Workpiece machining automation system and control method therefor
Patent Information
- Application Number
- PCT/KR2026/004778
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-27
- Filing Date
- 2026-03-26
- Publication Date
- 2026-10-01
Smart Images
Figure KR2026004778_01102026_PF_FP_ABST
Abstract
Description
Workpiece processing automation system and control method thereof
[0001] The present invention relates to a workpiece processing automation system and a control method thereof that automatically aligns the rotational center of a workpiece with the rotational center of a machine tool to continuously process a workpiece.
[0002] High-tech precision machinery, such as semiconductor manufacturing equipment, uses parts (workpieces) that require precision, such as quartz or glass, which are hard, non-brittle, and easy to work with.
[0003] Since these workpieces are primarily manufactured through precision grinding, it takes several hours to process a single workpiece.
[0004] In addition, in order to process such a workpiece, the amount of clearance must be minimized so that the workpiece portion is small and the processing time can be reduced. Therefore, the processing operation must be performed after accurately aligning the center of rotation of the machine tool chuck or spindle that holds and rotates the workpiece with the center of rotation of the workpiece.
[0005] To align the rotational center of a workpiece with the rotational center of a machine tool chuck or spindle, the workpiece is gripped in the machine tool chuck or spindle, and the chuck or spindle is slowly rotated while measuring the outer diameter of the workpiece with a precision measuring instrument such as an indicator to align the rotational center of the workpiece with the rotational center of the machine tool chuck or spindle.
[0006] This operation must be performed every time a workpiece is machined, and it takes several hours depending on the operator's skill level. In addition, if the rotational center of the workpiece is misaligned, the machining allowance increases, leading to the problem of excessively long machining times.
[0007] Furthermore, in machine tools such as machining centers where the chuck or clamp device that grips and rotates the workpiece is not installed at a specific location like in turning centers but at an arbitrary position on the rotary table, accurately determining the center of rotation of the clamp device installed on the table and aligning it with the center of rotation of the workpiece requires more working time and skill.
[0008] For this reason, in the case of workpieces that have high hardness, low brittleness, and require precision machining, automated production is impossible because a worker must intervene in each step of the series of processes for machining the workpiece, and the work is carried out as a manual process involving worker intervention.
[0009] Furthermore, when multiple identical workpieces need to be processed, automation is not implemented, so the operator must go through the process of aligning the center of rotation of the workpiece with the center of rotation of the machine tool and gripping the workpiece at length each time, which reduces productivity. In addition, even after the workpiece is processed, it takes a long time to separate the workpiece from the machine tool and precisely measure each processed part. Moreover, there is a problem in that quality control of the workpiece cannot be stabilized because the measured parts are inconsistent and there are differences in the measurement methods each time the workpiece is measured.
[0010] Meanwhile, an automated production system using a robot for the automated production of workpieces can be cited. However, an automated production system using a robot can move the workpiece to the processing area of a machine tool while automatically aligning the rotational center of a circular workpiece by mounting a gripper with three jaws on the tip of a robot arm.
[0011] However, for workpieces requiring high precision, gripping the outer diameter of the workpiece with a constant force using a gripper results in the workpiece breaking or being damaged. Furthermore, considering that the positional and repeatability precision of a robot's rotation and joint movements is lower than that of a machine tool, there is a problem in being unable to accurately transfer the workpiece to the machine tool's chuck or spindle.
[0012] As such, if the workpiece is not gripped in the correct position, there is a problem in that the machining allowance increases, leading to longer machining times. In particular, in the case of grinding workpieces that are hard and brittle, such as quartz, there is a problem in that it takes several additional hours to machine a single workpiece.
[0013] Meanwhile, referring to the prior art patent document 1 (the parentheses are the drawing symbols of patent document 1), there is a supply unit (1) that sequentially supplies various types of workpieces, a scanning unit (2) that scans an identification tag on the surface of the supplied workpiece and provides the scanning information to a control unit (8), a robot unit (3) that feeds the workpiece into a fixing unit (4) according to processing information provided by the control unit (8) for the scanned workpiece, a fixing unit (4) that fixes the workpiece so that its center is automatically aligned according to processing information provided by the control unit (8) for the feedpiece, a processing unit (5) that processes the fixed workpiece according to processing information provided by the control unit (8), an inspection unit (6) that inspects the processed surface of the workpiece discharged from the fixing unit (4) by the robot unit (3) after processing is completed and provides the inspection result to the control unit (8), a discharge unit (7) that discharges the workpiece after inspection is completed, and the supply unit (1), the scanning unit (2), the robot unit (3). An automatic workpiece processing system is introduced that includes a control unit (8) which exchanges information between a fixed unit (4), a processing unit (5), an inspection unit (6), and a discharge unit (7) for monitoring, and controls and manages the operation of each unit.
[0014] In addition, Patent Document 2 (the parentheses are the drawing symbols of Patent Document 2) describes a clamping device for a workpiece being machined, comprising means for centering a workpiece in a workpiece holder (2) in which the holder (2) rotates about an axis (X) during the machining of the workpiece, and means for clamping the workpiece against the workpiece holder (2). The clamping means is structured to include at least one member (10) that supports the workpiece fixed to the rotating holder (2) and is detachably fixed to the workpiece by magnetic force.
[0015] The patent documents introduced above are equipped with a fixing part or a clamping device that grips the outer side of a workpiece by an external force as a means of aligning or setting the center of a workpiece, and rely on a control unit and a robot for the process of moving the workpiece to the processing part of a machine tool for processing. In the case of a workpiece that is hard and brittle but requires high-precision processing, as in the present invention, as previously pointed out, the workpiece may be broken or damaged during the workpiece clamping process by an external force. Furthermore, in the process of mounting the workpiece to the machine tool using a robot, the rotational center of the workpiece cannot be accurately aligned with the rotational center of the machine tool due to the limitations of the robot's positional reproduction precision, resulting in an excessive amount of processing allowance during workpiece processing and an increase in unnecessary processing time.
[0016] [Prior Art Literature]
[0017] [Patent Literature]
[0018] (Patent Document 1) Korean Published Patent Application No. 10-2023-0152910
[0019] (Patent Document 2) Korean Published Patent Application No. 10-2007-0029209
[0020] The objective of the present invention to solve the above-mentioned problems is to provide a workpiece machining automation system and a control method thereof that grips a workpiece requiring high precision machining without breakage or damage, and enables the rotation center of the workpiece and the rotation center of the machine tool to be accurately aligned, thereby minimizing the machining allowance of the workpiece and shortening the preparation time and machining time for machining the workpiece.
