Water-cooled integrated stir head for friction stir additive manufacturing

Abstract

The application discloses a water-cooling and gas-supply integrated stirring head for frictional additive manufacturing, which comprises a rotating stirring head and a cooling jacket, the rotating stirring head is provided with a feeding channel, and the lower end of the rotating stirring head is coaxially and integrally connected with a stirring disc; the rotating stirring head is driven to rotate by a rotating driving device; the cooling jacket is rotatably sleeved on the rotating stirring head; fixed connecting seats are integrally arranged on the two sides of the cooling jacket, and the fixed connecting seats are fixed on a displacement support; the inner rings of the upper end and the lower end of the cooling jacket are respectively in rotatable sealing cooperation with the outer wall surface of the rotating stirring head through an upper sealing ring and a lower sealing ring, and an annular water cooling groove is formed between the upper sealing ring and the lower sealing ring of the cooling jacket; the part of the rotating stirring head penetrating through the cooling jacket is soaked in the liquid in the annular water cooling groove, and the protective gas flow is adaptively matched under the low-speed and high-speed working conditions of the same stirring head.

Description

Technical Field

[0001] This invention belongs to the field of triboelectric additive manufacturing. Background Technology

[0002] Friction stir additive manufacturing relies on the frictional heat and intense plastic deformation between the stirring head and the material to achieve material deposition and shaping. During this process, the stirring head needs to withstand high temperatures and mechanical loads for a long time. If heat dissipation is insufficient, the stirring head material will soften, wear will accelerate, or even fail, thus affecting the forming quality and equipment life.

[0003] Meanwhile, to prevent oxidation of the deposition area at high temperatures, an effective inert gas protective atmosphere must be formed around the stirring zone. Existing stirring heads typically separate the cooling and gas supply structures, resulting in limited cooling efficiency and a bulky structure.

[0004] In terms of gas protection, a common practice is to use the centrifugal force generated by the rotation of the stirring head to throw inert gas outward to form a gas curtain. However, when the stirring head speed changes, especially during the switch from low speed to high speed, the centrifugal force increases significantly, and the gas is ejected at high speed to a position far away from the deposition zone. This causes a sharp drop in the local concentration of protective gas, severely weakening the protective effect. This makes it difficult for a single-structure stirring head to simultaneously meet the stability requirements of the protective atmosphere under both low-speed and high-speed operating conditions. Summary of the Invention

[0005] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the present invention provides a water-cooled air supply integrated stirring head manufactured by friction stirring additive manufacturing, which realizes the adaptive matching of protective airflow under low-speed and high-speed operating conditions of the same stirring head.

[0006] Technical Solution: To achieve the above objectives, the present invention provides a water-cooled, air-supply integrated stirring head manufactured by friction stirring additive manufacturing, characterized in that: it includes a rotating stirring head and a cooling sleeve; the rotating stirring head is hollow, forming a through feeding channel; the lower end of the rotating stirring head is coaxially and integrally connected to a stirring disc; it also includes a rotary drive device capable of driving the rotating stirring head to rotate; the cooling sleeve is rotatably fitted onto the outside of the rotating stirring head; fixed connecting seats are integrally provided on both sides of the cooling sleeve, and the fixed connecting seats are fixed on displacement supports; the inner rings of the upper and lower ends of the cooling sleeve are respectively rotary sealed with the outer wall surface of the rotating stirring head through an upper sealing ring and a lower sealing ring, forming an annular water-cooling groove between the upper sealing ring and the lower sealing ring of the cooling sleeve; the portion of the rotating stirring head passing through the cooling sleeve is immersed in the liquid in the annular water-cooling groove.

[0007] Furthermore, the cooling jacket has radially arranged inlet and outlet water channels that connect to the two sides of the annular water-cooling tank, respectively; the external water supply pipe and return pipe connect to the inlet and outlet water channels, respectively.

[0008] Furthermore, the upper end of the cooling jacket has several inert gas inlet holes arranged in a circumferential array for connecting to an external inert gas supply pipe. The lower end of each inert gas inlet hole passes through a coaxial air hole channel from the lower end face of the cooling jacket.

[0009] Furthermore, the pore channels are expansion channels that gradually increase in diameter downwards from the inner radial direction.

