Article transfer device

Abstract

To provide an article transfer device capable of reducing an influence of disturbance on a sensor.SOLUTION: An article movement system 1 includes: a robot hand 15 for gripping a part of an article by inserting a grip claw 30a of a grip unit 30 to an article group X placed in a container 50 and transferring the gripped article to a transfer destination position; a sensor 9 provided above the container 50 to detect an article height in an insertion direction of the grip claw 30a in the article group X placed in the container 50 by irradiating the article group X with light; a control unit 70 for controlling grip operation of the robot hand on the basis of the article height detected by the sensor 9; and a fan 80 for blowing or exhausting air with respect to a space that is below the sensor 9 and is between the sensor 9 and the article group X irradiated with light.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention particularly relates to an article transfer device that grips and transfers an article. [Background technology]

[0002] As described in Patent Document 1, an article gripping system is known that grips, weighs, and discharges articles from a group of articles stored in a container. In this system, a control unit positions the container below a gripping unit and then raises the container. At a certain point, the container stops rising. The gripping claws of the gripping unit enter the group of articles inside the stopped container. The control unit switches the gripping claws to a closed state, causing the gripping claws to grip the articles. The container is then lowered and moved horizontally. During this time, the weight of the articles gripped by the gripping unit is measured. When a predetermined condition is met, the control unit releases the gripping claws from gripping the articles and discharges the articles into a discharge chute below. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-148621 Summary of the Invention [Problem to be solved by the invention]

[0004] In the system described above, a group of items is placed on a placement section such as a container. The placement section is moved relative to the gripping unit, and the gripping claws of the gripping unit penetrate into the group of items. The amount of insertion of the gripping claws affects the amount of items gripped by the gripping unit, and is therefore important in controlling the system. One possible method is to use a sensor to detect the height of the group of items placed on the placement section, and adjust the insertion amount based on the detection results of the sensor. However, when detecting the height of the group of items in the placement section by irradiating light or the like onto the group of items, there is a possibility that steam or the like may be generated from the group of items (especially if the items are heated food), or that some of the items may fly up from the group of items. The steam or some of the flying items may cause disturbance to the sensor.

[0005] An object of the present invention is to provide an article transfer device that can reduce the influence of disturbances on sensors. [Means for solving the problem]

[0006] An article transfer device according to one embodiment of the present invention comprises a robotic hand having at least one gripping section for gripping an article, inserting the gripping member of the gripping section into a group of articles placed on a loading section to grip a portion of the article and transferring the gripped article to a destination position; a sensor provided above the loading section for detecting the article height in the direction of insertion of the gripping member in the group of articles placed on the loading section by shining light onto the group of articles; a control section for controlling the gripping operation of the robotic hand based on the article height detected by the sensor; and a fan below the sensor for blowing or exhausting air into the space between the sensor and the group of articles onto which light is irradiated.

[0007] According to this article transfer device, a fan blows or exhausts air into the space below the sensor between the sensor and the group of articles onto which light is irradiated. Even if steam or parts of articles are generated from the group of articles, the air blowing or exhausting can remove or reduce the steam or parts of articles from the space. Neither the air blowing nor the exhausting of air affects the sensor's detection operation due to light irradiation (even if it does, the effect is slight and negligible). Therefore, the effect of external disturbances on the sensor can be reduced.

[0008] The at least one gripping unit may be a plurality of gripping units, and the article transfer device may further include a weight calculation unit that calculates the weight (mass) of the articles gripped by each of the gripping members of the plurality of gripping units, and the control unit may control the gripping units, perform a combination calculation based on the calculation results of the weight calculation unit, select a combination of gripping units that will result in a predetermined target weight value, and have the selected gripping unit discharge the articles. In this case, the sensor accurately detects the article height, and the control unit can accurately control the insertion amount of the gripping members into the group of articles when performing combination weighing. This improves the weighing accuracy and efficiency of combination weighing.

[0009] The control unit may control the fan to blow or exhaust air into the space, and stop the fan, and may blow or exhaust air into the space at a timing other than the weight calculation period when the weight of the item is calculated by the weight calculation unit. If the air flow hits the item held by the gripping member, the calculation of the weight of the item may be affected. With the above configuration, the impact of the air blowing or exhausting on the calculation of the weight of the item can be reduced.

