Cutting method and cutting system

Abstract

The present invention relates to a cutting method and system capable of reducing manufacturing costs and cycle time while automatically cutting a portion of a material passage. The cutting method includes the following steps: preparing a cutting device capable of moving within an automatically controlled coordinate system; arranging a molded product in a non-stationary manner; detecting the shape of the molded product using a sensor; acquiring the position of the material passage portion within the coordinate system; determining the position of a cutting portion within the material passage portion as a target position within the coordinate system; moving the cutting device within the coordinate system and positioning the cutting device at an operating position for cutting the cutting portion; and cutting the cutting portion using the cutting device positioned at the operating position.

Description

[0001] This application is a divisional application of the Chinese invention patent application with the application date of September 28, 2017, application number 201710898563.0, and invention name “Cutting Method and Cutting System”. Technical Field

[0002] The present invention relates to a cutting method and a cutting system for cutting a gate portion formed in a molded product. Background Art

[0003] There is known a cutting method in which a gate portion formed in a molded product is cut using a robot having a cutting device (for example, Japanese Patent Application Laid-Open No. 5-57686 and Japanese Utility Model Application Laid-Open No. 5-16195).

[0004] Conventionally, it was necessary to prepare different jigs for holding molded products when cutting off the gate, depending on the type of molded product. This increased manufacturing costs and cycle time. Summary of the Invention

[0005] In one embodiment of the present invention, a cutting method for automatically cutting off a raw material path portion from a molded product including a product portion and a raw material path portion includes the following steps: preparing a cutting device capable of moving in an automatically controlled coordinate system; placing the molded product in an unfixed manner; and using a sensor to detect the shape of the placed molded product.

[0006] The cutting method also includes the following steps: obtaining the position of the raw material passage portion in the coordinate system according to the detected shape of the formed product; and determining the position of the cutting part in the raw material passage portion as the target position in the coordinate system based on the obtained position of the raw material passage portion.

[0007] The cutting method further includes the following steps: moving a cutting device in a coordinate system based on the determined target position, disposing the cutting device at an operating position for cutting the cutting portion; and cutting the cutting portion using the cutting device at the operating position.

[0008] The method also includes the following steps: after cutting off the cutting portion, further detecting the shape of the formed product using a sensor; further acquiring the position of the raw material passage portion in the coordinate system based on the shape of the formed product detected after cutting off the cutting portion; and determining the position of the second cutting portion in the raw material passage portion as the second target position in the coordinate system based on the position of the raw material passage portion acquired after cutting off the cutting portion.

[0009] The method further includes the following steps: based on the determined second target position, moving the cutting device in the coordinate system and configuring the cutting device to a second operating position for cutting the second cutting portion; and cutting the second cutting portion using the cutting device configured at the second operating position.

[0010] Alternatively, the shape of the placed first molded product may be detected by the first sensor, and the shape of the placed second molded product may be detected by the second sensor. Alternatively, the cutting device may be mounted on a manipulation device, and the manipulation device may move the cutting device in the coordinate system.

[0011] The method further includes the following steps: after cutting the cutting portion, using a robot mounted on a manipulation device to grip the raw material passage portion; and operating the manipulation device to transport the raw material passage portion gripped by the robot to a predetermined location.

[0012] The method further includes the steps of: after cutting the cut portion, holding the product portion using a robot arm mounted on a manipulation device; and operating the manipulation device to transport the product portion held by the robot arm to a predetermined location.

[0013] In another embodiment of the present invention, a cutting system is used to automatically cut off a raw material path portion from a molded product including a product portion and a raw material path portion, and the cutting system comprises: a cutting device capable of moving in an automatically controlled coordinate system; a manipulation device that moves the cutting device in the coordinate system; and a sensor that detects the shape of the molded product.

[0014] The cutting system also includes: an acquisition unit, which acquires the position of the raw material passage portion in the coordinate system based on the shape of the formed product detected by the sensor; and a determination unit, which determines the position of the cutting portion in the raw material passage portion as the target position in the coordinate system based on the position of the raw material passage portion acquired by the acquisition unit.

[0015] The cutting system further includes: a manipulator control unit that operates the manipulator to move the cutting device in the coordinate system based on the target position determined by the determination unit, and configures the cutting device at an operating position for cutting the cutting portion; and a cutting control unit that operates the cutting device to cut the cutting portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, features and advantages of the present invention will become more apparent from the following description of preferred embodiments with reference to the accompanying drawings.

[0017] Figure 1 This is a diagram of a cutting system according to one embodiment.

[0018] Figure 2Observed from above Figure 1 The diagram obtained by cutting off the system is shown.

[0019] Figure 3 Yes Figure 1 Flowchart showing an example of the operation flow of the cutting system.

[0020] Figure 4 Yes Figure 3 Step S3 in Figure 6 A flowchart of an example of the process of S33 and S35 in .

[0021] Figure 5 This is a diagram showing a cutting system according to another embodiment as viewed from vertically above.

