Robot System

Abstract

To provide a technology that can safely and highly accurately perform flaring processing of a resin tube. [Solution] The robot system 1 has an articulated robot 3 capable of grasping a tube, a tube preparation stage 41, a heating stage 42, a processing stage 43, and a control unit 10. The control unit 10 performs the following steps: a) a tube receiving step in which the articulated robot 3 receives a tube 9 at the preparation stage 41, b) a first movement step in which the articulated robot 3 moves the tube 9 to the heating stage 42, c) a heating step in which the end of the tube 9 is heated at the heating stage 42, d) a second movement step in which the articulated robot 3 moves the tube 9 from the heating stage 42 to the processing stage 43, and e) a processing step in which the articulated robot 3 inserts the end into a processing tool 431 and processes the end.

Description

[Technical Field]

[0001] The present invention relates to a robot system for processing a resin tube. [Background technology]

[0002] High-purity liquids and ultrapure water handled in various technical fields, such as semiconductor manufacturing, medical and pharmaceutical manufacturing, food processing, and the chemical industry, have traditionally used resin tubes as liquid pipelines, and resin pipe joints to connect the tubes to each other or to fluidic devices, such as pumps, valves, and filters.

[0003] Patent Document 1 discloses a conventional plastic pipe joint. In many plastic pipe joints, the end of the tube to be connected is flared to expand its diameter, and then the plastic pipe joint and the tube are fixed together. The flaring process is performed by heating the end of the tube and inserting a processing tool into the heated, plasticized end of the tube. Currently, this type of flaring process requires skill and is therefore performed manually. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5542484 Summary of the Invention [Problem to be solved by the invention]

[0005] In flaring processes, the heating process of tube ends and the process of enlarging the heated tube ends are dangerous tasks. Large-scale equipment has many connections between tubes and fluidic devices, so these dangerous flaring processes must be performed frequently during the manufacturing and maintenance of the equipment. Furthermore, performing multiple flaring processes over a long period of time can reduce the worker's concentration, increasing the likelihood of defective products.

[0006] An object of the present invention is to provide a technique that can perform flaring processing of a resin tube safely and with high precision. [Means for solving the problem]

[0007] In order to solve the above problem, a first invention is a robot system for processing a resin tube, comprising a plurality of stages for processing the tube, an articulated robot having an end effector for gripping the tube and transporting the tube between the plurality of stages, and a control unit for controlling the operation of the articulated robot, wherein the plurality of stages include a tube preparation stage for preparing the tube, a heating stage for heating the end of the tube, and a processing stage for placing a processing tool for processing the end of the tube, and the control unit performs the following steps: a) a tube receiving process in which the articulated robot receives the tube at the tube preparation stage; b) a first movement process in which the articulated robot moves the received tube to the heating stage; c) a heating process in which the end of the tube is heated at the heating stage; d) a second movement process in which the articulated robot moves the tube with the heated end from the heating stage to the processing stage; and e) a processing process in which the articulated robot inserts the processing tool into the end and processes the end.

[0008] A second invention is a robot system according to the first invention, wherein the tube preparation stage has a roll holding unit that holds a tube roll on which the tube is wound before cutting, a tube feeding unit that pulls out the tube from the tube roll, and a tube cutting unit that cuts the tube pulled out by the tube feeding unit to a set length, and the control unit f) causes the articulated robot to perform a part attachment process before step a) in which an annular part is attached to the tube pulled out by the tube feeding unit.

[0009] A third invention is a robot system according to the first or second invention, wherein the articulated robot has a motion detection unit that detects motion caused by application of an external force, and the control unit is capable of performing a motion teaching step p) prior to steps a) to e) of storing a movement trajectory of the end effector caused by a manual operation performed by an operator on the articulated robot, and in step e), the control unit controls the articulated robot based on the movement trajectory stored in step p).

[0010] A fourth invention is a robot system according to the first or second invention, wherein the articulated robot has a motion detection unit that detects motion caused by application of an external force, and the control unit is capable of performing a motion teaching step q) prior to steps a) to e) of storing a movement trajectory of the end effector caused by a manual operation performed by an operator on the articulated robot, and in step c), the control unit controls the articulated robot based on the movement trajectory stored in step q).