[0010] Furthermore, the upper end of the mixing plate is integrally provided with an externally threaded stepped annular wall near the edge;

[0011] Within the enclosure of the external threaded stepped annular wall is an annular centrifugal blade groove, in which several swirling centrifugal drive blades extending radially are arranged in a circumferential array; it also includes an inert gas overflow ring, the inner thread of which is coaxially threaded to the outside of the external threaded stepped annular wall, and in the threaded state, the upper end face of the inert gas overflow ring is higher than the upper end face of the external threaded stepped annular wall, and the upper end face of the inert gas overflow ring is clearance-fitted with the lower end face of the cooling jacket; the part of the upper end of the inert gas overflow ring that is higher than the external threaded stepped annular wall has several obliquely downward inert gas overflow ports arranged in a circumferential array.

[0012] Furthermore, an annular centrifugal airflow shield plate is coaxially fitted to the lower surface of the cooling jacket. The annular centrifugal airflow shield plate has several perforations, each of which corresponds to the lower end of an air vent channel. Vertical expansion joints are fixedly installed in several vertical expansion joint installation channels inside the cooling jacket, and the vertical expansion joints can drive the centrifugal airflow shield plate to move up and down. The outer diameter of the centrifugal airflow shield plate is between the inner diameter of the external threaded stepped ring wall and the inner diameter of the inert gas overflow ring. A disc-shaped centrifugal air chamber is formed between the centrifugal airflow shield plate and the stirring plate. The outer periphery of the centrifugal air chamber is connected to the outside through the inert gas overflow port.

[0013] Furthermore, during high-speed rotation, the vertical expansion joint drives the centrifugal airflow shield plate to move downwards, thereby separating the centrifugal airflow shield plate from the cooling jacket. This continues until the centrifugal airflow shield plate descends to a point where its lower surface is close to but does not contact the upper end face of the external threaded stepped annular wall. The centrifugal airflow shield plate divides the original centrifugal chamber into upper and lower parts. The four edges of the annular space located on the upper side of the centrifugal airflow shield plate are connected to the inert gas overflow ports; the lower ends of each air passage are connected to the annular space located on the upper side of the centrifugal airflow shield plate; while the high-speed centrifugal vortex generated by the annular space where the centrifugal driving blades are located on the lower side of the centrifugal airflow shield plate is... The centrifugal airflow shield is isolated and shielded, so that the high-speed swirling flow generated by the centrifugal drive blades cannot be transmitted to the annular space on the upper side of the centrifugal airflow shield. Because the edge of the annular space on the upper side of the centrifugal airflow shield will still rotate with the high-speed rotating inert gas overflow ring under the gas viscosity effect, a relatively low intensity of swirling flow and centrifugal force can still be formed in the annular space on the upper side of the centrifugal airflow shield and in each inert gas overflow port. The argon gas entering the annular space on the upper side of the centrifugal airflow shield is driven by the relatively low intensity of swirling centrifugal force and overflows centrifugally in a rotating form through each inert gas overflow port.

[0014] Beneficial effects: The present invention uses an annular water-cooled tank structure constructed between the cooling jacket and the rotating stirring head to allow the rotating inner core to be directly immersed in the flowing coolant, thereby achieving efficient forced heat exchange in the main heat-generating section of the stirring head.

[0015] At low speeds, the controlled centrifugal force generated by the swirling centrifugal drive blades gently covers the deposition area with inert gas in the form of a rotating air curtain. A liftable centrifugal airflow shield is introduced between the cooling jacket and the stirring plate. When the stirring head enters high-speed rotation mode, the vertical expansion joint drives the shield to descend to near the upper end face of the external threaded stepped ring wall, dividing the original centrifugal gas chamber into upper and lower parts. This physically shields the high-speed centrifugal swirling flow generated by the blades in the lower area, preventing it from being transmitted upwards to the gas supply and overflow channels. The gas in the upper chamber of the shield relies solely on the viscosity of the inert gas overflow ring to form a weak swirling flow, generating limited centrifugal force. This allows the inert gas to still rotate and overflow from the downward-sloping overflow port at a suitable speed, forming a stable local protective gas close to the deposition area. This achieves adaptive matching of the protective airflow under low-speed and high-speed conditions for the same stirring head. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall plan.

[0017] Figure 2 This is a sectional view of the scheme.

[0018] Figure 3 This is a breakdown diagram of the solution.