[0022] Figure 6 Yes Figure 5 Flowchart showing an example of the operation flow of the cutting system.

[0023] Figure 7 It is a diagram of a robot according to another embodiment. DETAILED DESCRIPTION

[0024] Below, embodiments of the present invention are described in detail based on the accompanying drawings. In the various embodiments described below, identical components are labeled with the same reference numerals, and duplicate descriptions are omitted. In the following description, the directions are based on the orthogonal coordinate system in the drawings. For ease of description, the positive x-axis direction is set to the left, the positive y-axis direction is set to the front, and the positive z-axis direction is set to the top.

[0025] Reference Figure 1 A cutting system 10 according to an embodiment of the present invention will be described. The cutting system 10 includes a conveyor 12 , a robot 14 , a vision sensor 16 , and a control unit 18 .

[0026] The conveyor 12 is a roller conveyor or a belt conveyor, etc., and conveys the molded product 50 forward. Specifically, the conveyor 12 includes a movable portion 20 for placing the molded product 50 thereon and a driving portion 22 for generating power to move the movable portion 20.

[0027] The driving unit 22 includes, for example, a servo motor, and moves the movable unit 20 in accordance with a command from the control unit 18 , thereby conveying the molded product 50 placed on the movable unit 20 forward.

[0028] The robot 14 is a vertical multi-jointed robot having a robot base 24, a rotating body 26, a robot arm 28, a wrist 30, and a cutting device 32. The robot base 24 is fixed to the floor of the operation room. The rotating body 26 is mounted on the robot base 24 so as to be rotatable about a vertical axis.

[0029] The robot arm 28 includes an upper arm 35 rotatably connected to the rotating body 26 and a forearm 37 rotatably connected to the front end of the upper arm 35. The wrist 30 is attached to the front end of the forearm 37 and supports the cutting device 32 rotatably around three axes.

[0030] The cutting device 32 includes a base 34, a pair of cutters 36 and 38, and a cutter driver 40. The base 34 is connected to the wrist 30. The cutters 36 and 38 are mounted on the base 34 so as to be openable and closable. The cutter driver 40 includes, for example, a servo motor or an air cylinder, and opens and closes the cutters 36 and 38 in response to commands from the control unit 18.

[0031] The visual sensor 16 is fixed above the movable portion 20 of the conveyor 12. The visual sensor 16 is, for example, a three-dimensional visual sensor, and includes an imaging sensor, an optical lens, an image processor, a storage unit, and the like.

[0032] The vision sensor 16 detects the shape of the molded product 50 placed on the movable portion 20 of the conveyor 12 in accordance with instructions from the control unit 18. Specifically, the vision sensor 16 images the molded product 50 placed on the movable portion 20, detects feature points of the molded product 50 based on the captured image data, and detects the positions of these feature points in the sensor coordinate system.

[0033] The sensor coordinate system is one of the coordinate systems for automatic control, and is a three-dimensional coordinate system defined based on the line of sight of the vision sensor 16 .

[0034] The control unit 18 includes a CPU, a storage unit, and the like, and directly or indirectly controls each component of the cutting system 10. Specifically, the control unit 18 sends a command to the driving unit 22 of the conveyor 12 to move the movable unit 20.

[0035] The control unit 18 also sends a command to the cutter driver 40 of the cutting device 32 to open and close the cutters 36 and 38. The control unit 18 also sends a command to the vision sensor 16 to use the vision sensor 16 to capture an image of the molded product 50 placed on the movable portion 20 of the conveyor 12.

[0036] Furthermore, the control unit 18 sends commands to the rotating body 26 , the robot arm 28 , and the servo motors (not shown) built into the wrist 30 of the robot 14 to operate these movable parts.

[0037] The control unit 18 operates the rotating body 26, the robot arm 28, and the wrist 30, thereby arranging the cutting device 32 at an arbitrary position and posture in the robot coordinate system. The robot coordinate system is one of the coordinate systems for automatic control, and is defined as Figure 1 and Figure 2 The orthogonal coordinate system shown.

[0038] The control unit 18 generates commands to the rotating body 26 , the robot arm 28 , and the servo motors (not shown) built into the wrist 30 in order to move the cutting device 32 in the robot coordinate system.

[0039] As described above, in this embodiment, the rotating body 26 , the robot arm 28 , and the wrist 30 constitute a manipulator for moving the cutting device 32 .

[0040] Next, refer to Figure 2 Next, the molded product 50 will be described. In this embodiment, the molded product 50 includes a material passage portion 54 and a total of four product portions 52 arranged around the material passage portion 54.

[0041] When the molded article 50 is manufactured, the raw material (e.g., resin) for the molded article 50 is passed through the sprue, runner, and gate of the mold (not shown) and filled into the mold portion corresponding to the product portion 52. The raw material passage portion 54 is formed by the raw material for the molded article 50 remaining in the sprue, runner, and gate of the mold when the molded article 50 is manufactured.

