the same time, through the alternating continuous rod feeding mode, it can realize the additive manufacturing of gradient composite materials with adjustable light alloy composition. The present invention belongs to the field of solid phase additive manufacturing technology;

[0028] 2. The lateral rod feeding method proposed in the present invention can realize the lateral continuous feeding of materials and the coaxial material uninterrupted feeding deposition additive manufacturing through the design of the continuous feeding mechanism;

[0029] 3. In the present invention, the rod material for side feeding has a large diameter and strong rigidity, and is close to the additive deposition position, which effectively reduces the contact area of ​​the thermoplastic material in the coaxial rod feeding mode, and effectively solves the problems of poor material delivery or blockage caused by overheating of traditional stir friction additive manufacturing materials;

[0030] 4. The present invention can realize additive manufacturing of gradient composite materials with adjustable light alloy composition through the alternating continuous rod feeding mode;

[0031] 5. The present invention uses rod raw materials, which have a wide range of application and the diameter can be selected as needed, avoiding the inherent mode that traditional rod feeding additives must use large diameter rods, and can achieve gradient preparation of light alloys and their composite materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of a friction stir additive manufacturing device with adjustable lateral alternating rod feeding components according to the present invention;

[0033] Figure 2 It is a structural schematic diagram of the support mechanism of the present invention;

[0034] Figure 3 is a cross-sectional schematic diagram of the material adding mechanism of the present invention;

[0035] Figure 4 It is a structural schematic diagram of the rod feeding mechanism of the present invention;

[0036] Figure 5 It is a structural schematic diagram of the conveying mechanism of the present invention;

[0037] Figure 6 It is a structural schematic diagram of the feeding mechanism of the present invention;

[0038] Figure 7 It is a partial enlarged view of the jacking structure in the feeding mechanism of the present invention;

[0039] Figure 8 It is a partial enlarged view of the location of the photoelectric sensor of the present invention;

[0040] Figure 9-12 It is a schematic diagram of the feeding process of the present invention. DETAILED DESCRIPTION

[0041] Specific implementation method 1: The present implementation method is a friction stir additive manufacturing device with adjustable lateral alternating rod feeding composition, such as Figure 1As shown, it includes an additive mechanism 1, a rod feeding mechanism 2, a conveying mechanism 3, a loading mechanism 4 and a supporting mechanism 5. The additive mechanism 1, the rod feeding mechanism 2, the conveying mechanism 3 and the loading mechanism 4 are all connected to the supporting mechanism 5. The supporting mechanism 5 is responsible for the installation and position adjustment of other mechanisms. The loading mechanism 4 is responsible for ejecting a single rod in the silo and transporting it to the conveyor belt of the conveying mechanism 3. The conveying mechanism 3 is responsible for transporting the rod to the rod feeding wheel of the rod feeding mechanism 2, and then transported by the rod feeding mechanism 2 to the feeding port of the additive mechanism 1. The rod is sheared and plasticized in the additive mechanism, moves along the spiral cavity to the bottom for extrusion, and forms a deposition layer.

[0042] like Figure 2 As shown, the support mechanism 5 includes a mounting plate 50, a support plate 51, an aluminum profile bracket 52, and a crossbeam 53. One end of the crossbeam 53 is connected to the additive mechanism 1 through the mounting plate 50, and the other end is fixed to one end of the support plate 51. The other end of the support plate 51 is fixedly connected to one end of the crossbeam 53 close to the mounting plate 50 through the aluminum profile bracket. The rod feeding mechanism 2, the conveying mechanism 3, and the loading mechanism 4 are all installed on the support plate 51.

[0043] Specific implementation method 2: Figure 3 As shown, the additive mechanism 1 described in this embodiment includes a screw 11, a sleeve 12, a dynamic shoulder tool holder 13, a static shoulder bracket 14 and a static shoulder bracket end cover 15. The lower end of the static shoulder bracket 14 and the upper end of the sleeve 12 are connected through the bracket end cover 15, and the side wall of the sleeve 12 is provided with a feeding hole 120; the dynamic shoulder tool holder 13 is located in the static shoulder bracket 14, the upper end of the screw 11 is connected to the dynamic shoulder tool holder 13, and the lower end is located in the sleeve 12, the lower outer side of the screw 11 is provided with a screw ridge 110, and the bottom end of the screw 11 is provided with a stirring needle 111.

