Underwater polishing system and underwater polishing method

Abstract

To solve such a problem that in the case of dry polishing, a brown burn occurred due to frictional heat and it was difficult to reduce a surface roughness of a polished surface, and polishing quality and productivity could not be simultaneously improved.SOLUTION: An underwater polishing system comprises a water tank, a robot, and a polishing machine. In a state that a work-piece held by an arm part of the robot and at least a part of a second rotary roller and a polishing tool of the polishing machine are immersed in a liquid accumulated in the water tank, the arm part of the robot is operated to press the work-piece held thereby against the polishing tool, and polishing is executed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an underwater polishing system and an underwater polishing method. [Background technology]

[0002] A known polishing device is one that rotates a belt-shaped sandpaper to contact the surface of a workpiece placed on a stand and polish it, as described in Patent Document 1. Meanwhile, in the manufacturing process of semiconductor devices, a method of polishing or cutting in liquid is also known (see, for example, Patent Documents 2 and 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-132063 A [Patent Document 2] JP 2006-24910 A [Patent Document 3] JP 2017-94455 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of dry polishing, brown marks occur due to frictional heat, and it is difficult to reduce the surface roughness of the polished surface, making it impossible to simultaneously improve polishing quality and productivity. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided an underwater polishing system including a water tank capable of storing liquid, a robot having an arm unit for holding a workpiece as a workpiece and moving at least a part of the held workpiece from outside the water tank to the liquid stored in the water tank and from the liquid stored in the water tank to outside the water tank by operating the arm unit, and a polisher having a first rotating roller, a second rotating roller, and a polishing tool bridged between the first rotating roller and the second rotating roller, in which at least a part of the second rotating roller and the polishing tool are immersed in the liquid stored in the water tank. The system is characterized in that, with the workpiece held by the arm unit of the robot and at least a part of the second rotating roller and the polishing tool of the polisher immersed in the liquid stored in the water tank, the arm unit of the robot is operated to press the held workpiece against the polishing tool to perform polishing.

[0006] According to one aspect of the present invention, there is provided an underwater polishing method comprising: a workpiece holding step of holding a workpiece, which is an object to be processed, with an arm portion of a robot; a polishing machine driving step of driving a polishing tool bridged between a first rotating roller and a second rotating roller of a polishing machine; a liquid storing step of storing liquid in a water tank; and a polishing step of operating the arm portion of the robot to press the held workpiece against the polishing tool and polish it while immersing the workpiece held by the arm portion of the robot and at least a portion of the second rotating roller and the polishing tool of the polishing machine in the liquid stored in the water tank. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an underwater polishing system according to the first embodiment. [Diagram 2] FIG. 2 is a functional block diagram of the control unit. [Diagram 3] FIG. 3 is an enlarged view of the polishing point and its surroundings. [Figure 4]FIG. 4 is a diagram showing an underwater polishing system according to the second embodiment. [Diagram 5] FIG. 5 is a diagram showing an underwater polishing system according to the third embodiment. [Figure 6] FIG. 6 is a diagram showing a modified example of the third embodiment. [Figure 7] FIG. 7 is a diagram showing an underwater polishing system according to the fourth embodiment. [Figure 8] FIG. 8 is an enlarged view of the main part of the measurement mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (First embodiment) Fig. 1 is a diagram showing an underwater polishing system according to a first embodiment, Fig. 2 is a functional block diagram of a control unit, and Fig. 3 is an enlarged view showing the periphery of a polishing point. The underwater polishing system 1 shown in FIG. 1 includes a water tank 10, a robot 30, a polishing machine 50, and a control unit 70.

[0009] In this embodiment, the water tank 10 is a rectangular parallelepiped container that opens to the top. The water tank 10 is capable of storing a liquid L therein. In this embodiment, the liquid L is water. A liquid other than water can also be used as the liquid L. The shape of the water tank 10 is not particularly limited, and is determined to be a shape that can exhibit the required liquid storage function in the underwater polishing system 1.

[0010] The robot 30 includes an arm unit 31 that holds a workpiece W, which is a workpiece, and a base unit 32 that supports the arm unit 31. The robot 30 of this embodiment is a six-axis articulated robot. That is, the arm unit 31 is a articulated arm that has six joint axes, a first axis to a sixth axis, from the base unit 32 side. A known articulated arm can be used as the arm unit 31.