[0011] A fifth aspect of the present invention is the robot system according to the first or second aspect of the present invention, wherein in the step e), the end portion is expanded in diameter. [Effects of the Invention]

[0012] According to the first to fifth aspects of the present invention, the flaring process of a resin tube can be carried out safely and with high precision.

[0013] According to the third aspect of the present invention, the processing step of flaring the tube end can be performed with high precision.

[0014] According to the fourth aspect of the present invention, the heating step of heating the tube can be carried out with high precision. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic side view of a robot system according to a first embodiment. [Figure 2]FIG. 1 is a schematic top view of a robot system according to a first embodiment. [Figure 3] 10A to 10C are diagrams illustrating a procedure for attaching a plastic pipe joint to a tube. [Figure 4] FIG. 1 is a functional block diagram of a robot system according to a first embodiment. [Figure 5] 10 is a flowchart showing the flow of a flare processing process in the robot system according to the first embodiment. [Figure 6] FIG. 10 is a diagram showing a heating process. [Figure 7] FIG. 10 is a diagram showing the processing process. [Figure 8] 10 is a flowchart showing the flow of a direct teaching process in the robot system according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the components described in the embodiment are merely examples and are not intended to limit the scope of the present invention. In the drawings, the dimensions and numbers of each part may be exaggerated or simplified as necessary to facilitate understanding.

[0017] <1. Robot System> <1-1. Overview of the robot system> Fig. 1 is a schematic side view of a robot system 1 according to a first embodiment. Fig. 2 is a schematic top view of the robot system 1. Fig. 3 is a diagram showing a procedure for attaching a plastic pipe fitting 8 to a plastic tube 9. The robot system 1 shown in Figs. 1 and 2 is a system for expanding the diameter of the end of a plastic tube 9 to fit the plastic pipe fitting 8.

[0018] 3, in this robot system 1, first, as shown in (a), a nut 82 of a plastic pipe fitting 8 is inserted into an unprocessed cylindrical tube 9. Then, the end of the tube 9 is heated to plasticize it, and as shown in (b), a processing tool 431 (described later) is inserted into the end of the tube 9 to perform a flaring process. Thereafter, the flared end of the tube 9 is removed from the processing tool 431, and then, as shown in (c), the flared end of the tube 9 is press-fitted into the body 81 of the plastic pipe fitting 8, and the nut 82 is fixed to the body 81 while the end of the tube 9 is sandwiched between the body 81 and the nut 82.

[0019] When flaring only one of the two ends of the tube 9, it is not necessarily required to insert the nut 82 before the flaring process. However, when flaring both ends of the tube 9, it is not possible to insert the nut 82 after the flaring process, so it is absolutely necessary to insert both nuts 82 before the flaring process.

[0020] 1 and 2, the robot system 1 includes a base 2, an articulated robot 3, a plurality of stages 41 to 44, and a control unit 10. The control unit 10 of the robot system 1 is connected to a control PC 7 so as to be able to communicate with each other.

[0021] The base 2 is a platform on which the articulated robot 3 and the multiple stages 41 to 44 are placed. The articulated robot 3 has three or more joints in its arm, allowing it to move its arm freely like a human arm. The articulated robot 3 has an end effector 30 at its tip. The end effector 30 is capable of appropriately gripping a tube 9 or a nut 82.

[0022] The multiple stages 41 to 44 include a tube preparation stage 41, a heating stage 42, a processing stage 43, and a finished product placement stage 44.

[0023] The tube preparation stage 41 has a tube feeding section 411, a nut storage 412, and a tube cutter 413. The tube feeding section 411 is disposed at an end of the base 2.

[0024] Furthermore, a plurality of roll holding units 419 are arranged adjacent to the end of the base 2 on which the tube unwinding unit 411 is arranged. Each of the roll holding units 419 holds a tube roll on which long tubes of different diameters, materials, and the like are wound in a roll shape. Each of the plurality of roll holding units 419 is movable to a set position where the tip end of the tube of the tube roll it holds can be set in the tube unwinding unit 411. Note that in this embodiment, a movement mechanism 418 is provided for moving each roll holding unit 419 to the set position, but the roll holding units 419 may also be moved manually.