[0042] The raw material passage portion 54 includes one gate portion 58 , a total of four runner portions 56 extending from the gate portion 58 toward each product portion 52 , and a gate portion 60 formed at a front end of the runner portion 56 and connected to the product portion 52 .

[0043] The gate portion 58 is a generally cylindrical member, and each runner portion 56 is a slender, rod-shaped member. The gate portion 60 has a slightly smaller cross-sectional area than the gate portion 58. The cutting system 10 according to this embodiment cuts each runner portion 56 at a predetermined position, thereby automatically removing the raw material passage portion 54 from each product portion 52.

[0044] Next, refer to Figure 3 The operation of the cutting system 10 will be described. Figure 3 The illustrated flow starts when the control unit 18 detects that the molded product 50 is placed on the upstream end of the movable portion 20 of the conveyor 12 .

[0045] For example, the cutting system 10 further includes a placement sensor (not shown) capable of detecting that the molded product 50 is placed on the upstream end of the movable portion 20. The placement sensor includes a visual sensor or a displacement sensor, and detects that the molded product 50 is placed on the upstream end of the movable portion 20 in a non-contact manner.

[0046] The placement sensor sends a placement detection signal to the control unit 18 when detecting that the molded product 50 is placed on the upstream end of the movable unit 20. The control unit 18 starts the process of placing the molded product 50 when receiving the initial placement detection signal from the placement sensor. Figure 3 The process shown.

[0047] Here, in this embodiment, the molded product 50 is not fixed by a jig or the like, but is placed on the upstream end of the movable portion 20 by a user or a placing robot other than the robot 14 .

[0048] In step S1, the control unit 18 operates the conveyor 12 to transport the molded product 50 placed on the movable unit 20. Specifically, the control unit 18 sends a command to the drive unit 22 of the conveyor 12 to transport the molded product 50 placed on the upstream end of the movable unit 20 to a predetermined detection position located below the visual sensor 16.

[0049] When the molded product 50 is located at the detection position, the visual sensor 16 can capture an image of the entire molded product 50. The control unit 18 stops the conveyor 12 when the molded product 50 is located at the detection position.

[0050] In step S2, the control unit 18 activates the vision sensor 16 to detect the shape of the molded product 50. Specifically, the control unit 18 sends a detection command to the vision sensor 16. Upon receiving the detection command from the control unit 18, the vision sensor 16 captures an image of the molded product 50 placed on the movable portion 20 of the conveyor 12.

[0051] In this embodiment, the visual sensor 16 obtains Figure 2 The image shown is obtained by observing the molded product 50 from vertically above. The vision sensor 16 detects characteristic points of the molded product 50 in the sensor coordinate system based on the acquired image of the molded product 50. The vision sensor 16 sends the detected image of the molded product 50 and information on the characteristic points to the control unit 18.

[0052] In step S3, the control unit 18 executes the cutting plan. Figure 4 This step S3 will be described.

[0053] In step S11, control unit 18 executes the first raw material passage portion detection scheme. Specifically, control unit 18 compares the image of molded product 50 acquired by vision sensor 16 in the most recently executed step S2 with a reference image of molded product 50 (e.g., a two-dimensional model in the xy plane) pre-stored in control unit 18's memory. Control unit 18 then detects the position of gate portion 58 in the sensor coordinate system within the image data of molded product 50.

[0054] As described above, in the present embodiment, the control unit 18 functions as an acquisition unit for acquiring the position of the material passage portion 54 (specifically, the gate portion 58 ) in the sensor coordinate system.

[0055] Next, the control unit 18 tracks the detected characteristic points (ie, contour lines) of the first runner portion 56 extending from the gate portion 58 in the direction from the gate portion 58 toward the corresponding product portion 52 in the image data of the molded product 50 .

[0056] In step S12, the control unit 18 determines whether a raw material passage portion has been detected. Specifically, the control unit 18 determines the result of tracing the outline of the first runner portion 56 in step S11, that is, whether the first runner portion 56 extends from the gate portion 58 to the first gate portion 60 formed at the front end of the first runner portion 56 (that is, whether the first runner portion 56 is cut off midway).

[0057] If the control unit 18 determines that the first runner portion 56 extends from the gate portion 58 to the first gate portion 60 (i.e., "Yes"), the control unit 18 proceeds to step S13. On the other hand, if the control unit 18 determines that the first runner portion 56 does not extend from the gate portion 58 to the product portion 52 (i.e., "No"), the control unit 18 proceeds to step S15.

[0058] In step S13, the control unit 18 determines the first target position. Specifically, the control unit 18 determines a predetermined position on the first runner portion 56 as the first cutting position. The predetermined position is, for example, Figure 2 As shown by point B in FIG, it is set at a position substantially in the center of the extending direction of the runner portion 56.