[0010] The space where the fan blows or exhausts air may be a space that avoids the location of the robot hand. If the air flow hits an item held by the robot hand, it may affect the quality or weight of the item being transferred. The above configuration can reduce such effects. [Effects of the Invention]

[0011] According to the present invention, the influence of disturbances on the sensor can be reduced. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a front view of an article movement system according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic perspective view showing a plurality of gripping portions. [Figure 3] FIG. 3 is a block diagram of an article movement system. [Figure 4] FIG. 4 is a cross-sectional plan view showing the arrangement of a plurality of gripping sections, placement sections, and sensors. [Figure 5] FIG. 5 is a perspective view showing an example of installation of the fan in FIG. [Figure 6] FIG. 6 is a perspective view showing another example of installation of the fan in FIG. [Figure 7] FIG. 7 is a front view of an article movement system according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicated description will be omitted.

[0014] First, an article moving system (article transfer device) 1 according to this embodiment will be described with reference to FIGS. 1 and 2. The article moving system 1 shown in FIG. 1 is a system that removes and moves some of the articles from a group of articles X contained in a container 50. The article moving system 1 removes some of the articles from the container 50 so that the weight (mass) of the some of the articles falls within a target weight range, and discharges the articles to the outside. In other words, the article moving system 1 is a weighing system that transfers articles of a predetermined target weight from the group of articles X. The articles discharged by the article moving system 1 are, for example, packaged in bags or placed in another container in a subsequent process of the article moving system 1, and shipped as merchandise. Examples of the articles include noodles such as spaghetti, foods containing a lot of sugar, etc. The articles may also be highly sticky foods. The articles may also be foods that are heated and contained in the container 50, generating steam, etc. Alternatively, the articles may be lightweight, small, and easily soaring foods.

[0015] The article moving system 1 includes a weighing device 120 for weighing articles. The weighing device 120 includes two robot hands (gripping units) 15, each having a plurality of grippers 30, two hand driving units 10 that move the robot hands 15 in the horizontal direction, a container (placing unit) 50 on which the group of articles X is placed, and a container driving unit 54 that moves the container 50 in the vertical and horizontal directions. The article moving system 1 also includes a control unit 70 that controls each part of the robot hand 15, the hand driving unit 10, and the container driving unit 54. The robot hands 15, the hand driving unit 10, and the container driving unit 54 are attached to a main body frame 121 of the weighing device 120, which is, for example, a rectangular parallelepiped.

[0016] In the article moving system 1, for example, a pair of robot hands 15 having the same configuration are arranged side by side on the left and right. In the following description, the robot hand 15 arranged on the left side as viewed from the front in Fig. 1 may be referred to as the first robot hand 15A, and the robot hand 15 arranged on the right side as viewed from the front may be referred to as the second robot hand 15B. However, when describing common configurations and functions, the name robot hand 15 is simply used.

[0017] In the robot hand 15, for example, four grippers 30 aligned in the left-right direction are arranged in four rows in the front-rear direction (the direction perpendicular to the plane of the paper in FIG. 1). In this way, if the number of grippers 30 aligned in the left-right direction is M and the number of grippers 30 aligned in the front-rear direction is N (both M and N are natural numbers), the robot hand 15 has a configuration in which (M × N) grippers 30 are arranged at lattice point positions. In this embodiment, each robot hand 15 has 16 grippers 30. The arrangement of the grippers 30 in the robot hand 15 may be changed as appropriate depending on the shape of the container 50, the type of article, etc. Both or either one of M and N may be a natural number other than 4.

[0018] As shown in Fig. 2, each gripping unit 30 has, for example, a plurality of gripping claws (gripping members) 30a, and grips an article by closing the gripping claws 30a. Each gripping unit 30 includes a gripping member drive mechanism 30b that drives the plurality of gripping claws 30a. The gripping member drive mechanism 30b drives the gripping claws 30a using, for example, a motor or fluid pressure as a drive source. The mechanism by which the gripping claws 30a grip an article by opening and closing them will be described later.

[0019] The robot hand 15 has a plurality of scales 40 that measure the weight of an article held by each gripper 30. That is, 16 ((M×N)) scales 40 are provided for 16 ((M×N)) grippers 30. The robot hand 15 has, for example, a single plate-shaped connecting member 16. Each gripper 30 and each scale 40 are integrally assembled via a connecting portion 40a. The top surface of each scale 40 is fixed to the connecting member 16 via a mounting bracket 400. Each gripper 30 is fixed to the bottom surface of each scale 40.

[0020] Each weighing device 40 includes a sensor unit housed within the housing of the weighing device 40 and an internal control unit (neither of which are shown). The sensor unit includes, for example, a force sensor and an acceleration sensor. For example, a strain gauge load cell is used as the force sensor. For example, a strain gauge load cell or a small MEMS acceleration sensor is used as the acceleration sensor.