[0044] In this embodiment, the screw 11 can rotate around its own axis, and the sleeve 12 is a hollow structure, and its inner wall can enclose a spiral cavity with the screw rib 110 of the screw. During the additive process, the screw 11 and the sleeve 12 rotate relative to each other, and the rod 10 is fed into the additive mechanism 1 through the feeding hole 120, and is cut into granular particles under the action of the screw rib 110, and is transported to the bottom of the mechanism along the spiral cavity and extruded. The particles are mixed with the substrate material through the stirring action of the stirring needle 111, and a dense deposition layer is formed under the forging action of the bottom surface 121 of the sleeve.

[0045] The other components and connection relationships of this embodiment are the same as those of the first embodiment.

[0046] Specific implementation method three: Figure 4As shown, the rod feeding mechanism 2 includes a stepper motor 20, a motor gear 21, two rod feeding wheel gears 22, two rod feeding wheels 23, a limiting tube 24, a first clamping frame 25 and a first spring knob 26. The stepper motor 20 is installed on the support plate 51, and its output shaft is fixedly connected to the motor gear 21. The motor gear 21 cooperates with the upper and lower rod feeding wheel gears 22 for transmission respectively. A rod feeding wheel 23 is installed on each rod feeding gear 22, and the motor gear 21 rotates to drive the rod feeding wheels 23 installed on the upper and lower rod feeding wheel gears 22 to rotate; the rod feeding wheel gear 22 and the rod feeding wheel 23 located at the upper part are connected to the support plate 51 through the clamping frame 25, the first clamping frame 25 is provided with a first spring knob 26, and the limiting tube 24 is installed on the left side of the two rod feeding wheels 23.

[0047] In this embodiment, the rod 10 is located between the upper and lower rod feeding wheels 23, one end of the first clamping frame 25 is rotatably connected to the support plate 51, and the other end is limited by the support shaft 25-1. One side of the first clamping frame 25 is pressed downward by the first spring knob 26, and the distance between the upper and lower rod feeding wheels 23 is adjusted by the first clamping frame 25 to clamp and transport the rod 10. A V-shaped groove 230 is processed on the side of the rod feeding wheel 23 to achieve automatic centering of the rod 10, and a small groove needs to be etched on the contact surface to prevent slipping. A bell mouth 240 is processed on the right end of the limiting tube 24 to limit the movement trajectory of the rod 10. The other components and connection relationships of this embodiment are the same as those of the specific embodiment one or two.

[0048] Specific implementation method four: Figure 5 As shown, the conveying mechanism 3 is mainly composed of two conveying wheels 31, two conveyor belts 32, a pressure wheel 33, a second clamping frame 34 and a second spring knob 35. The two conveying wheels 31 are respectively installed at both ends of the support plate 51, and the two conveying wheels 31 are connected by two conveyor belts 32. The two conveyor belts 32 are arranged side by side and have a gap. The two conveyor belts 32 are installed side by side on the conveying wheels 31 on both sides and are spaced a certain distance apart, so as to realize automatic centering of the bar 10. The pressure wheel 33 is installed on the support plate 51 and adjacent to the clamping frame 25 through the clamping frame 34. The distance between the pressure wheel 33 and the conveyor belt 32 is adjusted by adjusting the spring knob 35 on the clamping frame 34. The conveying wheel gear 30 is coaxially installed on the support plate 51 with the conveying wheel 31 located at the lower part of the pressure wheel 33, and the conveying wheel gear 30 cooperates with the motor gear 21 for transmission.

[0049] In this embodiment, the motor gear 21 is driven by the stepper motor 20, thereby driving the conveying gear 30 and the conveying wheel 30 on the conveying gear 30 to rotate, and the tension of the conveyor belt 32 is adjusted by adjusting the installation position of the far-end conveying wheel 31; a V-shaped groove 330 is provided on the side of the pressure wheel 33 to realize the automatic centering of the rod 10, and the distance between the pressure wheel 33 and the conveyor belt 32 is adjusted by adjusting the second spring knob 35 of the second clamping frame 34. The conveying device 3 can transport the rod 10 on the conveyor belt 32 to between the upper and lower rod feeding wheels 23 of the rod feeding mechanism 2, and limit the movement trajectory of the rod 10 by the pressure wheel 33. The second clamping frame 34 has the same structure as the first clamping frame 25.

