Turntable and manufacturing system having the same

Abstract

The present invention relates to a turntable used in a welding or additive manufacturing process and a processing system equipped with the same. A turntable according to one aspect of the present invention includes a frame having a hollow column shape and serving as a main body, which performs an additive manufacturing or welding process by positioning a workpiece on a plate provided on the upper part; a plate rotatably provided on the upper part of the frame and having a plurality of independent cooling sections formed therein so that a cooling fluid flows inside to enable differential cooling by region; and a rotary joint provided inside the frame to inject and discharge a cooling fluid into and out of the rotating plate. The rotary joint includes a housing to which an external cooling fluid pipe is connected and fixed, and a rotor that rotates in conjunction with the plate. The outer side of the housing is formed with a plurality of pairs of inlets and outlets to form independent flow paths for each of the plurality of independent cooling sections within the plate.

Description

Technology Field

[0001] The present invention relates to a turntable used in a welding or additive manufacturing process and a processing system equipped with the same. Background Technology

[0002] In general, in processing systems such as additive manufacturing systems including 3D printing or high-speed processing equipment, turntables are widely used to support workpieces (additives or objects to be processed) and to perform rotation or positioning.

[0003] In particular, in additive manufacturing processes or high-speed cutting processes that use high-energy heat sources, a massive thermal load is concentrated on the workpiece and the top surface of the turntable. This thermal load causes thermal deformation of the turntable and, furthermore, is a major cause of quality defects that reduce the dimensional accuracy of the parts being processed or added.

[0004] To solve this, conventional turntable structures have used methods such as forming a cooling channel in the form of a single passage through which cooling water simply flows, or attaching a cooling water jacket to the bottom. However, these conventional technologies had the following fatal problems.

[0005] First, conventional cooling channels have limited heat exchange surface areas and fail to provide uniform cooling performance. In particular, despite the fact that the degree of heat accumulation and heat dissipation environment differ between the center and the outer parts of the laminate, uniform cooling was performed, resulting in an uneven temperature gradient inside the turntable and throughout the workpiece. Consequently, there were limitations, such as warping, cracking, or deformation of the part due to uneven shrinkage when the shape of the laminated part was asymmetric or heat was concentrated locally.

[0006] Second, it was difficult to detect changes in workpiece weight or the precise temperature status of the additive interface in real time during the process. While real-time data feedback is essential for high-precision machining or dynamic control integrated with robots, existing structures made sensor placement and embedding difficult, posing technical challenges in achieving the smartification of the entire machining system and the optimization of automatic control.

[0007] Therefore, there is an urgent need to develop a next-generation smart turntable structure that maximizes the heat exchange area while enabling customized differential cooling for each region, simultaneously satisfies thermal conductivity performance and structural rigidity, and allows for feedback control by monitoring the process status in real time. Prior art literature

[0008] U.S. Patent Publication No. 2023-0144822 The problem to be solved

[0009] Therefore, the present invention is derived to solve the aforementioned problems and aims to provide a turntable and a processing system equipped with the same that can maximize the heat exchange area while enabling customized differential cooling for each region and satisfying heat conduction performance.

[0010] Other objects of the present invention will become more apparent through the embodiments described below. means of solving the problem

[0011] A turntable according to one aspect of the present invention comprises a frame having a hollow column shape and serving as a main body, which performs additive manufacturing or welding processes by positioning a workpiece on a plate provided on the upper side; a plate rotatably provided on the upper side of the frame and having a plurality of independent cooling sections formed therein so that a cooling fluid flows inside to enable differential cooling for each area; and a rotary joint provided inside the frame to inject and discharge a cooling fluid into and out of the rotating plate. The rotary joint includes a housing to which an external cooling fluid pipe is connected and fixed, and a rotor that rotates in conjunction with the plate. The outer side of the housing is formed with a plurality of pairs of inlets and outlets to form independent flow paths for each of the independent cooling sections within the plate.