[0021] Another objective of the present invention is to provide a workpiece processing automation system and a control method thereof that stabilizes the processing quality of a workpiece and further facilitates quality control by enabling automatic measurement of the workpiece after processing is completed.
[0022] The workpiece processing automation system of the present invention for solving the above-mentioned problems is,
[0023] A workpiece storage rack (10) loaded with workpieces (12), and
[0024] A machine tool (30) for processing the above workpiece (12), and
[0025] A robot (40) that moves the above workpiece (12) from the above workpiece storage rack (10) to the above machine tool (30), and
[0026] A gripper (50) having a part that grips the above workpiece (12) and is mounted on the robot (40), and a shank part (52) that is mounted on the spindle (34) of the machine tool (30),
[0027] The integrated control device (60) controls the robot (40) to transfer the workpiece (12) held by the gripper (50) to the position of the spindle (34) of the machine tool (30), and after the shank portion (52) of the gripper (50) is held by the spindle (34), controls the spindle (34) to move the workpiece (12) held by the gripper (50) to the clamp chuck (32) of the machine tool (30) for gripping.
[0028] In a preferred embodiment, the integrated control device (60) in a workpiece processing automation system is characterized by sharing control information with a robot control device (43) that controls the robot (40) and a machine tool control device (31) that controls the machine tool (30) and performing sequential control.
[0029] In a preferred embodiment, the workpiece processing automation system commands the robot control device (43) to transfer the workpiece (12) held by the gripper (50) to the spindle (34) position of the machine tool (30), and
[0030] The above machine tool control device (31) is commanded so that the spindle (34) grips the shank portion (52) of the gripper (50) that is gripping the workpiece (12), and the spindle (34) is moved to the rotational center position of the clamp chuck (32) to move the workpiece (12) gripped by the gripper (50) to the clamp chuck (32) to grip it, a specific tool (36) stored in the machine tool (30) is exchanged with the spindle (34), and the spindle (34) is moved to the rotational center position of the workpiece (12) to process the workpiece (12).
[0031] The above robot control device (43) is commanded to move the gripper (50) to the rotation center position of the clamp chuck (32) to grip and discharge the workpiece (12).
[0032] In a preferred embodiment, the workpiece processing automation system includes a workpiece alignment device (20) that aligns the rotational center of the workpiece (12) transferred from the workpiece storage stand (10) to the center of a predetermined position, and the integrated control device (60) commands the robot control device (43) so that the gripper (50) grasps the workpiece (12) from the storage section (11) of the workpiece storage stand (10), places it on the workpiece alignment device (20) to align the rotational center of the workpiece (12), and transfers the workpiece (12) from the workpiece alignment device (20) to the spindle (34) position of the machine tool (30).
[0033] In a preferred embodiment, the integrated control device (60) in the workpiece processing automation system commands the machine tool control device (31) to mount a measuring instrument (33) housed in the machine tool (30) onto the spindle (34) of the machine tool (30) to measure the clamp chuck (32) and calculate the rotation center coordinate value of the clamp chuck (32).
[0034]
[0035] In addition, the control method of the workpiece processing automation system of the present invention for solving the above-mentioned problems is,
[0036] A control method for a workpiece processing automation system that sequentially controls a workpiece storage rack (10) loaded with a workpiece (12), a machine tool (30) that processes the workpiece (12), a robot (40) that moves the workpiece (12) from the workpiece storage rack (10) to the machine tool (30) and discharges the workpiece (12) after processing is completed at the machine tool (30), a robot control device (43) that controls the robot (40), and an integrated control device (60) that shares control information with a machine tool control device (31) that controls the machine tool (30).
[0037] A clamp chuck rotation center verification step (S10) in which a measuring instrument (33) housed in the machine tool (30) is mounted on the spindle (34) of the machine tool (30) according to the command of the machine tool control device (31), and a clamp chuck (32) that grips the workpiece (12) is measured to calculate the rotation center coordinate value of the clamp chuck (32);
[0038] A workpiece chucking step (S30) in which the rotation and joint movement of the robot arm (42) are controlled according to the command of the robot control device (43) to transfer the workpiece (12) to a position where the spindle (34) of the machine tool (30) is waiting, and the machine tool control device (31) moves the spindle (34) to grip the shank portion (52) of the gripper (50) that has gripped the workpiece (12) onto the spindle (34), and then moves the spindle (34) to the rotation center position of the clamp chuck (32) calculated in the clamp chuck rotation center verification step (S10) to move the workpiece (12) gripped by the gripper (50) to the clamp chuck (32) to grip it.
[0039] A workpiece processing step (S50) in which a specific tool (36) stored in the machine tool (30) is exchanged with the spindle (34) according to the command of the machine tool control device (31), and the spindle (34) is moved to the rotation center position of the workpiece (12) to process the workpiece (12); and
[0040] The method includes a workpiece discharge step (S70) in which the robot arm (42) and the gripper (50) are moved to the rotation center coordinate position of the workpiece (12) of the clamp chuck (32) of the machine tool (30) according to the command of the robot control device (43), the workpiece (12) is gripped, and the gripped workpiece (12) is transferred to a predetermined workpiece (12) discharge position.
[0041] In a preferred embodiment, the control method of the workpiece processing automation system includes a workpiece alignment device (20) that aligns the rotation center of the workpiece (12) transferred from the workpiece storage rack (10) so that it is placed at the center of a predetermined position, and further includes a workpiece rotation center alignment step (S20) that controls the rotation and joint movement of a robot arm (42) equipped with a gripper (50) according to the command of the robot control device (43) to grasp the workpiece (12) from the storage portion (11) of the workpiece storage rack (10), place it on the workpiece alignment device (20), and align the rotation center of the workpiece (12).
[0042] The above workpiece chucking step (S30) is characterized by controlling the rotation and joint movement of the robot arm (42) according to the command of the robot control device (43) to transfer the workpiece (12) from the workpiece alignment device (20) to the spindle (34) position of the machine tool (30).
