Coaxial powder feeding device for multi-element metal powder

Abstract

The invention discloses a multi-element metal powder coaxial feeding device which comprises a spraying pipe, a spraying head is arranged at the front end of the spraying pipe, the center of the spraying pipe is connected with a laser generator, laser generated by the laser generator penetrates through a central pipe to be emitted downwards, a laser outlet is formed in the front end of the spraying head, and powder spraying outlets are formed in the periphery of the spraying head. A shielding gas injection opening is formed around the powder injection opening and inclines inwards to form a convergent point, the convergent point converges in front of the spray head and is located in the laser injection center, and shielding gas sprayed out of the shielding gas injection opening forms rotating gas flow. The multi-element metal powder coaxial feeding device provided by the invention can gather powder to a welding position in a more focused manner, so that a better laser welding effect is achieved, and fewer materials are used.

Description

Technical Field

[0001] The invention relates to a nozzle mechanism of a 3D printing device, and in particular to a coaxial powder feeding device for multi-element metal powders. Background Art

[0002] The invention patent publication with announcement number CN107052339A discloses a coaxial powder feeding device for 3D printing metal workpieces, including: a lens assembly, including a lens holder and a lens mounted on the lens holder; a powder feeding assembly arranged below the lens assembly, the powder feeding assembly including, from top to bottom, a vertically arranged cylinder assembly, a first arc assembly connected to the cylinder assembly, and a first cone assembly connected to the first arc assembly; the shape of the first arc assembly is a shape that transitions from an inner arc to an outer arc; a cooling water chamber assembly is arranged outside the powder feeding assembly. Compared with the prior art, the coaxial powder feeding device provided by the present invention is provided with an arc assembly in the upper part of the cone assembly, the shape of which is a shape that transitions from an inner arc to an outer arc, and the powder passes through the arc assembly and then enters the first cone assembly, which can make the metal powder more gently transition from vertical motion to conical focusing motion during the conveying process, thereby achieving a more stable and uniform powder feeding effect and improving the workpiece forming quality.

[0003] However, the airflow of the above coaxial powder feeding device is a straight jet, which has no convergence effect, and the powder contained therein is easily dispersed and wasted. Therefore, it is necessary to provide a coaxial powder feeding device with better convergence effect and higher powder utilization rate. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a coaxial powder feeding device for multi-element metal powders, which has a better powder material gathering effect.

[0005] To this end, the present invention provides a coaxial powder feeding device for multi-element metal powders, including a jet tube, a nozzle at the front end of the jet tube, a laser generator connected to the center of the jet tube, the laser generated by the laser generator passes through the center tube and shoots downward, the front end of the nozzle is provided with a laser outlet, the nozzle is provided with a powder outlet around the nozzle, and a protective gas nozzle is provided around the powder outlet. The protective gas nozzle is inclined inward to form a convergence point, the convergence point converges in front of the nozzle and is at the center of laser emission, and the protective gas ejected from the protective gas nozzle forms a rotating airflow.

[0006] Preferably, the shielding gas injection port is rotatably connected to the nozzle, and an obliquely distributed airflow channel is provided at the shielding gas injection port outlet, and the reverse thrust forces the shielding gas injection port to rotate when the high-speed shielding gas is ejected.

[0007] Preferably, the air flow channels are distributed in an arc shape in the same direction.

[0008] Preferably, the protective gas injection port is rotatably sleeved on the outside of the nozzle, and the protective gas injection port and the outside of the nozzle body are surrounded to form an air cavity, and the nozzle body is provided with an air inlet channel and a gas filling port communicated with the air cavity.

[0009] Preferably, the protective gas injection port is sleeved with the nozzle housing, and the sleeved area has a ball fitting belt and an oil seal belt.

[0010] Preferably, the nozzle includes an upper nozzle and a lower nozzle, the upper nozzle is socketed with the lower nozzle, the shielding gas injection port is installed on the lower nozzle, and the lower nozzle is provided with a hydraulic lifting mechanism, which drives the lower nozzle to move up and down relative to the upper nozzle, and the welding accuracy is controlled by controlling the distance between the shielding gas injection port and the welding part.

[0011] Preferably, the upper nozzle has a plurality of axially distributed slide grooves on its outer wall, and the lower nozzle has a plurality of convex strips on its inner wall, which are embedded in the slide grooves. The hydraulic lifting mechanism is arranged on both sides of the upper nozzle, and the telescopic rod of the hydraulic lifting mechanism is connected to the side protrusions on both sides of the lower nozzle. The hydraulic lifting mechanism lifts and drives the lower nozzle to move up and down.