[0011] The arm unit 31 has an arm main body 33 in which multiple arms are connected via joint axes, a force sensor 34 attached to the tip of the arm main body 33, and a robot hand 35 attached to the tip side of the force sensor 34. The arm main body 33 is connected to the base unit 32 via a first axis. The robot hand 35 holds the workpiece W so that it can be transferred. The robot hand 35 holds the workpiece W by gripping or adsorbing it. The force sensor 34 detects an external force acting on the robot hand 35. A detection value of the force sensor 34 is output to the control unit 70.

[0012] The robot 30 operates the arm unit 31 to move the workpiece W that it holds into and out of the water tank 10. That is, the robot 30 moves at least a part of the workpiece W that it holds from outside the water tank 10 into the liquid L stored in the water tank 10. The robot 30 also moves at least a part of the workpiece W that it holds from the liquid L stored in the water tank 10 to outside the water tank 10.

[0013] In the robot 30, the parts that are immersed in the liquid L and the parts that may come into contact with the liquid L are subjected to necessary waterproofing treatment according to the parts. For example, the robot hand 35 and the force sensor 34 that are immersed in the liquid L, and the tip of the arm main body 33 that may be immersed in the liquid L, are configured to have dustproof and waterproof performance of about IP67 as specified by the IEC (International Electrotechnical Commission) and the JIS (Japanese Industrial Standards). The waterproof performance is a performance that allows the workpiece W to be immersed in the liquid L to a desired depth. On the other hand, the parts that are not immersed in the liquid L, such as the base end side of the arm main body 33, may have relatively low waterproof performance.

[0014] The polishing machine 50 includes a first rotating roller 51, a second rotating roller 52, a polishing tool 53, a belt arm 54, and a polishing machine body 55. The belt arm 54 is connected to the polishing machine body 55 at one end in the longitudinal direction. The belt arm 54 is rotatable about a rotation axis located at the connection portion with the polishing machine body 55.

[0015] A first rotating roller 51 and a second rotating roller 52 are attached to both ends of the belt arm 54 in the longitudinal direction. The first rotating roller 51 is located near the connection between the belt arm 54 and the grinder main body 55. The second rotating roller 52 is located at the tip of the belt arm 54. The first rotating roller 51 and the second rotating roller 52 are rotatable around a rotation axis extending in a direction perpendicular to the longitudinal direction of the belt arm 54. The rotation axis J1 of the first rotating roller 51 and the rotation axis J2 of the second rotating roller 52 are arranged parallel to each other.

[0016] The polishing tool 53 is an endless belt that is stretched with a constant tension between the first rotating roller 51 and the second rotating roller 52. The polishing tool 53 has a belt-shaped base material and abrasive grains fixed to one surface of the base material. The polishing tool 53 is stretched between the first rotating roller 51 and the second rotating roller 52 with the surface to which the abrasive grains are fixed facing outward.

[0017] The grinding machine body 55 has a drive mechanism 56 that drives the grinding tool 53. In this embodiment, the drive mechanism 56 of the grinding machine body 55 is a motor that rotates and drives the first rotating roller 51. The grinding tool 53 is driven to rotate by the rotation of the first rotating roller 51. The second rotating roller 52 rotates in association with the running of the grinding tool 53. That is, in this embodiment, the first rotating roller 51 is a drive roller, and the second rotating roller 52 is a driven roller.

[0018] The polishing machine 50 is used with a portion thereof that polishes the workpiece W immersed in the liquid L stored in the water tank 10. In this embodiment, as shown in FIG. 1, at least the second rotating roller 52 and a portion of the polishing tool 53 of the polishing machine 50 are immersed in the liquid L. In this embodiment, the second rotating roller 52 that is immersed in the liquid L is a driven roller that does not have any electrical components, and therefore does not require a waterproof structure to protect the electrical components. There is no need to add a configuration for underwater polishing to the polishing machine 50, and this makes it possible to suppress the polishing machine 50 from becoming complicated and increasing in cost.

[0019] The control unit 70 comprehensively controls the underwater polishing system 1. The control unit 70 is connected to the robot 30 and the polishing machine 50. The robot 30 has a robot control unit 71 that functions as a subordinate device of the control unit 70. The polishing machine 50 has a polishing machine control unit 72 that functions as a subordinate device of the control unit 70.

[0020] As shown in Fig. 2, the control unit 70 and the robot control unit 71, and the control unit 70 and the grinder control unit 72 are connected to each other so that they can communicate with each other. The robot control unit 71 is connected to the arm unit 31, the force sensor 34, and the robot hand 35 of the robot 30 via a bus 71a, and controls the operation of the robot 30. The grinder control unit 72 is connected to the drive mechanism 56 via a bus 72a, and controls the operation of the grinder 50. Note that Fig. 2 shows only the configuration necessary for explanation.