[0059] The control unit 18 determines the position of the identified first cutting portion B in the sensor coordinate system as the first target position. In this manner, in the present embodiment, the control unit 18 functions as a determination unit for determining the position of the cutting portion B as the target position.

[0060] The control unit 18 converts the determined position of the first cutting portion B in the sensor coordinate system (ie, the first target position) into a position in the robot coordinate system and stores the converted position in the storage unit.

[0061] In step S14 , the control unit 18 cuts the first cutting portion B. Specifically, based on the first target position in the robot coordinate system stored in step S13 , the control unit 18 sends commands to the rotating body 26 , the robot arm 28 , and the servo motors built into the wrist 30 , thereby placing the cutting device 32 in the first operating position.

[0062] When the cutting device 32 is in the first operating position, the first cutting portion B is located between the open blades 36 and 38. Thus, in this embodiment, the control unit 18 functions as a manipulator control unit for operating the manipulator (rotating body 26, robot arm 28, and wrist 30).

[0063] Next, the control unit 18 sends a command to the tool drive unit 40 to move the open tools 36 and 38 toward the closing direction so that they approach each other. As a result, the first runner portion 56 is clamped by the tools 36 and 38 at the cutting position B and cut. In this way, in this embodiment, the control unit 18 functions as a cutting control unit for operating the cutting device 32. Then, the control unit 18 returns to Figure 3 Step S2.

[0064] On the other hand, if the determination in step S12 is "NO", in step S15, the control unit 18 executes the second raw material path portion detection scenario.

[0065] Specifically, the control unit 18 detects the position of the gate portion 58 in the sensor coordinate system from the image data of the molded product 50 acquired from the vision sensor 16 in the most recent step S2 , similarly to the above-described step S11 .

[0066] Furthermore, the control unit 18 tracks the contour of the second runner portion 56, which is different from the first runner portion 56, in the direction from the gate portion 58 toward the corresponding product portion 52. For example, the second runner portion 56 is adjacent to the first runner portion 56 in the clockwise direction (or counterclockwise direction) when viewed from above.

[0067] In step S16, the control unit 18 determines whether the material passage portion has been detected. Specifically, the control unit 18 determines, based on the result of tracing the outline of the second runner portion 56 in step S15, whether the second runner portion 56 extends from the gate portion 58 to the second gate portion 60 formed at the front end of the second runner portion 56.

[0068] If the control unit 18 determines that the second runner portion 56 extends from the gate portion 58 to the second gate portion 60 (i.e., "Yes"), the control unit 18 proceeds to step S17. On the other hand, if the control unit 18 determines that the second runner portion 56 does not extend from the gate portion 58 to the second gate portion 60 (i.e., "No"), the control unit 18 proceeds to step S19.

[0069] In step S17 , the control unit 18 determines the second target position. Specifically, the control unit 18 determines a predetermined position (eg, substantially the center position in the extending direction) on the second runner portion 56 as the second cutting portion B.

[0070] The control unit 18 determines the position of the determined second cutting portion B in the sensor coordinate system as the second target position. The control unit 18 converts the determined second target position in the sensor coordinate system into a position in the robot coordinate system and stores it in the storage unit.

[0071] In step S18, the control unit 18 cuts the second cutting location B. Specifically, based on the second target position in the robot coordinate system stored in step S17, the control unit 18 operates the rotating body 26, the robot arm 28, and the wrist 30 to position the cutting device 32 in the second operating position. When the cutting device 32 is in the second operating position, the second cutting location B is positioned between the open blades 36 and 38.

[0072] Next, the control unit 18 sends a command to the tool driving unit 40 to move the open tools 36 and 38 in the closing direction to cut the second cutting portion B. Then, the control unit 18 returns to Figure 3 Step S2.

[0073] On the other hand, if the determination in step S16 is "No," the control unit 18 executes the third material path portion detection scheme in step S19. Specifically, the control unit 18 detects the position of the gate portion 58 in the sensor coordinate system from the image data of the molded product 50 acquired by the vision sensor 16 in the most recent step S2.

[0074] Then, the control unit 18 traces the contour of the third runner portion 56, which is different from the first runner portion 56 and the second runner portion 56, in a direction from the gate portion 58 toward the corresponding product portion 52. For example, the third runner portion 56 is adjacent to the second runner portion 56 in the clockwise direction (or counterclockwise direction) when viewed from above.

[0075] In step S20, the control unit 18 determines whether the raw material passage portion has been detected. Specifically, the control unit 18 determines, as a result of tracing the outline of the third runner portion 56 in step S19, whether the third runner portion 56 extends from the gate portion 58 to the third gate portion 60 formed at the front end of the third runner portion 56.

[0076] If the control unit 18 determines that the third runner portion 56 extends from the gate portion 58 to the third gate portion 60 (i.e., "Yes"), the control unit 18 proceeds to step S21. On the other hand, if the control unit 18 determines that the third runner portion 56 does not extend from the gate portion 58 to the third gate portion 60 (i.e., "No"), the control unit 18 proceeds to step S23.