[0025] The tube unwinding unit 411 can unwind the tube end of the set tube roll by a predetermined length in accordance with a control signal from the control unit 10. A plurality of types of nuts 82 corresponding to a plurality of types of tubes 9 are placed in the nut storage area 412. The tube cutter 413 cuts the tube 9 unwound by the tube unwinding unit 411 to a predetermined length.

[0026] The heating stage 42 is equipped with a heater 421. This heater 421 is provided with a recess 422 into which the end of the tube 9 is inserted. When the end of the tube 9 is inserted into the recess 422 while being held by the end effector 30 of the articulated robot 3, the tube 9 is heated inside the recess 422. This heater 421 can heat the end of the inserted tube 9 evenly. Therefore, there is no need to rotate the tube 9 after the end of the tube 9 is inserted into the heater 421.

[0027] Instead of the heater 421, a conventional heating mechanism that heats the tube 9 from one direction, such as a heat gun or a heated gas blowing device, may be used. In this case, the tube 9 needs to be rotated around its axis during the heating process. In this case, if it is difficult to rotate the tube 9 using the end effector 30 of the articulated robot 3, a separate tube holding and rotation mechanism may be provided on the heating stage 42. After the tube 9 is transferred from the articulated robot 3 to the tube rotation and holding mechanism, the tube rotation and holding mechanism rotates the tube 9 while hot air from the heater is supplied to the end of the tube 9. After the heating process is completed, the tube 9 is transferred from the tube rotation and holding mechanism to the end effector 30 of the articulated robot 3.

[0028] The processing stage 43 is a stage for flaring the end of the heated tube 9. A plurality of processing tools 431 for processing the end of the tube 9 are placed on the processing stage 43. The plurality of processing tools 431 are adapted to the shapes of the bodies 81 of the plurality of types of plastic pipe fittings 8 corresponding to the plurality of types of tubes 9. Therefore, the end of the tube 9 that has been flared by the processing tools 431 can be appropriately press-fitted and fixed into the body 81 corresponding to the processing tools 431.

[0029] Furthermore, each processing tool 431 is attached to a processing tool holder fixed to the base 2. Therefore, when inserting the tube 9 into the processing tool 431, the processing tool 431 does not wobble, and flaring can be performed in a stable position.

[0030] The finished product placement stage 44 has a camera 441, a good product placement section 442, and a defective product placement section 443. A finished product in the robot system 1 is, for example, a processed tube 9 that has been removed from the processing tool 431 after a processing step described below has been performed. The camera 441 photographs the shape of the end of the tube 9 that has been flared on the processing stage 43. The good product placement section 442 is a container for placing those processed tubes 9 that have been determined to be good products. The defective product placement section 443 is a container for placing those processed tubes 9 that have been determined to be defective products.

[0031] The control unit 10 is a PLC (Programmable Logic Controller) that controls each part of the robot system 1. The control unit 10 receives command signals from the control PC 70 and performs various processes according to a program, thereby controlling each part of the robot system 1.

[0032] Fig. 4 is a functional block diagram of the robot system 1. As shown in Fig. 4, the control unit 10 has an articulated robot control unit 101, a tube feed control unit 102, a cutter driving unit 103, a heating control unit 104, and an image processing unit 105 as functional units realized by a processor in the PLC executing a program.

[0033] The articulated robot control unit 101 controls the operation of the articulated robot 3. The tube feed control unit 102 controls the operation of the tube payout unit 411 and the movement mechanism 418 of the roll holding unit 419. The tube feed control unit 102 also receives a signal from a tube length measuring encoder provided in the tube payout unit 411, thereby being able to accurately determine the distance traveled by the tube payout unit 411 of the tube 9. The cutter driving unit 103 controls the driving of the tube cutter 413. The heating control unit 104 controls the on / off of the heater 421. The image processing unit 105 performs image processing on the image of the processed tube 9 taken by the camera 441, thereby determining whether the processed tube 9 is a good product or a defective product.

[0034] The control PC 70 is a computer that issues operational commands to the control unit 10. The control PC 70 includes a processor such as a CPU, a memory such as RAM, and a storage unit such as a hard disk drive. The control PC 70 sends commands to the control unit 10, such as the type of tube 9 to be processed, the type of plastic pipe fitting 8 to be used, and whether processing will be performed on only one end or both ends. The control unit 10 may also send the operating status of the robot system 1, the results of a pass / fail judgment of the processed tube 9, and the like, to the control PC 70.

