Workpiece transfer system

Abstract

To provide a workpiece conveying device capable of keeping a constant interval in a conveying direction between workpieces conveyed on a conveying surface.SOLUTION: When the time difference between the detection timing of the M-th workpiece from the downstream side among the N workpieces and the detection timing of the first workpiece in the M+ is longer than the detection cycle when the workpieces are arranged at the predetermined interval, the controller moves the positions of the M holding units on the downstream side in the second direction perpendicular to the first direction to the designated positions at which the workpieces can be held while moving the base unit in the first direction at the predetermined speed, and causes the M holding units to hold M workpieces from the first workpiece to the M-th workpiece on the downstream side among the N workpieces. The controller decelerates the base unit after the M workpieces are held, moves the positions of the N-M holding units from the upstream side in the second direction to the designated position, and causes the N-M holding units on the upstream side to hold the first to Nth workpieces in the M+.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present disclosure relates to a workpiece transport system. [Background technology]

[0002] Conventionally, systems for transporting workpieces have been known. For example, International Publication No. 2016 / 052014 (Patent Document 1) discloses a container transport device that transports a container pack (an example of a workpiece) that includes multiple containers.

[0003] The container conveying device of Patent Document 1 adjusts the pot pitch of each container in the container conveying direction to a predetermined pitch equivalent to the arrangement pitch of the mandrel heads in the film fitting process. The container conveying device is equipped with multiple movable claws that move along the container conveying direction on both sides of the container conveying path. Each movable claw has a support upper surface that abuts against the underside of the flange portion of each container to suspend and support it, and a tip outer peripheral surface that fits between the pot portions of each container and contacts the outer peripheries of two pot portions adjacent to each other in the conveying direction. When containers are continuously conveyed, the movable claw fits between the two pot portions, adjusting the pitch between the two pot portions to a predetermined pitch. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2016 / 052014 Summary of the Invention [Problem to be solved by the invention]

[0005] If at least one of a number of workpieces transported in a line at a predetermined interval is determined to be defective during inspection, the defective workpiece may be removed. In such cases, the distance between the workpieces before and after the defective workpiece becomes longer than the predetermined distance. Considering post-processing, it is desirable to keep the distance between the workpieces constant.

[0006] The present disclosure provides a workpiece transport device that can maintain a constant distance between workpieces being transported on a transport surface in the transport direction. [Means for solving the problem]

[0007] According to the present disclosure, a workpiece transport system includes a transport device having a transport surface extending in a first direction and transporting each of a plurality of workpieces supplied onto the transport surface while aligned at at least a first interval in the first direction at a predetermined speed in one direction in the first direction, a holding device capable of simultaneously holding N adjacent workpieces (N is a natural number greater than or equal to 3) from the plurality of workpieces, a sensor provided upstream of the holding device in the transport direction and for detecting the workpieces, and a controller for controlling the operation of the holding device. The holding device includes N holding units, each holding one workpiece and aligned at a first interval in the first direction, and a base unit movable in the first direction and supporting the N holding units. The base unit has N movement mechanisms that move each of the different holding units in a second direction perpendicular to the first direction and parallel to the transport surface. When the controller determines that the time difference between the sensor detection timing of the Mth (M is a natural number greater than or equal to 1 and less than or equal to N-1) workpiece and the M+1th workpiece from the downstream side of the conveyance among the N workpieces is longer than the workpiece detection period when the workpieces are lined up at a first interval, the controller moves the base unit at a predetermined speed in one direction in the first direction, and causes the M downstream holding units of the N holding units to move in the second direction to designated positions where the workpieces can be held by the M downstream moving mechanisms, thereby causing the M holding units to hold M workpieces from the leading workpiece on the downstream side among the N workpieces. After the M workpieces have been held, the controller decelerates the speed of the base unit from the predetermined speed, and moves the NM upstream holding units from the upstream side to designated positions in the second direction by the NM upstream moving mechanisms, thereby causing the NM upstream holding units to hold the M+1th to Nth works. After the N workpieces are held by the N holding units, the controller causes the N holding units to release the N workpieces at a predetermined timing. [Effects of the Invention]

[0008] According to the above disclosure, it is possible to make the distance between the workpieces being transported on the transport surface constant in the transport direction. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a transport system. [Figure 2] FIG. 2 is an enlarged view of the main part of the conveyance system 1. [Figure 3] 10A and 10B are schematic diagrams for explaining again the movement directions of the above-mentioned components. [Figure 4] FIG. 2 is a diagram for explaining the functional configuration of the transport system 1. [Figure 5] 10 is a diagram showing state transitions between the states of the 16 gripping units and the state of the product W. FIG. [Figure 6] FIG. 6 is a diagram showing state transitions following the state transitions of FIG. 5. [Figure 7] FIG. 7 is a diagram showing state transitions following the state transitions of FIG. 6. [Figure 8] FIG. 8 is a diagram showing state transitions following the state transitions of FIG. 7. [Figure 9] FIG. 9 is a diagram showing state transitions following the state transitions of FIG. 8. [Figure 10] FIG. 10 is a flowchart showing the flow of processing executed in the transport system. DETAILED DESCRIPTION OF THE INVENTION

[0010] The transport robot in the embodiment will be described below with reference to the drawings. In the embodiment described below, the same or equivalent parts will be given the same reference numerals, and redundant description may not be repeated. The drawings are not drawn according to the actual dimensional ratio, and in some places, the ratio is changed to make the structure clearer in order to make it easier to understand. The modified examples described below can be combined as appropriate. In the following, "grasping" and "suction" are each an example of "holding."

[0011] <Overall structure> Fig. 1 is a perspective view of a conveying system 1 according to this embodiment. As shown in Fig. 1, the conveying system 1 includes a gripping device 5, a sensor 8, and a conveying device 9. The operations of the gripping device 5 and the conveying device 9 are controlled by a controller 7 (Fig. 4) described later.