[0050] The other components and connection relationships of this embodiment are the same as those of the first, second or third embodiment.

[0051] Specific implementation method five: Figures 6 to 8 As shown, the feeding mechanism 4 includes a swing cylinder 40, a cam 41, a top block 42, a top block connecting beam 43, a guide shaft 44, a guide block 45, a photoelectric sensor 46 and a silo 47. The swing cylinder 40 can rotate in the range of 0 to 90 degrees. The swing cylinder 40 is connected to the cam 41. When it is deflated, it swings to 0 degrees, corresponding to the cam low point 410 vertically upward, and when it is inflated, it swings to 90 degrees, corresponding to the cam high point 411 vertically upward. The two top blocks 42 are connected to the support plate 51 through the guide shaft 44 and the guide shaft seat 440. The two top blocks 42 are connected by the top block connecting beam 43. The top blocks 42 on the left and right sides are connected by the top block connecting beam 43 and can move synchronously. An adjustment block 430 is designed at the contact position between the middle part of the top block connecting beam 43 and the cam 41 to adjust the position of the top block 42. Two guide blocks 45 are fixed on the support plate 51 and each guide block 45 is located on the outside of the top block 42. A limit baffle 450 is installed at the contact position with the rod 100 to adjust the position. The baffle 48 is installed on the two guide blocks 45. The baffle 48 is located on the outside of the conveyor belt 32 and is used to limit the movement trajectory of the rod 10. The photoelectric sensor 46 is installed on the baffle 48 through the mounting bracket 460. The position is adjusted through the mounting hole 480 of the baffle so that the laser emitted by the transmitter 461 can pass through the gap between the two conveyor belts 32 and enter the receiver 462, which is used to control the action of the swing cylinder 40. The silo 47 is tilted on one side of the two top blocks 42 and fixed to the support plate 51.

[0052] Combination Figures 9 to 12The specific process of continuous feeding is described, and the relative positions of the top block 42 and the guide block 45 require extra attention. When the swing cylinder 40 is deflated, the cam 41 swings to the 0° position, and the corresponding cam low point 410 is vertically upward, contacting the adjustment block 430 of the top block connecting beam. At this time, the top block 42 is at the lowest position, and its upper surface slope should be lower than the silo bottom plate 470; when the swing cylinder 40 is inflated, the cam 41 swings to the 90° position, and the corresponding cam high point 411 is vertically upward, contacting the adjustment block 430 of the top block connecting beam. At this time, the top block 42 is at the highest position, and its upper surface slope should be higher than the upper surface slope of the guide block. The action of the swing cylinder 40 is controlled by the photoelectric sensor 46. When the receiver 462 is light-transmitting, the swing cylinder 40 is in a deflated state; and when the receiver 462 is not light-transmitting, the swing cylinder 40 is in an inflated state.

[0053] The specific process of continuous feeding is as follows:

[0054] The initial state is Fig. 9 As shown, the swing cylinder 40 is in the deflated state, the cam low point 410 contacts the top block connecting beam adjustment block 430, the top block 42 is in the lowest position, and its upper surface slope is lower than the silo bottom plate 470. Since the silo bottom plate 470 is a slope, the rods 100 in the silo 47 roll downward due to gravity and are close to the guide block limit baffle 450. At this time, the light path of the photoelectric sensor 46 is blocked, the receiver 462 is not sensitive to light, the swing cylinder 40 is controlled to inflate, and the cam 41 rotates from 0° to 90°, so that the top block 42 moves upward to the highest position. The top block lifting process is shown in FIG. Fig.10 As shown, the upper surface slope of the top block 42 moves upward from below the bottom plate 470 of the silo to above the bottom plate 470 of the silo, and a single bar 10 is ejected. The ejection width of the top block 42 is adjusted by the guide block limit baffle 450, and its ejection width should be exactly equal to the diameter of a bar 10, and the excess bar will fall back into the silo 47. The highest position of the top block is shown in FIG. Fig.11 As shown, the upper surface of the top block 42 is higher than the upper surface of the guide block 45, and the rod 10 rolls along the top block toward the ground and stops close to the front end limit. At this time, the photoelectric sensor 46 is released, the receiver 462 senses light, controls the swing cylinder 40 to deflate, and the cam 41 rotates from 90° to 0°, so that the top block 42 falls down to the lowest position, as shown in FIG. Fig.12 As shown, at this time, the bar 10 is free from the blocking of the front end limit of the top block 42, rolls downward along the upper surface of the guide block 45, and falls into the middle of the two conveyor belts 32 under the limit of the guide block 45 and the baffle 48, reaching the loading position. At this time, the upper surface of the top block 42 is lower than the bottom plate 470 of the silo, and the next bar 100 rolls again to the position close to the guide block limit baffle 450, waiting for the next loading.