[0043] In a preferred embodiment, the control method of the workpiece processing automation system is characterized by measuring the coordinate value of the outer diameter of the clamp chuck (32) in the clamp chuck rotation center verification step (S10) to calculate the coordinate value of the rotation center of the clamp chuck (32).
[0044] In a preferred embodiment, in the step (S10) of verifying the rotation center of the clamp chuck in the control method of the workpiece processing automation system, the rotation center coordinate value of the clamp chuck (32) is detected by installing a datum ball (37) at the installation position of the clamp chuck on the table (35) of the machine tool (30) and measuring the coordinate value of the datum ball (37) with a measuring instrument (33) housed in the machine tool (30).
[0045] In a preferred embodiment, in the workpiece rotation center alignment step (S20) of the control method of the workpiece processing automation system, the gripper (50) is coupled to the tip of the robot arm (42), and the workpiece (12) is vacuum-adsorbed by the front vacuum suction part (53) and mounted on the workpiece alignment device (20).
[0046] In a preferred embodiment, in the workpiece rotation center alignment step (S20) of the control method of the workpiece processing automation system, the gripper (50) is formed with three jaws that are variablely operated to be extendable toward the center point, and the gripping force of the jaws is adjusted by a motor to vacuum-adsorb the workpiece (12) and mount it on the workpiece alignment device (20).
[0047] In a preferred embodiment, in the workpiece rotation center alignment step (S20) of the control method of the workpiece processing automation system, the workpiece (12) mounted on the workpiece alignment device (20) is guided by a center guide pin (21) and a support pin (22) installed in the center of the workpiece alignment device (20), so that the rotation center of the workpiece (12) is aligned with the center of the workpiece alignment device (20).
[0048] In a preferred embodiment, when the shank portion (52) of the gripper (50) that has grasped the workpiece (12) is inserted into the spindle (34) during the workpiece chucking step (S30) of the control method of the workpiece processing automation system, the robot control device (43) inserts the shank portion (52) of the gripper (50) by conformal control of the robot (40) to prevent the shank portion (52) of the gripper (50) from being inserted into the spindle (34) of the machine tool (30) with malocclusion.
[0049] In a preferred embodiment, the control method of the workpiece processing automation system further includes a workpiece position verification step (S40) in which, after the workpiece chucking step (S30) of the workpiece processing automation system, the spindle (34) equipped with the measuring instrument (33) is moved to a specific coordinate position of the workpiece (12) that is predefined, and the specific position of the workpiece (12) held by the clamp chuck (32) is measured to check whether the center of rotation of the workpiece (12) coincides with the center of rotation of the clamp chuck (32) calculated in the clamp chuck center of rotation verification step (S10), and if the result of the verification is that the center of rotation of the workpiece (12) does not coincide with the center of rotation of the clamp chuck (32) within an allowable tolerance range, the workpiece (12) is discharged from the machine tool (30) and the workpiece center of rotation alignment step (S20) and the workpiece chucking step (S30) are performed again.
[0050] In a preferred embodiment, the method further includes a workpiece quality measurement step (S60) in which, after the workpiece processing step (S50) of the control method of the workpiece processing automation system, the measuring instrument (33) is replaced and mounted on the spindle (34) according to the command of the machine tool control device (31), and a plurality of pre-specified processing parts of the workpiece (12) are measured to determine whether they fall within a predetermined allowable tolerance range.
[0051] In a preferred embodiment, the values of a plurality of processed parts of the workpiece (12) measured in the workpiece quality measurement step (S60) of the control method of the workpiece processing automation system are stored in a database and utilized as quality control information.
[0052] In a preferred embodiment, in the workpiece quality measurement step (S60) of the control method of the workpiece processing automation system, if the measured value of the processing part of the workpiece (12) does not fall within a predetermined allowable tolerance range, the fact of the processing defect of the workpiece (12) is displayed through an alarm or display device, and measures are taken according to a predetermined procedure.
[0053] The present invention allows a workpiece (12) that has high hardness, low brittleness, and requires high precision to be held without breakage or damage, and enables the rotation center of the workpiece (12) and the rotation center of the machine tool (30) to be accurately aligned, thereby minimizing the processing allowance of the workpiece (12), automating the processing of the workpiece (12), and improving processing productivity.
[0054] In addition, the present invention enables automatic measurement of the workpiece (12) after the processing of the workpiece (12), thereby stabilizing the processing quality of the workpiece (12) and further facilitating quality control.
[0055] FIG. 1 is a layout diagram of a machine device constituting a workpiece processing automation system as an embodiment of the present invention.
[0056] FIG. 2 is a block diagram of a workpiece processing automation system as an embodiment of the present invention.
[0057] FIG. 3 is a perspective view showing the upper surface of a workpiece alignment device as an embodiment of the present invention.
[0058] FIG. 4 is a schematic diagram of an embodiment of the present invention, showing how to measure a reference point using a datum ball and a measuring instrument on a table of a machine tool.
[0059] Figure 5 is a photograph showing the outer diameter of a clamp chuck mounted on a machine tool table using a measuring instrument mounted on a machine tool as an embodiment of the present invention.
[0060] FIG. 6 is a cross-sectional view of a gripper mounted on the tip of a robot arm of a robot as an embodiment of the present invention.
[0061] FIG. 7 is a control flowchart of a workpiece processing automation system as an embodiment of the present invention.
[0062] FIG. 8 is a partial perspective view of an embodiment of the present invention, in which a workpiece is mounted on the spindle of a machine tool using a robot and a gripper, and then the spindle is moved to grip the workpiece in a clamp chuck.
[0063] FIG. 9 is a schematic diagram of an embodiment of the present invention, in which a workpiece that has been processed is measured while being held in a clamp chuck using a measuring instrument built into a machine tool.
[0064] Unless otherwise specifically limited in the following embodiments, a machine tool refers to a multi-axis composite machine tool, such as a machining center, comprising a rotary axis system including a spindle that grips a tool and rotates and a table that supports a workpiece and rotates by angle division, and a feed axis system that moves a body or a specific component of the rotary axis system linearly in one direction, wherein a clamp chuck for gripping a workpiece is provided on the table of the rotary axis system.
[0065] However, in the following embodiments, if the machine tool is specified as a turning center, the spindle of the machine tool is understood to be replaced by the tool post of the turning center, and the table that clamps the workpiece or the clamp chuck installed on the table is understood to be replaced by the main spindle of the turning center that rotates while fixed in a specific position.