[0012] Technical effects of the present invention:

[0013] 1. The powder injection convergence point of the multi-element metal powder coaxial powder feeding device provided by the present invention converges in front of the nozzle and is at the center of laser emission. The shielding gas ejected from the shielding gas injection port forms a rotating airflow. Therefore, the powder injected by the rotating airflow will not be blown away, but will be concentrated at the convergence point of the rotating airflow. Moreover, since the convergence point is in front of the nozzle and at the center of laser emission, the converged powder will be efficiently used for laser welding or 3D printing, the powder application efficiency is higher, and the welding or printing effect is better.

[0014] 2. The lower nozzle of the coaxial powder feeding device for multi-element metal powder provided by the present invention can move up and down relative to the upper nozzle, which can achieve better powder convergence and control the area of ​​powder printing and solidification. For example, when the lower nozzle moves downward, the distance from the powder to the welding point is shorter, which has a better convergence effect. At the same time, the convergence point of the airflow also moves downward during the downward movement of the lower nozzle. Therefore, the area of ​​the convergence center formed by the airflow ejected by the lower nozzle can be increased, and the welding or printing area can be controlled to increase, which is conducive to more flexible control of the printing effect and printing method. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic cross-sectional view of the structure of the coaxial powder feeding device for multi-element metal powders provided by the present invention.

[0016] Figure 2 for Figure 1 A schematic plan view of the local structure of the inner wall of the protective gas injection port after being flattened.

[0017] Figure 3 for Figure 1 Schematic diagram of the split structure.

[0018] Figure 4 for Figure 1 A schematic cross-sectional view of the structure of the coaxial powder feeding device for multi-element metal powders after the lower nozzle moves downward relative to the upper nozzle. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0020] Refer to the attached Figure 1-4 As shown, the coaxial powder feeding device of multi-element metal powder provided by the present invention includes a jet tube, a nozzle 1 is provided at the front end of the jet tube, a laser generator 2 is connected to the center of the jet tube, the laser generated by the laser generator 2 passes through the center tube and shoots downward, the front end of the nozzle 1 is provided with a laser outlet 3, the nozzle 1 is provided with a powder outlet 4, and the powder outlet 4 is provided with a protective gas jet 5, the protective gas jet 5 is tilted inward to form a convergence point, the convergence point converges in front of the nozzle and is at the center of the laser emission, and the protective gas ejected from the protective gas jet 5 forms a rotating airflow. The protective gas jet 5 is rotatably connected to the nozzle 1, and an obliquely distributed airflow channel 6 is provided at the outlet of the protective gas jet 5. When the high-speed protective gas is ejected, the reverse thrust causes the protective gas jet 5 to rotate. In this embodiment, the airflow channel 6 is distributed in the same arc direction. The powder injection convergence point of the multi-metal powder coaxial powder feeding device provided by the present invention converges in front of the nozzle and is at the center of laser emission. The shielding gas ejected from the shielding gas injection port 5 forms a rotating airflow. Therefore, the powder injected by the rotating airflow is not easily blown away, but is concentrated at the convergence point of the rotating airflow. Moreover, since the convergence point is in front of the nozzle 1 and at the center of laser emission, the powder formed by the convergence can be efficiently used for laser welding or 3D printing, the powder application efficiency is higher, and the welding or printing effect is better.

[0021] Reference Figure 1-3 As shown, in order to improve the rotation effect and sealing performance, the protective gas injection port 5 is rotatably sleeved on the outside of the nozzle 1, and the protective gas injection port 5 and the outside of the nozzle 1 body are surrounded to form an air cavity 7, and the nozzle 1 body is provided with an air inlet channel 71 and a gas filling port 72 that are connected to the air cavity 7. The protective gas injection port 5 is sleeved with the outer shell of the nozzle 1, and the sleeve area has a ball matching belt and an oil seal belt.