[0055] When the bar 10 falls onto the conveyor belt 32, it will block the optical path of the photoelectric sensor 46, and the swing cylinder 40 will be controlled to make the top block 42 push upward to push out the next bar 100; during the feeding process, the stepper motor 20 of the rod feeding mechanism 2 is always in the on state, and the rod feeding wheel 23 and the conveying wheel 31 are controlled by gears to rotate synchronously, driving the conveyor belt 32 to always convey the bar 10 to the front end; when the bar 10 completely passes the position of the photoelectric sensor 46, the receiver 462 is sensitive to light, and the swing cylinder 40 is controlled to make the top block 42 fall downward, and the next bar 100 passes through the upper surface of the guide block 45 and falls onto the conveyor belt 32 again, blocking the photoelectric sensor again, so as to realize the continuous feeding process in this cycle. By adjusting the installation position 480 of the sensor, the positions of the front and rear conveying bars 10 can be connected end to end, and the existing gap is within an acceptable range.

[0056] The other components and connection relationships of this embodiment are the same as those of the first, second, third or fourth embodiment.

[0057] Specific implementation method 6: A stir friction additive manufacturing method with adjustable lateral alternating rod feeding described in this implementation method comprises the following steps:

[0058] Step 1: According to the size of the rod material, the dimensions of the screw 11 and the sleeve 12 are designed to ensure that the rod can pass through the feeding hole 120 into the spiral cavity and be cut into material particles of appropriate size;

[0059] Step 2: Install the static shoulder bracket 14 onto the mounting ring at the lower end of the mounting plate 50, install the screw 11 onto the dynamic shoulder handle 13, and install the sleeve 12 onto the static shoulder bracket 14. By adjusting the installation positions of the screw 11 and the sleeve 12, ensure that the two have a certain degree of coaxiality. A certain gap should be maintained between the side wall of the screw 11 and the inner wall of the sleeve 12 to prevent the two from wearing during the rotation process. In addition, the bottom surface of the screw 11 and the bottom surface of the sleeve 12 are in the same plane, and the stirring needle 111 is fully extended to ensure that the stirring needle 111 has sufficient effect on the extruded material, which is conducive to enhancing the interlayer bonding.

[0060] Step 3: Select a suitable rod feeding wheel 23 according to the rod size, install the rod feeding mechanism 2 on the support plate 51, and rotate the spring knob 26 of the first clamping frame 25 to adjust the gap between the upper and lower rod feeding wheels 23 to prevent the rod 10 from slipping during the feeding process;

[0061] Step 4: Select appropriate conveying wheels 31, pressure wheels 33 and conveyor belt 32 according to the size of the rods, install the conveying mechanism 3 on the support plate 51, adjust the tension of the conveyor belt 32 by adjusting the installation position of the distal conveying wheel 31, rotate the spring knob 35 of the second clamping frame 34 to adjust the gap between the proximal conveying wheel 31 and the pressure wheel 33, and ensure that the rod 10 can pass through the proximal conveying wheel 31 and the pressure wheel 33 on the conveyor belt 32 and enter between the upper and lower rod feeding wheels 23;