[0021] In the article moving system 1, for example, two hand driving units 10 having the same configuration are provided corresponding to the first robot hand 15A and the second robot hand 15B. In the following description, the hand driving unit 10 located on the left side as viewed from the front of FIG. 1 and moving the first robot hand 15A may be referred to as the first hand driving unit 10A, and the hand driving unit 10 located on the right side as viewed from the front and moving the second robot hand 15B may be referred to as the second hand driving unit 10B. However, when describing common configurations and functions, the name hand driving unit 10 is simply used.

[0022] In the entire robot including the first robot hand 15A and the second robot hand 15B, eight grippers 30 are arranged in the left-right direction and four rows in the front-rear direction. That is, the weighing device 120 has 4 × 2 (pairs) × 4 rows = a total of 32 grippers 30 (generalized as (M × 2 × N)).

[0023] The hand driving unit 10 has two frames 12 extending parallel to one another and a forward / backward movement mechanism 11 that moves the robot hand 15 horizontally along the frames 12. The hand driving unit 10 can move a block 111 that holds the robot hand 15 forward or backward using the forward / backward movement mechanism 11. The hand driving unit 10 has, for example, a servo motor, an air cylinder, or the like that moves the block 111. The above-mentioned connecting member 16 is connected to the block 111 by, for example, screws.

[0024] In the article moving system 1, the first hand driving unit 10A moves the first robot hand 15A in the front-to-back direction (horizontally), and the second hand driving unit 10B moves the second robot hand 15B in the front-to-back direction (horizontally). This makes it possible to align the position of the article group X in the container 50 with the article gripping position set in each robot hand 15. Note that the hand driving unit 10 or the front-to-back movement mechanism 11 may be omitted from the weighing device 120.

[0025] The internal control unit of the weighing device 40 measures the weight of the item gripped by the gripping unit 30 based on the force measured by the sensor unit. Note that the weighing device 40 is not limited to a method of measuring the weight of an item based on the force measured when the gripping unit 30 is moving. The weighing device 40 may also use a load cell or the like to measure the weight of an item gripped by the gripping unit 30 in a stationary state. The internal control unit of the weighing device 40 may measure the weight of the item by dividing the force measured by the force sensor by the acceleration measured by the acceleration sensor. Each weighing device 40 is a weight calculation unit that calculates the weight of the item gripped by the gripping jaws 30a of each gripping unit 30.

[0026] The container 50 is a member on which the group of articles X is placed. The container 50 is held or placed on a holding unit 52 that moves horizontally and vertically. The container 50 can be moved, for example, by a container driving unit 54, between a first position P1 located below the first robot hand 15A and a second position P2 located below the second robot hand 15B. The first position P1 and the second position P2 are separated in the left-right direction, and the area occupied by the container 50 located at the first position P1 does not overlap with the area occupied by the container 50 located at the second position P2. The container 50 is a rectangular parallelepiped container that opens upward. In a plan view, the container 50 is slightly larger than the area in which the multiple grippers 30 are arranged. In a plan view, the container 50 has a shape and size that can surround the multiple grippers 30. The container 50 has a shape and size that exactly corresponds to one robot hand 15.

[0027] When the container 50 is located at the first position P1, the container 50 can be moved upward and closer to the gripper 30 of the first robot hand 15A, allowing the gripper 30 to grasp an item from the group of items X in the container 50. At this time, the gripper 30 of the second robot hand 15B cannot grasp an item from the group of items X in the container 50. When the container 50 is located at the second position P2, the container 50 can be moved upward and closer to the gripper 30 of the second robot hand 15B, allowing the gripper 30 to grasp an item from the group of items X in the container 50. At this time, the gripper 30 of the first robot hand 15A cannot grasp an item from the group of items X in the container 50.

[0028] When the amount of the group of articles X stored inside the container 50 decreases, the container 50 with the reduced amount of the group of articles X inside is replaced by a new container 50 (containing a larger amount of the group of articles X) by a person or a machine. Note that instead of replacing the container 50, the article movement system 1 may be provided with an article supply mechanism for supplying articles to the container 50.

[0029] The container driving unit 54 uses a motor and fluid pressure as driving sources to move the container 50 in the up-down (vertical) and left-right (horizontal) directions. The container driving unit 54 includes a drive box 55 fixed to a frame (not shown) adjacent to the weighing device 120, a first main arm 56A and a second main arm 56B that can swing around two parallel axes, a first axis L1 and a second axis L2, respectively, provided on the drive box 55, and a first sub-arm 57A and a second sub-arm 57B that are rotatably connected to the tip of the first main arm 56A and the tip of the second main arm 56B, respectively. The drive box 55 is fixed to, for example, another frame 200 (see FIG. 5) adjacent to the rear of the frame to which the robot hand 15 is attached. The first axis L1 and the second axis L2 extend in the front-to-rear direction (the direction perpendicular to the plane of FIG. 1 and the horizontal direction). The tip of the first sub-arm portion 57A and the tip of the second sub-arm portion 57B are each rotatably connected to the rear end of the holding portion 52. The holding portion 52 is supported by these link mechanisms.