[0012] The conveying device 9 has a conveying surface 91 extending in the X direction. The conveying device 9 conveys each of a plurality of products W (see FIG. 5) that are supplied onto the conveying surface 91 while being arranged in the X direction at least at a predetermined interval D1, in the positive direction of the X direction (one direction of the first direction) at a predetermined speed V1.

[0013] In this example, the conveying device 9 is a belt conveyor. The conveying surface 91 is the outer peripheral surface of the belt. A plurality of products W are sequentially supplied to the conveying surface 91. In this example, the plurality of products W are supplied onto the conveying surface 91 in two rows arranged in the X direction. As the conveying surface 91 moves, the products W are conveyed in the direction of the arrow A1 (from the upstream side to the downstream side). The products W are, for example, yogurt (containers). The products W are an example of a "work" in the present disclosure.

[0014] The gripping device 5 can simultaneously grip a plurality of products W (16 in this example). The gripping device 5 has a plurality of gripping units 101a-108a, 101b-108b arranged in the X direction, each of which holds one product W. The gripping device 5 is an example of a "holding device" in the present disclosure. For ease of explanation, any one of the 16 gripping units 101a-108a, 101b-108b will hereinafter also be referred to as a "gripping unit 100."

[0015] In this example, the products W are supplied in two rows, so the 16 gripping units 100 are arranged in two rows, just like the products W. The 16 gripping units 100 include eight gripping units 101a to 108a that grip eight products W (an example of a first workpiece) that make up a first row (one row), and eight gripping units 101b to 108b that hold eight products W (an example of a second workpiece) that make up a second row (the other row).

[0016] Hereinafter, any one of the gripping units 101a to 108a will also be referred to as "gripping unit 100a." Similarly, any one of the eight gripping units 101b to 108b will also be referred to as "gripping unit 100b." Note that gripping unit 100a is an example of a "first gripping unit" in the present disclosure. Gripping unit 100b is an example of a "second gripping unit" in the present disclosure.

[0017] The eight gripping units 100a are lined up in a row in the X direction. The eight gripping units 100b are also lined up in a row in the X direction. The eight gripping units 100a and the eight gripping units 100b face each other so as to sandwich the 16 products W lined up in two rows. One gripping unit 100a and one gripping unit 100b face each other in the Y direction. For example, the gripping unit 101a and the gripping unit 101b face each other in the Y direction.

[0018] The sensor 8 is provided upstream of the gripping device 5 (more specifically, each gripping unit 100). The sensor 8 detects the products W. The sensor 8 detects each product W that is conveyed in two rows. The sensor 8 detects the product W that has reached a predetermined position. The sensor 8 can individually detect two products in different rows. The sensor 8 notifies the controller 7 of the detection result. When the sensor 8 detects the product W, it transmits a predetermined signal to the controller 7 in real time. In this example, when the products W are lined up in the X direction at an interval D1, the sensor 8 detects the products W at a period T1.

[0019] 2 is an enlarged view of a main part of the conveyance system 1. As shown in FIG.

[0020] The hand 113 can grasp the product W by transitioning from an open state to a closed state. More specifically, the hand 113 has a finger 113a, a finger 113b, and a finger 113c. The finger 113a is spaced apart from the two finger portions 113b and 113c in the X direction. The finger portions 113b and 113c are spaced apart from each other in the Z direction. The finger portion 113b is located directly above the finger portion 113c. The finger portions are also referred to as claws.

[0021] The three fingers 113a, 113b, and 113c are configured to be movable in the X direction. The product W can be gripped by bringing the finger 113a and the two fingers 113b and 113c closer to each other. While gripping the product W, the finger 113a and the two fingers 113b and 113c move away from each other, thereby releasing the gripped product W. In this example, the finger 113a and the two fingers 113b and 113c are configured to be moved closer to each other by supplying air to the main body 112.

[0022] As will be described in detail later, the gripping device 5 allows the distance between the gripping units 100 in the X direction to be adjusted. When the distance becomes shorter than a predetermined distance, the finger 113a fits between the finger 113b and the finger 113c of the adjacent gripping unit 100. For example, the finger 113a of the gripping unit 101b is configured to be able to fit between the finger 113b and the finger 113c of the adjacent gripping unit 102b. In this case, the finger 113b of the gripping unit 102b, the finger 113a of the gripping unit 101b, and the finger 113c of the gripping unit 102b are aligned in this order in the vertical direction. This allows the minimum separation distance to be reduced.

[0023] The gripping device 5 includes a base unit 200 and a feed screw 310. The base unit 200 includes a substrate 210, a distance adjustment mechanism 220, eight support plate portions 230, and 16 gripping unit movement mechanisms 240. The distance adjustment mechanism 220 has two cams 221 (see FIG. 3). The gripping unit movement mechanism 240 has a fixed portion 241 and a gripping unit mounting base 242 as a movable portion. A servo motor 2419 is built into the fixed portion 241.

[0024] The base unit 200 is movable in the X direction. In this example, the base unit 200 moves in the X direction by rotating the feed screw 310. In this example, the base unit 200 is configured to be movable at a speed equal to or greater than the above-mentioned speed V1. The base unit 200 movably supports 16 gripping units 100. Specifically, the base unit 200 supports the 16 gripping units 100 so that the gripping units 100 are movable relative to the base unit 200 in the X and Y directions.

[0025] The substrate 210 has beams 211 and 212 to increase the rigidity of the substrate 210. The beams 211 and 212 extend parallel to each other in the X direction. A similar beam (not shown) is provided on the opposite side of the beam 211 from the beam 212.

[0026] The eight support plate portions 230 are arranged side by side in the X direction. Each support plate portion 230 supports two gripping unit movement mechanisms 240 that face each other in the Y direction. Each support plate portion 230 is connected to a cam 221 of the distance adjustment mechanism 220. The cam 221 is installed on the substrate 210 so as to be movable relative to the substrate 210. The cam 221 is movable in the Y direction relative to the substrate 210.