[0012] The turntable according to the present invention may have one or more of the following embodiments. For example, each of the plurality of independent cooling sections formed on the plate may include a first cooling channel formed in an arc shape adjacent to the center of the plate, a second cooling channel formed in an arc shape adjacent to the edge of the plate with a curve length greater than that of the first cooling channel, and a third cooling channel in a straight line shape that interconnects both ends of the first cooling channel and the second cooling channel in a radial direction.

[0013] The first cooling channel and the second cooling channel can be formed as a sealed flow path by means of a first channel processing part and a second channel processing part processed on the lower surface of the plate, and a first cover and a second cover that prevent fluid leakage by being joined with a rubber packing interposed at the inlet of the channel processing parts.

[0014] Inside the plate, at least one of a load cell for detecting changes in the weight of a workpiece being stacked during additive manufacturing in real time and a thin film temperature sensor for receiving feedback on the temperature of the plate and controlling the flow rate of a cooling fluid may be embedded.

[0015] The plate may be a heterogeneous material composite in which the upper part in contact with the workpiece is made of aluminum, aluminum alloy, copper, or copper alloy having high thermal and electrical conductivity, and the lower part is made of carbon steel having high rigidity.

[0016] A plurality of hose adapters are provided on the upper surface of the rotor, and the hose adapters are connected to a refrigerant inlet or refrigerant outlet formed on the lower surface of the plate via a flexible hose and a rotary connecting member, so as to rotate integrally with the rotor.

[0017] The frame may further include a charging member provided at the upper part of the frame to charge the plate as either a positive (+) or a negative (-). The charging member may include a charging bracket coupled to the upper flange of the frame, a spring housing provided on the charging bracket and containing a spring inside, and a charging bar that is elastically pressed upward by the spring, maintains constant contact with the lower surface of the rotating plate, and transmits external power.

[0018] It may further include a motor and a reduction gear provided on the side of the frame, a first gear coupled to the reduction gear, and a second gear coupled to the lower surface of the plate and rotating integrally, formed with a larger diameter than the first gear and meshing with the first gear to rotate.

[0019] A processing system according to one aspect of the present invention may include a turntable and a robot tower, a first robot tower and a second robot tower each having a first welding gun and a second welding gun arranged opposite each other with the turntable in between, which melts a supplied wire using an arc heat source and performs an additive process on a plate of the turntable, and a control unit that controls the linear movement speed of the first and second robot towers and the rotation RPM of the turntable in real time so that the heat input to the workpiece is maintained constant regardless of changes in linear speed for each processing position.

[0020] The processing system according to the present invention may further include the following embodiments. For example, the first robot tower and the second robot tower may include a hydraulic brake or a fixing outrigger that fixes the tower itself to the ground when performing an additive process at a specific location in order to suppress vibrations occurring at the end of the robot arm during additive processing. Effects of the invention

[0021] According to the means for solving the problem of the present invention as described above, various effects including the following can be expected. However, the present invention is not required to exhibit all of the following effects to be valid.

[0022] The present invention can provide a turntable and a processing system equipped with the same that can maximize the heat exchange area while enabling customized differential cooling for each region and satisfying thermal conductivity performance. Brief explanation of the drawing

[0023] FIGS. 1 and FIGS. 2 are perspective views illustrating a turntable according to an embodiment of the present invention. FIG. 3 is a front view of the turntable exemplified in FIG. 1. Figure 4 is a cross-sectional view along line AA of Figure 1. Figure 5 is a cross-sectional view along line BB of Figure 1. FIG. 6 is a cross-sectional view of the turntable exemplified in FIG. 1. FIG. 7 is a drawing illustrating the internal structure of the turntable exemplified in FIG. 1. FIG. 8 is a drawing illustrating the back of the turntable exemplified in FIG. 1. FIG. 9 is a drawing illustrating a processing system according to one embodiment of the present invention. Specific details for implementing the invention

[0024] The present invention is capable of various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention. In describing the present invention, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions may obscure the essence of the present invention.

[0025] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0026] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0027] Hereinafter, embodiments according to the present invention will be described in detail with reference to the attached drawings. In describing with reference to the attached drawings, identical or corresponding components are given the same reference number regardless of the drawing symbols, and redundant descriptions thereof will be omitted.