[0030] The first main arm portion 56A and the second main arm portion 56B are each swung in any direction by a separate motor housed in a drive box 55. The rotation axes of the first sub-arm portion 57A and the second sub-arm portion 57B relative to the first main arm portion 56A and the second main arm portion 56B are parallel to the first axis L1 and the second axis L2. For example, the rotation angle of the second sub-arm portion 57B relative to the second main arm portion 56B is adjustable. The rotation axes of the first sub-arm portion 57A and the second sub-arm portion 57B relative to the holder 52 are also parallel to the first axis L1 and the second axis L2. With the positions of the first axis L1 and the second axis L2 as fixed points, the first main arm portion 56A, the first sub-arm portion 57A, the second main arm portion 56B, the second sub-arm portion 57B, and the holder 52 form five sides of a hexagon. With this configuration, the container driving unit 54 has a two-axis parallel link mechanism. The container driving unit 54 is controlled by the control unit 70 to rotate each arm, thereby moving the holding unit 52 in the vertical and horizontal directions. The position of the holding unit 52 is maintained horizontally by the rod 58.

[0031] Under the control of the control unit 70, the holder 52 can be moved freely to a first position P1, a position closer to the first robot hand 15A than the first position P1, a second position P2, and a position closer to the second robot hand 15B than the second position P2 while maintaining a horizontal posture. This allows the relative position of the container 50 with respect to the first robot hand 15A and the relative position of the container 50 with respect to the second robot hand 15B to be adjusted freely. The configuration is not limited to the above, and the container drive unit 54 may have a left-right movement mechanism that moves the holder 52 left-right and a vertical movement mechanism that moves the holder 52 vertically. The position of the container 50 can also be adjusted freely using such a two-axis drive mechanism.

[0032] The container driving unit 54 raises the holder 52 and the container 50, thereby bringing the container 50 and the group of articles X closer to the robot hand 15. The container driving unit 54 lowers the holder 52 and the container 50, thereby moving the container 50 and the group of articles X away from the robot hand 15. The container driving unit 54 inserts the gripping claws 30a into the group of articles X contained (placed) in the container 50, and then moves the gripping claws 30a, which have gripped the articles, away from the container 50. In other words, the first robot hand 15A and the second robot hand 15B insert the gripping claws 30a of each gripping unit 30 into the group of articles X in the container 50, to grip a portion of the articles.

[0033] The article moving system 1 is equipped with two discharge chutes 60. For example, two discharge chutes 60 having the same size and shape are arranged side by side on the left and right. In the following description, the discharge chute 60 arranged on the left side as viewed from the front in FIG. 1 may be referred to as the first discharge chute 60A, and the discharge chute 60 arranged on the right side as viewed from the front may be referred to as the second discharge chute 60B. However, when describing common configurations and functions, the name discharge chute 60 is simply used.

[0034] The discharge chute 60 is a funnel-shaped member. The discharge chute 60 is disposed below the robot hands 15. Specifically, the first discharge chute 60A is disposed below the first robot hand 15A, and the second discharge chute 60B is disposed below the second robot hand 15B. A first position P1 of the container 50 is located between the first robot hand 15A and the first discharge chute 60A, and a second position P2 of the container 50 is located between the second robot hand 15B and the second discharge chute 60B.

[0035] When the container 50 is located at the second position P2, the first discharge chute 60A receives the item that the gripper 30 of the first robot hand 15A releases and drops, and discharges it outside the article movement system 1. Similarly, when the container 50 is located at the first position P1, the second discharge chute 60B receives the item that the gripper 30 of the second robot hand 15B releases and drops, and discharges it outside the article movement system 1. In this way, the first robot hand 15A and the second robot hand 15B transfer the items gripped by their respective grippers 30 to their destination positions. In other words, in this specification, the "releasing of grip" by each robot hand 15 and the accompanying "dropping of the item" refer to the transfer of the item to the discharge chute 60.

[0036] Although two discharge chutes are used in this embodiment, the present invention is not limited to this, and the first robot hand 15A and the second robot hand 15B may share one discharge chute. In this case, the upper opening of one discharge chute is set to a size and position that encompasses the entire first position P1 and the second position P2 in a plan view. Also, an object dropped from the robot hand 15 may be discharged directly to the outside without using a discharge chute.

