Device and method for realizing friction extrusion additive manufacturing of metal pipe fitting based on stirring consumable rod preheating

Abstract

The invention discloses a device and method for achieving friction extrusion additive manufacturing of metal pipe fittings based on stirring consumable rod preheating, the device comprises a hollow main shaft, a heating sleeve and a hollow inner shaft, the bottom end of the hollow inner shaft is connected with a shaft shoulder, and a circular through hole is formed in the center of the shaft shoulder; a flow dividing type spiral component used for promoting deposited metal to form a pipe fitting structure is arranged in the circular through hole, and a groove used for promoting plasticizing of the consumable rod is formed in the inner wall of the circular through hole of the shaft shoulder. Firstly, the consumable rod is heated to the needed temperature through the heating sleeve, under the driving of the upsetting pressure and the flow dividing type spiral component, the consumable rod gradually enters the round hole of the shaft shoulder in a flow dividing mode, after the round through hole is filled with plasticized metal, the plasticized metal overflows, and under the rotating effect of the shaft shoulder and the stirring effect of the protrusions, the consumable rod is heated to the needed temperature. The plasticized metal gradually fills the gap between the shaft shoulder and the surface of the substrate, and then the device is lifted by the height of the gap for further deposition until the deposited metal forms a tubular member on the surface of the substrate. According to the device disclosed by the invention, a metal tubular component with fine grains and excellent mechanical properties can be formed at any position of a formed part through a material adding method by adopting a mode that the hollow static inner shaft does not rotate, so that the manufacturing process is simplified.

Description

Technical Field

[0001] The present invention belongs to the technical field of friction extrusion additive manufacturing, and in particular relates to a device and method for realizing friction extrusion additive manufacturing of metal pipe fittings by preheating a stirring consumable rod. Background Art

[0002] The friction stir extrusion deposition technology is based on the principle of friction stir welding. It replaces the stirring needle in the friction stir welding stirring head with a solid metal bar. Under the push of the ejector rod, the metal bar is tightly fitted with the surface to be deposited. Under the high-speed rotation driven by the hollow spindle, the metal bar and the surface to be deposited generate heat due to friction, resulting in continuous plasticization of the metal bar. The plasticized metal gradually fills the gap between the lower end face of the spindle and the surface to be deposited. Under the relative rotation of the lower end face of the spindle and the surface to be deposited, the plasticized metal forms an effective metallurgical bond with the surface to be deposited, ultimately achieving the purpose of solid phase deposition.

[0003] Based on the friction stir extrusion deposition technology, a device and method are studied to form a tubular component at any position of the formed part by adding materials, and the hollow static inner shaft no longer rotates, which simplifies the equipment structure and the process of adding materials. Summary of the invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a device and method for friction extrusion additive manufacturing of metal pipe fittings by preheating a stirring consumable rod. The device adopts a hollow stationary inner shaft that does not rotate and can form a metal tubular component with fine grains and excellent mechanical properties at any position of the formed part by an additive method, thereby simplifying the manufacturing process.

[0005] Technical solution: The present invention is a device for friction extrusion additive manufacturing of metal pipe fittings based on stirring consumable rod preheating, comprising a hollow main shaft for accommodating the consumable rod, a heating sleeve for heating the consumable rod, and a hollow inner shaft, which are sequentially sleeved from the inside to the outside, wherein the bottom end of the hollow inner shaft is connected to a shoulder with a circular through hole in the center, and the upper surface of the shoulder is in contact with the bottom end surface of the hollow main shaft;

[0006] A flow-dividing spiral component is arranged in the circular through hole of the shoulder to promote the deposition of metal to form a pipe structure, and a plurality of grooves are arranged on the inner wall of the circular through hole of the shoulder to promote the plasticization of the consumable rod.

[0007] Furthermore, the flow-dividing spiral component used in the device includes a flow-dividing plate connected to the hollow main shaft and a cylindrical rod located at the lower end of the flow-dividing plate and provided with a threaded structure.