[0077] In step S21, the control unit 18 determines the third target position. Specifically, the control unit 18 determines a predetermined position (eg, a substantially central position in the extending direction) on the third runner portion 56 as the third cutting portion B.

[0078] The control unit 18 determines the position of the determined third cutting portion B in the sensor coordinate system as a third target position. The control unit 18 converts the determined third target position in the sensor coordinate system into a position in the robot coordinate system and stores the converted position in the storage unit.

[0079] In step S22, the control unit 18 cuts the third cutting location B. Specifically, the control unit 18 operates the rotating body 26, the robot arm 28, and the wrist 30 based on the third target position in the robot coordinate system stored in step S21, thereby positioning the cutting device 32 in the third operating position. When the cutting device 32 is positioned in the third operating position, the third cutting location B is positioned between the open blades 36 and 38.

[0080] Next, the control unit 18 sends a command to the tool driving unit 40 to move the open tools 36 and 38 in the closing direction to cut the third cutting portion B. Then, the control unit 18 returns to Figure 3 Step S2.

[0081] On the other hand, if the determination in step S20 is "No," the control unit 18 executes the fourth material path portion detection scheme in step S23. Specifically, the control unit 18 detects the position of the gate portion 58 in the sensor coordinate system from the image data of the molded product 50 acquired in the most recent step S2.

[0082] Then, the control unit 18 tracks the contour of the fourth runner portion 56, which is different from the first runner portion 56, the second runner portion 56, and the third runner portion 56, in a direction from the gate portion 58 toward the corresponding product portion 52. For example, the fourth runner portion 56 is adjacent to the third runner portion 56 in the clockwise direction (or counterclockwise direction) when viewed from above.

[0083] In step S24, the control unit 18 determines whether the raw material passage portion has been detected. Specifically, the control unit 18 determines whether the fourth runner portion 56 extends from the gate portion 58 to the fourth gate portion 60 formed at the front end of the fourth runner portion 56 as a result of tracing the outline of the fourth runner portion 56 in step S23.

[0084] If it is determined that the fourth runner portion 56 extends from the gate portion 58 to the fourth gate portion 60 (i.e., "Yes"), the control unit 18 proceeds to step S25. On the other hand, if it is determined that the fourth runner portion 56 does not extend from the gate portion 58 to the fourth gate portion 60 (i.e., "No"), the control unit 18 proceeds to step S26. Figure 3 Step S4.

[0085] In step S25 , the control unit 18 determines a fourth target position. Specifically, the control unit 18 determines a predetermined position (eg, a substantially central position in the extending direction) on the fourth runner portion 56 as the fourth cutting location B.

[0086] The control unit 18 determines the position of the determined fourth cutting portion B in the sensor coordinate system as a fourth target position. The control unit 18 converts the determined fourth target position in the sensor coordinate system into a position in the robot coordinate system and stores the converted position in the storage unit.

[0087] In step S26, the control unit 18 cuts the fourth cutting location B. Specifically, the control unit 18 operates the rotating body 26, the robot arm 28, and the wrist 30 based on the fourth target position in the robot coordinate system stored in step S25, thereby positioning the cutting device 32 in the fourth operating position. When the cutting device 32 is positioned in the fourth operating position, the fourth cutting location B is positioned between the open blades 36 and 38.

[0088] Next, the control unit 18 sends a command to the tool driving unit 40 to move the open tools 36 and 38 in the closing direction to cut the fourth cutting portion B. Then, the control unit 18 enters Figure 3 By executing the cycle of steps S2 to S3, the raw material passage portion 54 is cut off, forming Figure 2 The molded product 50' is shown.

[0089] Refer again Figure 3 In step S4, the control unit 18 sends a command to the driving unit 22 of the conveyor 12 to convey the molded product 50' forward.

[0090] In step S5, the control unit 18 determines whether the next molded product 50 is placed on the upstream end of the movable unit 20. For example, the control unit 18 determines whether a second placement detection signal is received from the placement sensor.

[0091] If the control unit 18 determines that the next molded product 50 is placed on the upstream end of the movable part 20 (ie, "Yes"), the control unit 18 returns to step S1. On the other hand, if the control unit 18 determines that the next molded product 50 is not placed on the upstream end of the movable part 20 (ie, "No"), the control unit 18 ends the process. Figure 3 The process shown.

[0092] As described above, in this embodiment, the cutting portion B is determined as a target position based on the shape of the molded product 50 detected by the vision sensor 16 , and the cutting device 32 is positioned at the operating position for cutting the cutting portion B by the operation of the robot 14 .

[0093] This structure allows the cutting portion B to be cut without requiring a fixture to hold the molded product 50. This reduces production line space and increases the flexibility of the production line layout. This allows for a highly versatile production line at low cost. Furthermore, the process of placing the molded product 50 in the fixture can be omitted, thus reducing cycle time.