[0037] FIG. 2 is a block diagram of the article moving system 1. In FIG. 2, a control unit 70 controls the operation of various components of the article moving system 1, such as the gripping member driving mechanism 30b and the container driving unit 54. The control unit 70 performs combination calculations and the like using the weight values ​​of the articles weighed by the scale 40. The control unit 70 is configured as a computer device including a processor such as a CPU, memories such as ROM and RAM, storage, and communication devices. The control unit 70 is electrically (or communicably) connected to the hand driving unit 10, the gripping member driving mechanism 30b, the scale 40, and the container driving unit 54. The ideal weight value and the like are input to the control unit 70 via an operation panel 100.

[0038] The control unit 70 controls the operation of various components of the article moving system 1, such as the hand driving unit 10, the gripping member driving mechanism 30b, and the container driving unit 54, and performs combination calculations using the weight values ​​of the articles measured by the weighing device 40, by having the CPU execute programs stored in the memory. The various functions of the control unit 70 do not have to be realized by software, but may be realized by hardware, or by a combination of hardware and software.

[0039] The control unit 70 moves the hand driving unit 10 and the container 50 to bring the gripping unit 30 and the container 50 closer together. The control unit 70 controls the gripping member driving mechanism 30b to cause the gripping claws 30a of each gripping unit 30 to grip some of the articles of the article group X placed on the container 50.

[0040] Each weighing device 40 measures the weight of an item gripped by the corresponding gripping unit 30. The weight of the item gripped by each gripping unit 30 is acquired by the control unit 70. The control unit 70 performs a combination calculation based on the weight of the item gripped by the gripping unit 30. The combination calculation is a process of adding up the weights of the items gripped by each gripping unit 30 and finding a combination of weights that results in a target weight value. The control unit 70 first acquires each weight value. Next, based on the result of the combination calculation, the control unit 70 selects the gripping claws 30a of the gripping unit 30 that corresponds to the combination of weights that results in the target weight value, and performs control to release the grip of the selected gripping unit 30. At this time, the control unit 70 releases the grip of the item by the gripping unit 30 above the discharge chute 60, causing the item to fall into the discharge chute 60. The item with the target weight value is then discharged from the discharge chute 60. If a combination of weight values ​​that results in the target weight value is impossible, and if the gripping claws 30a of the gripping unit 30 that corresponds to a combination of weight values ​​that is close to the target weight value are found, the control unit 70 selects the gripping unit 30 that corresponds to that combination and performs control to release the grip of the selected gripping unit 30. This control is performed, for example, using the weight values ​​of the gripping units 30 other than the gripping unit 30 that corresponds to the combination of weight values ​​that results in the target weight value.

[0041] The target weight value is a predetermined weight range that includes the target weight value (target weight value or ideal weight value). For example, the lower limit of the target weight value is 90% or 95% of the target weight value, and the upper limit of the target weight value is 110% or 105% of the target weight value. Furthermore, the vicinity of the target weight value may be, for example, 90% or more but less than 100% of the lower limit, or 95% or more but less than 100% of the lower limit, or may be greater than 100% but less than 110% of the upper limit, or greater than 100% but less than 105% of the upper limit.

[0042] As described above, in the article moving system 1 of this embodiment, the control unit 70 controls the gripping member driving mechanism 30b (grip unit 30) and the container driving unit 54, performs combination calculations based on the calculation results of the weighing machine 40, and selects a combination of grip units 30 that will result in a preset target weight value. The control unit 70 causes the selected multiple grip units 30 to discharge articles.

[0043] As shown in Figures 1, 3, and 4, a plurality of sensors 9 are arranged in the front-to-rear direction (the direction perpendicular to the plane of the paper in Figure 1) above the movable area of ​​the holding unit 52. In this embodiment, four sensors 9 are attached, corresponding to the number of rows of the gripping unit 30 in that direction (the above-mentioned N, specifically four rows). The four sensors 9 are fixed, for example, to the main body frame 121, and irradiate light vertically downward and detect light reflected from the surface of the group of articles X. As a result, each sensor 9 detects the height of the articles (height of the group of articles X) in the insertion direction (vertical direction) of the gripping jaws 30a in the group of articles X in the container 50.