[0008] Furthermore, the bottom end surface of the device shoulder is provided with a plurality of protrusions arranged along the circumferential direction.

[0009] Furthermore, the upper end of the hollow inner shaft of the device is connected to the motor by setting a synchronous pulley to drive the hollow inner shaft and the shaft shoulder to rotate.

[0010] Furthermore, the hollow inner shaft of the device is assembled with the hollow outer shaft through a bearing, and a rotating flange is provided on the outer ring of the hollow outer shaft, and the hollow outer shaft is fixed to the external bracket through the rotating flange.

[0011] Furthermore, the hollow outer shaft, the hollow inner shaft, the shaft shoulder and the hollow main shaft of the device have the same rotation center.

[0012] Furthermore, a rotating flange is provided on the hollow main shaft of the device, and the hollow main shaft is fixed to the external bracket through the rotating flange.

[0013] The method for additively manufacturing a metal pipe fitting using the above device of the present invention comprises the following steps:

[0014] (1) Turn on the power to start the heating sleeve, which gradually heats the hollow main shaft to the set temperature, drives the hollow inner shaft and the shaft shoulder to rotate, and feeds the consumable rod into the hollow main shaft. As the feeding progresses, the consumable rod fills the hollow main shaft. When the hollow main shaft heats the consumable rod to the required temperature, the consumable rod is gradually diverted into the circular hole of the shaft shoulder under the driving of the upsetting pressure and the diverting spiral component, and the consumable rod is further plasticized by the cooperation of the thread on the diverting spiral component and the groove on the inner wall of the circular through hole of the shaft shoulder to form plasticized metal;

[0015] (2) After the plasticized metal fills the circular through hole, the plasticized metal overflows, and a gap exists between the bottom end surface of the shoulder and the surface of the fixed substrate. After the plasticized metal overflows, the gap between the shoulder and the surface of the substrate is gradually filled by the rotation of the shoulder and the stirring of the protrusion. The device is then lifted to a height of the gap and further deposited until the deposited metal forms a tubular component on the surface of the substrate.

[0016] Beneficial effects: Compared with the prior art, the significant advantages of the present invention are: the device realizes friction extrusion additive manufacturing of metal pipe fittings by stirring the consumable rod preheating, and can form metal tubular components with fine grains and excellent mechanical properties at any position of the formed parts by the additive method, thereby simplifying the manufacturing process; and the use of a hollow static inner shaft that does not rotate simplifies the equipment structure and simplifies the process of adding materials; in addition, the plasticity of the metal to be deposited is enhanced by the method of preheating the consumable rod, and under the cooperation of the shoulder inner hole and the diverter-type inner hole constraint structure, the plasticization of the consumable rod is further promoted in the form of stirring and spiral extrusion, forming plasticized metal, and forming pressure to push the plastic flowing metal downward, thereby reducing the top forging pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the device of the present invention;

[0018] Figure 2 It is a front view of the device of the present invention;

[0019] Figure 3 A vertical cross-sectional view of the device of the present invention Figure 1 (rendering);

[0020] Figure 4 A vertical cross-sectional view of the device of the present invention Figure 2 (rendering);

[0021] Figure 5 For along Figure 2 Sectional view along AA direction (line drawing). DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings.

[0023] like Figures 1 to 5 As shown, the device for achieving friction extrusion additive manufacturing of metal pipe fittings based on stirring consumable rod preheating of the present invention includes a hollow main shaft 1 for accommodating the consumable rod, and the consumable rod is driven by applying a top forging pressure. A heating sleeve 2 is sleeved on the hollow main shaft 1 to heat the consumable rod. The heating sleeve 2 can adopt a structure known in the art as long as it can achieve heating. A hollow inner shaft 3 is sleeved outside the heating sleeve 2, and the lower end of the hollow inner shaft 3 is fixedly connected to the shoulder 4, and the upper surface of the shoulder 4 is connected to the bottom end face of the hollow main shaft 1. The hollow inner shaft 3 is connected and fixed to the shoulder 4, and then the shoulder 4 is driven to rotate by the rotation of the intermediate inner shaft 3, so that the friction extrusion additive manufacturing of metal pipe fittings can be achieved while keeping the hollow main shaft 1 from rotating.