[0035] <1-2. Flare processing flow> Next, the flow of the flaring process for a resin tube in the robot system 1 will be described with reference to Fig. 5. Fig. 5 is a flowchart showing the flow of the flaring process in the robot system 1.

[0036] When a command to execute flaring processing is sent from the control PC 70 to the control unit 10, the control unit 10 first selects the tube type at the tube preparation stage 41 and pays out the tube (step S101). Specifically, the tube feed control unit 102 first controls the operation of the movement mechanism 418 of the roll holding unit 419, and sets the roll holding unit 419, which holds the tube roll of the selected tube type, to the set position. Thereafter, the tube feed control unit 102 causes the tube payout unit 411 to hold the tip end of the tube 9 on the tube roll held by the roll holding unit 419, and pays out the tube by a specified length.

[0037] Next, the articulated robot 3 attaches the nut 82, which is an annular part, to the tip of the tube 9 held by the tube feed-out unit 411 (step S102). Specifically, first, the articulated robot control unit 101 causes the articulated robot 3 to grasp an appropriate nut 82 from the plurality of nuts 82 placed in the nut storage area 412 with the end effector 30. Thereafter, the articulated robot control unit 101 causes the articulated robot 3 to attach the grasped nut 82 to the tip of the tube 9 held by the tube feed-out unit 411.

[0038] Next, the articulated robot 3 grips the tube 9, and the tube cutter 413 cuts the tube 9 (step S103). Specifically, first, the articulated robot control unit 101 causes the articulated robot 3 to grip the tube 9 with the end effector 30. Thereafter, the cutter driving unit 103 causes the tube cutter 413 to cut the tube 9. The above steps S101 to S103 are a tube receiving process in which the articulated robot 3 receives the tube 9 at the tube preparation stage 41.

[0039] Then, the articulated robot 3 moves the received tube 9 to the heating stage 42 (step S104: first movement step). Specifically, the articulated robot control unit 101 moves the end effector 30 of the articulated robot 3, which is holding the tube 9, from the tube preparation stage 41 to the heating stage 42.

[0040] Next, the end of the tube 9 is heated in the heating stage 42 (step S105: heating step). Figure 6 shows the heating step of step S105. Specifically, in step S105, the articulated robot control unit 101 controls the operation of the articulated robot 3 so that the end of the tube 9 gripped by the end effector 30 is placed in the recess 422 of the heater 421, and the heating control unit 104 drives the heater 421 to heat the end of the tube 9. As a result, the heater 421 heats the end of the tube 9 to, for example, 400°C.

[0041] After the heating is completed, the articulated robot 3 moves the tube 9 with the heated end from the heating stage 42 to the processing stage 43 (step S106: second movement step). Specifically, the articulated robot control unit 101 moves the end effector 30 of the articulated robot 3 holding the tube 9 from the heating stage 42 to the processing stage 43.

[0042] The articulated robot 3 then inserts a processing tool 431 corresponding to the type of plastic pipe fitting 8 being used into the end of the tube 9, and performs flaring on the end of the tube 9 (step S107: processing step). FIG. 7 is a diagram showing the processing step of step S107. Specifically, in step S107, the articulated robot control unit 101 controls the operation of the articulated robot 3, causing the articulated robot 3 to appropriately insert the processing tool 431 into the end of the tube 9. As a result, the end of the tube 9, which has been plasticized by heating, is processed into a flared shape that conforms to the outer surface of the processing tool 431.

[0043] In the processing step S107, if the tube 9 is simply lowered straight down in the vertical direction, distortion known as buckling may occur. Therefore, as shown by the arrow in Figure 7, the central axis of the tube 9 must be slightly tilted from the vertical direction, and the tube 9 must be lowered while the upper end of the tube 9 rotates in a circular motion. Such complex movements cannot be achieved with a device that simply moves up and down, and have traditionally been performed manually. However, in this robot system 1, the articulated robot 3 controls the movement of the tube 9 during the processing step, making it possible to achieve such complex movements.