[0028] FIGS. 1 and FIGS. 2 are perspective views showing the upper and lower parts of a turntable (100) according to an embodiment of the present invention, respectively, and FIG. 3 is a front view of the turntable (100) illustrated in FIG. 1. FIGS. 4 and FIG. 5 are longitudinal cross-sectional views along lines AA and BB of FIG. 1, respectively, and FIG. 6 is a cross-sectional view of the turntable (100) illustrated in FIG. 1. FIG. 7 is a drawing illustrating the internal structure of a plate (200) illustrated in FIG. 1, and FIG. 8 is a drawing illustrating the rear side of a plate (200) illustrated in FIG. 1. FIG. 9 is a drawing illustrating a processing system (300) according to an embodiment of the present invention.

[0029] For reference, the plate (200) illustrated in FIG. 8 illustrates a state in which the first cover (234) and the second cover (240) are removed, exposing the first channel processing part (232) and the second channel processing part (238).

[0030] Referring to FIGS. 1 to 9, a turntable (100) according to one embodiment of the present invention allows a workpiece to be positioned on a plate (200) provided on its upper surface to perform welding or additive manufacturing processes. For example, the turntable (100) is provided in a processing system (300) illustrated in FIG. 9 to enable wire arc additive manufacturing (WAAM) to be performed on the plate (200) on its upper surface.

[0031] A turntable (100) according to one embodiment of the present invention is characterized by being able to efficiently cool a plate (200) in which a large amount of heat is concentrated during the processing process. To this end, the turntable (100) according to the present embodiment can efficiently cool the plate (200) by injecting a cooling fluid (gaseous refrigerant or cooling water, etc.) into the interior of the plate (200). In addition, the turntable (100) according to the present embodiment is characterized by being able to perform differential cooling by dividing the entire plate (200) into a plurality of cooling zones.

[0032] The turntable (100) according to the present embodiment includes a frame (110) corresponding to the main body. The frame (110) has a hollow hexagonal column shape, and an upper flange (112) and a lower flange (116) are provided at the top and bottom, respectively. The frame (110) also has a side (114) having a certain height. The frame (110) may be made of a steel material having rigidity, but the present invention is not limited by the material of the frame (110).

[0033] The lower flange (116) has a certain length and protrudes vertically outward from the bottom of the frame (110) to support the frame (110). The lower flange (116) is provided with a plurality of leveling pads (118) for adjusting the height and leveling of the plate (200). Additionally, the lower flange (116) is provided with a plurality of anchor bolts (120) for fixing the frame (110) to a floor surface, etc., after adjusting the height and leveling.

[0034] The side (114) of the frame (110) allows the plate (200) to have a certain height from the lower flange (116). The side (114) may be formed in six, but the present invention is not limited by the number and arrangement structure of the side (114) (i.e., the cross-sectional shape of the frame (110)). A motor bracket (122) may be attached to one of the side (114). Additionally, a window (not shown in the drawing) communicating with the interior of the frame (110) may be formed on another of the side (114).

[0035] The motor bracket (122) is formed integrally with or combined with the side of the frame (110). The motor bracket (122) may have a structure in which a pair of parts protrude at a certain distance apart, and a reduction gear (126) may be located in that distance. A motor (124) is coupled to one side of the reduction gear (126). Additionally, a first gear (128) is coupled to the upper part of the reduction gear (126), and the first gear (128) is located inside the protrusion (142) of the gear cover (140).

[0036] The upper flange (112) corresponds to a portion that protrudes vertically inward and outward with a certain length from the upper part of the frame (110), and the upper surface of the upper flange (110) has a flat shape. On the upper surface of the upper flange (110), a gear cover (140), a second gear (148), and a bearing (150) are respectively provided in the direction from the outer side to the inner side. The gear cover (140), the second gear (148), and the bearing (150) are all ring-shaped members and have the same center.