[0044] As shown in FIGS. 1 and 4 , each sensor 9 emits and receives light at a central position between the first robot hand 15A and the second robot hand 15B. While the container drive unit 54 moves the holder 52 and the container 50 between the first position P1 and the second position P2, each sensor 9 detects the height of the item a number of times corresponding to the position and number of grippers 30 in the left-right direction (M, specifically, four). The detection timing may be adjusted by the control unit 70 (e.g., to be synchronized with the movement of the container drive unit 54) taking into account the left-right movement speed of the container drive unit 54. As a result, height detection signals are output for 16 points (multiple points corresponding to the planar arrangement of the grippers 30) distributed in a grid pattern in the left-right direction (movement direction) and the front-back direction within the container 50 each time the container 50 moves (passes) from the first position P1 to the second position P2 or from the second position P2 to the first position P1. That is, the sensor 9 is provided above the container 50 and detects the height of the articles in the article group X in the inserting direction of the gripping claws 30a by irradiating the article group X with light.

[0045] The control unit 70 is electrically (or communicably) connected to the multiple sensors 9. Based on the detection results of each sensor 9, the control unit 70 calculates the insertion amount and opening angle of the gripping jaws 30a of each gripping unit 30 relative to the group of articles X. The height of the articles varies in each part of the container 50. Meanwhile, the container 50 (holding unit 52) ​​is brought close to the robot hand 15 while maintaining a horizontal posture. Therefore, the insertion amount of the gripping jaws 30a of each gripping unit 30 is not constant (uniform) for a container 50 located at a certain height.

[0046] The control unit 70 stores, for example, a correspondence relationship between insertion amounts and opening angles for gripping a desired amount of articles. When the control unit 70 receives height detection signals from each sensor 9, it sets the vertical positions of the container 50 and the group of articles X and calculates the insertion amount of each gripping unit 30 accordingly. The control unit 70 further references the stored correspondence relationship and calculates the opening angle of the gripping jaws 30a corresponding to the insertion amount of each gripping unit 30. The control unit 70 controls the gripping operation of either the first robot hand 15A or the second robot hand 15B (whichever is to grip the article) so that the calculated insertion amount and opening angle are achieved. That is, the control unit 70 controls the gripping operation of the robot hand 15 based on the article height detected by the sensor 9.

[0047] Returning to FIG. 1, the item movement system 1 is equipped with a mechanism for reducing the influence of steam or other disturbances, for example, as a measure for items that are generating steam. As shown in FIG. 1, the item movement system 1 is equipped with a fan 80 that blows air toward the inside of the weighing device 120. The fan 80 is disposed, for example, on the rear side of the sensor 9. The configuration of the fan 80 is not particularly limited, and a known blowing device may be used. The fan 80 has, for example, a motor built into a casing and an impeller attached to the casing. A power source is supplied to the fan 80. The control unit 70 is electrically (or communicatively) connected to the fan 80.

[0048] In addition to steam generated from a heated item, other possible disturbances to sensing by the sensor 9 include parts of food that fly up from food that tends to fly up (for example, food containing grated kelp, dried bonito flakes, or seaweed). If the item is something other than food, other disturbances may also be the target.

[0049] The fan 80 is installed so as to be tilted slightly downward with respect to the horizontal direction. The fan 80 blows air into a space S (see FIG. 4) below the sensor 9, between the sensor 9 and the group of articles X in the container 50 that is irradiated with light. This space S overlaps with the irradiation space into which light is irradiated by the sensor 9. That is, as shown in FIG. 4, the space S is located between a first position P1 and a second position P2 in a plan view.

[0050] The fan 80 will be described from another perspective with reference to Figure 5. As shown in Figure 5, the fan 80 is attached to, for example, the separate frame 200 adjacent to the weighing device 120. The fan 80 is directed, for example, diagonally downward, and supplies wind (airflow) of a predetermined strength (volume) toward the space S. The space S through which air is blown by the fan 80 is the space between the first gripping area RA, which includes the area of ​​the first robot hand 15A, and the second gripping area RB, which includes the area of ​​the second robot hand 15B. In other words, the space through which air is blown by the fan 80 is a space that avoids the positions of the first robot hand 15A and the second robot hand 15B.

[0051] The control unit 70 controls the fan 80 to start and stop blowing air into the space S. In particular, the control unit 70 blows air into the space S at timings other than the weight calculation period in which the weight of the items is calculated by the weighing device 40. More specifically, the control unit 70 controls the fan 80 to be on and blow air into the space S while the sensor 9 is detecting the height of the items. More specifically, the control unit 70 may drive the fan 80 so as to include the period in which the sensor 9 is detecting the height of the items, or may drive the fan 80 only during the period in which the sensor 9 is detecting the height of the items. Alternatively, the control unit 70 may drive the fan 80 so as to include at least the period in which the container 50 moves (passes) from the first position P1 to the second position P2 or from the second position P2 to the first position P1, or only during that period. This is to prevent the air blown by the fan 80 (air flow) from hitting the hanging items gripped by the gripping jaws 30a and affecting the weighing.