[0066] In addition, in this embodiment, the term "measuring device" refers to a three-dimensional measuring mechanism that includes a digital indicator that detects three-dimensional (X, Y, Z direction) coordinate values of a specific point on a workpiece or tool and provides them to a machine tool control device.
[0067]
[0068] Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. 1 to 9.
[0069] First, FIG. 1 is a layout diagram of a machine device constituting a workpiece processing automation system as an embodiment of the present invention, and FIG. 2 is a block diagram constituting a workpiece processing automation system as an embodiment of the present invention.
[0070] Referring to FIGS. 1 and 2, the workpiece processing automation system of the present embodiment comprises a workpiece storage rack (10) loaded with several workpieces (12) to be processed, a workpiece alignment device (20) that aligns the rotation center of a workpiece (12) transferred from the workpiece storage rack (10) to the center of a predetermined position, a machine tool (30) that processes the workpiece (12), and a robot (40) that moves the workpiece (12) from the workpiece storage rack (10) to the workpiece alignment device (20) or moves the workpiece (12) from the workpiece alignment device (20) to the machine tool (30), and also discharges the workpiece (12) that has been processed by the machine tool (30).
[0071] The above workpiece storage rack (10), the above workpiece alignment device (20), and the above machine tool (30) are positioned in a location accessible by the robot arm (42) through rotation and joint movement.
[0072] Preferably, in this embodiment, the robot (40) is positioned between the workpiece storage rack (10) and the workpiece alignment device (20), and the machine tool (30) is positioned to the side of the robot (40), so that the workpiece storage rack (10), the workpiece alignment device (20), and the machine tool (30) are each positioned in a location accessible by the robot arm (42) through rotation and joint movement.
[0073]
[0074] Additionally, referring to FIG. 2, the workpiece processing automation system of the present embodiment is configured such that a robot control device (43) controlling a robot (40) and a machine tool control device (31) controlling a machine tool (30) are connected to communicate with each other so as to share control information, and the robot control device (43) and the machine tool control device (31) are connected to communicate with an integrated control device (60) so as to communicate control information, and are sequentially controlled by the integrated control device (60).
[0075]
[0076] Additionally, referring to FIG. 1, the workpiece storage unit (10) is equipped with a tower-type multi-stage drawer storage unit (11) to accommodate workpieces (12) to be processed.
[0077] Although various types of workpieces (12) can be stored in the storage portion (11), in this embodiment, a workpiece (12) formed in the shape of a disc or annular shape with low brittleness and high hardness is stored.
[0078] The workpiece (12) of the storage unit (11) is stored at a specific location due to the structure of the storage unit (11), and this location of the workpiece (12) of the storage unit (11) is shared with the robot control device (43).
[0079]
[0080] FIG. 3 is a perspective view showing the upper surface of a workpiece alignment device (20) as an embodiment of the present invention. Referring to FIG. 3, a center guide pin (21) is installed at the upper center of the workpiece alignment device (20) to guide the center of the workpiece (12) to be positioned at the center when the workpiece (12) is mounted, and a plurality of support pins (22) are installed radially around the center guide pin (21) to support the workpiece (12) in an upward direction.
[0081] The above center guide pin (21) and support pin (22) are each installed to have elasticity in the vertical direction so that the lower surface of the workpiece (12) does not come into contact with the upper surface of the workpiece alignment device (20) and is supported without impact on the upper end of each support pin (22), thereby preventing the lower surface of the workpiece (12) from being contaminated by the upper surface of the alignment device.
[0082] Additionally, the center guide pin (21) guides the center formed in the workpiece (12) during the process of mounting the workpiece (12) on the upper part of the workpiece alignment device (20) from the workpiece storage stand (10), so that the rotation center of the workpiece (12) is guided to a predetermined position by the center guide pin (21).
[0083]
[0084] FIG. 4 is a schematic diagram of a reference point being measured using a datum ball (37) and a measuring instrument (33) on a table (35) of a machine tool (30) as an embodiment of the present invention. FIG. 5 is a photograph of a clamp chuck (32) mounted on a table (35) of a machine tool (30) being measured using an indicator mounted on the machine tool (30) as an embodiment of the present invention.
[0085] Referring to FIG. 4 and 5, the machine tool (30) of the present embodiment is equipped with a machine tool control device (31), a spindle (34) that holds and rotates a tool (36), and a table (35) that has at least one rotation axis system and is equipped with a clamp chuck (32) that holds a workpiece (12) on its upper side, and the spindle (34) is configured with a feed axis system in which its body moves up and down or left and right.
[0086] In addition, the machine tool (30) of the present embodiment includes a plurality of tools (36) and a measuring instrument (33) that are stored in a tool magazine (not shown) and mounted on a spindle (34) by a tool exchange control command of a machine tool control device (31) to process a workpiece (12).
[0087] In this embodiment, the measuring device (33) is mounted on the spindle (34) by a command from the machine tool control device (31) as an indicator and is used to measure a designated part of the workpiece (12) or the outer diameter of the clamp chuck (32).
[0088] In addition, the control device of the machine tool (30) shares control information with the robot control device (43) and the integrated control device (60), and is sequentially controlled by the integrated control device (60).
[0089]
[0090] In another embodiment, a turning center may be used as the machine tool (30) used in the workpiece processing automation system. In this case, the spindle (34) in the above embodiment is replaced by a tool holder (not shown) of the turning center, and the table (35) for clamping the workpiece (12) and the clamp chuck (32) on the table (35) are replaced by the main spindle of the turning center.
[0091]
[0092] Meanwhile, referring to FIG. 1 and 2, the robot (40) is a collaborative robot with lower positional precision or repeatability precision compared to an industrial robot, and is equipped with a base part (41) placed between a workpiece storage rack (10) and a workpiece alignment device (20), and a robot arm (42) consisting of multiple joints that rotate and joint movements on the upper part of the base part (41).
[0093] Additionally, the robot (40) is equipped with a robot control device (43) that controls the rotational movement and joint movement of the robot arm (42). The robot control device (43) is connected via data communication to share control information, including work information and position information, with a machine tool control device (31) that controls the machine tool (30), and is also connected to share control information with an integrated control device (60).