[0027] The interval adjustment mechanism 220 changes the interval between the gripping units 100 in the X direction. The interval adjustment mechanism 220 changes the interval between the gripping units 100 in the X direction by operating (moving) a cam 221. In this example, the interval adjustment mechanism 220 simultaneously changes the interval between the gripping units 100a lined up in a row in the X direction and the interval between the gripping units 100b lined up in a row in the X direction.

[0028] Specifically, the interval adjustment mechanism 220 can simultaneously change the interval between the gripping units 100a in the X direction and the interval between the gripping units 100b in the X direction to the same length. That is, the interval adjustment mechanism 220 changes the interval between the gripping units 100 in the X direction so that the intervals (intervals of 14 units) between the gripping units 100 are kept equal. The interval adjustment mechanism 220 can change the interval at least between the interval D1 described above and an interval D2 narrower than the interval D1. The controller 7 sets the interval before and after the change as appropriate.

[0029] The 16 gripping unit moving mechanisms 240 each move a different gripping unit 100 in the Y direction. Specifically, one gripping unit moving mechanism 240 moves one gripping unit 100 in the Y direction. The Y direction is perpendicular to the X direction and parallel to the conveying surface 91.

[0030] Specifically, the support part 111 of the gripping unit 100 is attached to a gripping unit mounting base 242 of the gripping unit moving mechanism 240. A servo motor 2419 of the gripping unit moving mechanism 240 moves the gripping unit mounting base 242 in the Y direction on the fixed part 241. The gripping unit mounting base 242 slides on the fixed part 241. With this configuration, the gripping unit moving mechanism 240 can move the gripping unit 100 in the Y direction.

[0031] <Movement direction> In the following, the two-dimensional XY coordinate system consisting of the X and Y directions described above is referred to as a global coordinate system, and the two-dimensional local coordinate system based on the substrate 210 moving in the X direction is referred to as an xy coordinate system.

[0032] 3 is a schematic diagram for explaining the movement direction of each of the above-mentioned components. FIG. 3 simulates the state when the distance between the gripping units 100 in the X direction is narrowest. In this example, the state is shown where the distance is narrower than distance D2. As shown in FIG. 3, the substrate 210 of the base unit 200 can be moved in the positive and negative directions in the X direction by the above-mentioned feed screw 310.

[0033] Each of the two cams 221 is a plate-shaped guide plate (slide plate). A plurality of (four in this example) elongated holes 2219 are formed in each of the two cams 221. Each elongated hole 2219 is linear and extends in the x and y directions. The shapes of the elongated holes 2219 in the downstream cam 221 and the upstream cam 221 are line-symmetrical with respect to a line segment (not shown) parallel to the y direction. In the cams 221, the inclinations of the elongated holes 2219 in the xy plane are different.

[0034] Each support plate portion 230 has a cam follower 239. Each of the plurality of cam followers 239 is engaged with a different elongated hole 2219 of the cam 221. Each of the two cams 221 guides the cam follower 239 by means of the elongated hole 2219.

[0035] The two cams 221 are movable in the Y direction relative to the substrate 210. Specifically, the two cams 221 are movable only in the y direction in an xy coordinate system (local coordinate system) based on the substrate 210. The inclination of each of the elongated holes 2219 in the xy plane is set so that the distance between the support plate portions 230 in the x direction becomes uniform as the cams 221 move in the y direction.

[0036] More specifically, the two cams 221 are configured to be movable in the negative and positive directions of the y direction by a servo motor 222 (FIG. 4) described later. In this example, the two cams 221 move simultaneously and in the same direction by the same distance in response to a command from the controller 7. More specifically, the two cams 221 move in a direction corresponding to the rotation direction of the servo motor 222.

[0037] Each support plate portion 230 is movable in the X direction relative to the substrate 210 by the cam 221. More specifically, each support plate portion 230 is movable only in the x direction in the xy coordinate system.

[0038] 3, when the cam 221 moves in the negative y direction, the cam follower 239 engages with the elongated hole 2219, and therefore each support plate portion 230 moves in the x direction while being restricted by the elongated hole 2219. Specifically, as described above, the shapes of the grooves in the downstream cam 221 and the upstream cam 221 are line-symmetric, and therefore the downstream support plate portion 230 and the upstream support plate portion 230 move in different directions in the x direction. Specifically, the downstream support plate portion 230 moves in the positive x direction, and the upstream support plate portion 230 moves in the negative x direction.

[0039] 3, when the downstream cam 221 moves in the negative y direction, the support plate portion 230 closer to the positive x direction moves a longer distance in the positive x direction. When the upstream cam 221 moves in the negative y direction, the support plate portion 230 closer to the negative x direction moves a longer distance in the negative x direction. With this configuration, the distance between the support plate portions 230 in the x direction can be kept uniform.

[0040] When the movement of each cam 221 in the negative y direction is completed, each cam 221 is then moved in the positive y direction, returning to the state shown in FIG.

[0041] Since each gripping unit 100 is mounted on the support plate 230, it moves in the x direction as the support plate 230 moves in the x direction. Each gripping unit 100 can move in the Y direction relative to the substrate 210 as the gripping unit mounting base 242 moves as described above. More specifically, each gripping unit 100 can also move in the y direction in the xy coordinate system.

[0042] <Functional configuration> 4 is a diagram for explaining the functional configuration of the conveyance system 1. As shown in FIG. 4, the conveyance system 1 further includes a controller 7 in addition to the gripping device 5 and the conveyance device 9.

[0043] The gripping device 5 includes the 16 gripping units 100 (gripping units 101a to 108a, 101b to 108b) and the base unit 200, as well as a base unit moving mechanism 300 and an air supply device 400.