[0021] The underwater polishing system 1 having the above-described configuration polishes the workpiece W with the second rotating roller 52 of the polisher 50 and the workpiece W immersed in the liquid L stored in the water tank 10, as shown in FIG.

[0022] The underwater polishing method of this embodiment includes a work holding process in which the workpiece W, which is the object to be processed, is held by the arm portion 31 of the robot 30; a polishing machine driving process in which a polishing tool 53 bridged between the first rotating roller 51 and the second rotating roller 52 of the polishing machine 50 is driven; a liquid storage process in which a liquid L is stored in the water tank 10; and a polishing process in which the arm portion 31 of the robot 30 is operated to press the held workpiece W against the polishing tool 53 and polish it while immersing the workpiece W held by the arm portion 31 of the robot 30 and at least a portion of the second rotating roller 52 and the polishing tool 53 of the polishing machine 50 in the liquid L stored in the water tank 10.

[0023] In the workpiece holding step, the control unit 70 outputs a command to the robot 30 to move the workpiece W to a polishing position. Under the control of the robot control unit 71, the robot 30 operates the arm unit 31 and picks up the workpiece W from a workpiece supply position (not shown) using the robot hand 35. The robot 30 moves the workpiece W held by the robot hand 35 into the liquid L.

[0024] In the grinder driving step, the control unit 70 operates the grinder 50. The control unit 70 outputs a command to the grinder control unit 72 to run the grinding tool 53. Under the control of the grinder control unit 72, the grinder 50 rotates the first rotating roller 51 by the drive mechanism 56 to drive the grinding tool 53 to rotate.

[0025] In the polishing process, the robot 30 brings the workpiece W into contact with the polishing tool 53 in the liquid L. As a result, as shown in FIG. 3, a predetermined position of the workpiece W comes into contact with the polishing tool 53 in the liquid L, and the workpiece W is polished by the polishing tool 53. At this time, the position where the workpiece W comes into contact with the polishing tool 53 is the polishing point P. In the case of this embodiment, the polishing point P is the apex position where the second rotating roller 52 protrudes most in the horizontal direction in the liquid L. The robot 30 polishes the workpiece W while moving the workpiece W from below to above the polishing point P.

[0026] The control unit 70 continues polishing the workpiece W until a preset end condition is satisfied. The end condition is, for example, the passage of a predetermined polishing time, the detection value of the force sensor 34 reaching a set value, or a stop due to an error.

[0027] During polishing, the robot 30 measures the external force acting on the robot hand 35 using the force sensor 34. The measured detection value is output from the robot control unit 71 to the control unit 70. The control unit 70 manages the state of the polishing process based on the detection value of the force sensor 34. For example, the control unit 70 presses the workpiece W against the polishing tool 53 with a constant force based on the detection value of the force sensor 34.

[0028] The control unit 70 may be capable of adjusting the conditions of the polishing process based on the detection value of the force sensor 34. The conditions of the polishing process include, for example, the posture of the workpiece W, the part of the workpiece W that comes into contact with the polishing tool 53, the pressing force of the workpiece W against the polishing tool 53, the position of the polishing point P on the polishing tool 53, the traveling speed of the polishing tool 53, etc. For example, when an excessive load is detected, the control unit 70 may change the polishing part or posture of the workpiece W or stop the polishing process.

[0029] When the predetermined polishing process is completed, the control unit 70 moves the workpiece W from within the liquid L to the outside of the water tank 10. The control unit 70 moves the workpiece W to a workpiece discharge position (not shown) of the underwater polishing system 1. With the above, the polishing process of the workpiece W is completed.

[0030] According to the underwater polishing system 1 of this embodiment, polishing is performed by contacting the polishing tool 53, which is suspended between the first rotating roller 51 and the second rotating roller 52, with the workpiece W to be polished in the liquid L. According to this configuration, polishing is performed in a liquid with high cooling efficiency, so that the temperature rise due to friction between the polishing tool 53 and the workpiece W is suppressed. Since the workpiece W can be pressed against the polishing tool 53 with a stronger force, the polishing rate can be increased and the processing efficiency can be improved. In addition, by polishing in the liquid L, chips generated by polishing the workpiece W are less likely to adhere to the surface of the polishing tool 53. Since polishing can be performed with the polishing tool 53 in a state where the chips are less attached, scratches are less likely to occur on the polished surface of the workpiece W, and the surface roughness of the polished surface can be reduced. Since the quality of the polished surface is improved, there is a possibility that the polishing process, which previously required two steps of rough polishing and finish polishing, can be performed in one step.