[0094] Next, refer to Figure 5 Next, a cutting system 10' according to another embodiment will be described. The cutting system 10' according to this embodiment differs from the aforementioned cutting system 10 in that it includes a first vision sensor 16A and a second vision sensor 16B. The first vision sensor 16A and the second vision sensor 16B have the same structure as the aforementioned vision sensor 16.

[0095] The cutting system 10' cuts the raw material passage portion 54 of the molded products 50A and 50B placed on the movable portion 20 of the conveyor 12 so as to be adjacent to each other in the x-axis direction. Figure 6 The operation of the cutting system 10' will be described.

[0096] Figure 6 The illustrated process begins when the control unit 18 of the cutting system 10' detects that molded articles 50A and 50B are placed at the upstream end of the movable section 20 of the conveyor 12 (e.g., upon receiving the initial placement detection signal from the placement sensor). Here, the molded articles 50A and 50B are not secured by a clamp or the like; instead, the molded articles 50A and 50B are placed at the upstream end of the movable section 20 by a user or a placement robot.

[0097] In step S31 , the control unit 18 operates the conveyor 12 in the same manner as in step S1 described above, and conveys the molded products 50A and 50B placed on the upstream end of the movable unit 20 .

[0098] In step S32 , the control unit 18 operates the vision sensor 16A in the same manner as in the above-described step S2 to detect the shape of the molded product 50A.

[0099] In step S33, the control unit 18 executes the same first cutting scheme as in step S3 above. Specifically, the control unit 18 executes the first cutting scheme based on the image data of the molded product 50A acquired in the most recent step S32. Figure 4In the steps S11 to S26 shown in FIG, the cutting device 32 is used to cut each cutting portion B of the molded product 50A. As a result, the raw material passage portion 54 of the molded product 50A is cut off, forming Figure 5 The molded product 50A' is shown.

[0100] In step S34, the control unit 18 operates the vision sensor 16B in the same manner as in step S2 described above to detect the shape of the molded product 50B. Here, the control unit 18 executes step S34 simultaneously with step S26 in step S33.

[0101] In this case, the image of the next molded product 50B is captured by the vision sensor 16B in parallel with the operation of cutting the molded product 50A at the fourth cutting location B. This configuration can effectively reduce the cycle time of the operation.

[0102] In step S35, the control unit 18 executes the second cutting scheme similar to the above-mentioned step S3. Specifically, the control unit 18 executes the second cutting scheme based on the image data of the molded product 50B acquired in the most recent step S34. Figure 4 In the steps S11 to S26 shown in FIG, the cutting device 32 is used to cut each cutting portion B of the molded product 50B. As a result, the raw material passage portion 54 of the molded product 50B is cut off, forming Figure 5 The molded product 50B' is shown.

[0103] In step S36 , the control unit 18 sends a command to the driving unit 22 of the conveyor 12 in the same manner as in step S4 described above, so as to convey the molded articles 50A′ and 50B′ forward.

[0104] In step S37 , similarly to step S5 described above, the control unit 18 determines whether the next molded products 50A and 50B are placed on the upstream end of the movable unit 20 .

[0105] In this embodiment, the cutting system 10 ′ includes a first vision sensor 16A and a second vision sensor 16B, and sequentially cuts the material passage portion 54 of the molded products 50A and 50B placed in two rows.

[0106] According to this structure, the material passage portion 54 of the molded products 50A and 50B arranged in two rows can be quickly cut without requiring a jig for fixing the molded products 50A and 50B. This can significantly improve the work efficiency.

[0107] Furthermore, according to this embodiment, by detecting the shape of the other molded product 50B while cutting the one molded product 50A, or repeating the reverse combination, it is possible to reduce waiting time, thereby further effectively improving work efficiency.

[0108] Alternatively, the cutting system 10' may include multiple robots 14, with the first robot 14 cutting the material passage portion 54 of the molded product 50A, while the second robot 14 cuts the material passage portion 54 of the molded product 50B. In this case, the control unit 18 may execute steps S32-S33 and steps S34-S35 synchronously (i.e., in parallel).

[0109] In addition, the robot 14 may also have a manipulator capable of holding the cut raw material passage portion 54 in addition to the cutting device 32. Figure 7 Such a robot 14 ′ is shown in .

[0110] The robot 14' differs from the robot 14 described above in the following structure. Specifically, the robot 14' further includes a manipulator 42 connected to the wrist 30. The manipulator 42 includes a hand base 44 connected to the wrist 30 and fingers 46 and 48 provided on the hand base 44 in an openable and closable manner.

[0111] Immediately before or after the aforementioned steps S4 or S36, the control unit 18 operates the robot 14' to grip the cut material passage portion 54 with the robot hand 42. The control unit 18 then operates the rotating body 26, the robot arm 28, and the wrist 30 to transport the material passage portion 54 gripped by the robot hand 42 to a predetermined disposal location.