[0019] Figure 4 for Figure 3 A sectional view.

[0020] Figure 5 This is a cross-sectional view of the cooling jacket.

[0021] Figure 6 This is a schematic diagram showing two states of annular centrifugal airflow shielding plate.

[0022] In the diagram: 1-Inert gas inlet; 2-Cooling jacket; 3-Perforated hole; 4-Vertical expansion joint; 5-Centrifugal airflow shield; 6-Internal thread of the ring sleeve; 7-Inert gas overflow port; 8-Inert gas overflow ring sleeve; 9-Swirl centrifugal drive blade; 10-Rotating stirring head; 11-Annular centrifugal blade groove; 12-Externally threaded stepped ring wall; 13-Stirring plate; 14-Annular water cooling tank; 15-Upper sealing ring; 16-Lower sealing ring; 17-Water inlet channel; 18-Water outlet channel; 19-Fixed connecting seat; 20-Gas passage; 21-Centrifugal gas chamber; 32-Vertical expansion joint installation channel. Detailed Implementation

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] like Figures 1 to 6 The water-cooled, air-supply integrated stirring head for friction stir additive manufacturing shown includes a rotary stirring head 10 and a cooling jacket 2. The rotary stirring head 10 is hollow, with a feeding channel running through its internal elongation direction. The feeding channel is used to continuously transport the bar stock or powder required for additive manufacturing from above the stirring head to the stirring area, ensuring a stable supply of materials in a sealed environment. The lower end of the rotary stirring head 10 is coaxially and integrally connected to the stirring disc 13. It also includes a rotary drive device that can drive the rotary stirring head 10 to rotate. The rotary drive device includes a servo motor, a reducer, and a coupling, which can precisely control the speed and torque of the rotary stirring head 10 according to the additive manufacturing process requirements.

[0025] The cooling jacket 2 is rotatably fitted onto the outside of the rotary stirring head 10; fixed connecting seats 19 are integrally provided on both sides of the cooling jacket 2, and the fixed connecting seats 19 are locked and fixed to the displacement support by bolts; the inner rings of the upper and lower ends of the cooling jacket 2 are respectively rotated and sealed with the outer wall surface of the rotary stirring head 10 through the upper sealing ring 15 and the lower sealing ring 16. The upper sealing ring 15 and the lower sealing ring 16 are both high temperature resistant and low friction coefficient polytetrafluoroethylene composite sealing rings, which can maintain reliable sealing performance under high speed rotation and continuous high temperature conditions.

[0026] An annular water-cooling groove 14 is formed between the upper sealing ring 15 and the lower sealing ring 16 of the cooling jacket 2; the part of the rotating stirring head 10 that passes through the cooling jacket 2 is immersed in the liquid in the annular water-cooling groove 14; the annular water-cooling groove 14 has sufficient width along the axial direction to cover the main heat-generating section of the rotating stirring head 10, ensuring that the heat generated inside the stirring head due to friction and plastic deformation is efficiently removed.

[0027] The cooling jacket 2 has radially arranged water inlet channels 17 and water outlet channels 18 that connect to the two sides of the annular water cooling tank 14 respectively; the external water supply pipe and return pipe connect to the water inlet channel 17 and water outlet channel 18 respectively; the water inlet channel 17 and water outlet channel 18 are connected to the external circulating cooling unit through quick-connect couplings. The cooling medium is deionized water or special coolant, and the external cooling system has flow regulation and temperature monitoring functions, and can automatically adjust the coolant flow rate according to the real-time temperature feedback of the stirring head.

[0028] The upper end of the cooling jacket 2 has several inert gas inlet holes 1 arranged in a circumferential array for connecting to an external inert gas supply pipe. The lower end of each inert gas inlet hole 1 passes through a coaxial air hole channel 20 from the lower end face of the cooling jacket 2. The air hole channel 20 is an expanding channel that gradually increases in diameter downwards in the inner radial direction. The design of the expanding channel causes the inert gas flowing through it to gradually decrease in velocity, restore static pressure and tend to be evenly distributed, so that it enters the subsequent chamber in a stable flow state.

[0029] The upper end of the mixing plate 13 is coaxially and integrally provided with an external threaded stepped ring wall 12 near the edge; the thread of the external threaded stepped ring wall 12 is a fine thread and is coated with a high temperature resistant anti-seize coating, so as to facilitate repeated disassembly and maintenance with the inert gas overflow ring 8 and ensure that it can still be easily turned after high temperature cycling.