[0022] Reference Figure 1 , 3As shown in , 4, in order to improve controllability, the nozzle 1 includes an upper nozzle 11 and a lower nozzle 12, the upper nozzle 11 is sleeved with the lower nozzle 12, the shielding gas injection port 5 is installed on the lower nozzle 12, and the lower nozzle 12 is equipped with a hydraulic lifting mechanism 8, the hydraulic lifting mechanism 8 drives the lower nozzle 12 to move up and down relative to the upper nozzle 11, and the welding accuracy is controlled by controlling the distance between the shielding gas injection port 5 and the welding part. The outer wall of the upper nozzle 11 has multiple axially distributed slide grooves, the inner wall of the lower nozzle has multiple convex strips, and the convex strips are embedded in the slide grooves. The hydraulic lifting mechanism 8 is arranged on both sides of the upper nozzle 11, and the telescopic rod of the hydraulic lifting mechanism 8 is connected to the side convex blocks 81 on both sides of the lower nozzle 12. The hydraulic lifting mechanism 8 drives the lower nozzle 12 to move up and down. The lower nozzle 12 of the coaxial powder feeding device for multi-metal powder provided by the present invention can move up and down relative to the upper nozzle 11, so as to achieve better powder convergence and control the area of ​​powder printing and solidification. For example, when the lower nozzle 12 moves downward, the distance from the powder to the welding point is shorter, which has a better convergence effect. At the same time, the convergence point of the airflow also moves downward during the downward movement of the lower nozzle 12. Therefore, the area of ​​the convergence center formed by the airflow ejected by the lower nozzle can be increased, and the welding or printing area can be controlled to increase, which is conducive to more flexible control of the printing effect and printing method.

[0023] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A coaxial powder feeding device for multi-element metal powders, comprising a spray tube, a nozzle at the front end of the spray tube, a laser generator connected to the center of the spray tube, the laser generated by the laser generator passes through the center tube and lases downward, the front end of the nozzle is provided with a laser outlet, the nozzle is provided with a powder outlet around the nozzle, and a protective gas injection port is provided around the powder outlet, wherein: The shielding gas injection port is tilted inward to form a convergence point, which converges in front of the nozzle and is located at the laser emission center. The shielding gas ejected from the shielding gas injection port forms a rotating airflow.

2. The coaxial powder feeding device for multi-element metal powder according to claim 1 is characterized in that: The protective gas injection port is rotatably connected to the nozzle, and an obliquely distributed airflow channel is arranged at the outlet of the protective gas injection port. When the high-speed protective gas is sprayed out, the reverse thrust forces the protective gas injection port to rotate.

3. The coaxial powder feeding device for multi-element metal powder according to claim 2 is characterized in that: The air flow channels are distributed in the same arc shape.

4. The coaxial powder feeding device for multi-element metal powder according to claim 2 or 3, characterized in that: The protective gas injection port is rotatably sleeved on the outside of the nozzle, and the protective gas injection port and the outside of the nozzle body are surrounded to form an air cavity. The nozzle body is provided with an air inlet channel and a gas filling port communicated with the air cavity.

5. The coaxial powder feeding device for multi-element metal powders according to claim 4 is characterized in that: The protective gas injection port is sleeved with the nozzle shell, and the sleeved area is provided with a ball matching belt and an oil seal belt.

6. The coaxial powder feeding device for multi-element metal powder according to claim 2 or 3, characterized in that: The nozzle includes an upper nozzle and a lower nozzle. The upper nozzle is sleeved with the lower nozzle. The shielding gas injection port is installed on the lower nozzle. The lower nozzle is provided with a hydraulic lifting mechanism. The hydraulic lifting mechanism drives the lower nozzle to move up and down relative to the upper nozzle. The welding accuracy is controlled by controlling the distance between the shielding gas injection port and the welding part.

7. The coaxial powder feeding device for multi-element metal powders according to claim 5 is characterized in that: The nozzle includes an upper nozzle and a lower nozzle. The upper nozzle is sleeved with the lower nozzle. The shielding gas injection port is installed on the lower nozzle. The lower nozzle is provided with a hydraulic lifting mechanism. The hydraulic lifting mechanism drives the lower nozzle to move up and down relative to the upper nozzle. The welding accuracy is controlled by controlling the distance between the shielding gas injection port and the welding part.

8. The coaxial powder feeding device for multi-element metal powders according to claim 6 is characterized in that: The outer wall of the upper nozzle has multiple axially distributed slide grooves, the inner wall of the lower nozzle has multiple convex strips, the convex strips are embedded in the slide grooves, the hydraulic lifting mechanism is arranged on both sides of the upper nozzle, the telescopic rod of the hydraulic lifting mechanism is connected to the side protrusions on both sides of the lower nozzle, and the hydraulic lifting mechanism lifts and drives the lower nozzle to move up and down. The multi-element metal powder coaxial powder feeding device according to claim 7 is characterized in that: The outer wall of the upper nozzle has multiple axially distributed slide grooves, the inner wall of the lower nozzle has multiple convex strips, the convex strips are embedded in the slide grooves, the hydraulic lifting mechanism is arranged on both sides of the upper nozzle, the telescopic rod of the hydraulic lifting mechanism is connected to the side protrusions on both sides of the lower nozzle, and the hydraulic lifting mechanism lifts and drives the lower nozzle to move up and down.

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