[0044] Next, the control unit 10 determines whether the processed tube 9 is a pass or fail by checking the image (step S108). Specifically, the articulated robot control unit 101 controls the operation of the articulated robot 3 to move the tube 9 held by the end effector 30 from the processing stage 43 into the shooting range of the camera 441 on the finished product placement stage 44. Then, the image processing unit 105 causes the camera 441 to capture an image of the tip of the processed tube 9. Thereafter, the image processing unit 105 performs image processing on the captured image to determine whether the processed tube 9 is a pass or fail product. At this time, the image captured by the camera 441 may be one or more still images or may be a video.

[0045] Finally, based on the determination result in step S108, the articulated robot 3 places the processed tube 9 on the non-defective product placement section 442 or the defective product placement section 443 (step S109). Specifically, if the determination result in step S108 is a non-defective product, the articulated robot control section 101 causes the articulated robot 3 to place the processed tube 9 on the non-defective product placement section 442. On the other hand, if the determination result in step S108 is a defective product, the articulated robot control section 101 causes the articulated robot 3 to place the processed tube 9 on the defective product placement section 443.

[0046] It should be noted that this robot system 1 can also perform flaring on both ends of a single tube 9. In this case, two nuts 82 are attached to the tube 9 in step S102. Then, step S103 is performed, and steps S104 to S108 are performed on one end. If it is determined to be a non-defective product in step S108, steps S104 to S109 are performed on the other end. It should be noted that if it is determined to be a defective product in step S108 after steps S104 to S108 have been performed on one end, the process proceeds to step S109 without performing flaring on the other end, and the articulated robot 3 places the machined tube 9 on the defective product placement unit 443.

[0047] In such flaring processes, the process of heating the end of the tube 9 and the process of flaring the end of the heated and hot tube 9 are dangerous tasks. When manufacturing or maintaining large equipment, there are many connections between tubes or between tubes and fluid equipment, so such dangerous flaring processes must be performed many times. Furthermore, performing multiple flaring processes over a long period of time increases the probability of producing defective products due to a decrease in worker concentration.

[0048] In this robot system 1, dangerous tasks such as the heating process of the tube 9 and the processing process of the heated tube 9 are performed using an articulated robot 3, making it possible to perform flaring processing of the resin tube 9 safely and with high precision.

[0049] <1-3. Direct teaching> Next, a description will be given of the direct teaching control in the robot system 1. Fig. 8 is a flowchart showing the flow of the direct teaching process. This direct teaching process is performed before the above-mentioned flare processing process is performed.

[0050] The articulated robot 3 has a motion sensor 31 (see FIG. 4) that detects movement caused by the application of an external force. That is, the motion sensor 31 can detect movement when an external worker directly touches and moves the articulated robot 3. The motion sensor 31 then transmits the detected movement of the articulated robot 3 to the articulated robot control unit 101. This allows the articulated robot control unit 101 to reproduce the movement detected by the motion sensor 31.

[0051] 8, in the direct teaching process, first, direct teaching of the operation in the heating process in step S105 is performed (step S201: first operation teaching process). In step S201, an operator directly touches and moves the articulated robot 3, thereby performing exemplary operations of the articulated robot 3 including the end effector 30 in the heating process. Then, the control unit 10 stores the operation of the articulated robot 3 and the movement trajectory of the end effector 30 during the manual operation, which are detected via the motion sensor 31.

[0052] Next, direct teaching of the operation in the processing step is performed in step S107 (step S202: second operation teaching step). In step S202, the worker directly touches and moves the articulated robot 3, thereby performing exemplary operations of the articulated robot 3 including the end effector 30 in the processing step. Then, the control unit 10 stores the operation of the articulated robot 3 and the movement trajectory of the end effector 30 during the manual operation, which are detected via the motion sensor 31.

[0053] After such a direct teaching process is performed, the above-described flare processing is performed. Then, in the heating step of step S105 of the flare processing, the control unit 10 controls the articulated robot 3 based on the movement of the articulated robot 3 and the movement trajectory of the end effector 30 stored in the first movement teaching step of step S201. This allows the tube 9 to be moved in an appropriate positional relationship with the heater 421, thereby preventing uneven heating of the tube 9. In other words, the heating step of step S105 of the flare processing can be performed with high precision.