[0062] Step 5: Install the feeding mechanism 4 on the support plate 51, design a suitable cam 41 according to the relative positions of the top block 42, the silo bottom plate 470 and the guide block 45, so that the 0° and 90° of the swing cylinder 40 correspond to the low point and the high point of the edge of the cam 41 respectively, when the top block connecting beam 43 adjusting block 430 contacts the cam low point 410, the upper surface position of the top block 42 is below the silo bottom plate 470, and when the top block connecting beam 43 adjusting block 430 contacts the cam high point 411, the upper surface position of the top block 42 is above the upper surface of the guide block 45;

[0063] Step 6: Adjust the installation position of the photoelectric sensor 46 so that the laser emitted by the transmitter 461 just passes through the gap between the two conveyor belts 32 and enters the receiver 462; when the receiver 462 is not sensitive to light, the swing cylinder 40 is inflated and swung to 90°, the cam high point 411 contacts the adjustment block 430, and the top block 42 rises; when the receiver 462 is sensitive to light, the swing cylinder 40 is deflated and swung to 0°, the cam low point 410 contacts the adjustment block 430, and the top block 42 falls; adjust the left and right positions of the photoelectric sensor 46 so that the next bar slides onto the conveyor belt 32 through the guide block 45 and just connects with the previous bar;

[0064] Step 7: Connect the mounting plate 50 of the support mechanism 5 to the friction stir welding machine, adjust the mounting position of the support plate 51 of the support mechanism 5 to keep a certain distance and inclination angle from the main shaft of the welding machine, and insert the limiting tube 24 into the feeding hole 120 of the sleeve 12, so that the rod 10 can pass through the feeding hole of the material adding mechanism in a straight line after passing through the rod feeding wheel 23 and the limiting tube 24;

[0065] Step 8: According to the size and shape of the additive component, design a reasonable additive path and select appropriate process parameters; install the substrate on the tooling platform and clamp it with a fixture, set the coordinate origin, write the additive program, and prepare for additive;

[0066] Step 9: When performing additive manufacturing, the screw 11 rotates at a high speed, and the bottom stirring needle 111 penetrates into the substrate. After reaching a predetermined depth, the stepper motor 20 is started, and the rod 10 is fed into the rod feeding wheel 23 by the conveyor belt 32, and then continues to be transported into the additive mechanism 1; the rod 10 is sheared and plasticized by the additive mechanism 1, and is continuously extruded from the bottom and deposited on the substrate. At this time, the welding machine is started to feed, and the additive process is carried out stably;

[0067] Step 10: After the additive mechanism 1 traverses a layer of the path and needs to proceed to the next layer, the screw 11 and the sleeve 12 are lifted up to a layer height, and then the welder continues to feed, and the additive process continues to proceed stably on the previous deposition layer;

[0068] Step 11: After the additive process is completed, the screw 11 and the sleeve 12 are lifted upward, and the rod feeding mechanism 2, the transmission mechanism 3 and the feeding mechanism 4 are closed at the same time. The screw 11 is kept rotating for a period of time and then stopped to squeeze out the remaining material in the spiral cavity to obtain the additive component.

[0069] Preferably, in this embodiment, the rod material can be a light metal such as magnesium alloy, aluminum alloy, or a composite material such as magnesium-based or aluminum-based. The rod diameter should be 3 to 10 mm, and the length should be 200 to 4000 mm.

[0070] Preferably, in this embodiment, the number of screw fins 110 of the screw 11 may be 1 to 3, the number of stirring pins 111 at the bottom of the screw 11 may be 1 to 6, the diameter of the screw 11 should be 4 to 40 mm, the length of the stirring pins 111 should be 0.2 to 6 mm, the height of the screw fins 110 should be 1 to 5 mm, the width of the screw fins should be 2 to 10 mm, and the pitch should be 10 to 50 mm;

[0071] Preferably, in this embodiment, a V-shaped groove 230 is provided on the side of the rod feeding wheel 23 in the rod feeding mechanism 2, which can realize automatic centering of the rod, and the cone angle should be 10-45°. The contact surface with the rod needs to be etched with fine grooves, which can increase the friction coefficient between the two and prevent the occurrence of slipping.