[0037] The gear cover (140) protrudes vertically for a certain length from the upper flange (112) and covers the side of the second gear (148) located inside it. Therefore, the side of the second gear (148) is not exposed by the gear cover (140). In addition, a certain gap is formed between the gear cover (140) and the second gear (148), so the gear cover (140) does not hinder the rotation of the second gear (148).

[0038] A protrusion (142) having a curved shape is formed in the portion of the gear cover (140) where the motor bracket (122) is formed. The protrusion (142) is located on the upper part of a flat plate (not shown in the drawing) that is coupled to the motor bracket (122), and a first gear (128) is rotatably positioned inside it. The side of the first gear (128) is covered by the protrusion (142) so that it is not exposed to the outside.

[0039] The upper portion of the gear cover (140) including the protrusion (142) has a certain gap with the lower surface of the plate (200). Therefore, the rotation of the plate (200) is not restricted by the gear cover (140).

[0040] The gear cover (140) can be manufactured by a method in which multiple parts having an arc shape are joined together. The gear cover (140) and the gear cover (140) can be joined together by means of bolts, etc. Since the gear cover (140) is manufactured as parts in this way, when repair or replacement is required, only the relevant part can be removed and replaced.

[0041] A second gear (148) is provided inside the gear cover (140). The second gear (148) is rotatably supported by a bearing (150) located inside it. The second gear (148) is coupled with the plate (200) and rotates as a unit. Therefore, the rotational force of the motor (124) is transmitted through the first gear (128) to the second gear (148), and as a result, the second gear (148) and the plate (200) rotate as a unit.

[0042] The second gear (148) can be formed with a larger diameter than the first gear (128). Therefore, the rotation angle of the second gear (148) becomes smaller than the rotation angle of the first gear (128), and as a result, precise rotation angle of the plate (200) and strong torque transmission are possible.

[0043] The lower surface of the second gear (148) is spaced apart from the upper surface of the upper flange (112) by a certain distance. Therefore, the rotation of the second gear (148) is not restricted by the upper flange (112).

[0044] The bearing (150) is located inside the second gear (148) and rotatably supports the second gear (148). That is, the bearing (150) has a ring shape, and the second gear (148) is rotatably coupled to its outer surface. The bearing (150) is fixed to the upper surface of the upper flange (112) and does not rotate.

[0045] The bearing (150) may be a ball bearing, but the present invention is not limited by the structure of the bearing (150) that rotatably supports the second gear (148).

[0046] A charging member (154) is attached to the upper flange (112). The charging member (154) charges the table (200) as a positive (+) or negative (-). For example, when the welding gun (304, 308) in the processing system (300) is positive, the charging member (154) charges the table (200) as a negative. As a result, an electrical circuit is formed in which current flows from the welding gun (304, 308) toward the table (200), and the welding gun (304, 308) can quickly melt the wire to increase productivity and clean the surface of the base material.

[0047] The charging member (154) includes a charging bracket (156) that is detachably coupled to the upper flange (112). The charging bracket (156) is formed of a metal material and can be coupled to the upper flange (112) by means of a bolt or the like. A spring housing (158) can be coupled to the charging bracket (156). The spring housing (158) may be equipped with a spring (not shown) inside, and the spring can elastically press the charging bar (160) inserted into the spring housing (158) upward. In this way, since the charging bar (160) is elastically supported by the spring, the charging bar (160) can stably maintain contact with the plate (200) even if the plate (200) rotates.

[0048] The charging bar (160) can receive electricity from an external source and charge the plate (200) as a negative electrode. In addition, a plurality of charging members (154) including the charging bar (160) may be provided, and the turntable (100) according to the present embodiment is exemplified as having a total of six charging members (154). In this way, by providing a plurality of charging members (154), it is possible to accommodate a large-area plate (200) and improve additive manufacturing or welding performance. Of course, the number and spacing of the charging members (154) may be changed depending on the size of the plate (200), etc.

[0049] A hole (not shown in the drawing) is formed in the lower part of the frame (110), and a support member (170) is provided on the upper part of the hole. The support member (170) is connected to the bottom surface of the frame (110), and a rotary joint (172) is provided on the upper part thereof.