[0030] Within the enclosure of the external threaded stepped annular wall 12 is an annular centrifugal blade groove 11, in which several swirling centrifugal drive blades 9 extending radially are distributed in a circular array.

[0031] It also includes an inert gas overflow ring 8, the inner ring of which has an internal thread 6. The internal thread of the inert gas overflow ring 8 is coaxially threaded to the outer thread stepped ring wall 12. When the thread is tightened, the upper end face of the inert gas overflow ring 8 is higher than the upper end face of the outer thread stepped ring wall 12, and the upper end face of the inert gas overflow ring 8 is in clearance fit with the lower end face of the cooling jacket 2. The clearance is controlled within the range of 0.2mm to 0.5mm to prevent mechanical interference during high-speed rotation. The clearance forms an air seal effect to help prevent external air from being entrained. The part of the upper end of the inert gas overflow ring 8 that is higher than the outer thread stepped ring wall 12 has several obliquely downward inert gas overflow ports 7 arranged in a circumferential array.

[0032] A ring-shaped centrifugal airflow shield plate 5 is coaxially fitted on the lower surface of the cooling jacket 2. The ring-shaped centrifugal airflow shield plate 5 has several perforated holes 3, and each perforated hole 3 is connected to the lower end of an air vent channel 20. Vertical expansion joints 4 are fixedly installed in several vertical expansion joint installation channels 32 inside the cooling jacket 2. The vertical expansion joints 4 can drive the centrifugal airflow shield plate 5 to move up and down. The vertical expansion joints 4 are miniature electric push rods. The control system receives the speed signal and triggers the lifting action, thereby realizing the function of automatically switching the shielding mode according to the speed of the stirring head.

[0033] The outer diameter of the centrifugal airflow shield 5 is between the inner diameter of the external threaded stepped annular wall 12 and the inner diameter of the inert gas overflow ring 8; this allows the centrifugal airflow shield 5 to maintain a small gap with the inner wall of the inert gas overflow ring 8 when it descends to the working position, avoiding mechanical contact wear and forming an effective flow channel isolation; a disc-shaped centrifugal gas chamber 21 is formed between the centrifugal airflow shield 5 and the stirring plate 13; the outer periphery of the disc-shaped centrifugal gas chamber 21 is connected to the outside through the inert gas overflow port 7.

[0034] Working principle:

[0035] During operation, cooling water flows continuously through the annular water-cooling tank 14, thereby providing real-time and efficient cooling to the rotating stirring head 10. The coolant forms a circulating flow within the annular water-cooling tank 14, resulting in forced convection heat exchange with the outer wall of the high-speed rotating stirring head 10. This helps control the temperature below the material softening temperature, preventing overheating that could lead to a decrease in the strength of the stirring head material or premature softening and blockage of the material in the feeding channel. Simultaneously, each air vent 20 continuously supplies inert gases such as argon to the disc-shaped centrifugal gas chamber 21 through the connected perforated holes 3. Subsequently, the argon gas entering the disc-shaped centrifugal gas chamber 21 overflows outward through the inert gas overflow port 7 at the edge.

[0036] Depending on the processing material or the working scenario, the rotary stirring head 10 and the stirring plate 13 can be in two states: low-speed rotation and high-speed rotation. For example, the low-speed rotation mode is used when processing low-melting-point materials such as aluminum alloys or in scenarios where the protective atmosphere is required, while the high-speed rotation mode is used when processing steel or titanium alloys, which require high stirring heat input.

[0037] During low-speed rotation, the argon gas entering the centrifugal gas chamber 21 is driven by the centrifugal drive blades 9 to form a swirling flow that rotates synchronously with the rotating stirring head 10 at a low speed. The swirling argon gas at the edge of the disc-shaped centrifugal gas chamber 21 overflows outward in a rotating manner through each inert gas overflow port 7 under the action of low-speed centrifugal force. The overflowing argon gas forms a local argon gas protective layer around the stirring plate 13 and in the deposition area. Under low-speed rotation, the gas swirling centrifugal force is moderate, and the gas jet velocity is well matched with the distance to the deposition area. The protective gas layer can adhere tightly to the surface of the deposition layer, effectively dissipating ambient air and preventing oxidation of the additive layer.