[0031] In this embodiment, the tip portion of the belt arm 54 including the second rotating roller 52 is immersed in the liquid L, but if the polishing point P shown in FIG. 3 is located in the liquid L, the above-mentioned action and effect can be obtained. For example, the portion of the second rotating roller 52 and the workpiece W located above the polishing point P may be exposed above the liquid surface of the liquid L. Therefore, in a state in which the workpiece W and at least a portion of the second rotating roller 52 and polishing tool 53 of the polishing machine 50 are immersed in the liquid L, the arm portion 31 of the robot 30 is operated to press the held workpiece W against the portion of the polishing tool 53 located in the liquid L to perform polishing. In other embodiments described later, a portion of the workpiece W or the polishing tool 53 can be placed outside the liquid L as long as there is no contradiction in the configuration.

[0032] Second embodiment Fig. 4 is a diagram showing an underwater polishing system according to a second embodiment. Among the components shown in Fig. 4, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description of the components will be simplified. The underwater polishing system 1 shown in FIG. 4 includes a water tank 10, a robot 30, a polishing machine 50A, and a control unit 70.

[0033] The polishing machine 50A includes a first rotating roller 51, a second rotating roller 52, a polishing tool 53, a belt arm 54, a polishing machine body 55, a first pulley 57a and a second pulley 57b, an extension arm 58, a drive belt 59, and a polishing table 60.

[0034] The first pulley 57a is connected to a drive mechanism 56 of the grinder body 55. An extension arm 58 extends downward from the connection position between the first pulley 57a and the drive mechanism 56. The upper end of the extension arm 58 is fixed to the housing of the grinder body 55. One end of the belt arm 54 is connected to the lower end of the extension arm 58. The belt arm 54 is rotatable about the connection position with the extension arm 58.

[0035] The first rotating roller 51 and the second pulley 57b are attached to the end of the belt arm 54 on the extension arm 58 side. The first rotating roller 51 and the second pulley 57b are fixed to each other and rotate together around the rotation axis J1. A drive belt 59 is stretched between the first pulley 57a and the second pulley 57b. The drive belt 59 is an endless belt.

[0036] A second rotary roller 52 is attached to the tip of the belt arm 54. A polishing tool 53 is stretched between the first rotary roller 51 and the second rotary roller 52. A polishing table 60 is fixed to the center of the belt arm 54 in the longitudinal direction. The polishing table 60 is located between the polishing tool 53 and the belt arm 54. The polishing table 60 has a tool support surface 60a that faces the inner surface of the polishing tool 53. The polishing tool 53 slides on the tool support surface 60a when traveling.

[0037] A driving mechanism 56 of the grinding machine body 55 drives and rotates the first pulley 57a. This drives the driving belt 59 to rotate, and the second pulley 57b rotates. This causes the first rotating roller 51 fixed to the second pulley 57b to rotate about the rotation axis J1. The rotation of the first rotating roller 51 drives and rotates the grinding tool 53, and causes the second rotating roller 52 to rotate about the rotation axis J2.

[0038] In the polishing machine 50A, polishing is performed with the belt arm 54, the first rotating roller 51, the second rotating roller 52, and the polishing tool 53 all immersed in the liquid L. The robot 30 brings the held workpiece W into contact with the polishing tool 53, which travels by the power of the drive mechanism 56. In this embodiment, a polishing point P where the workpiece W and the polishing tool 53 come into contact is located on the tool support surface 60a of the polishing table 60. By supporting the polishing tool 53 by the polishing table 60, it is possible to prevent the polishing tool 53 from bending at the polishing point P, and the workpiece W can be polished with high precision.

[0039] According to the underwater polishing system 1 of the present embodiment, polishing is performed with the polishing tool 53 entirely immersed in the liquid L, so that the polishing tool 53 is constantly in contact with the liquid L and chips adhering to the surface are easily removed. Since the polishing tool 53 does not travel outside the liquid L, scattering of the liquid L and chips by the polishing tool 53 can be suppressed.

[0040] Although the drive belt 59 moves in and out of the liquid L, an endless belt that is thinner than the polishing tool 53 can be used for the drive belt 59, so that less liquid L and chips are stirred up by the movement of the drive belt 59. In addition, since the drive belt 59 does not come into contact with the workpiece W, even if a cover to prevent scattering is attached to the drive belt 59, it does not interfere with the execution of polishing.

[0041] Third embodiment Fig. 5 is a diagram showing an underwater polishing system according to a third embodiment. Among the components shown in Fig. 5, the same components as those in the first and second embodiments are denoted by the same reference numerals as those in the first and second embodiments, and the description of the components will be simplified. The underwater polishing system 1 shown in FIG. 5 includes a water tank 10A, a robot 30, a polishing machine 50A, and a control unit .