[0072] Preferably, in this embodiment, the conveyor belt 32 of the conveying mechanism 3 is an O-shaped belt, the length of which varies according to the length of the rod used, and the diameter varies according to the diameter of the rod used, which should be 0.6 to 0.8 times the diameter of the rod used. When installed, two O-shaped belts are placed side by side to maintain a certain gap; the main function of the pressure wheel 33 is to limit and center, and a pressure wheel V-shaped groove 330 is provided on the side, and the cone angle should be 60 to 120 degrees;

[0073] Preferably, in this embodiment, if the top block 42 and the top block connecting beam 43 in the feeding mechanism 4 cannot fall by their own gravity, the cam structure can be changed to a connecting rod slider structure, which has higher reliability; the relative height of the top block 42, the silo bottom plate 470 and the guide block 45 can be adjusted by the top block connecting beam adjusting block 430 in addition to the cam size adjustment;

[0074] Preferably, in this embodiment, the limit baffle 450 of the guide block 45 can adjust the width of the material lifted by the top block 42, ensuring that the top block 42 can only push out a single rod each time it is lifted, and the excess material will be squeezed out by the limit baffle 450 and fall back into the silo 47 during the lifting process;

[0075] Preferably, in this embodiment, the limiting tube 24 of the rod feeding mechanism 2 needs to be inserted into the sleeve feeding hole 120 of the material adding mechanism 1. When the rod 10 being transported completely passes through the rod feeding wheel 23, the power for its continued transportation comes from the pushing effect of the next rod passing through the rod feeding wheel.

[0076] Preferably, in this embodiment, in order to prevent interference between the device and the workpiece during the material addition process, the support mechanism 5 can adjust the rod feeding angle, and the adjustment range is 0 to 30°;

[0077] Preferably, in this embodiment, the rotation speed range should be 50-3000 rpm, the travel speed should be 50-2000 mm / min, the layer height should be 0.2-6 mm, the rod feeding rate should be 100-10000 mm / min, and the deposition efficiency can reach 0.5-60 kg / h.

[0078] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A friction stir additive manufacturing device with adjustable lateral alternating rod feeding composition, characterized in that: The device comprises an additive mechanism (1), a rod feeding mechanism (2), a conveying mechanism (3), a loading mechanism (4) and a supporting mechanism (5); the loading mechanism (4) transports the rods in the silo to the rod feeding mechanism (2) through the conveying mechanism (3), and the rod feeding mechanism (2) transports the rods to the additive mechanism (1); the supporting mechanism (5) comprises a mounting plate (50), a supporting plate (51), an aluminum profile bracket (52) and a crossbeam (53); one end of the crossbeam (53) is connected to the additive mechanism (1) through the mounting plate (50), and the other end is fixed to one end of the supporting plate (51); the other end of the supporting plate (51) is fixedly connected to one end of the crossbeam (53) close to the mounting plate (50) through the aluminum profile bracket (52); the rod feeding mechanism (2), the conveying mechanism (3) and the loading mechanism (4) are all mounted on the supporting plate (51).

2. A friction stir additive manufacturing device with adjustable lateral alternating rod feeding composition according to claim 1, characterized in that: The material adding mechanism (1) comprises a screw (11), a sleeve (12), a dynamic shoulder shank (13), a static shoulder bracket (14) and a static shoulder bracket end cover (15); the lower end of the static shoulder bracket (14) and the upper end of the sleeve (12) are connected via the bracket end cover (15); a feeding hole (120) is provided on the side wall of the sleeve (12); the dynamic shoulder shank (13) is located in the static shoulder bracket (14); the upper end of the screw (11) is connected to the dynamic shoulder shank (13), and the lower end is located in the sleeve (12); a screw ridge (110) is provided on the outer side of the lower part of the screw (11); and a stirring pin (111) is provided at the bottom end of the screw (11).

3. The friction stir additive manufacturing device with adjustable lateral alternating rod feeding composition according to claim 1, characterized in that: The rod feeding mechanism (2) comprises a stepping motor (20), a motor gear (21), two rod feeding wheel gears (22), two rod feeding wheels (23), a limiting tube (24), a first clamping frame (25) and a first spring knob (26). The stepping motor (20) is mounted on a support plate (51), and its output shaft is fixedly connected to the motor gear (21). The motor gear (21) is respectively matched with the upper and lower rod feeding wheel gears (22) for transmission. Each rod feeding gear (22) is mounted with a rod feeding wheel (23) for connection. The rotation of the motor gear (21) drives the rod feeding wheels (23) mounted on the upper and lower rod feeding wheel gears (22) to rotate. The rod feeding wheel gear (22) and the rod feeding wheel (23) located at the upper part are connected to the support plate (51) through the first clamping frame (25). The first spring knob (26) is provided on the first clamping frame (25). The limiting tube (24) is installed on the left side of the two rod feeding wheels (23).