[0044] As described above, each gripping unit 100 has a main body 112 and a hand 113. As described above, the base unit 200 has the interval adjustment mechanism 220 and the 16 gripping unit moving mechanisms 240. The interval adjustment mechanism 220 has the servo motor 222 in addition to the two cams 221 described above. As described above, each gripping unit moving mechanism 240 has the gripping unit mounting base 242 and the servo motor 2419 (FIG. 2). The base unit moving mechanism 300 has the servo motor 320 in addition to the feed screw 310 described above. The air supply device 400 has an air compressor 401 and eight control valves 411 to 418.

[0045] The controller 7 transmits commands to the base unit 200, the base unit moving mechanism 300, the air supply device 400, and the transport device 9. In detail, the controller 7 transmits drive commands to the servo motors 2419 of the gripping unit moving mechanisms 240 and the servo motors 222 of the distance adjustment mechanisms 220. The controller 7 also transmits drive commands to the servo motors 320 of the base unit moving mechanism 300. The controller 7 transmits commands to the air compressor 401 to control the operation of the air compressor 401. The controller 7 transmits commands to the control valves 411 to 418 to control the opening and closing of the control valves 411 to 418.

[0046] The servo motor 320 operates the lead screw 310. When the servo motor 320 is driven, the lead screw 310 rotates. When the rotation direction of the servo motor 320 is switched, the rotation direction of the lead screw 310 is also switched. As a result, the base unit 200 can move in the positive and negative directions in the X direction at a speed according to the drive command by a distance according to the drive command.

[0047] The servo motor 222 operates the two cams 221. When the servo motor 222 is driven, each cam 221 moves in the Y direction relative to the substrate 210. When the rotation direction of the servo motor 222 is switched, the direction of movement of each cam 221 is switched. The controller 7 controls the operation of the two cams 221 by controlling the driving of the servo motor 222.

[0048] The operation of each cam 221 causes the 16 gripping unit moving mechanisms 240 to move in the X direction relative to the substrate 210. The operation of each cam 221 changes the interval between the gripping unit moving mechanisms 240 in the X direction. This changes the interval between the gripping units 100 in the X direction.

[0049] Each servo motor 2419 moves the gripping unit mount 242. When the servo motor 2419 is driven, the gripping unit mount 242 moves (slides) in the Y direction relative to the fixed part 241. When the rotation of the servo motor 2419 is switched, the direction of movement of the gripping unit mount 242 in the Y direction is also switched. Each gripping unit mount 242 moves in the positive or negative direction in the Y direction at a speed according to the drive command and by a distance according to the drive command.

[0050] The air supply device 400 can supply air at a predetermined pressure to each gripping unit 100. More specifically, an air compressor 401 generates compressed air at a predetermined pressure.

[0051] Each of the control valves 411 to 418 is connected to the air compressor 401. The control valve 411 is connected to the main body 112 of the gripping unit 101a and the main body 112 of the gripping unit 101b. Similarly, the control valve 412 is connected to the main body 112 of the gripping unit 102a and the main body 112 of the gripping unit 102b. The other control valves 413 to 418 are also connected to the different gripping units 100a and 100b, respectively.

[0052] When each of the control valves 411 to 418 receives an operation command from the controller 7, the valve closes, thereby transitioning from an open state to a closed state. Specifically, when electricity is applied to each of the control valves 411 to 418, the valve transitions from a steady open state to a closed state. However, without being limited to this, each of the control valves 411 to 418 may be in a closed state in the steady state.

[0053] When compressed air of a predetermined pressure is generated by the air compressor 401, and each of the control valves 411 to 418 is opened, compressed air is supplied to the main body 112. This causes the hand 113 to close (grasp). That is, the finger 113a and the two fingers 113b and 113c move toward each other. When each of the control valves 411 to 418 is transitioned from the open state to the closed state, compressed air is released from the main body 112. This causes the hand 113 to transition from the closed state (grasp) to the open state (release) due to a return mechanism such as a spring. The finger 113a and the two fingers 113b and 113c move in directions away from each other.

[0054] In this example, the controller 7 transmits the same command (open command, close command) to each of the control valves 411 to 418 at the same timing. That is, each of the control valves 411 to 418 transitions from a closed state to an open state at the same timing. Furthermore, each of the control valves 411 to 418 transitions from an open state to a closed state at the same timing.

[0055] Although the above description has been given with reference to an example in which one control valve is provided for two gripping units 100, the present invention is not limited to this. Each gripping unit 100 may be provided with an individual control valve.

[0056] <State transition> Fig. 5 is a diagram showing state transitions between the states of the 16 gripping units 100 and the state of the product W. Fig. 6 is a diagram showing state transitions following the state transitions of Fig. 5. Fig. 7 is a diagram showing state transitions following the state transitions of Fig. 6. Fig. 8 is a diagram showing state transitions following the state transitions of Fig. 7. Fig. 9 is a diagram showing state transitions following the state transitions of Fig. 8.

[0057] The reference lines Ls shown in Figures 5 to 9 are the same imaginary line. The position (absolute position) of each reference line Ls in the X direction is the same in each of Figures 5 to 9. Each reference line Ls is a line that indicates a specific position in the X direction relative to the conveying device 9.

[0058] As shown in state (A) of FIG. 5, products W are sequentially supplied in two rows onto the conveying surface 91. Products W1a to W7a are lined up in the X direction at equal intervals (distance D1 in this example). Products W1b to W7b are also lined up in the X direction at the same interval D1 as products W1a to W7a. Products W1b to W7b face products W1a to W7a, respectively, in the Y direction. For example, product W1b faces product W1a in the Y direction.

[0059] Between product W7a and product W8a, there is a gap (hereinafter also referred to as gap D3) that is the width of one product. Note that D3>D1. Similarly, between product W7b and product W8b, there is a gap D3 that is the width of one product. In this example, two products W (not shown) facing each other in the Y direction are determined to be defective in a quality inspection or the like, resulting in a gap of one product as described above.