[0042] Aquarium 10A comprises a box-shaped aquarium body 10a that opens upward, a circulation pipe 11 that opens at two points on the bottom surface of aquarium body 10a, a pump 12 and a filter 13 located on the path of circulation pipe 11, a baffle plate 14 located within aquarium body 10a, and an aquarium control unit 73 that controls the operation of aquarium 10A.

[0043] Liquid L is stored in water tank body 10a. Water tank body 10a is divided into two regions 101 and 102 by baffle plate 14. Polishing tool 53 of polisher 50A is entirely immersed in liquid L stored in region 101 of water tank body 10a.

[0044] The circulation pipe 11 has a first pipe 11a that opens into the bottom surface of area 101 of aquarium body 10a, a second pipe 11b that opens into the bottom surface of area 102, and a third pipe 11c that connects first pipe 11a and second pipe 11b. First pipe 11a and third pipe 11c are connected via filter 13. Second pipe 11b and third pipe 11c are connected via pump 12.

[0045] The first pipe 11a is a funnel-shaped pipe whose diameter increases toward the open end on the water tank body 10a side. The second pipe 11b and the third pipe 11c are pipes each having a uniform inner diameter along the direction in which they extend.

[0046] In this embodiment, the water tank control unit 73 drives and controls the pump 12. The water tank control unit 73 is capable of communicating with the control unit 70. The water tank control unit 73 functions as a subordinate device of the control unit 70. The water tank control unit 73 may also be capable of controlling other electronic devices (e.g., a supply valve, a discharge valve, a heater, etc.) installed in the water tank 10A.

[0047] In the underwater polishing system 1 of this embodiment, the workpiece W can be polished while the liquid L is circulated in the water tank 10A. In the polishing process of the workpiece W, the operation of the robot 30 and the polisher 50A is the same as in the first and second embodiments. In the polishing process, the control unit 70 outputs a command to the water tank control unit 73 to drive the pump 12. Under the control of the water tank control unit 73, the water tank 10A pumps the liquid L in the circulation pipe 11 by the pump 12.

[0048] The pump 12 sucks the liquid L from the third pipe 11c and discharges it to the second pipe 11b. As a result, in the water tank 10A, the liquid L is sucked from the water tank body 10a to the first pipe 11a. The liquid L in the first pipe 11a passes through the filter 13, then passes through the third pipe 11c, the pump 12, and the second pipe 11b, and returns to the water tank body 10a. The liquid L discharged from the bottom surface of the area 102 of the water tank body 10a has its flow velocity distribution uniformed by the straightening plate 14 and flows into the area 101. As a result, as shown in FIG. 5, a flow wf of the liquid L is formed along the traveling direction of the polishing tool 53 at the polishing point P where the workpiece W and the polishing tool 53 come into contact with each other.

[0049] The control unit 70 drives the robot 30 to bring the workpiece W into contact with the polishing tool 53 in the liquid L and perform polishing. At this time, a flow wf of the liquid L is formed in the same direction as the traveling direction of the polishing tool 53 at the polishing point P where the workpiece W and the polishing tool 53 come into contact with each other, so that the cuttings of the workpiece W are quickly carried away from the polishing point P by the flow wf of the liquid L and the polishing tool 53.

[0050] 5, the flow wf of the liquid L flows uniformly to the left side in the depth direction of the water tank body 10a due to the action of the straightening plate 14. Therefore, the chips carried by the flow wf are hardly carried toward the polishing point P, but are sucked into the circulation pipe 11 from the opening of the first pipe 11a. The chips sucked into the circulation pipe 11 are collected by the filter 13 and do not return to the water tank body 10a.

[0051] In the underwater polishing system 1 of this embodiment, by forming a flow of the liquid L toward the front side in the traveling direction of the polishing tool 53 at the polishing point P where the polishing tool 53 and the workpiece W come into contact with each other, chips generated during polishing can be quickly removed from the polishing point P. This makes it possible to prevent scratches on the workpiece W due to chips, and thus makes it possible to stabilize the surface roughness of the machined surface of the workpiece W.

[0052] Furthermore, in this embodiment, the water tank 10A is provided with the filter 13, so that the filter 13 can remove chips, detached abrasive grains, and other impurity particles contained in the liquid L circulating within the water tank 10A. This can prevent these particles from entering the polishing point P. This can prevent scratches and the like caused by these particles. Furthermore, because the liquid L is purified by the filter 13, the service life of the liquid L can be extended.

