JP7852913B2 - Goods transfer device - Google Patents

Description

This invention relates, in particular, to an article transfer device for gripping and transferring articles.

As described in Patent Document 1, an article gripping system is known that grips articles from a group of articles stored in a container, weighs them, and discharges them. In this system, the control unit positions the container below the gripping unit and then raises the container. At a certain point, the container stops rising. The gripping claws of the gripping unit are engaged with the group of articles inside the stopped container. The control unit switches the gripping claws to a closed state, allowing them to grip the articles. The container then descends and moves horizontally. During this time, the weight of the articles gripped by the gripping unit is weighed. When predetermined conditions are met, the control unit releases the gripping claws from the articles and discharges them into a lower discharge chute.

Japanese Patent Publication No. 2021-148621

In the system described above, the group of items is placed on a mounting surface such as a container. The mounting surface is moved relative to the gripping unit, and the gripping claws of the gripping unit engage with the group of items. The amount of insertion of these gripping claws affects the amount the gripping unit holds the items, and is therefore important for system control.

The present invention aims to provide an article transfer device capable of detecting the height of a group of articles .

An article transfer device according to one aspect of the present invention comprises a robot hand having at least one gripping part for gripping articles, inserting the gripping member of the gripping part into a group of articles placed on a mounting part to grip a portion of the articles, and transferring the gripped articles to a destination position; a sensor provided above the mounting part that detects the height of the articles in the insertion direction of the gripping member in the group of articles placed on the mounting part by irradiating the group of articles with light ; and a control unit that controls the gripping operation of the robot hand based on the article height detected by the sensor . With this article transfer device, the article height is detected by the sensor. Based on the detection result, the gripping operation of the robot hand is controlled to grip an article of a desired amount.

The article transfer device may further include a fan that blows or exhausts air into the space below the sensor between the sensor and the group of articles being illuminated. With this article transfer device, the fan blows or exhausts air into the space below the sensor between the sensor and the group of articles being illuminated. Even if steam or parts of the articles are generated from the group of articles, the blowing or exhausting can remove or reduce the steam or parts of the articles from the space. Neither blowing nor exhausting affects the sensor's detection operation due to light illumination (or if it does, it is only slightly and negligible). Therefore, the effect of disturbances on the sensor can be reduced.

At least one gripping section may be composed of multiple gripping sections. The article transfer device further includes a weight calculation unit that calculates the weight (mass) of the articles gripped by each of the multiple gripping sections. The control unit may control the gripping sections, perform combination calculations based on the calculation results from the weight calculation unit, select a combination of gripping sections that achieves a preset target weight, and discharge the articles to the selected gripping sections. In this case, the article height is accurately detected by a sensor, and the control unit can accurately control the insertion amount of the gripping members into the group of articles during combined weighing. Therefore, the weighing accuracy and efficiency of combined weighing are improved.

The control unit controls the fan's airflow or exhaust into the space, and its stopping, and may perform airflow or exhaust into the space at times other than the weight calculation period during which the weight calculation unit calculates the weight of the item. If airflow hits an item held by the gripping member, the weight calculation of the item may be affected. According to the above configuration, the influence of airflow or exhaust on the weight calculation of the item can be reduced.

The space where air is blown or exhausted by the fan may be a space that avoids the position of the robot hand. If airflow hits an item grasped by the robot hand, it may affect the quality or weight of the item being transferred. The above configuration can reduce such effects.

According to the present invention, the height of an object is detected by a sensor. Based on the detection result, the gripping operation of the robot hand is controlled to grip an object of a desired amount .

Figure 1 is a front view of an article transfer system according to one embodiment of the present disclosure. Figure 2 is a schematic perspective view showing multiple gripping parts. Figure 3 is a block diagram of the item movement system. Figure 4 is a plan cross-sectional view showing the arrangement of multiple gripping parts, mounting parts, and sensors. Figure 5 is a perspective view showing an example of the fan installation shown in Figure 1. Figure 6 is a perspective view showing another example of the fan installation shown in Figure 1. Figure 7 is a front view of an article transfer system according to another embodiment of the present disclosure.

The embodiments of this disclosure will be described below with reference to the drawings. In the description of the drawings, identical elements will be denoted by the same reference numerals, and redundant descriptions will be omitted.

First, with reference to Figures 1 and 2, the article transfer system (article transfer device) 1 according to this embodiment will be described. The article transfer system 1 shown in Figure 1 is a system that removes and moves some articles from a group of articles X contained in a container 50. The article transfer system 1 removes some articles from the container 50 and discharges them to the outside so that the weight (mass) of those articles falls within a target weight range. In other words, the article transfer system 1 is a weighing system that moves articles of a predetermined target weight from the group of articles X. The articles discharged by the article transfer system 1 are, for example, packaged in bags or placed in other containers in a subsequent process and shipped as products. Examples of articles include noodles such as spaghetti, and foods containing a large amount of sugar. The articles may also be foods with high viscosity. The articles may be foods that are heated and contained in the container 50, generating steam, etc. Alternatively, the articles may be lightweight, fine, and easily dispersed foods.