[0060] Products W8a, W9a, ..., W15a, W16a, ... are also lined up at equal intervals (distance D1) in the X direction. Products W8b, W9b, ..., W15b, W16b, ... are also lined up at equal intervals (distance D1) in the X direction. Product W8b faces product W8a in the Y direction. Product W9b faces product W9a in the Y direction. Products W1a, W2a, ..., W16a, ... are located in the negative direction of the Y direction relative to products W1b, W2b, ..., W16b, ....

[0061] In the following, any one of products W1a, W2a, ..., W16a, ... will also be referred to as "product Wa." Any one of products W1b, W2b, ..., W16b, ... will be referred to as "product Wb." Any one of products W1a, W2a, ..., W16a, ... and products W1b, W2b, ..., W16b, ... will also be referred to as "product W." The positions of the 16 gripping units 100 shown in state (A) will also be referred to as "reference positions."

[0062] In this example, sensor 8 detects the presence of product W in cycle T1 up to products W7a and W7b. The time difference between the detection of products W7a and W7b and the detection of products W8a and W8b is longer than cycle T1. After products W8a and W8b are detected, the detection cycle by sensor 8 returns to cycle T1.

[0063] The controller 7 continues to acquire detection results from the sensor 8 in real time. Therefore, the controller 7 can determine that products W8a and W8b were not detected within the period T1. Based on the detection results of the sensor 8, the controller 7 can determine whether the interval between products W7a and W8a and the interval between products W7b and W8b have widened beyond the interval D1. The controller 7 executes the X-direction interval adjustment control, which will be described later, based on the fact that the time difference between the detection timings from when products W7a and W7b are detected until when products W8a and W8b are detected has become longer than the period T1. The controller 7 executes the interval adjustment control based on the time difference between the detection timings.

[0064] In state (B) immediately after state (A), the controller 7 controls the base unit moving mechanism 300 to start processing to accelerate the base unit 200 in the positive X direction up to a predetermined speed V1. As a result, the multiple gripping units 100 start accelerating in the positive X direction.

[0065] In state (C) after state (B), when the base unit 200 reaches velocity V1, the controller 7 stops the acceleration of the base unit 200, thereby maintaining the velocity of the base unit 200 at V1. This also maintains the velocity of the multiple gripping units 100 in the positive X direction at velocity V1. As a result, the movement velocity of the multiple gripping units 100 becomes the same as velocity V1 of each product W. In other words, tracking of each product W by the gripping units 100 begins.

[0066] Specifically, in state (C), the acceleration and acceleration time of the base unit 200 are set so that each gripping unit 100a faces the product Wa in the Y direction and each gripping unit 100b faces the product Wb in the Y direction.

[0067] After state (C), the controller 7 starts control to move the positions in the Y direction of the seven downstream gripping units 101a to 107a from their initial positions to designated positions where they can grip products W1a to W7a.The controller 7 also starts control to move the positions in the Y direction of the seven downstream gripping units 101b to 107b from their initial positions to designated positions where they can grip products W1b to W7b, at the same timing and speed.

[0068] In this way, the controller 7 moves the gripping units 101a to 107a and the gripping units 101b to 107b in directions in which they approach each other. The controller 7 does not move the gripping units 108a and 108b in the Y direction at this point.

[0069] Naturally, the initial positions of the gripping units 100a and 100b are different. Naturally, the designated positions of the gripping units 100a and 100b are also different. Information on the initial positions and designated positions (typically, coordinate values ​​in the Y direction) is set (stored) in advance in the controller 7.

[0070] Thereafter, as shown in state (D), the gripping units 101a to 107a reach the designated positions, and the gripping units 101b to 107b reach the designated positions. After state (D), the controller 7 controls the air supply device 400 to cause the gripping units 101a to 107a to grip the products W1a to W7a, and cause the gripping units 101b to 107b to grip the products W1b to W7b, as shown in state (E) in FIG.

[0071] Immediately after state (E), the controller 7 continues to decelerate the speed of the base unit 200 and stops the base unit 200 (state (F)). The controller 7 stops the base unit 200 until the positions of the products W8a, W9a, ... and the positions of the products W8b, W9b, ... reach the positions shown in state (G). During this time, the movement of each of the gripping units 100a, 100b in the X direction is stopped.

[0072] When the controller 7 enters state (G), the controller 7 controls the base unit moving mechanism 300 to start processing to accelerate the base unit 200 in the positive X direction up to a predetermined speed V1. As a result, the multiple gripping units 100 start accelerating in the positive X direction (state (H)).

[0073] In state (I) after state (H), when the base unit 200 reaches velocity V1, the controller 7 stops the acceleration of the base unit 200, thereby maintaining the velocity of the base unit 200 at V1. This also maintains the velocity of the multiple gripping units 100 in the positive X direction at velocity V1. As a result, the movement velocity of the multiple gripping units 100 becomes the same as velocity V1 of each product W. That is, gripping unit 108a starts tracking product W8a, and gripping unit 108b starts tracking product W8b.

[0074] Specifically, in state (I), the acceleration and acceleration time of the base unit 200 are set so that each gripping unit 108a faces the product W8a in the Y direction and each gripping unit 108b faces the product W8b in the Y direction.

[0075] After state (I), the controller 7 starts control to move the position in the Y direction of the eighth gripping unit 108a from the downstream side to the specified position (position where product W8a can be gripped).The controller 7 starts control to move the position in the Y direction of the eighth gripping unit 108b from the downstream side to the specified position (position where product W8b can be gripped) at the same timing and speed.

[0076] In state (J), when the position of gripping unit 108a in the Y direction and the position of gripping unit 108b in the Y direction each reach their designated positions, controller 7 causes gripping unit 108a to grip product W8a and gripping unit 108b to grip product W8b, as shown in state (K).