[0024] The upper end of the hollow inner shaft 3 is connected with a synchronous pulley 9, which is connected to the motor through the synchronous pulley 9, and then driven by the motor to drive the hollow inner shaft 3 and the shaft shoulder 4 to rotate. The hollow inner shaft 3 is assembled with the hollow outer shaft 11 through a bearing 10 below the synchronous pulley 9. The outer ring of the hollow outer shaft 11 is provided with a rotating flange, and the hollow outer shaft 11 is fixed to the external bracket through the rotating flange. The hollow main shaft 1 is provided with a rotating flange, and the hollow main shaft 1 is fixed to the external bracket through the rotating flange. The entire device can be lifted or lowered with the help of the external bracket.

[0025] A circular through hole is provided at the center of the shaft shoulder 4, and a flow-dividing inner hole constraint structure is provided in the circular through hole, that is, a flow-dividing spiral component to promote the deposition of metal to form a pipe structure. The separate spiral component includes a cylindrical rod 7 connected to the hollow main shaft 1 through a flow-dividing plate 6, and a threaded structure is provided on the cylindrical rod 7. A plurality of grooves 5 are provided on the inner wall of the circular through hole of the shaft shoulder 4, and the plurality of grooves 5 are arranged circumferentially along the inner wall of the circular through hole. The cylindrical rod 7 with a threaded structure is combined with the grooves 5. Under the rotation of the shaft shoulder 4, not only the consumable rod is further plasticized, but also a downward pushing pressure can be generated on the plastically flowing metal to reduce the top forging pressure.

[0026] The bottom end of the shoulder 4 is provided with a plurality of protrusions 8, which are preferably arranged along the circumference of the shoulder 4. Under the rotation of the shoulder 4 and the stirring of the protrusions 8, the plasticized metal can gradually fill the gap between the shoulder 4 and the substrate surface and form an effective metallurgical bond with the substrate. The cylindrical rod 7 of the split-flow spiral component extends to the lower end of the shoulder 4 and is flush with the bottom end of the protrusion 8, so that the deposited metal can be annular under the split-flow inner hole constraint structure, and multiple annular deposited metals are gradually superimposed to form a tubular component.

[0027] The hollow outer shaft 11, the hollow inner shaft 3, the shaft shoulder 4 and the hollow main shaft 1 of the present invention have the same rotation center.

[0028] The method for additive manufacturing based on the above device of the present invention comprises the following steps:

[0029] (1) The heating sleeve 2 is powered on and started. The heating sleeve 2 gradually heats the hollow spindle 1 to a set temperature, drives the hollow inner shaft 3 to rotate, and feeds multiple sections of consumable rods into the hollow spindle 1. As the feeding progresses, the consumable rods fill the hollow spindle 1. When the hollow spindle 1 heats the consumable rods to a required temperature, the consumable rods gradually enter the circular through hole of the shaft shoulder 4 under the driving of the upsetting pressure. Under the action of the groove 5 on the inner wall of the circular through hole and the thread on the diverter spiral component, the consumable rods are further plasticized to form plasticized metal. After the plasticized metal fills the circular through hole, the plasticized metal overflows.

[0030] (2) There is a certain gap between the bottom end face of the shoulder 4 and the surface of the fixed substrate, and the gap is less than 1 / 5 of the diameter of the bottom end face of the shoulder. After the plasticized metal overflows, under the rotation of the shoulder 4 and the stirring action of the protrusion 8, the plasticized metal gradually fills the gap between the shoulder and the surface of the substrate. Then the device is lifted to a height of the gap and further deposited until the deposited metal forms a tubular component on the surface of the substrate.