[0112] Furthermore, immediately before or after step S4 or S36, robot 14' is operated to grip product portion 52 with hand 42. Then, control unit 18 operates rotating body 26, robot arm 28, and wrist 30 to transport product portion 52 gripped by hand 42 to a predetermined storage location.

[0113] In addition, in the above-mentioned embodiment, the control unit 18 executes Figure 4 The cases of steps S11 to S13, S15 to S17, S19 to S21, and S23 to S25 are described.

[0114] However, it is also possible that the vision sensor 16 performs Figure 4 Steps S11-13, S15-S17, S19-21 and S23-25 ​​are shown.

[0115] Specifically, in the above-mentioned step S11, the image processor of the visual sensor 16 (or the CPU built into the visual sensor 16) compares the image of the molded product 50 acquired in the most recent step S2 with the reference image of the molded product 50 pre-stored in the storage unit of the visual sensor 16, and detects the position of the casting nozzle portion 58 in the sensor coordinate system in the image data of the molded product 50.

[0116] In this embodiment, the image processor of the visual sensor 16 functions as an acquisition unit for acquiring the position of the material passage portion 54 in the sensor coordinate system.

[0117] Next, the image processor of the vision sensor 16 tracks the characteristic points (i.e., contour lines) of the first runner portion 56 extending from the gate portion 58 detected in the image data of the molded product 50 in the direction from the gate portion 58 to the corresponding product portion 52 .

[0118] In the above-mentioned step S12, the image processor of the visual sensor 16 determines the result of tracing the contour line of the first runner portion 56 in step S11, that is, whether the first runner portion 56 extends from the gate portion 58 to the first gate portion 60 formed at the front end of the first runner portion 56.

[0119] In step S13 , the image processor of the vision sensor 16 determines a predetermined position on the first runner portion 56 as the first cutting location, and determines the position of the determined second cutting location B in the sensor coordinate system as the first target position.

[0120] The image processor of the visual sensor 16 sends the determined first target position to the control unit 18. In this embodiment, the image processor of the visual sensor 16 functions as a determination unit for determining the position of the cutting part B as the target position. Similarly, the image processor of the visual sensor 16 may also execute Figure 4 S15~S17, S19~21 and S23~25 shown.

[0121] In addition, instead of the visual sensor 16 , 16A, or 16B, a sensor capable of recognizing the shape of an object, such as a laser displacement sensor or an infrared sensor, may be used to detect the shape of the molded product 50 , 50A, or 50B.

[0122] The robot 14 is not limited to a vertical articulated robot and may be any type of robot. Alternatively, a loader may be used in place of the robot 14 to move the cutting device 32. In this case, the loader functions as a manipulator for moving the cutting device 32.

[0123] Alternatively, the cutting device 32 may include a circular cutter rotatably provided on the base 34 instead of the pair of cutters 36 and 38 , and the cutter driving unit 40 may rotationally drive the circular cutter in response to a command from the control unit 18 .

[0124] In this case, in the above-described steps S14 , S18 , S22 , and S26 , the control unit 18 operates the robot 14 to push the circular cutter toward the cutting portion B from vertically above, thereby cutting the cutting portion B.

[0125] When the cutting device 32 has a circular blade, the molded products 50 , 50A, and 50B have a shape such that the cut portion B does not shift when a vertically downward force is applied to the cut portion B while the molded products 50 , 50A, and 50B are placed on the movable portion 20 .

[0126] In the above embodiment, the control unit 18 stops the conveyor 12 when the molded product 50 is positioned at the detection position in steps S1 and S31. However, the present invention is not limited to this. The control unit 18 may execute steps S2-S3 and S32-35 without stopping the conveyor 12 in steps S1 and S31.

[0127] In this case, the control unit 18 may reduce the speed at which the molded products 50 , 50A, and 50B are conveyed by the conveyor 12 while executing steps S2 to S3 and S32 to S35 .

[0128] Alternatively, the vision sensors 16, 16A, and 16B may be provided so as to be movable in the y-axis direction, and the cutting systems 10 and 10' may further include a moving mechanism for moving the vision sensors 16, 16A, and 16B. In this case, the control unit 18 operates the moving mechanism so as to follow the molded products 50, 50A, and 50B conveyed by the conveyor 12, thereby moving the vision sensors 16, 16A, and 16B forward.

[0129] According to this configuration, when steps S2 , S32 , and S34 are executed, the vision sensors 16 , 16A, and 16B can be always arranged above the molded products 50 , 50A, and 50B conveyed by the conveyor 12 .

[0130] In addition, in the above-mentioned steps S13 , S17 , S21 and S25 , the control unit 18 may determine the result of tracing the contour line of the runner portion 56 , that is, whether the gate portion 60 formed at the front end of the runner portion 56 is connected to the corresponding product portion 52 .

[0131] In this case, in steps S12 , S16 , S20 , and S24 , the control unit 18 may determine the gate portion 60 as the cutting portion and determine the position of the determined cutting portion in the sensor coordinate system as the target position.