[0053] FIG. 6 is a diagram showing a modified example of the third embodiment. 6, the underwater polishing system 1 of this embodiment may have a tool cleaning mechanism 15 for cleaning the polishing tool 53 in the water tank 10A. In this embodiment, the tool cleaning mechanism 15 is a cylindrical rotating brush extending along a rotation axis J3. The rotation axis J3 is parallel to the rotation axis J1 of the first rotating roller 51. The tool cleaning mechanism 15 made of a rotating brush is rotatable around the rotation axis J3. The rotation axis J3 is fixed to the water tank 10A or the polishing machine 50.

[0054] The tool cleaning mechanism 15 is located near the first rotating roller 51. The tool cleaning mechanism 15 is located at the opening of the first pipe 11a on the bottom surface of the water tank body 10a. In other words, the tool cleaning mechanism 15 is located upstream of the filter 13 (see FIG. 5) in the flow direction of the liquid L in the water tank 10A.

[0055] The outer peripheral surface of the tool cleaning mechanism 15 contacts the outward surface of the polishing tool 53. In this embodiment, the tool cleaning mechanism 15 sandwiches the polishing tool 53 between itself and the first rotating roller 51. The tool cleaning mechanism 15 is rotated in the opposite direction to the first rotating roller 51 by the running polishing tool 53. The tool cleaning mechanism 15 may be a rotating brush that follows the running of the polishing tool 53 as in this embodiment, or may be configured to include a drive mechanism such as a motor that rotates the rotating brush. When the rotating brush is rotated by the drive mechanism, the rotating brush may be rotated against the running of the polishing tool 53.

[0056] In the underwater polishing system 1 of the modified example, chips adhering to the polishing tool 53 can be removed from the polishing tool 53 by the tool cleaning mechanism 15 that comes into contact with the polishing tool 53. This improves the cleanliness of the polishing tool 53 and stabilizes the polishing rate and the surface roughness of the machined surface of the workpiece W. In addition, the chips detached from the polishing tool 53 are sucked into the first pipe 11a by the flow of the liquid L and collected by the filter 13.

[0057] (Fourth embodiment) Fig. 7 is a diagram showing an underwater polishing system according to a fourth embodiment. Fig. 8 is an enlarged view of a main part of a measuring mechanism. Among the components shown in Fig. 7 and Fig. 8, the same components as those in the first to third embodiments are given the same reference numerals as those in those embodiments, and the description of the components is also simplified. The underwater polishing system 1 shown in FIG. 7 includes a water tank 10, a robot 30, a polishing machine 50A, a measuring mechanism 80, and a control unit 70.

[0058] The measuring mechanism 80 is a mechanism for measuring the amount of polishing of the workpiece W. The measuring mechanism 80 has a base 81, a slider 82, a measuring device 83, and a measuring device control unit 74. The base 81 is fixed to the upper surface of the polishing machine body 55. The fixed position of the base 81 is not limited to the polishing machine body 55. The slider 82 is installed on the upper surface of the base 81. The slider 82 is movable in the horizontal direction relative to the base 81. The slider 82 supports the measuring device 83. The measuring device 83 is movable in the horizontal direction together with the slider 82.

[0059] The measuring device 83 includes a cylindrical cylinder 83a that is supported by the slider 82 and extends horizontally, a rod 83b that can advance and retreat relative to the cylinder 83a, and a pad 83c located at the tip of the rod 83b. A displacement measuring unit 83d that detects the displacement of the rod 83b is installed inside the cylinder 83a.

[0060] The measuring device 83 detects the horizontal movement of the rod 83b caused by the external force input to the pad 83c by the displacement measuring unit 83d in the cylinder 83a. The measuring device control unit 74 acquires the detection value of the displacement measuring unit 83d. The measuring device control unit 74 outputs the detection value of the gauge to the control unit 70 as the positional displacement amount of the rod 83b (pad 83c).

[0061] In this embodiment, a positioning member 85 is attached to the grinding machine body 55 via a bracket 84. The positioning member 85 determines the relative position between the workpiece W and the measurement mechanism 80. By contacting a predetermined position of the robot 30 with the positioning member 85, the position of the workpiece W held by the robot hand 35 can be fixed with respect to the positioning member 85. This allows the workpiece W to be positioned with respect to the base 81, which is fixed to the grinding machine body 55 like the positioning member 85. The bracket 84 and the positioning member 85 are made of high rigidity members that can suppress deformation when the robot 30 comes into contact with them. The bracket 84 and the positioning member 85 are made of, for example, metal.