[0094] The robot control device (43) controls the robot arm (42) to transfer the workpiece (12) from the storage section (11) of the workpiece storage rack (10) to the workpiece alignment device (20), and also sequentially controls the workpiece (12) to transfer from the workpiece alignment device (20) to the machine tool (30).
[0095]
[0096] FIG. 6 is a cross-sectional view of a gripper (50) mounted on the tip of a robot arm (42) as an embodiment of the present invention. Referring to FIG. 1 and FIG. 6, the gripper (50) has a mounting hole (51) formed on one side so as to be detachably formed on the tip of the robot arm (42), a shank portion (52) at the rear that can be mounted on the spindle (34) of a machine tool (30), such as a tool (36) stored in a tool magazine (not shown) of a machine tool (30), and a vacuum suction portion (53) at the front that can vacuum suction a workpiece (12).
[0097] In another embodiment, the vacuum suction part (53) of the gripper (50) can be formed by replacing it with three jaws that are variablely operated to extend and retract toward the center point, and the jaws can be formed with a structure in which the gripping force is controlled by a motor.
[0098]
[0099] Meanwhile, the integrated control device (60) of the workpiece processing automation system of the present embodiment is connected in a state capable of communication to share control information with the robot control device (43) that controls the robot (40) and the machine tool control device (31) that controls the machine tool (30).
[0100] Accordingly, the integrated control device (60) controls the robot arm (42) to transfer the workpiece (12) from the storage section (11) of the workpiece storage unit (10) to the workpiece alignment device (20), sequentially controls the workpiece (12) to be transferred from the workpiece alignment device (20) to the machine tool (30), and controls the machine tool (30) to discharge the workpiece (12) after processing is completed.
[0101]
[0102] Hereinafter, a control method for a workpiece processing automation system will be described with reference to the configuration of the present invention of the above embodiment and FIGS. 7 to 9.
[0103] FIG. 7 is a control flowchart of a workpiece processing automation system as an embodiment of the present invention, FIG. 8 is a partial perspective view as an embodiment of the present invention in which a workpiece (12) is mounted on a spindle (34) of a machine tool (30) using a robot (40) and a gripper (50), and then the spindle (34) is moved to grip the workpiece (12) in a clamp chuck (32), FIG. 9 is a schematic diagram as an embodiment of the present invention in which a measuring device (33) built into the machine tool (30) measures the workpiece (12) that has been processed while gripping it in the clamp chuck (32).
[0104] Hereinafter, a control method for a workpiece processing automation system will be explained with a focus on FIG. 7, and with auxiliary reference to FIGS. 8 and 9 and FIGS. 1 to 6 introduced earlier.
[0105]
[0106] First, the clamp chuck rotation center verification step (S10) is performed.
[0107] In this step, according to the sequential control command of the integrated control device (60), the machine tool control device (31) controls the mounting of a measuring device (33), which is detachably mounted on a tool magazine installed on the machine tool (30), onto the spindle (34) through a tool change command. At this time, the measuring device (33) mounted on the spindle (34) is an indicator that provides three-dimensional coordinate values by the contact point of the tip touching.
[0108] The machine tool control device (31) moves the spindle (34) equipped with a measuring instrument (33) to the position of the clamp chuck (32) mounted on one side of the table (35) of the machine tool (30) to hold the workpiece (12), measures the coordinate values of the outer diameter of the clamp chuck (32) at least three points, and calculates the coordinate values of the rotation center of the clamp chuck (32) according to the measured coordinate values.
[0109] In addition, the machine tool control device (31) shares the calculated rotation center coordinate value of the clamp chuck (32) with the robot control device (43), and at the same time shares the information on the completion of the calculation of the rotation center coordinate value of the clamp chuck (32) with the integrated control device (60), so that the integrated control device (60) sequentially controls the next operation.
[0110] Meanwhile, in another embodiment as disclosed in FIG. 4, the rotation center coordinate value of the clamp chuck (32) can be detected as the rotation center coordinate value of the clamp chuck (32) by installing a datum ball (37) at the installation position of the clamp chuck (32) on the table (35) and by measuring the coordinate value of the datum ball (37) through the control of the spindle (34) of the machine tool control device (31) by the measuring instrument (33).
[0111] Meanwhile, in another embodiment, when a turning center is used as a machine tool (30), a measuring instrument (33) is mounted on the tool holder of the turning center through a tool change command of the machine tool control device (31), and the tool holder is moved to measure the outer diameter coordinate value of the main spindle or the clamp chuck (32) mounted on the main spindle, thereby calculating the rotation center coordinate value of the main spindle or the clamp chuck (32).
[0112] However, if the machine tool (30) is a turning center, the position of the main spindle is specified to a specific position, so this step of detecting the rotation center coordinate value of the main spindle or clamp chuck (32) may be omitted.
[0113] However, considering the weak brittleness and high hardness of the workpiece (12), when gripping the workpiece (12) by mounting a clamp chuck (32) for gripping the workpiece (12) on the main spindle, it is preferable to go through the process of detecting the center of rotation of the clamp chuck (32) as described above.
[0114] Meanwhile, the clamp chuck rotation center verification step (S10) is performed only once when processing the first workpiece (12) when processing the same workpiece (12) repeatedly, and is omitted from the second workpiece (12) onwards.
[0115]
[0116] Next, the workpiece rotation center alignment step (S20) is executed.
[0117] In this step, as illustrated in FIGS. 1 to 3, when the completion signal of the clamp chuck rotation center verification step (S10) is received, the robot control device (43) controls the rotation and joint movement of the robot arm (42) equipped with a gripper (50) at its tip according to the sequential control command of the integrated control device (60) to grasp the workpiece (12) from the storage section (11) of the workpiece storage stand (10) and place it on the workpiece alignment device (20).
[0118] At this time, as shown in FIG. 6, the front end of the robot arm (42) is connected to the mounting hole (51) installed on one side of the gripper (50), and the workpiece (12) is vacuum-adsorbed to the front vacuum suction part (53) to move the workpiece (12).
[0119] In another embodiment, the gripper (50) may be formed with three jaws that are variably operated to extend toward a center point, and the gripper (50) may be capable of adjusting the gripping force of the jaws by a motor.
[0120] Additionally, referring to FIG. 3, at this stage, the robot (40) transfers and mounts the workpiece (12) to the upper center of the workpiece alignment device (20) under the control of the robot control device (43). However, the robot (40) used at this time is a collaborative robot (40), and the positional precision or repeatability of the robot arm (42) is relatively low, so the rotation center of the workpiece (12) may have an error with the center of the workpiece alignment device (20).