[0038] During high-speed rotation, if the original state is maintained, the argon gas entering the centrifugal gas chamber 21 will form a high-speed swirling flow that rotates synchronously with the rotating stirring head 10 under the drive of the swirling centrifugal drive blades 9. The swirling argon gas at the edge of the disc-shaped centrifugal gas chamber 21, under the action of high-speed swirling centrifugal force, will be ejected at high speed to a more distant location through each inert gas overflow port 7 in a rotating form. This causes the ejected argon gas to diffuse significantly outward around the stirring disc 13, making it difficult to deposit a high-concentration local argon gas protective layer. This situation will lead to excessive dilution of the protective gas, which not only wastes gas resources but also increases the oxygen content in the deposition area, directly affecting the additive manufacturing forming quality and even causing weld porosity or oxide inclusion defects.

[0039] Therefore, in this design, during high-speed rotation, the vertical expansion joint 4 drives the centrifugal airflow shield 5 to move downwards, thereby separating the centrifugal airflow shield 5 from the cooling jacket 2, until the centrifugal airflow shield 5 descends to its lower surface close to but not in contact with the upper end face of the external threaded stepped annular wall 12, avoiding frictional wear. Figure 6In the diagram below, the centrifugal airflow shield 5 divides the original centrifugal chamber 21 into upper and lower parts. The four edges of the annular space on the upper side of the centrifugal airflow shield 5 are connected to the inert gas overflow ports 7; the lower ends of each air passage 20 are connected to the annular space on the upper side of the centrifugal airflow shield 5; while the high-speed centrifugal vortex generated by the annular space where the centrifugal driving blades 9 are located on the lower side of the centrifugal airflow shield 5 are isolated and shielded by the centrifugal airflow shield 5, so that the high-speed vortex generated by the centrifugal driving blades 9 cannot be transmitted to the annular space on the upper side of the centrifugal airflow shield 5. Therefore, even if the rotating stirring head 10 and the stirring plate 13 rotate at high speed, the annular space on the upper side of the non-rotating centrifugal airflow shield 5 cannot form The high-speed swirling flow prevents the generation of high-intensity centrifugal force in the upper annular space of the centrifugal airflow shield plate 5. At the same time, due to the gas viscosity effect, the edge of the upper annular space of the centrifugal airflow shield plate 5 will still rotate with the upper inner wall of the high-speed rotating inert gas overflow ring 8. Relatively low-intensity swirling flow and centrifugal force can still be formed in the upper annular space of the centrifugal airflow shield plate 5 and each inert gas overflow port 7. Therefore, the argon gas entering the upper annular space of the centrifugal airflow shield plate 5 is driven by the relatively low-intensity swirling centrifugal force and overflows centrifugally in a rotating manner through each inert gas overflow port 7. The overflowing argon gas forms a local argon gas protective layer around the stirring plate 13 and in the deposition forming area.

[0040] By switching the structure as described above, the adaptive control of the protective gas flow field of the same stirring head is achieved within a wide speed range, ensuring sufficient protective gas coverage under low-speed conditions and avoiding failure caused by protective gas scattering under high-speed conditions.