4. The device for friction stir additive manufacturing with adjustable lateral alternating rod feeding according to claim 3, characterized in that: A V-shaped groove (230) is provided on the side surface of the rod feeding wheel (23).

5. The friction stir additive manufacturing device with adjustable lateral alternating rod feeding composition according to claim 1, characterized in that: The conveying mechanism (3) mainly comprises two conveying wheels (31), two conveying belts (32), a pressure wheel (33), a second clamping frame (34) and a second spring knob (35). The two conveying wheels (31) are respectively mounted at two ends of a support plate (51). The two conveying wheels (31) are connected via two conveying belts (32). The two conveying belts (32) are arranged side by side with a gap therebetween. The pressure wheel (33) is mounted on the support plate (51) adjacent to the first clamping frame (25) via the second clamping frame (34). The distance between the pressure wheel (33) and the conveying belt (32) is adjusted by adjusting the second spring knob (35) on the second clamping frame (34). The conveying wheel gear (30) is coaxially mounted on the support plate (51) with the conveying wheel (31) located below the clamping wheel (33). The conveying wheel gear (30) cooperates with the motor gear (21) for transmission.

6. The device for friction stir additive manufacturing with adjustable lateral alternating rod feeding according to claim 1, characterized in that: The feeding mechanism (4) comprises a swing cylinder (40), a cam (41), a top block (42), a top block connecting beam (43), a guide shaft (44), a guide block (45), a photoelectric sensor (46) and a silo (47); the swing cylinder (40) is connected to the cam (41); the two top blocks (42) are connected to the support plate (51) via the guide shaft (44) and the guide shaft seat (440); the two top blocks (42) are connected via the top block connecting beam (43); the top blocks (42) on the left and right sides are connected by the top block connecting beam (43) so as to be able to move synchronously; An adjusting block (430) is designed at the contact position between the top block (41) and the cam (41); two guide blocks (45) are fixed on the support plate (51) and each guide block (45) is located on the outside of the top block (42); a limit baffle (450) is installed at the contact position with the rod (100); a baffle (48) is installed on the two guide blocks (45); the baffle (48) is located on the outside of the conveyor belt (32); a photoelectric sensor (46) is installed on the baffle (48) through a mounting frame (460); and a silo (47) is tilted on one side of the two top blocks (42) and fixed to the support plate (51).

7. The friction stir additive manufacturing device with adjustable lateral alternating rod feeding composition according to claim 6, characterized in that: The swing cylinder (40) has a rotation angle range of 0 to 90 degrees. When the cam (41) swings to the 0 degree position, the corresponding cam low point (410) is vertically upward and contacts the adjustment block (430) of the top block connecting beam. At this time, the top block (42) is located at the lowest position, and its upper surface slope is lower than the silo bottom plate (470); when the swing cylinder (40) is inflated, the cam (41) swings to the 90 degree position, and the corresponding cam high point (411) is vertically upward and contacts the adjustment block (430) of the top block connecting beam. At this time, the top block (42) is located at the highest position, and its upper surface slope is higher than the upper surface slope of the guide block (45).