[0121] Nevertheless, the workpiece (12) mounted on the workpiece alignment device (20) by the robot arm (42) is guided by the center guide pin (21) and support pin (22) installed in the center of the workpiece alignment device (20), so that the rotation center of the workpiece (12) is aligned with the center of the workpiece alignment device (20).
[0122] Therefore, the rotation center of the workpiece (12) transferred from the workpiece storage rack (10) to the workpiece alignment device (20) can be accurately aligned without using an expensive industrial robot with high positional precision.
[0123]
[0124] Next, the workpiece chucking step (S30) is performed.
[0125] Referring to FIG. 8, in this step, when the completion signal of the workpiece rotation center alignment step (S20) is received, the robot control device (43) controls the rotation and joint movement of the robot arm (42) equipped with a gripper (50) at its tip according to the sequential control command of the integrated control device (60) to transfer the gripper (50) that has grasped the workpiece (12) from the workpiece alignment device (20) to a position where the spindle (34) of the machine tool (30) is waiting, and the machine tool control device (31) moves the spindle (34) to a position where the workpiece (12) is to be transferred, inserts the shank portion (52) of the gripper (50) that has grasped the workpiece (12) into the tool pocket (not shown) of the spindle (34) to grasp it, and then moves the spindle (34) to the rotation center position of the clamp chuck (32) calculated in the clamp chuck rotation center verification step (S10) so that the gripper (50) is grasped The workpiece (12) is moved to the clamp chuck (32) and gripped.
[0126] At this time, the control process for the robot (40) to grasp the workpiece (12) from the workpiece alignment device (20) involves the robot control device (43) moving the robot arm (42) to a position corresponding to the predefined position coordinate value of the workpiece (12) on the workpiece alignment device (20), and using the gripper (50) mounted on the tip of the robot arm (42) to grasp the workpiece (12) mounted on the workpiece alignment device (20).
[0127] In addition, the control process for moving and gripping the workpiece (12) from the robot (40) to the spindle (34) of the machine tool (30) at this time is such that the robot control device (43) moves the gripper (50) gripping the workpiece (12) at the tip of the robot arm (42) to the position of the spindle (34) of the machine tool (30) according to control information previously shared with the machine tool control device (31), and the machine tool control device (31) moves the spindle (34) to a position where the shank portion (52) of the gripper (50) gripping the workpiece (12) at the tip of the robot arm (42) can be inserted according to control information previously shared with the robot control device (43), thereby gripping the workpiece (12) on the spindle (34) by the spindle (34) gripping the shank portion (52) of the gripper (50) inserted into the tool pocket.
[0128] Meanwhile, when the robot control device (43) controls the rotation and joint movement of the robot arm (42) so that the shank portion (52) of the gripper (50) is inserted into the spindle (34) of the machine tool (30), the robot control device (43) overcomes the limitations of the positional precision of the robot (40) through conformal control of the robot (40) to prevent the shank portion (52) of the gripper (50) from being inserted into the spindle (34) of the machine tool (30) with malocclusion due to an error in the positional precision of the robot (40).
[0129] Here, compliance control of the robot (40) is a known technique for controlling the robot (40) so that it can move in response to an external force.
[0130] In this way, because the positional precision of the robot (40) is not as precise as the feed axis system precision of the spindle (34) of the machine tool (30), the robot (40) does not directly grip the workpiece (12) on the clamp chuck (32), but instead mounts the workpiece (12) on the spindle (34) and then grips it by precisely aligning the center of rotation of the workpiece (12) with the center of rotation of the clamp chuck (32) through precise control of the spindle (34).
[0131] In this way, by accurately aligning the center of rotation of the workpiece (12), which has low brittleness and high hardness, with the clamp chuck (32), the amount of processing allowance during processing is minimized, thereby shortening the processing time.
[0132]
[0133] Next, the workpiece position verification step (S40) is executed.
[0134] In this step, when the completion signal of the above workpiece chucking step (S30) is received, the measuring device (33) is replaced and mounted on the spindle (34) by the tool exchange control of the machine tool control device (31), and the spindle (34) is moved to a specific coordinate position of the workpiece (12) that is predefined, so that the specific position of the workpiece (12) held in the clamp chuck (32) is measured and the position of the workpiece (12) is detected. At this time, the position of the workpiece (12) detected through the measuring device (33) can be calculated as the rotation center coordinate value of the workpiece (12).
[0135] It is checked whether the position of the detected workpiece (12) or the rotation center coordinate value of the workpiece (12) matches the rotation center of the clamp chuck (32) calculated in the clamp chuck rotation center verification step (S10) within a predetermined tolerance range.
[0136] If, upon verification, the position of the workpiece (12) does not match the rotation center of the clamp chuck (32) within the allowable tolerance range, the workpiece (12) is discharged to a workpiece alignment device (20) outside the machine tool (30) by the operation of the robot arm (42) through the control of the robot control device (43), thereby performing the workpiece rotation center alignment step (S20) and the workpiece chucking step (S30) again.
[0137] In another embodiment, when a turning center is used as the machine tool (30), the machine tool control device (31) controls the clamp chuck (32) of the above embodiment by replacing it with the main spindle of the turning center and the spindle (34) by replacing it with the tool holder of the turning center.
[0138] Meanwhile, the step of confirming the correct position of the workpiece (S40) may be omitted if the workpiece (12) held in the clamp chuck (32) has a rotation center position error that is not important.
[0139]
[0140] Next, the workpiece processing step (S50) is performed.
[0141] In this step, when the completion signal of the above workpiece position verification step (S40) is received, the machine tool control device (31) changes a specific tool (36) stored in the tool magazine of the machine tool (30) to the spindle (34) according to the sequential control command of the integrated control device (60), and controls the spindle (34) to move to a position corresponding to the rotation center coordinate value of the clamp chuck (32) detected in the above clamp chuck rotation center verification step (S10) or to the rotation center position of the workpiece (12) detected in the above workpiece position verification step (S40) to process the workpiece (12).
[0142]
[0143] Next, the workpiece quality measurement step (S60) is executed.