Claims

1. A device for friction extrusion additive manufacturing of metal pipes based on preheating of stirring consumable rods, characterized in that: The device comprises a hollow main shaft (1) for accommodating a consumable rod, a heating sleeve (2) for heating the consumable rod, and a hollow inner shaft (3) which are sequentially sleeved from the inside to the outside, wherein the bottom end of the hollow inner shaft (3) is connected to a shaft shoulder (4) with a circular through hole in the center, and the upper surface of the shaft shoulder (4) is in contact with the bottom end surface of the hollow main shaft (1); A split-flow spiral component is provided in the circular through hole of the shoulder (4) to promote the deposition of metal to form a pipe structure, and a plurality of grooves (5) are provided on the inner wall of the circular through hole of the shoulder to promote the plasticization of the consumable rod.

2. The device for realizing friction extrusion additive manufacturing of metal pipe fittings based on preheating of stirring consumable rods according to claim 1, characterized in that: The flow-dividing spiral component comprises a flow-dividing plate (6) connected to a hollow main shaft (1) and a cylindrical rod (7) located at the lower end of the flow-dividing plate (6) and provided with a threaded structure.

3. The device for realizing friction extrusion additive manufacturing of metal pipe fittings based on preheating of stirring consumable rods according to claim 2, characterized in that: The bottom end surface of the shaft shoulder (4) is provided with a plurality of protrusions (8) arranged along the circumferential direction.

4. The device for realizing friction extrusion additive manufacturing of metal pipes based on preheating of stirring consumable rods according to claim 3, characterized in that: The cylindrical rod (7) passes through the circular through hole of the shaft shoulder (4), and the bottom end of the cylindrical rod (7) is flush with the bottom end of the protrusion (8).

5. The device for friction extrusion additive manufacturing of metal pipes based on preheating of stirring consumable rods according to claim 1, characterized in that: The upper end of the hollow inner shaft (3) is connected to a motor by means of a synchronous pulley (9) to drive the hollow inner shaft (3) and the shaft shoulder (4) to rotate.

6. The device for realizing friction extrusion additive manufacturing of metal pipes based on preheating of stirring consumable rods according to claim 1, characterized in that: The hollow inner shaft (3) is assembled with the hollow outer shaft (11) via a bearing (10); a rotating flange is provided on the outer ring of the hollow outer shaft (11); and the hollow outer shaft (11) is fixed to an external bracket via the rotating flange.

7. The device for friction extrusion additive manufacturing of metal pipes based on preheating of stirring consumable rods according to claim 6, characterized in that: The hollow outer shaft (11), the hollow inner shaft (3), the shaft shoulder (4) and the hollow main shaft (1) have the same rotation center.

8. The device for realizing friction extrusion additive manufacturing of metal pipes based on preheating of stirring consumable rods according to claim 1, characterized in that: The hollow main shaft (1) is provided with a rotation flange, and the hollow main shaft (1) is fixed to the external bracket via the rotation flange.

9. A method for additive manufacturing of metal pipes using the device of claim 1, characterized in that: The steps include: (1) Turn on the power to start the heating sleeve (2), the heating sleeve (2) gradually heats the hollow main shaft (1) to a set temperature, drives the hollow inner shaft (3) and the shaft shoulder (4) to rotate, and feeds the consumable rod into the hollow main shaft (1). As the feeding progresses, the consumable rod fills the hollow main shaft (1). When the hollow main shaft (1) heats the consumable rod to a required temperature, the consumable rod is gradually diverted into the circular hole of the shaft shoulder (4) under the driving force of the top forging pressure and the diverting spiral component, and the consumable rod is further plasticized through the cooperation of the thread on the diverting spiral component and the groove on the inner wall of the circular through hole of the shaft shoulder (4) to form a plasticized metal; (2) After the plasticized metal fills the circular through hole, the plasticized metal overflows, and a gap exists between the bottom end surface of the shoulder (4) and the surface of the fixed substrate. After the plasticized metal overflows, the gap between the shoulder (4) and the surface of the substrate is gradually filled by the rotation of the shoulder (4) and the stirring of the protrusion (8). The device is then lifted to a height of the gap and further deposited until the deposited metal forms a tubular component on the surface of the substrate.

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