[0050] The rotary joint (172) is located in the center of the support member (170), and as a result, the rotary joint (172) is located in the center of the bottom surface of the frame (110) and the lower center of the plate (200).

[0051] The rotary joint (172) is for supplying cooling fluid to a rotating plate (200) and includes a housing (174) corresponding to a fixed part and a rotor (176) rotatably positioned inside the housing (174). A sealant and a bearing (not shown) may be provided between the housing (174) and the rotor (176).

[0052] The housing (174) is fixed to the support member (170) and does not rotate, and corresponds to an outer body to which an external cooling fluid supply hose (not shown) is connected.

[0053] The rotor (176) passes through the center of the housing (174) and is coupled with the rotating plate (200) to rotate together. The rotor (176) has a hollow shaft shape with a hole in its center, and cooling fluid moves from the housing (174) to the plate (200) through this internal hole.

[0054] The mechanical seal, which serves as a sealing material, is a rotary sealing device that prevents cooling fluid from leaking through the fine gap between the fixed housing (174) and the rotating rotor (176). The mechanical seal is formed such that the cross-sections of the stationary ring fixed to the housing (174) and the rotating ring rotating together with the rotor (176) are in precise contact with each other, and because an internal spring presses these two surfaces together with constant pressure, fluid does not leak through the gap even when the rotor (176) rotates at high speed. Since the mechanical seal must withstand frictional heat and wear, it can be made of hard and smooth materials such as ceramic, carbon, or carbide (hard alloy).

[0055] A plurality of fixed connecting members (175) corresponding to the inlet and outlet of a cooling fluid may be provided on the outer side of the housing (174). The fixed connecting members (175) may be provided in pairs, one corresponding to the part where the cooling fluid is introduced and the other to the part where the cooling fluid is discharged. The turntable (100) according to the present embodiment is exemplified as having two pairs of fixed connecting members (175), thereby allowing the turntable (100) to have two independent cooling zones.

[0056] Four hose adapters (190) are provided on the upper surface of the rotor (176), and each hose adapter (190) is connected to a flexible hose (192). A rotary connecting member (194) is provided at the end of the hose (192). The rotary connecting member (194) is connected to a refrigerant inlet (220) or a refrigerant outlet (222) formed on the lower surface of the plate (200). The hose adapter (190), the hose (192), and the rotary connecting member (194) can rotate together with the rotor (176).

[0057] A plate connecting member (178) is attached to the upper surface of the rotor (176). The plate connecting member (178) interconnects the lower surface of the rotor (176) and the plate (200), thereby causing the rotor (176) and the plate (200) to rotate as a single unit. The plate connecting member (178) may be formed with two or more members depending on the distance between the rotor (176) and the plate (200), the shape of the plate (200), etc.

[0058] The plate (200) corresponds to the part where a workpiece (not shown) is placed or where a workpiece is created by additive manufacturing. The plate (200) has a circular disc shape with a constant thickness, and the upper surface (202) can be formed flat. The lower surface (230) of the plate (200) is coupled with the second gear (148) and rotates integrally with the second gear (148).

[0059] The plate (200) can be made of steel or aluminum. In particular, if the plate (200) is formed from aluminum, which has a relatively higher thermal conductivity than steel, the cooling efficiency can be improved. Additionally, since the aluminum plate (200) has excellent electrical conductivity, the efficiency of the welding or lamination process can be increased.

[0060] The plate (200) may be made of different materials. For example, the upper part that comes into direct contact with the workpiece may be made of aluminum (including alloys) or copper (including alloys) with high thermal conductivity, and the lower part may be made of carbon steel with high rigidity.

[0061] At least one of a load cell and a thin film temperature sensor may be embedded inside the plate (200). The load cell can detect changes in the weight of the workpiece being stacked in real time during additive manufacturing and reflect this in the dynamic control of the welding gun (304, 308). The thin film temperature sensor can receive feedback on the temperature of the plate (200) and adjust the flow rate of the cooling fluid.