[0144] Referring to FIG. 9, this step involves, after the workpiece processing step (S50) is completed, replacing the workpiece processing tool (36) on the spindle (34) with a measuring device (33) according to the command of the machine tool control device (31), and measuring the coordinates of a plurality of pre-specified processing parts of the workpiece (12) and storing them in a database.
[0145] The coordinate value of the measurement result of the workpiece (12) is compared with a previously stored reference value to determine whether it falls within a predetermined allowable tolerance range, and if the measurement value of the measurement part of the workpiece (12) exceeds the allowable tolerance range as a result of the determination, the fact of the machining defect is displayed through an alarm or display device and measures are taken according to a predetermined procedure.
[0146] At this time, the measurement values accumulated in the database through the repeated processing of the workpiece (12) are used for quality control of the workpiece (12) through analysis and statistical processes by a separate quality control means.
[0147] Meanwhile, the workpiece quality measurement step (S60) may also be omitted depending on the selective control of the integrated control device (60).
[0148]
[0149] Next, the workpiece discharge step (S70) is performed.
[0150] In this step, when a completion signal of the workpiece quality measurement step (S60) is received, or when the workpiece quality measurement step (S60) is omitted and a completion signal of the workpiece (12) processing in the workpiece processing step (S50) is received, the robot control device (43) moves the robot arm (42) and the gripper (50) to the rotation center coordinate position of the workpiece (12) in the clamp chuck (32) of the machine tool (30) to grip the workpiece (12), and transfers the gripped workpiece (12) to a predetermined workpiece (12) discharge position to discharge it.
[0151] Meanwhile, at this stage, the integrated control device (60) may command the robot control device (43) to discharge the workpiece (12) only if the value measured in the workpiece quality measurement step (S60) is compared with a previously stored reference value and is within the allowable tolerance range, and if the measured value deviates from the allowable tolerance range, it may transmit a signal to the worker to perform additional work or take measures and stop the discharge of the workpiece (12).
[0152]
[0153] As shown in the above embodiment, the present invention grips a workpiece (12) that has high hardness, low brittleness, and requires high precision without breakage or damage, and enables the rotation center of the workpiece (12) and the rotation center of the machine tool (30) to be accurately aligned, thereby minimizing the processing allowance of the workpiece (12), automating the processing of the workpiece (12), and improving processing productivity.
[0154] In addition, the present invention enables automatic measurement of the workpiece (12) after the processing of the workpiece (12), thereby stabilizing the processing quality of the workpiece (12) and further facilitating quality control.
[0155] [Explanation of the symbol]
[0156] 10 Workpiece Storage Rack
[0157] 11 Storage compartment
[0158] 12 works
[0159] 20 Workpiece Alignment Device
[0160] 21 Center guide pin
[0161] 22 support pin
[0162] 30 machine tools
[0163] 31 Machine tool control device
[0164] 32 clamp chuck
[0165] 33 measuring instrument
[0166] 34 spindles
[0167] 35 tables
[0168] 36 tools
[0169] 37 Datum Ball
[0170] 40 robots
[0171] 41 Base section
[0172] 42 robotic arm
[0173] 43 Robot Control Unit
[0174] 50 grippers
[0175] 51 mounting holes
[0176] 52 Sanctuary
[0177] 53 Vacuum suction part
[0178] 60 Integrated Control Unit
[0179] S10 Clamp Chuck Rotation Center Verification Step
[0180] S20 Workpiece rotation center alignment step
[0181] S30 Workpiece Chucking Step
[0182] S40 Workpiece position verification step
[0183] S50 Workpiece processing stage
[0184] S60 Workpiece quality measurement stage
[0185] S70 Workpiece discharge stage
Claims
1. A workpiece storage rack (10) loaded with workpieces (12), and A machine tool (30) for processing the above workpiece (12), and A robot (40) that moves the above workpiece (12) from the above workpiece storage rack (10) to the above machine tool (30), and A workpiece processing automation system comprising a gripper (50) having a part that grips the workpiece (12) and is mounted on the robot (40), and a shank part (52) that is mounted on the spindle (34) of the machine tool (30).
2. A workpiece processing automation system according to claim 1, further comprising an integrated control device (60) that shares control information with a robot control device (43) that controls the robot (40) and a machine tool control device (31) that controls the machine tool (30) and performs sequential control.
3. In paragraph 2, the integrated control device (60) The above robot control device (43) is commanded to transfer the workpiece (12) held by the gripper (50) to the spindle (34) position of the machine tool (30), and The above machine tool control device (31) is commanded so that the spindle (34) grips the shank portion (52) of the gripper (50) that is gripping the workpiece (12), and the spindle (34) is moved to the rotational center position of the clamp chuck (32) to move the workpiece (12) gripped by the gripper (50) to the clamp chuck (32) to grip it, a specific tool (36) stored in the machine tool (30) is exchanged with the spindle (34), and the spindle (34) is moved to the rotational center position of the workpiece (12) to process the workpiece (12). A workpiece processing automation system characterized by commanding the above-mentioned robot control device (43) to move the above-mentioned gripper (50) to the rotational center position of the above-mentioned clamp chuck (32) to grip and discharge the above-mentioned workpiece (12).
4. The workpiece processing automation system according to claim 2, comprising a workpiece alignment device (20) that aligns the rotational center of the workpiece (12) transferred from the workpiece storage stand (10) so that it is at the center of a predetermined position, and wherein the integrated control device (60) commands the robot control device (43) so that the gripper (50) grasps the workpiece (12) from the storage section (11) of the workpiece storage stand (10), places it on the workpiece alignment device (20) to align the rotational center of the workpiece (12), and transfers the workpiece (12) from the workpiece alignment device (20) to the spindle (34) position of the machine tool (30).
5. A workpiece processing automation system according to claim 2, wherein the integrated control device (60) commands the machine tool control device (31) to mount a measuring instrument (33) housed in the machine tool (30) onto the spindle (34) of the machine tool (30) to measure the clamp chuck (32) and calculate the rotation center coordinate value of the clamp chuck (32).