[0132] Then, the control unit 18 cuts off the gate portion 60 as the cutting portion in steps S14, S18, S22, and S26. According to this configuration, the material passage portion 54 remaining in the product portion 52 after cutting can be reduced in size.

[0133] While the present invention has been described above using embodiments thereof, these embodiments do not limit the invention as set forth in the claims. Furthermore, combinations of features described in the embodiments of the present invention are also encompassed within the technical scope of the present invention, but not all combinations of these features are necessarily required for the invention. Furthermore, those skilled in the art will appreciate that various modifications and improvements may be incorporated into the above embodiments.

[0134] In addition, it should be noted that the order of execution of actions, processes, steps, procedures, and stages in the devices, systems, programs, and methods described in the claims, specifications, and drawings does not specifically state "before...", "before...", etc., and that they may be executed in any order as long as the output of a previous process is not used in a subsequent process. Although the action flows in the claims, specifications, and drawings are described using phrases such as "first," "next," and "following" for ease of explanation, this does not necessarily mean that they must be executed in this order.

Claims

1. A cutting method for automatically cutting a raw material passage portion from a molded article comprising a plurality of product portions and a raw material passage portion, the raw material passage portion comprising a gate portion, a plurality of runner portions extending from the gate portion, and a plurality of gate portions formed at respective front ends of the plurality of runner portions and connected to the plurality of product portions, wherein the cutting method comprises the following processes: Preparing a cutting device capable of moving in an automatically controlled coordinate system; placing the formed article in a non-fixed manner; photographing the placed formed product using a visual sensor; detecting the gate portion in the coordinate system by comparing pre-stored reference image data with the image data of the molded product; In the image data, a characteristic point of a runner portion extending from the detected gate portion is tracked from the gate portion toward a corresponding one of the product portions; Based on the tracking result, determining whether the one runner portion extends to the one gate portion formed at the front end of the one runner portion, or whether the one gate portion extends to the one product portion, thereby determining whether the one runner portion or the one gate portion is cut off; If it is determined that the one runner portion or the one gate portion is not cut off, determining a predetermined position of the one runner portion or the one gate portion that has been tracked as a target position in the coordinate system; Based on the determined target position, moving the cutting device in the coordinate system, and cutting the one runner portion or the one gate portion at the target position by the cutting device; as well as When it is determined that one of the runner parts or one of the gate parts is cut off, all of the runner parts or the gate parts are cut off at the target position by repeating the tracking, the determination, the decision and the cutting on the other runner parts or the other gate parts formed at the front end of the other runner parts.

2. The cutting method according to claim 1, wherein: The gate portion of the placed first molded product is detected by the first visual sensor, and the gate portion of the placed second molded product is detected by the second visual sensor.

3. The cutting method according to claim 1, wherein: The cutting device is mounted on a manipulation device, and the cutting device is moved in the coordinate system by the manipulation device.

4. The cutting method according to claim 3, wherein: The following steps are also included: After cutting the target position, the raw material passage portion is grasped by a manipulator mounted on the manipulation device; as well as The handling device is operated to transport the material passage portion gripped by the robot to a predetermined location.

5. The cutting method according to claim 3, wherein: The following steps are also included: After cutting off the target position, the product portion is grasped by a manipulator mounted on the manipulation device; as well as The handling device is operated to transport the product portion held by the robot to a predetermined location.

6. A cutting system for automatically cutting off a raw material passage portion from a molded article comprising a plurality of product portions and the raw material passage portion, the raw material passage portion comprising a gate portion, a plurality of runner portions extending from the gate portion, and a plurality of gate portions formed at respective front ends of the plurality of runner portions and connected to the plurality of product portions, the cutting system comprising: a cutting device capable of moving in an automatically controlled coordinate system; a manipulator for moving the cutting device in the coordinate system; a visual sensor that captures the non-fixedly placed formed product; as well as Control Department, The control unit performs the following processing: detecting the gate portion in the coordinate system by comparing pre-stored reference image data with image data of the molded product captured by the vision sensor; In the image data, a characteristic point of a runner portion extending from the detected gate portion is tracked from the gate portion toward a corresponding one of the product portions; Based on the tracking result, determining whether the one runner portion extends to a gate portion formed at a front end of the one runner portion, or whether the one gate portion extends to the one product portion, thereby determining whether the one runner portion or the one gate portion is cut off; If it is determined that the one runner portion or the one gate portion is not cut off, determining a predetermined position of the one runner portion or the one gate portion that has been tracked as a target position in the coordinate system; Based on the determined target position, the manipulation device is operated to move the cutting device in the coordinate system, and the runner portion or the gate portion is cut off at the target position by the cutting device; and When it is determined that the one runner portion or the one gate portion is cut off, all the runner portions or the gate portions are cut off at the target position by repeating the tracking, the determination, the decision and the cutting on other runner portions or other gate portions formed at the front end of the other runner portions.

Images