[0052] According to the article movement system 1 of this embodiment, the fan 80 blows air into the space S below the sensor 9, between the sensor 9 and the group of articles X onto which light is irradiated. Even if steam or parts of articles are generated from the group of articles X, the air blowing can remove or reduce the steam or parts of articles from the space S. The air blowing does not affect the detection operation of the sensor 9 due to light irradiation (even if it does, the effect is slight and negligible). Therefore, the effect of external disturbances on the sensor 9 can be reduced.

[0053] In the past, if no measures were taken against external disturbances that may occur on the group of articles X, for example, there was a possibility that the sensor 9 would erroneously detect the article height. The control unit 70 controls the height of the container 50, for example, by calculating the average of the detection results (detection values) of the 16 points (M × N items) described above. If a detection result higher than the actual article height is output, the position of the container 50 raised by the container driving unit 54 may be too low, which may result in insufficient insertion of the gripping jaws 30a (or may result in a miss). If a detection result lower than the actual article height is output, the position of the container 50 raised by the container driving unit 54 may be too high, which may result in excessive insertion of the gripping jaws 30a. According to the present embodiment, such problems are avoided.

[0054] When combination weighing is performed, the height of the items is detected with high accuracy by the sensor 9. The control unit 70 can accurately control the insertion amount of the gripping jaws 30a into the group of items X when performing combination weighing. This improves the weighing accuracy and efficiency of combination weighing.

[0055] If the airflow hits an item held by the gripping claws 30a, the calculation of the weight of the item may be affected. By configuring the airflow to be blown into the space at a time other than the weight calculation period, the impact of the airflow on the calculation of the weight of the item can be reduced.

[0056] If the air flow hits an object held by the robot hand 15, it may affect the quality or weight of the object being transferred. By blowing air into the space S away from the robot hand 15, such an effect can be reduced.

[0057] The fan 80 is attached to a separate frame 200 outside the weighing device 120. By blowing air from a position as far away as possible from the space S, it is possible to reliably eliminate the influence of external disturbances. In this case, the timing of blowing air can be limited to reduce the influence on the gripping and weighing operations. For example, the control unit 70 may blow air only while the container 50 is passing below the sensor 9.

[0058] Although the embodiments of the present disclosure have been described above, the present invention is not limited to the above embodiments. For example, in the above embodiments, a configuration has been described in which the robot hand 15 grasps an article by moving the container 50 (holding unit 52) ​​and bringing it close to the robot hand 15. However, instead of this configuration, a configuration in which the robot hand 15 or the gripping unit 30 grasps an article by moving (e.g., lowering) the robot hand 15 or the gripping unit 30 and bringing it close to the container 50 may be adopted. In this case, an appropriate known movement mechanism is provided in the robot hand 15 or the gripping unit 30. By moving (e.g., raising) the robot hand 15 or the gripping unit 30, the gripping claws 30a that have grasped the article can be separated from the container 50.

[0059] The transfer of an object by a robot hand is not limited to "releasing the grip" and the subsequent "dropping of the object into the discharge chute." The robot hand holding the object may move horizontally or vertically to transfer the object to another container, another hopper, or a transport device such as a conveyor.

[0060] The robot hand may have only one gripping portion. The sensor for detecting the height of the group of articles X may be omitted.

[0061] The article moving system may not need to perform combination weighing. The article moving system may not be provided with a weight calculation unit that calculates the weight of the article gripped by the gripper, and the weight may be calculated after the article is transferred.

[0062] The fan may be a fan that exhausts (or draws) air into the space S, rather than the fan 80 that blows air into the space S. A known exhaust fan or suction fan having a motor and an impeller may be used. Such a fan exhausts air from the space S between the sensor 9 and the container 50 (group of articles X) to which light from the sensor 9 is irradiated, thereby achieving the same effect as described above. The fan may also be a fan that can both blow air and exhaust air. The fan may perform blowing and exhaust air in a combination, for example, alternating between them.

[0063] 6, the fan 80 may be attached to the main body frame 121 of the weighing device 120. In this case, the fan 80 is also disposed on the rear side of the sensor 9. Compared to the above embodiment, blowing or exhausting air from a position closer to the space S can narrow the target space, further reducing the impact on the gripping and weighing operations.