6. A control method for a workpiece processing automation system comprising: a workpiece storage rack (10) loaded with a workpiece (12); a machine tool (30) for processing the workpiece (12); a robot (40) that moves the workpiece (12) from the workpiece storage rack (10) to the machine tool (30) and discharges the workpiece (12) after processing is completed at the machine tool (30); a gripper (50) that grasps the workpiece (12) and can be mounted on the spindle (34) of the robot (40) and the machine tool (30); and an integrated control device (60) that sequentially controls by sharing control information with a robot control device (43) that controls the robot (40) and a machine tool control device (31) that controls the machine tool (30). A clamp chuck rotation center verification step (S10) in which a measuring instrument (33) housed in the machine tool (30) is mounted on the spindle (34) of the machine tool (30) according to the command of the machine tool control device (31), and a clamp chuck (32) that grips the workpiece (12) is measured to calculate the rotation center coordinate value of the clamp chuck (32); A workpiece chucking step (S30) in which the rotation and joint movement of the robot arm (42) are controlled according to the command of the robot control device (43) to transfer the workpiece (12) to a position where the spindle (34) of the machine tool (30) is waiting, and the machine tool control device (31) moves the spindle (34) to grip the shank portion (52) of the gripper (50) that has gripped the workpiece (12) onto the spindle (34), and then moves the spindle (34) to the rotation center position of the clamp chuck (32) calculated in the clamp chuck rotation center verification step (S10) to move the workpiece (12) gripped by the gripper (50) to the clamp chuck (32) to grip it. A workpiece processing step (S50) in which a specific tool (36) stored in the machine tool (30) is exchanged with the spindle (34) according to the command of the machine tool control device (31), and the spindle (34) is moved to the rotation center position of the workpiece (12) to process the workpiece (12); and A control method for a workpiece processing automation system comprising a workpiece discharge step (S70) in which the robot arm (42) and the gripper (50) are moved to the rotation center coordinate position of the workpiece (12) of the clamp chuck (32) of the machine tool (30) according to the command of the robot control device (43), thereby gripping the workpiece (12), and transferring the gripped workpiece (12) to a predetermined workpiece (12) discharge position.
7. In claim 6, the method further includes a workpiece alignment device (20) that aligns the rotation center of the workpiece (12) transferred from the workpiece storage stand (10) so that it is placed at the center of a predetermined position, and further includes a workpiece rotation center alignment step (S20) that controls the rotation and joint movement of a robot arm (42) equipped with a gripper (50) according to a command of the robot control device (43) to grasp the workpiece (12) from the storage section (11) of the workpiece storage stand (10), place it on the workpiece alignment device (20), and align the rotation center of the workpiece (12). The above workpiece chucking step (S30) is characterized by controlling the rotation and joint movement of the robot arm (42) according to the command of the robot control device (43) to transfer the workpiece (12) from the workpiece alignment device (20) to the spindle (34) position of the machine tool (30), thereby controlling the workpiece (12).
8. A control method for a workpiece processing automation system, characterized in that, in the clamp chuck rotation center verification step (S10) of claim 6, the coordinate value of the outer diameter of the clamp chuck (32) is measured to calculate the coordinate value of the rotation center of the clamp chuck (32).
9. A control method for a workpiece processing automation system according to claim 6, wherein in the clamp chuck rotation center verification step (S10), the rotation center coordinate value of the clamp chuck (32) is detected by installing a datum ball (37) at the installation position of the clamp chuck (32) on the table (35) of the machine tool (30) and measuring the coordinate value of the datum ball (37) with a measuring instrument (33) housed in the machine tool (30).
10. A control method for a workpiece processing automation system according to claim 7, wherein in the workpiece rotation center alignment step (S20), the gripper (50) is coupled to the tip of the robot arm (42), and the workpiece (12) is vacuum-adsorbed by a front vacuum suction part (53) and mounted on the workpiece alignment device (20).
11. A control method for a workpiece processing automation system according to claim 7, wherein in the workpiece rotation center alignment step (S20), the gripper (50) is formed with three jaws that are variablely operated to extend and retract toward a center point, and the gripping force of the jaws is adjusted by a motor to vacuum-adsorb the workpiece (12) and mount it on the workpiece alignment device (20).
12. A control method for a workpiece processing automation system according to claim 7, wherein in the workpiece rotation center alignment step (S20), the workpiece (12) mounted on the workpiece alignment device (20) is guided by a center guide pin (21) and a support pin (22) installed in the center of the workpiece alignment device (20), so that the rotation center of the workpiece (12) is aligned with the center of the workpiece alignment device (20).
13. A control method for a workpiece processing automation system according to claim 6, wherein when the shank portion (52) of the gripper (50) that has grasped the workpiece (12) in the workpiece chucking step (S30) is inserted into the spindle (34) and grasped, the robot control device (43) inserts the shank portion (52) of the gripper (50) by conformal control of the robot (40) to prevent the shank portion (52) of the gripper (50) from being inserted into the spindle (34) of the machine tool (30) in a malocclusion.
14. A control method for a workpiece processing automation system according to claim 7, further comprising a workpiece position verification step (S40) in which, after the workpiece chucking step (S30), the spindle (34) equipped with the measuring instrument (33) is moved to a specific coordinate position of the workpiece (12) that is predefined, and the specific position of the workpiece (12) held in the clamp chuck (32) is measured to check whether the center of rotation of the workpiece (12) coincides with the center of rotation of the clamp chuck (32) calculated in the clamp chuck center of rotation verification step (S10), and if the center of rotation of the workpiece (12) does not coincide with the center of rotation of the clamp chuck (32) within an allowable error range as a result of the verification, the workpiece (12) is discharged from the machine tool (30) and the workpiece center of rotation alignment step (S20) and the workpiece chucking step (S30) are performed again.
15. A control method for a workpiece processing automation system according to claim 6, further comprising a workpiece quality measurement step (S60) in which, after the workpiece processing step (S50), the measuring instrument (33) is replaced and mounted on the spindle (34) according to the command of the machine tool control device (31), and a plurality of pre-specified processing parts of the workpiece (12) are measured to determine whether they fall within a predetermined allowable tolerance range.
16. A control method for a workpiece processing automation system, characterized in that, in the workpiece quality measurement step (S60) of claim 15, the values of a plurality of processing parts of the workpiece (12) are stored in a database and utilized as quality control information.
17. A control method for a workpiece processing automation system according to claim 15, characterized in that if the measured value of the processed part of the workpiece (12) in the workpiece quality measurement step (S60) does not fall within a predetermined allowable tolerance range, the fact of the processing defect of the workpiece (12) is displayed through an alarm or display device and measures are taken according to a predetermined procedure.