[0054] Furthermore, in the processing step of step S107 of the flare processing, the control unit 10 controls the articulated robot 3 based on the motion of the articulated robot 3 and the movement trajectory of the end effector 30 stored in the second motion teaching step of step S202. This allows the complex movements required in the processing step to be performed appropriately. Therefore, appropriate flaring can be performed on the tube 9. In other words, the processing step of step S107 of the flare processing can be performed with high precision.

[0055] <2. Modifications> Although the embodiments have been described above, the present invention is not limited to the above and various modifications are possible.

[0056] In the above embodiment, the tube 9 is cut at the tube preparation stage 41, but the present invention is not limited to this. A configuration may be adopted in which a plurality of cut tubes 9 are prepared at the tube preparation stage 41, and the articulated robot 3 selects one tube 9 from among them.

[0057] In the above embodiment, the tube unwinding unit 411 unwinds the tube from the tube roll, but the roll holding unit 419 may rotate the tube roll to unwind the tube from the tube roll. In this case, it is preferable to provide a tube length measuring encoder near the tube cutter 413.

[0058] In the above embodiment, the nut 82 is attached at the tube preparation stage 41, but the present invention is not limited to this. When performing flaring processing on only one end of the tube 9, the nut 82 may be attached after the heating step and the processing step.

[0059] Although the present invention has been described in detail, the above description is merely illustrative in all respects and does not limit the present invention. It is understood that countless variations not illustrated can be envisioned without departing from the scope of the present invention. The configurations described in the above embodiments and variations can be combined or omitted as appropriate as long as they are not mutually inconsistent. [Explanation of symbols]

[0060] 1: Robot system 3: Articulated robot 8: Resin pipe joints 9: Tube 10: Control section 30: End effector 31: Motion sensor 41: Tube preparation stage 42: Heating stage 43: Processing stage 44: Finished product placement stage 81: Body 82: Nut 101: Articulated robot control unit 102: Tube feed control unit 103: Cutter drive unit 104: Heating control unit 105: Image processing unit 411: Tube feeding section 412: Nut storage area 413: Tube cutter 419: Roll holder 421: Heater 431: Processing tools 441: Camera 442: Good product placement area 443: Defective product placement area

Claims

1. A robotic system for processing a resin tube, comprising: a plurality of stages for performing processing on the tube; an articulated robot having an end effector that grips the tube and transports the tube between the plurality of stages; a control unit for controlling the operation of the articulated robot; Equipped with The plurality of stages include: a tube preparation stage for preparing the tube; a heating stage for heating the end of the tube; a processing stage on which a processing tool for processing the end of the tube is placed; Including, The control unit a) a tube receiving step in which the articulated robot receives the tube in the tube preparation stage; b) a first moving step in which the articulated robot moves the received tube to the heating stage; c) a heating step in which the end of the tube is heated in the heating stage; d) a second moving step in which the articulated robot moves the tube, the end of which has been heated, from the heating stage to the processing stage; e) a processing step in which the articulated robot inserts the processing tool into the end portion and processes the end portion; A robot system that performs the above.

2. The robot system according to claim 1, The tube preparation stage includes: a roll holding section for holding a tube roll around which the tube is wound before being cut; a tube feed unit that draws out the tube from the tube roll; a tube cutting unit that cuts the tube drawn out by the tube feeding unit to a set length; and The control unit f) a component mounting step in which, before the step a), the articulated robot mounts an annular component on the tube drawn out by the tube feed unit. A robot system that performs the above.

3. 3. The robot system according to claim 1, the articulated robot has a motion detection unit that detects motion caused when an external force is applied, The control unit, prior to the steps a) to e), p) a motion teaching step of storing a movement trajectory of the end effector according to a manual motion performed by an operator on the articulated robot; can be implemented, In the step e), the control unit controls the articulated robot based on the movement trajectory stored in the step p).

4. 3. The robot system according to claim 1, the articulated robot has a motion detection unit that detects motion caused when an external force is applied, The control unit, prior to the steps a) to e), q) a motion teaching step of storing a movement trajectory of the end effector according to a manual motion performed by an operator on the articulated robot; can be implemented, In the step c), the control unit controls the articulated robot based on the movement trajectory stored in the step q).

5. 3. The robot system according to claim 1, In step e), the end portion is expanded in diameter.

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