[0062] In the underwater polishing system 1 of this embodiment, the measuring mechanism 80 can measure the amount of polishing of the workpiece W held by the robot 30. The underwater polishing method by the underwater polishing system 1 of this embodiment includes a polishing step of polishing the workpiece W, and a polishing amount measuring step of estimating the amount of polishing of the workpiece W.

[0063] In the polishing process of the workpiece W, the control unit 70 measures the dimensions of the workpiece W before polishing the workpiece W. The control unit 70 outputs a command to the robot 30 to transport the workpiece W to the measurement position shown in FIG. 7 and FIG. 8. The robot 30 places the workpiece W held by the robot hand 35 at a position horizontally facing the pad 83c of the measuring device 83. At this time, the robot 30 brings the force sensor 34 into contact with the positioning member 85. The robot 30 adjusts the horizontal position of the workpiece W based on the detection value of the force sensor 34. That is, by controlling the force of pressing the force sensor 34 against the positioning member 85 to a preset value, the horizontal position of the workpiece W can be controlled with high repeatability and high precision.

[0064] After the workpiece W is placed at a predetermined measurement position, the slider 82 of the measurement mechanism 80 is moved to place the measuring device 83 at the measurement reference position. At the measurement reference position, the slider 82 is fixed to the base 81. The pad 83c of the measuring device 83 located at the measurement reference position is in contact with the polished portion of the workpiece W, and the rod 83b is located at a position slightly pushed in from the position where it protrudes maximally from the cylinder 83a. The measuring device control unit 74 outputs the detection value of the displacement measuring unit 83d at the measurement reference position to the control unit 70. The control unit 70 stores the acquired detection value as the initial position of the polished portion of the workpiece W (the position before polishing). The slider 82 may be moved manually by the measurer, or may be moved by a motorized slider or a linear motor, which is driven and controlled by the measurement device control unit 74 .

[0065] After the measurement of the initial position of the workpiece W is completed, the control unit 70 executes polishing of the workpiece W. In the process of polishing the workpiece W, the operations of the robot 30 and the polisher 50A are similar to those of the first to third embodiments.

[0066] After polishing the workpiece W, the control unit 70 measures the polishing amount of the workpiece W. The control unit 70 outputs a command to the robot control unit 71 to move the workpiece W to a measurement position. Under the control of the robot control unit 71, the robot 30 brings the workpiece W it holds into contact with the pad 83c of the measuring device 83. At this time, the robot 30 presses the force sensor 34 against the positioning member 85, and adjusts the position of the arm unit 31 so that the detection value of the force sensor 34 matches the detection value of the force sensor 34 before polishing. By adjusting the position of the workpiece W based on the detection value of the force sensor 34, the workpiece W can be positioned in the same position with high precision in the two measurement steps before and after polishing.

[0067] By pressing the workpiece W against the pad 83c, the rod 83b is pressed toward the cylinder 83a. The measuring device control unit 74 outputs the detection value of the displacement measuring unit 83d in the cylinder 83a to the control unit 70. The control unit 70 stores the acquired detection value of the displacement measuring unit 83d as the processing position of the workpiece W (position after polishing).

[0068] The control unit 70 calculates the amount of polishing of the workpiece W (the amount removed by polishing) from the initial position and the processed position of the workpiece W measured before and after polishing. The control unit 70 determines whether to continue or end the polishing process based on the amount of polishing of the workpiece W. For example, if the amount of polishing of the workpiece W falls below the range set as the normal amount of polishing, the control unit 70 polishes the workpiece W again. If the amount of polishing of the workpiece W is within the normal range of the amount of polishing, the control unit 70 ends the polishing process and classifies the workpiece W as a non-defective product. If the amount of polishing of the workpiece W exceeds the normal range of the amount of polishing, the control unit 70 ends the polishing process and classifies the workpiece W as a defective product.

[0069] According to the underwater polishing system of this embodiment, the polishing amount of the workpiece W can be measured, so polishing can be performed while grasping the polishing amount of the workpiece W, and it becomes easy to finish polishing to the desired amount. In addition, since the polishing amount can be measured while the workpiece W is held by the robot 30, no positional deviation of the workpiece W due to attachment / detachment to / from the robot hand 35 occurs, and the polishing amount can be measured multiple times with high accuracy.

[0070] In this embodiment, a case has been described in which a step of measuring the initial position of the polishing portion of the workpiece W is performed before the polishing step, but if the value of the initial position is known in advance, for example, it is not necessary to measure the initial position. Also, if the variation in the initial positions of multiple workpieces W is very small, the initial position of only the first workpiece W may be measured, and the initial measurement value may be used for the other workpieces W thereafter.