8. A friction stir additive manufacturing method with adjustable composition and lateral alternating rod feeding, characterized in that: The method comprises the following: Step 1: According to the size of the rod material, the dimensions of the screw (11) and the sleeve (12) are designed to ensure that the rod can pass through the feeding hole (120) into the spiral cavity and be cut into material particles; Step 2: Install the static shoulder bracket (14) onto the mounting ring at the lower end of the mounting plate (50), install the screw (11) onto the dynamic shoulder handle (13), and install the sleeve (12) onto the static shoulder bracket (14). By adjusting the mounting positions of the screw (11) and the sleeve (12), ensure that the two have a certain degree of coaxiality. A certain gap should be maintained between the side wall of the screw (11) and the inner wall of the sleeve (12) to prevent the two from wearing during the rotation process. In addition, the bottom surface of the screw (11) and the bottom surface of the sleeve (12) are in the same plane, and the stirring needle (111) is fully extended. Step 3: Select a suitable rod feeding wheel (23) according to the rod size, install the rod feeding mechanism (2) on the support plate (51), rotate the first spring knob (26) of the first clamping frame (25) to adjust the gap between the upper and lower rod feeding wheels (23) to prevent the rod (10) from slipping during the feeding process; Step 4: Select appropriate conveying wheels (31), pressure wheels (33) and conveyor belts (32) according to the size of the rods, install the conveying mechanism (3) on the support plate (51), adjust the tension of the conveyor belt (32) by adjusting the installation position of the distal conveying wheel (31), rotate the second spring knob (35) of the second clamping frame (34) to adjust the gap between the proximal conveying wheel (31) and the pressure wheel (33), and ensure that the rod (10) can pass through the proximal conveying wheel (31) and the pressure wheel (33) on the conveyor belt (32) and enter between the upper and lower rod feeding wheels (23); Step 5: Install the feeding mechanism (4) onto the support plate (51), design a suitable cam (41) according to the relative positions of the top block (42), the silo bottom plate (470) and the guide block (45), so that the 0° and 90° of the swing cylinder (40) correspond to the low point and the high point of the edge of the cam (41) respectively, and when the top block connecting beam (43) adjusting block (430) contacts the cam low point (410), the upper surface of the top block (42) is located below the silo bottom plate (470), and when the top block connecting beam (43) adjusting block (430) contacts the cam high point (411), the upper surface of the top block (42) is located above the upper surface of the guide block (45); Step 6: Adjust the installation position of the photoelectric sensor (46) so that the laser emitted by the transmitter (461) just passes through the gap between the two conveyor belts (32) and enters the receiver (462); when the receiver (462) is not sensitive to light, the swing cylinder (40) is inflated and swung to 90°, the cam high point (411) contacts the adjustment block (430), and the top block (42) rises; when the receiver (462) is sensitive to light, the swing cylinder (40) is deflated and swung to 0°, the cam low point (410) contacts the adjustment block (430), and the top block (42) descends; adjust the left and right positions of the photoelectric sensor (46) so that the next rod slides onto the conveyor belt (32) through the guide block (45) and connects with the previous rod; Step 7: Connect the mounting plate (50) of the support mechanism (5) to the friction stir welding machine, adjust the mounting position of the support plate (51) of the support mechanism (5) so that it maintains a certain distance and inclination angle with the main shaft of the welding machine, and insert the limiting tube (24) into the feeding hole (120) of the sleeve (12) so that the rod (10) can pass through the material adding mechanism in a straight line after passing through the rod feeding wheel (23) and the limiting tube (24); Step 8: Design the additive path and select the process parameters according to the size and shape of the additive component; install the substrate on the tooling platform and clamp it with a fixture, set the coordinate origin, write the additive program, and prepare for additive manufacturing; Step 9: When performing additive manufacturing, the screw (11) rotates at a high speed, and the bottom stirring needle (111) penetrates into the substrate. After reaching a predetermined depth, the stepper motor (20) is started, and the rod (10) is fed into the rod feeding wheel (23) by the conveyor belt (32), and then continues to be transported into the additive mechanism (1); the rod (10) is sheared and plasticized by the additive mechanism (1), and is continuously extruded from the bottom and deposited on the substrate. At this time, the welding machine is started to feed, and the additive process is carried out stably; Step 10: After the additive mechanism (1) has traversed a layer of the path and needs to proceed to the next layer, the screw (11) and the sleeve (12) are lifted up to a layer height, and then the welding machine continues to feed, and the additive process continues to proceed stably on the previous deposition layer; Step 11: After the additive process is completed, the screw (11) and the sleeve (12) are lifted upwards, and the rod feeding mechanism (2), the transmission mechanism (3) and the feeding mechanism (4) are closed at the same time. The screw (11) is kept rotating for a period of time and then stopped to allow the remaining material in the spiral cavity to be squeezed out, thereby obtaining the additive component.

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