[0062] A plurality of upper surface grooves (204) may be formed on the upper surface of the plate (200). The upper surface grooves (204) are grooves formed with a certain depth on the upper surface of the plate (200) and may serve to support a base (not shown) located at the bottom of the workpiece. Additionally, a plurality of upper surface holes (206) may be formed on the upper surface of the plate (200). A fastening screw (not shown in the drawing) for coupling with the second gear (148) may be inserted into the upper surface holes (206).

[0063] A side processing hole (212) may be formed on the side (210) of the plate (200). The side processing hole (212) corresponds to an inlet for forming a third cooling channel (218) among the cooling channels formed inside the plate (200). In order to prevent leakage of cooling fluid, the side processing hole (212) may be closed by a sealing member (not shown in the drawing) after processing.

[0064] A cooling channel corresponding to a flow passage for a cooling fluid is formed inside the plate (200). The cooling channel may include a first cooling channel (214), a second cooling channel (216), and a third cooling channel (218).

[0065] Referring to FIGS. 7 and 8, the first cooling channel (214) corresponds to an arc-shaped passage formed adjacent to the center hole (208) of the plate (200). Two first cooling channels (214) form a pair, and two pairs can be formed across the entire plate (200). Thus, one cooling unit may have two first cooling channels (214). Also, both ends of the first cooling channel (214) may be connected to the ends of the third cooling channel (218), which is formed in a straight line in the radial direction.

[0066] The first cooling channel (214) can be formed through the first channel processing part (232) formed on the lower surface (230) of the plate (200). That is, after processing the lower surface (230) of the plate (200) to form the first channel processing part (232) and the arc-shaped first cooling channel (214), the leakage of cooling fluid can be prevented by covering the first channel processing part (232) using the first cover (234).

[0067] The first cooling channel (214) can be manufactured using a cutting tool such as a CNC mill or an end mill. Such CNC milling or end milling can form grooves of almost any shape, including straight lines, curves, blind grooves, and through slots, and has the advantage of allowing depth control in micrometer units. When the plate (200) is made of aluminum, it has high ductility, allowing for rapid cutting, but because chips tend to stick to the tool, a two-blade end mill dedicated to aluminum, high-speed rotation, and a smooth supply of cooling water are required. Additionally, when the plate (200) is made of steel, it is harder than aluminum, so a carbide end mill with high rigidity is used, and cutting using strong force is required instead of lowering the rotational speed.

[0068] The first cooling channel (214) and the second cooling channel (216) can be formed by the same processing method, and the present invention is not limited by the processing method of the cooling channels (214, 216). Accordingly, the cooling channels (214, 216) can be formed by sinker EDM or laser processing, etc.

[0069] The first cover (234) covers the inlet of the first cooling channel (214) and is coupled to the lower surface (230) of the plate (200) by means of fastening bolts (not shown in the drawing), etc. The first cover (234) may be equipped with a rubber packing (not shown) to enhance sealing performance.

[0070] The second cooling channel (216) corresponds to an arc-shaped passage formed adjacent to the edge of the plate (200). Three second cooling channels (216) form a pair, and two pairs can be formed across the entire plate (200). Thus, one cooling unit may be equipped with three second cooling channels (216). Additionally, both ends of the second cooling channel (216) may be connected to the ends of the third cooling channel (218), which is formed in a straight line in a radial direction.

[0071] The second cooling channel (216) can be formed through the second channel processing part (238) formed on the lower surface (230) of the plate (200). That is, the lower surface (230) of the plate (200) is processed to form the second channel processing part (238) and the arc-shaped second cooling channel (216), and then the second channel processing part (238) is covered using the second cover (240) to prevent leakage of the cooling fluid. Furthermore, the second cooling channel (216) is formed on the outer side of the plate (200) compared to the first cooling channel (214) and has a larger curve length.

[0072] In the plate (200) according to the present embodiment, one cooling section (not shown in the drawing) consisting of a first cooling channel (214), a second cooling channel (216), and a third cooling channel (218) covers half of the circular plate (200). The one cooling section includes two first cooling channels (214), three second cooling channels (216), and six third cooling channels (218). In addition, the plate (200) according to the present embodiment is equipped with two cooling sections, and one cooling section covers one cooling area corresponding to half of the plate (200). Each cooling section operates independently to control the flow of cooling fluid according to the temperature of the corresponding area, etc.