[0064] The fan may be mounted facing horizontally and blow or exhaust air horizontally. Alternatively, the fan may blow or exhaust air diagonally upward. A fan installed at a lower position (at about the same position as the container 50 that moves left and right) may blow or exhaust air upward.

[0065] Furthermore, the arrangement is not limited to the case where the fan 80 is disposed behind the sensor 9. For example, as shown in FIG. 7, a weighing device 120A (item movement system 1A) may be employed in which fans 80A and 80B, which can switch between blowing and exhausting air, are provided on the right and left sides of the main body frame 121, respectively. These fans 80A and 80B may be fixed, for example, to left and right doors (not shown) attached to the main body frame 121. At least one fan 80A and one fan 80B are fixed to the inner surface of each door. The fans 80A and 80B are, for example, oriented horizontally and face each other. The left fan 80A is provided to the left of the first gripping area RA (horizontally outward), and the right fan 80B is provided to the right of the second gripping area RB (horizontally outward). In other words, the fans 80A and 80B are located outside the first gripping area RA and the second gripping area RB. The fans 80A and 80B are provided at the center of the first gripping area RA and the second gripping area RB in the front-rear direction.

[0066] For example, while the container 50 is moving from the first position P1 to the second position P2 (moving to the right), the control unit 70 controls the right fan 80B to blow air and the left fan 80A to exhaust air. For example, while the container 50 is moving from the second position P2 to the first position P1 (moving to the left), the control unit 70 controls the left fan 80A to blow air and the right fan 80B to exhaust air. That is, in control using a pair of left and right fans, the fan located in front of the moving container 50 (the fan facing the approaching container 50) blows air, and the fan located behind the moving container 50 exhausts air.

[0067] In this case, the space through which the fans 80A and 80B blow and exhaust air is a space including the first gripping area RA and the second gripping area RB. The fans 80A and 80B blow and exhaust air across the first gripping area RA and the second gripping area RB. However, even in this case, the control unit 70 blows and exhausts air at a timing other than the weight calculation period in which the weight of the items is calculated by the weighing device 40. The control unit 70 may drive the fans 80A and 80B so that the period includes the period in which the item height is detected by the sensor 9, or may drive the fans 80A and 80B only during the period in which the item height is detected by the sensor 9. The drive timing of the fans 80A and 80B can be determined in the same manner as the drive timing of the fan 80 in the above embodiment. The item movement system 1A, which combines blowing and exhaust air depending on the movement direction of the container 50, can effectively reduce the influence of disturbances on the sensor 9, similar to the item movement system 1.

[0068] The timing of the fan blowing or exhausting air may overlap with the weight calculation period in the weighing device 40 (weight calculation unit). The space S where the fan blows or exhausts air may overlap with the position of the robot hand 15, i.e., the first gripping area RA or the second gripping area RB. [Explanation of symbols]

[0069] 1, 1A...article movement system (article transfer device), 9...sensor, 10...hand drive unit, 15...robot hand, 15A...first robot hand, 15B...second robot hand, 30...gripping unit, 30a...gripping claw (gripping member), 40...weighing scale (weight calculation unit), 50...container (placing unit), 52...holding unit, 54...container drive unit, 60...discharge chute, 70...control unit, 80...fan, RA...first gripping area, RB...second gripping area, S...space, X...group of articles.

Claims

1. a robot hand having at least one gripping portion for gripping an object, the robot hand inserting a gripping member of the gripping portion into a group of objects placed on a placement portion to grip a part of the objects and transferring the gripped objects to a destination position; a sensor provided above the placement section for detecting an article height in the insertion direction of the gripping member in the article group placed on the placement section by irradiating light onto the article group; a control unit that controls a gripping operation of the robot hand based on the height of the object detected by the sensor; An article transfer device comprising:

2. An article transfer device as described in claim 1, further comprising a fan located below the sensor for blowing or exhausting air into the space between the sensor and the group of articles onto which the light is irradiated.

3. the at least one gripping portion is a plurality of gripping portions; A weight calculation unit that calculates a weight of the object gripped by each of the gripping members of the plurality of gripping units, The item transfer device described in claim 1 or 2, wherein the control unit controls the gripping units, performs a combination calculation based on the calculation results in the weight calculation unit, selects a combination of the gripping units that results in a predetermined target weight value, and causes the selected gripping units to eject the item.

4. The item transfer device of claim 2, wherein the control unit controls the fan to blow or exhaust air into the space, and to stop the fan, and blows or exhausts air into the space at a time other than a weight calculation period in which the weight of the item is calculated by a weight calculation unit.

5. 5. The article transfer device according to claim 2, wherein the space into which the fan blows or exhausts air is a space that avoids the position of the robot hand.

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