[0041] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A water-cooled, integrated air-supply stirring head manufactured by friction stirring additive manufacturing, characterized in that: It includes a rotary stirring head (10) and a cooling jacket (2), with the lower end of the rotary stirring head (10) connected to a stirring plate (13). The cooling jacket (2) is rotatably fitted onto the outside of the rotary stirring head (10); the inner ring of the cooling jacket (2) is rotaryly sealed with the outer wall surface of the rotary stirring head (10) through the upper sealing ring (15) and the lower sealing ring (16), and an annular water cooling groove (14) is formed between the upper sealing ring (15) and the lower sealing ring (16); the part of the rotary stirring head (10) that passes through the cooling jacket (2) is immersed in the liquid in the annular water cooling groove (14); The upper edge of the mixing plate (13) has an externally threaded stepped ring wall (12) coaxially; the area enclosed by the externally threaded stepped ring wall (12) is an annular centrifugal blade groove (11), in which swirling centrifugal drive blades (9) are distributed; it also includes an inert gas overflow ring sleeve (8), which is threadedly fitted outside the externally threaded stepped ring wall (12). When the threads are tightened, the upper end face of the inert gas overflow ring sleeve (8) is higher than the upper end face of the externally threaded stepped ring wall (12), and the part of the upper end of the inert gas overflow ring sleeve (8) that is higher than the externally threaded stepped ring wall (12) has several inert gas overflow ports (7). The upper end of the cooling jacket (2) has several inert gas inlet holes (1), and the lower end of each inert gas inlet hole (1) passes through the air hole channel (20) from the lower end face of the cooling jacket (2). A ring-shaped centrifugal airflow shield plate (5) is attached to the lower surface of the cooling jacket (2). The centrifugal airflow shield plate (5) has several perforated holes (3). Each perforated hole (3) is connected to the lower end of an air vent channel (20). There is a vertical telescopic device (4) inside the cooling jacket (2). The vertical telescopic device (4) can drive the centrifugal airflow shield plate (5) to rise and fall. A disc-shaped centrifugal air chamber (21) is formed between the centrifugal airflow shield plate (5) and the stirring plate (13). The outer periphery of the centrifugal air chamber (21) is connected to the outside through an inert gas overflow port (7). The air pore channel (20) is an expanding channel that gradually widens radially downwards; the rotating stirring head (10) is a hollow structure that runs vertically through the interior.

2. The water-cooled, air-supply integrated stirring head manufactured by friction stirring additive manufacturing according to claim 1, characterized in that: The cooling jacket (2) has an inlet channel (17) and an outlet channel (18) connecting the annular water cooling tank (14) on both sides; the external water supply pipe and return pipe are respectively connected to the inlet channel (17) and the outlet channel (18).

3. The water-cooled air-supply integrated stirring head manufactured by friction stirring additive manufacturing according to claim 1, characterized in that: Both the upper sealing ring (15) and the lower sealing ring (16) are polytetrafluoroethylene composite sealing rings.

4. The water-cooled air-supply integrated stirring head manufactured by friction stirring additive manufacturing according to claim 1, characterized in that: The cooling sleeve (2) is integrally provided with fixed connecting seats (19) on both sides, and the fixed connecting seats (19) are fixed on the displacement support.

5. The water-cooled, air-supply integrated stirring head manufactured by friction stirring additive manufacturing according to claim 1, characterized in that: The upper end face of the inert gas overflow ring (8) is fitted with the lower end face of the cooling sleeve (2) with a clearance.

6. The water-cooled air-supply integrated stirring head manufactured by friction stirring additive manufacturing according to claim 5, characterized in that: The outer diameter of the centrifugal airflow shield (5) is between the inner diameter of the external threaded stepped ring wall (12) and the inner diameter of the inert gas overflow ring (8).

7. The water-cooled air-supply integrated stirring head manufactured by friction stirring additive manufacturing according to claim 1, characterized in that: During high-speed rotation, the vertical expansion joint (4) drives the centrifugal airflow shield (5) to move downward, thereby separating the centrifugal airflow shield (5) from the cooling jacket (2) until the centrifugal airflow shield (5) descends to the lower surface close to but not in contact with the upper end face of the external threaded step ring wall (12). The centrifugal airflow shield (5) divides the original centrifugal air chamber (21) into upper and lower parts. The four edges of the annular space located on the upper side of the centrifugal airflow shield (5) are connected to each inert gas overflow port (7). The lower end of each air passage (20) is connected to the annular space located on the upper side of the centrifugal airflow shield plate (5); while the high-speed centrifugal vortex generated by the annular space where each vortex centrifugal drive blade (9) is located on the lower side of the centrifugal airflow shield plate (5) is isolated and shielded by the centrifugal airflow shield plate (5), so that the high-speed vortex generated by the vortex centrifugal drive blade (9) cannot be transmitted to the annular space on the upper side of the centrifugal airflow shield plate (5). Since the edge of the annular space on the upper side of the centrifugal airflow shield plate (5) will still rotate with the high-speed rotating inert gas overflow ring (8) under the gas viscosity effect, a relatively low intensity vortex and centrifugal force can still be formed in the annular space on the upper side of the centrifugal airflow shield plate (5) and each inert gas overflow port (7). The argon gas entering the annular space on the upper side of the centrifugal airflow shield plate (5) is driven by a relatively low intensity vortex centrifugal force and overflows centrifugally to the surroundings in a rotating form through each inert gas overflow port (7).

Images