[0073] Although the turntable (100) according to the present embodiment is exemplified as having two cooling sections and two corresponding cooling zones, the present invention is not limited by the number of cooling sections. Therefore, the

[0074] One cooling unit is equipped with a refrigerant inlet (220) and a refrigerant outlet (222). The refrigerant inlet (220) and the refrigerant outlet (222) correspond to the ends of the third cooling channel (218) and provide a passage to which a hose (192) is connected to supply or discharge a cooling fluid to the cooling unit.

[0075] The cooling fluid injected into the cooling section may be cooling water or cooling gas, and the present invention is not limited by the type and properties of the cooling fluid. Water-soluble fluids or oil-based fluids may be used as cooling water. Water-soluble fluids have excellent heat capacity and economic advantages, and include ordinary tap water, distilled water, glycol mixtures, etc. Oil-based fluids are used in environments where electricity must not be conducted or when high-temperature cooling exceeding the boiling point of water is required. Oil-based fluids may include mineral oil and silicone oil. Cooling gas includes air, inert gas (nitrogen, argon, helium, etc.), carbon dioxide, etc. Cooling gas includes phase change refrigerants.

[0076] Since the plate (200) according to the present embodiment has two cooling sections that cover the entire surface area of ​​the plate, it can efficiently cool the heat generated during the processing process, thereby increasing work efficiency and precision.

[0077] Referring to FIG. 9, a wire arc additive manufacturing (WAAM) system is exemplified as a processing system (300). A WAAM system is a large metal 3D printing device that melts metal wire using an arc (welding flame) heat source and builds up layer by layer along a designated path. The processing system (300) includes two robot towers, namely a first robot tower (302) and a second robot tower (306). The first robot tower (302) is equipped with a first welding gun (304), and the second robot tower (306) is equipped with a second welding gun (308). The first welding gun (304) and the second welding gun (308) perform an additive process by melting the supplied wire with an arc. The first welding gun (304) and the second welding gun (308) correspond to industrial robot arms, and their operation is controlled independently.

[0078] Although a wire arc additive manufacturing system is illustrated as a processing system in FIG. 9, the present invention is not limited by the type and structure of the processing system. Accordingly, a processing system according to another embodiment of the present invention may include a welding system, etc.

[0079] The first robot tower (302) and the second robot tower (306) have the same structure and are positioned opposite each other so that they can each perform independent tasks. In particular, if a failure occurs in either the first robot tower (302) or the second robot tower (306), or if there is no need to use both, only one robot tower can operate independently.

[0080] A turntable (100) is located between the first robot tower (302) and the second robot tower (306). An additive manufacturing process or a welding process can be performed on the upper surface (202) of the turntable (100). The first robot tower (302) and the second robot tower (306) may be able to move linearly relative to the turntable (100). The turntable (100) may also be able to move linearly in response to the linear movement of the first robot tower (302) and the second robot tower (306). Such linear movement of the first robot tower (302), the second robot tower (306), and the turntable (100) through mutual independence or mutual interlocking increases work efficiency.

[0081] The rotation of the turntable (100) and the linear movement of the robot tower (302, 304) can be synchronized in real time. In particular, the problem of the linear speed changing as it moves from the center of the part to the outer edge can be controlled to maintain a constant heat input by precisely synchronizing the linear movement speed of the robot tower (302, 304) with the RPM of the turntable (200). This maintenance of a constant heat input can be performed by the control unit of the processing system (300). Also, a rotational error may occur when the center of gravity of a large workpiece does not coincide with the center of the turntable (100), and such a rotational error can be corrected in real time through the linear movement of the robot tower (302, 304) and fine adjustment of the robot arm.

[0082] The processing system (300) can be used for additive manufacturing of large parts of 3m or more, and to suppress vibrations occurring at the end of the robot arm when stacking large parts, a hydraulic brake or a fixing outrigger is applied to the tower itself so that the tower can be firmly fixed to the ground when stacking at a specific position.