[0071] The configurations of the first to fourth embodiments and the modified examples can be freely combined. For example, a system may be provided that includes the polisher 50 of the first embodiment and the tool cleaning mechanism 15 of the modified example of the third embodiment. Alternatively, a system may be provided that includes the water tank 10A of the second embodiment and the measurement mechanism 80 of the fourth embodiment. [Explanation of symbols]

[0072] 1...underwater polishing system, 10, 10A...water tank, 13...filter, 15...tool cleaning mechanism, 30...robot, 31...arm, 34...force sensor, 50, 50A...polishing machine, 51...first rotating roller, 52...second rotating roller, 53...polishing tool, 80...measuring mechanism, L...liquid, P...polishing point, W...work

Claims

1. A water tank capable of storing liquid; The machine includes an arm portion for holding a workpiece, and the arm portion is operated to hold the workpiece. At least a part of the workpiece is immersed in the liquid stored in the water tank from outside the water tank. and a robot that moves the liquid stored in the water tank from the liquid stored in the water tank to the outside of the water tank. A first rotating roller, a second rotating roller, and a roller between the first rotating roller and the second rotating roller and a polishing tool connected to a roller, and a small amount of liquid is poured into the liquid stored in the water tank. a grinding machine in which at least the second rotating roller and a portion of the grinding tool are immersed; Equipped with The water tank includes a water tank body and a second region disposed in the water tank body. a straightening plate dividing the liquid into two regions; and a first pipe opening into the first region and sucking the liquid therein; a second pipe that opens into the second area and discharges the liquid; The arm of the robot is placed in the liquid stored in the first area of ​​the water tank. The workpiece is supported by the second rotating roller of the grinding machine and at least the grinding tool. With some of it immersed in water, The workpiece is held by operating the arm of the robot and is then attached to the polishing tool. Press to perform polishing, At a polishing point where the polishing tool and the workpiece come into contact with each other, a flow of the liquid toward the front side in the traveling direction of the polishing tool; Medium polishing system.

2. The first rotating roller is a driving roller, and the second rotating roller is a driven roller. The underwater polishing system according to claim 1 .

3. The polishing step of claim 1 is performed by immersing the polishing tool entirely in the liquid in the water bath.

3. An underwater polishing system according to claim 2.

4. A circulation device for circulating the liquid in the water tank; and a purification device for purifying the liquid circulating in the water tank. and a filter for filtering the polishing liquid. 。

5. a tool cleaning mechanism for cleaning the polishing tool surface on the upstream side of the filter; The underwater polishing system according to claim 4.

6. The polishing machine according to any one of claims 1 to 5, further comprising a measuring mechanism for measuring the polishing amount of the workpiece. Underwater polishing system.

7. 7. The arm portion for holding the workpiece according to claim 1, further comprising a force sensor.

2. The underwater polishing system according to claim 1.

8. a workpiece holding step of holding a workpiece by an arm portion of the robot; A grinding tool is driven by the first and second rotating rollers of the grinding machine. A grinding machine driving process; a water tank body; and a separator located within the water tank body, which divides the water tank body into a first region and a second region. a first pipe that opens into the first region and sucks in the liquid; a second pipe for discharging the liquid from a nozzle; and a liquid storage tank for storing the liquid in the water tank. The process and The arm of the robot is placed in the liquid stored in the first area of ​​the water tank. The workpiece is supported by the second rotating roller of the grinding machine and at least the grinding tool. The arm of the robot was operated and held in a state where the whole was immersed in the liquid and a part of the liquid was immersed in the liquid. a polishing step of pressing the workpiece against the polishing tool and polishing the workpiece; having In the polishing process, the polishing tool and the workpiece are brought into contact with each other by the straightening plate. A flow of the liquid is formed at the polishing point toward the front side in the rotation direction of the second rotating roller. The underwater polishing method is characterized by:

9. In the polishing step, the first rotating roller and the second rotating roller of the polishing machine and immersing the polishing tool in the liquid.

10. After the polishing process, the workpiece held by the arm of the robot is placed in the water tank. a polishing amount measuring step for measuring the polishing amount of the workpiece by removing the workpiece from the liquid, claim Item 10. The underwater polishing method according to item 8 or 9.

11. Before the polishing process, the workpiece held by the arm of the robot is polished. A pre-polishing measurement step for measuring dimensions is provided, and in the pre-polishing measurement step, The underwater polishing method according to claim 10 , further comprising the step of calculating the amount of polishing based on the obtained results.

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