[0077] After state (K), as shown in state (L), the controller 7 controls the operation of the gap adjustment mechanism 220 to change the gap between the gripping units 100 in the X direction from gap D1 to gap D2. In this example, the gap between the gripping units 100 is narrowed. By narrowing the gap between the gripping units 100, the gap between product W8a and product W9a is wider than gap D1. Similarly, the gap between product W8b and product W9b is wider than gap D1.

[0078] After state (L), as shown in state (M), the controller 7 transitions the control valves 411 to 418 to a closed state, causing the gripping units 101a to 108a to release the products W1a to W8a and the gripping units 101b to 108b to release the products W1b to W8b.

[0079] After the release, the controller 7 starts control to move the positions of the eight gripping units 101a to 108a in the Y direction from the designated positions to the initial positions. The controller 7 starts control to move the positions of the eight gripping units 101b to 108b in the Y direction from the designated positions to the initial positions at the same timing and speed. In this way, the controller 7 moves the gripping units 101a to 107a and the gripping units 101b to 107b in directions away from each other.

[0080] Thereafter, as shown in state (N), the gripping units 101a to 107a reach their initial positions, and the gripping units 101b to 107b reach their initial positions.

[0081] In state (O) after state (N), the controller 7 starts decelerating the base unit 200. That is, the controller 7 starts decelerating the gripping unit 100. State (P) shows the state after deceleration. When the speed of the base unit 200 becomes 0 (state (Q)), the controller 7 accelerates the base unit 200 in the negative X direction. As a result, the gripping unit 100 and the base unit 200 accelerate in the negative X direction.

[0082] After state (Q), as shown in state (R), the controller 7 controls the operation of the distance adjustment mechanism 220 to change the distance between the gripping units 100 in the X direction from distance D2 to distance D1. That is, the controller 7 returns the distance between the gripping units 100 to the original state. The distance between the gripping units 100 is widened.

[0083] In state (S), the controller 7 controls the base unit moving mechanism 300 to reduce the speed (absolute value) of the base unit 200 in the negative X direction. That is, the speed (absolute value) of each gripping unit 100 in the negative X direction is reduced. In state (T), the controller 7 stops the base unit 200. As a result, the gripping units 100 also stop.

[0084] The above series of processes makes it possible to set the interval (interval in the X direction) between the products W being conveyed on the conveying surface 91 to a constant interval D1. In particular, in this example, the interval between the products W can also be adjusted from the interval D1 when supplied onto the conveying surface 91 to an interval D2.

[0085] After state (T), the controller 7 executes processing to adjust the spacing in the X direction of the next 16 products W using the 16 gripping units 100. The controller 7 executes processing for the next cycle. The spacing between adjacent products W9a to W16a and the spacing between adjacent products W9b to W16b are maintained at spacing D1. Therefore, in this cycle, unlike the above-described state (D), the controller 7 moves the positions in the Y direction of the eight gripping units 101a to 108a and the positions in the Y direction of the eight gripping units 101b to 108b from their initial positions to designated positions.

[0086] In the above description, as shown as state (T), when the controller 7 executes the next cycle of processing, the 16 gripping units 100 are shifted in the positive X direction from state (A). However, this is not limited to this. When executing the next cycle of processing, the controller 7 may control the movement of the base unit 200 so that the 16 gripping units 100 are at the positions shown in state (A). In other words, the controller 7 may be configured to return the positions of the 16 gripping units 100 to the above-mentioned reference positions when executing the next cycle of processing.

[0087] In the above, an example was given in which the distance between the seventh product W7a and the eighth product W8a is distance D3, and the distance between the seventh product W7b and the eighth product W8b is distance D3, but this is not limited to this.

[0088] The above processing can also be applied when the distance between the Mth (M is a natural number greater than or equal to 1 and less than or equal to N-1, N is 8 in this example) product W from the downstream side and the (M+1)th product W is the distance D3. For example, the processing can also be applied when the distance between the third product W3a and the fourth product W4a is the distance D3, and the distance between the third product W3b and the fourth product W4b is the distance D3.

[0089] Furthermore, the present invention can also be applied to a case where the distance between the Mth product W and the (M+1)th product W is a distance D4 longer than the distance D3. For example, the present invention can also be applied to a case where the distance between the third product W3a and the fourth product W4a is a distance D4 longer than the distance D3, and the distance between the third product W3b and the fourth product W4b is a distance D4.

[0090] The location where the spacing is D3 in the first row (the row of products on the negative side of the X direction) and the location where the spacing is D3 in the second row (the row of products on the positive side of the X direction) do not necessarily have to coincide in the Y direction, as shown in Figure 5. For example, this can also be applied to a case where the spacing between the third product W3a and the fourth product W4a is D3, and the spacing between the fifth product W5b and the sixth product W6b is D3. In this case, as described above, it is necessary to provide an individual control valve for each gripping unit 100.

[0091] <Summary and Benefits> [1] Hereinafter, when focusing on the gripping unit 100a, the controller 7 executes the following processing. The same applies when focusing on the gripping unit 100b.

[0092] (1) When the controller 7 determines that the time difference between the detection timing by the sensor 8 of the Mth (M is a natural number greater than or equal to 1 and less than or equal to N-1) product Wa and the M+1th product Wa from the downstream side of the conveyance among N workpieces (eight in this example) is longer than the detection cycle of the products Wa when the products Wa are lined up at intervals D1 (first intervals), the controller 7 executes the following process. Note that in Figures 5 to 9, the value of M is 7.

[0093] The controller 7 moves the base unit 200 in the positive direction of the X direction at a predetermined speed V1, and moves the positions in the Y direction of the downstream M gripping units 100a of the eight gripping units 100a to designated positions where the products Wa can be gripped by the downstream M gripping unit moving mechanisms 240, thereby causing the M gripping units 100a to grip the M products Wa from the downstream first product Wa to the Mth product Wa of the eight workpieces.