[0083] Although the present invention has been described above with reference to one embodiment, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as described in the following claims. Explanation of the symbols

[0084] 100: Turntable 110: Frame 154: Daejeon Absence 200: Plate 300: Machining System

Claims

Claim 1 A turntable for performing additive manufacturing or welding processes by positioning a workpiece on a plate provided on the upper part, comprising: a frame having a hollow column shape and serving as a main body; a plate rotatably provided on the upper part of the frame and having a plurality of independent cooling sections formed therein so that a cooling fluid flows inside to enable differential cooling by region; and a rotary joint provided inside the frame for injecting and discharging a cooling fluid into and out of the rotating plate, wherein the rotary joint includes a housing to which an external cooling fluid pipe is connected and fixed, and a rotor that rotates in conjunction with the plate, and a fixed connecting member provided on the outer side of the housing, the member comprising a plurality of pairs of inlets and outlets to form independent flow paths for each of the plurality of independent cooling sections within the plate. Claim 2 A turntable according to claim 1, wherein each of the plurality of independent cooling sections formed on the plate comprises: a first cooling channel formed in an arc shape adjacent to the center of the plate; a second cooling channel formed in an arc shape adjacent to the edge of the plate having a curve length greater than that of the first cooling channel; and a third cooling channel in a straight shape connecting both ends of the first cooling channel and the second cooling channel in a radial direction. Claim 3 In paragraph 2, the first cooling channel and the second cooling channel are formed as a sealed flow path by a first channel processing part and a second channel processing part processed on the lower surface of the plate, and a first cover and a second cover that prevent fluid leakage by being coupled with a rubber packing interposed at the inlet of the channel processing parts. Claim 4 A turntable according to claim 1, wherein at least one of a load cell for detecting a change in weight of a workpiece being stacked in real time during additive manufacturing and a thin film temperature sensor for receiving feedback on the temperature of the plate and controlling the flow rate of a cooling fluid is embedded inside the plate. Claim 5 In claim 1, the plate is a turntable that is a heterogeneous material combination in which the upper part in contact with the workpiece is made of aluminum, aluminum alloy, copper, and copper alloy having high thermal and electrical conductivity, and the lower part is made of carbon steel having high rigidity. Claim 6 In claim 1, a plurality of hose adapters are provided on the upper surface of the rotor, and the hose adapters are connected to a refrigerant inlet or refrigerant outlet formed on the lower surface of the plate via a flexible hose and a rotary connecting member, and the turntable rotates integrally with the rotor. Claim 7 A turntable according to claim 1, further comprising a charging member provided at the upper end of the frame to charge the plate to either a positive (+) or a negative (-). Claim 8 In claim 7, the charging member comprises a charging bracket coupled to the upper flange of the frame, a spring housing provided in the charging bracket and including a spring inside, and a charging bar that is elastically pressed upward by the spring, maintains constant contact with the lower surface of the rotating plate, and transmits external power to the turntable. Claim 9 A turntable according to claim 1, further comprising a motor and a reduction gear provided on the side of the frame, a first gear coupled to the reduction gear, and a second gear coupled to the lower surface of the plate and rotating integrally, having a larger diameter than the first gear and meshing with the first gear to rotate. Claim 10 A processing system comprising a turntable and a robot tower, the processing system comprising: a turntable according to any one of claims 1 to 9; a first robot tower and a second robot tower, each equipped with a first welding gun and a second welding gun respectively, which are arranged oppositely with the turntable in between and perform an additive process on a plate of the turntable by melting a supplied wire with an arc heat source; and a control unit that controls the linear movement speed of the first and second robot towers and the rotation RPM of the turntable in real time so that the heat input to the workpiece is maintained constant regardless of changes in linear speed for each processing position. Claim 11 In claim 10, the above-mentioned first robot tower and second robot tower are a processing system comprising a hydraulic brake or a fixing outrigger that fixes the tower itself to the ground when performing an additive process at a specific location in order to suppress vibrations occurring at the end of the robot arm during additive processing.

Images