[0094] After the M products Wa have been gripped, the controller 7 slows down the speed of the base unit 200 from the predetermined speed V1 and moves the positions of the 8-M gripping units 100a from the upstream side in the Y direction to specified positions using the 8-M gripping unit moving mechanisms 240 on the upstream side, thereby causing the 8-M gripping units 100a on the upstream side to grip the (M+1)th to 8th products Wa.

[0095] After the eight products Wa are gripped by the eight gripping units 100a, the controller 7 causes the eight gripping units 100a to release the eight products Wa at a predetermined timing.

[0096] With this configuration, when the gripping unit 100a grips the (M+1)th product Wa from the downstream side, the distance between the Mth product Wa and the (M+1)th product Wa from the downstream side can be adjusted to the distance in the X direction of the gripping unit 100a. In other words, when the gripping unit 100a grips the (M+1)th product Wa, the distance between the Mth product Wa and the (M+1)th product Wa from the downstream side can be set to distance D1. Therefore, when the gripping unit 100a grips the (M+1)th product Wa, it is possible to keep the distance in the X direction between the products Wa being conveyed on the conveying surface 91 constant (distance D1).

[0097] (2) After M products Wa have been gripped, the controller 7 decelerates based on the time difference in the detection timing described above, and then accelerates to a predetermined speed V1 after the deceleration, thereby aligning the positions of the 8-M gripping units 100a from the upstream side in the first direction with the X-direction positions of the (M+1)th to 8th products Wa.

[0098] After the positions in the X direction are aligned, the controller 7 moves the positions in the Y direction of the 8-M gripping units 100a from the upstream side to specified positions, thereby causing the 8-M gripping units 100a on the upstream side to grip the M+1th to 8th products Wa.

[0099] According to the above configuration, the 8-M gripping units 100a from the upstream side and the (M+1)th to 8th products Wa are directly opposite each other in the Y direction. Therefore, the 8-M gripping units 100a from the upstream side can grip the (M+1)th to 8th products Wa with high precision.

[0100] (3) The base unit 200 has a gap adjustment mechanism 220 that changes the gap between the gripping units 100a in the X direction. The predetermined timing described above occurs after the controller 7 causes the gap adjustment mechanism 220 to change the gap between the gripping units 100a from gap D1 to gap D2 (second gap).

[0101] According to the above configuration, after the interval between the products W in the X direction is set constant (interval D1), the interval can be further adjusted to interval D2.

[0102] [2] The conveying system 1 has the following configuration. The conveying system 1 includes an air supply device that supplies air at a predetermined pressure to each of the gripping units 100a. Each gripping unit 100a has a main body 112 connected to the base unit 200 and a hand 113 attached to the main body 112 and configured to grip the product Wa. The hand 113 can grip the product Wa by transitioning from an open state to a closed state. When air is supplied to the main body 112, the hand 113 transitions from an open state to a closed state.

[0103] Because the hand 113 is operated by air, it is possible to absorb dimensional errors of the product W compared to when the fingers 113a to 113c are operated by a servo motor or the like by a predetermined distance. Therefore, it is possible to grip the product W more reliably compared to when a servo motor or the like is used.

[0104] <Processing flow> Fig. 10 is a flow diagram showing the flow of processing executed by the conveyance system 1. Fig. 10 describes the flow of processing focusing on the gripping unit 100a. The processing is similar when focusing on the gripping unit 100b, so the explanation will not be repeated here. In detail, the processing in Fig. 10 is processing when the gap adjustment mechanism 220 is not performing gap adjustment (see state (L) in Fig. 7).

[0105] 10, in step S1, the controller 7 starts acquiring the detection results of the sensor 8. In step S2, the controller 7 determines whether the time difference between the detection timings of the Mth (1≦M≦7)th product Wa and the M+1th product Wa from the downstream side of the conveyance is longer than the detection cycle of the products W when they are lined up at intervals D1.

[0106] If it is determined that the product Wa is long (YES in step S2), in step S3, the controller 7 moves the base unit 200 in the positive X direction at a speed V1, and moves the relative positions in the Y direction of the downstream M gripping units 100a lined up in the X direction to the conveying surface 91 to designated positions where the product Wa can be gripped.

[0107] In step S4, the controller 7 causes the M gripping units 100a aligned in the X direction to grip M products Wa of the eight products, starting from the first product W on the downstream side to the Mth product Wa. In step S5, after the M products Wa have been gripped, the controller 7 decelerates the speed of the base unit 200 from speed V1 and moves the relative positions of the remaining NM gripping units 100a to designated positions.

[0108] In step S6, the controller 7 causes the NM gripping units 100a that have moved to the designated positions to grip the (M+1)th to Nth products Wa.

[0109] In step S7, after the eight workpieces are gripped at equal intervals in the X direction by the eight gripping units 100a lined up in a row in the X direction, the controller 7 causes each of the eight gripping units to release the product at a predetermined timing.

[0110] <Modification> (1) As an example of holding the product W, a configuration in which the product W is gripped has been described, but the present invention is not limited to this. In other words, a configuration in which the product W is held by gripping it has been described, but the present invention is not limited to this. For example, instead of gripping the product W, the product W may be sucked by a suction mechanism, thereby adjusting the spacing between the products W in the X direction and changing the position of each product W in the Y direction. In this case, for example, the top surface of the product W may be sucked.

[0111] (2) In the above, as shown in state (L) in FIG. 7, a configuration in which the gap adjustment mechanism 220 narrows the gap between the products W in the X direction has been described as an example, but this is not limiting. The gap may be widened depending on the processing content of the subsequent process. For example, if the products W are supplied to the conveying surface 91 at a gap D2, the gap between the gripping units 100 may be set to D2, and then the gap adjustment mechanism 220 may change the gap between the products W to D1.

[0112] (3) The controller that controls the operation of the gripping device 5 and the controller that controls the operation of the transport device 9 may be separate.

[0113] (4) In the above, a product is used as an example of a workpiece, but it may also be a work in progress that is being processed. Note that a product includes a finished product that is about to be boxed or bottled. A product also includes a product that has not yet undergone the required inspection.

[0114] (5) In the above, two cams 221 are used, but this is not limitative. A single cam in which the two cams 221 are integrated may also be used.

[0115] (6) The gap adjustment mechanism 220 that changes the gap between the gripping units 100 in the X direction is not limited to a configuration that includes the cam 221 formed with the long hole 2219. The gap adjustment mechanism 220 may be provided with a link mechanism such as a pantograph structure (a diamond-shaped contraction mechanism) instead of the cam 221.

[0116] (7) The values ​​of the interval D1 and the interval D2 can be appropriately selected (set) within a settable range.

[0117] (8) After adjusting the spacing of the products W in the X direction to spacing D1 or spacing D2, each product W may be gripped by all of the gripping units 100, and the gripping unit moving mechanism 240 may move the position of each product W in the Y direction from the specified position described above to a predetermined position (target position), and then each product W may be released. With this configuration, the separation distance in the Y direction between each product Wa and each product Wb can be adjusted.

[0118] <Additional Notes> The workpiece transport method is the controller determines whether or not a time difference between the detection timing of the Mth (M is a natural number of 1 or more and N-1 or less) workpiece and the M+1th workpiece from the downstream side of the conveyance among the N workpieces by the sensor is longer than a detection cycle of the workpieces when the workpieces are lined up at the first interval; Based on the determination that the time difference in the detection timing is longer than the breed mid-stage, the controller moves the base unit in the one direction of the first direction at the predetermined speed, and moves the positions of the downstream M holding units of the N holding units in the second direction to designated positions where the workpieces can be held, thereby causing the M holding units to hold M workpieces from the downstream first workpiece to the Mth workpiece of the N workpieces; a step in which the controller reduces the speed of the base unit from the predetermined speed after the M workpieces have been held, and moves the positions of the NM holding units from the upstream side in the second direction to the designated positions, thereby causing the NM holding units on the upstream side to hold the (M+1)th to Nth works; The method includes a step in which the controller causes the N holding units to release the N workpieces at a predetermined timing after the N workpieces have been held by the N holding units.

[0119] The embodiments disclosed herein are merely examples and are not limited to the above. The scope of the present invention is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0120] 1 conveying system, 5 gripping device, 7 controller, 8 sensor, 9 conveying device, 91 conveying surface, 101a to 108a, 101b to 108b gripping unit, 111 support part, 112 main body part, 113 hand, 113a, 113b, 113c finger part, 200 base unit, 210 substrate, 211, 212 beam part, 220 spacing adjustment mechanism, 221 cam, 222, 320, 2419 servo motor, 230 support plate part, 239 cam follower, 240 gripping unit moving mechanism, 241 fixed part, 242 gripping unit mounting base, 300 base unit moving mechanism, 310 feed screw, 400 air supply device, 401 air compressor, 411, 412, 413, 418 control valve, 2219 Long hole, A1 arrow, Ls reference line, W1a~W16a, W1b~W16b products.

Claims

1. a conveying device having a conveying surface extending in a first direction and configured to convey each of a plurality of workpieces supplied onto the conveying surface while being arranged at least at first intervals in the first direction at a predetermined speed in one direction of the first direction; a holding device capable of simultaneously holding N adjacent workpieces (N is a natural number equal to or greater than 3) among the plurality of workpieces; a sensor that is provided upstream of the holding device in the conveyance direction and detects the workpiece; a controller for controlling the operation of the holding device, the holding device includes N holding units, each holding one of the works and arranged at the first intervals in the first direction, and a base unit, movable in the first direction and supporting the N holding units; the base unit has N movement mechanisms that move the holding units different from each other in a second direction that is perpendicular to the first direction and parallel to the conveying surface, When the controller determines that the time difference between the detection timings of the Mth (M is a natural number of 1 or more and N-1 or less) workpiece and the M+1th workpiece from the downstream side of the conveyance among the N workpieces by the sensor is longer than the detection cycle of the workpieces when the workpieces are lined up at the first interval, With the base unit moved at the predetermined speed in one direction of the first direction, the positions of the downstream M holding units among the N holding units in the second direction are moved by the downstream M moving mechanisms to designated positions where the workpieces can be held, thereby causing the M holding units to hold M workpieces from the downstream leading workpiece to the Mth workpiece among the N workpieces, After the M workpieces have been held, the speed of the base unit is decelerated from the predetermined speed, and the positions of the N-M holding units from the upstream side in the second direction are moved to the designated positions by the N-M upstream moving mechanisms, thereby causing the N-M upstream holding units to hold the (M+1)th to N-th works; A workpiece transport system that causes the N holding units to release the N workpieces at a predetermined timing after the N workpieces have been held by the N holding units.

2. The controller After the M workpieces are held, the positions of the N-M holding units from the upstream side in the first direction are matched with the positions of the M+1th to Nth works in the first direction by the deceleration based on the time difference between the detection timings and the acceleration to the predetermined speed after the deceleration, 2. The work transport system of claim 1, wherein after the positions in the first direction are aligned, the positions in the second direction of the N-M holding units from the upstream side are moved to the designated positions, thereby causing the N-M holding units on the upstream side to hold the M+1th to Nth works.

3. the base unit further includes an adjustment mechanism for changing the interval between the holding units in the first direction; 2. The workpiece transport system according to claim 1, wherein the predetermined timing is after the controller causes the adjustment mechanism to change the interval between the holding units from the first interval to the second interval.

4. the holding unit holds the workpiece by gripping the workpiece, an air supply device that supplies air at a predetermined pressure to each of the holding units; Each of the holding units comprises: a main body connected to the base unit; and a hand attached to the main body and configured to grip the workpiece; The hand is capable of gripping the workpiece by transitioning from an open state to a closed state, The workpiece conveying system according to claim 1 , wherein when the air is supplied to the main body, the hand transitions from the open state to the closed state.

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