The item transfer system 1 includes a weighing device 120 for weighing items. The weighing device 120 comprises two robot hands (gripping units) 15, each having multiple gripping parts 30; two hand drive units 10 for moving the robot hands 15 horizontally; a container (placement part) 50 on which the group of items X is placed; and a container drive unit 54 for moving the container 50 vertically and horizontally, respectively. The item transfer system 1 also includes a control unit 70 for controlling each part of the robot hands 15, the hand drive units 10, and the container drive units 54, respectively. The robot hands 15, hand drive units 10, and container drive units 54 are attached to, for example, a rectangular parallelepiped main frame 121 of the weighing device 120.

In the object movement system 1, for example, a pair of robot hands 15 with identical configurations are arranged side by side on the left and right. In the following description, the robot hand 15 located on the left side in the front view of Figure 1 may be referred to as the first robot hand 15A, and the robot hand 15 located on the right side in the front view 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.

In the robot hand 15, for example, four gripping parts 30 arranged in the left-right direction are arranged in four rows in the front-back direction (perpendicular to the plane of the paper in Figure 1). Thus, if M is the number of gripping parts 30 arranged in the left-right direction, and N is the number of gripping parts 30 arranged in the front-back direction (both M and N are natural numbers), the robot hand 15 has a configuration in which (M × N) gripping parts 30 are arranged at grid points. In this embodiment, each robot hand 15 has 16 gripping parts 30. The arrangement of the gripping parts 30 in the robot hand 15 may be appropriately changed depending on the shape of the container 50 and the type of article. Both or either M and N may be natural numbers other than 4.

As shown in Figure 2, each gripping section 30 has, for example, multiple gripping claws (gripping members) 30a, and grips an article by closing the gripping claws 30a. Each gripping section 30 includes a gripping member driving mechanism 30b that drives the multiple gripping claws 30a. The gripping member driving mechanism 30b drives the gripping claws 30a using, for example, a motor or fluid pressure as a driving source. The mechanism for gripping an article by opening and closing the gripping claws 30a will be described later.

The robot hand 15 has multiple weighing devices 40 for weighing the weight of the object gripped by each gripping section 30. Specifically, 16 weighing devices 40 are provided for each of the 16 ((M x N)) gripping sections 30. The robot hand 15 has, for example, a single plate-shaped connecting member 16. Each gripping section 30 and each weighing device 40 are integrally assembled via a connecting section 40a. The top surface of each weighing device 40 is fixed to the connecting member 16 via a mounting bracket 400. Each gripping section 30 is fixed to the bottom surface of each weighing device 40.

Each measuring instrument 40 includes a sensor unit and an internal control unit housed within the casing of the measuring instrument 40 (neither of which are shown). The sensor unit includes, for example, a force sensor and an acceleration sensor. As the force sensor, for example, a strain gauge type load cell is used. As the acceleration sensor, for example, a strain gauge type load cell or a MEMS type miniature acceleration sensor is used.

In the object movement system 1, for example, two hand drive units 10, each 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 drive unit 10 located on the left side in the front view of Figure 1, which moves the first robot hand 15A, may be referred to as the first hand drive unit 10A, and the hand drive unit 10 located on the right side in the front view, which moves the second robot hand 15B, may be referred to as the second hand drive unit 10B. However, when describing common configurations and functions, the name "hand drive unit 10" is simply used.

In the entire system, including the first robot hand 15A and the second robot hand 15B, eight gripping units 30 are arranged in the left-right direction and four rows in the front-back direction. That is, the weighing device 120 has a total of 32 gripping units 30 (4 x 2 units (one pair) x 4 rows = (generalized to (M x 2 x N) units)).

The hand drive unit 10 has two parallel frames 12 and a forward/backward movement mechanism 11 that moves the robot hand 15 horizontally along the frames 12. The hand drive unit 10 can move the block 111 that holds the robot hand 15 forward or backward using the forward/backward movement mechanism 11. The hand drive unit 10 includes, for example, a servo motor, an air cylinder, etc., for moving the block 111. The connecting member 16 described above is connected to the block 111, for example, by screw fastening.

In the item movement system 1, the first hand drive unit 10A moves the first robot hand 15A in the forward/backward direction (horizontally), and the second hand drive unit 10B moves the second robot hand 15B in the forward/backward direction (horizontally). This allows the position of the group of items X in the container 50 to be matched with the item gripping position set for each robot hand 15. Note that in the weighing device 120, the hand drive unit 10 or the forward/backward movement mechanism 11 may be omitted.

The internal control unit of the weighing device 40 measures the weight of the object held 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 that measures the weight of the object based on the force measured when the gripping unit 30 moves. The weighing device 40 may also measure the weight of the object held by the gripping unit 30 in a stationary state using a load cell or the like. The internal control unit of the weighing device 40 may also measure the weight of the object 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 object held by the gripping claws 30a of each gripping unit 30.

The container 50 is a component 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 is movable between a first position P1 located below the first robot hand 15A and a second position P2 located below the second robot hand 15B, for example, by a container drive unit 54. The first position P1 and the second position P2 are separated in the left-right direction, and the area occupied by the container 50 at the first position P1 and the area occupied by the container 50 at the second position P2 do not overlap. The container 50 is a rectangular parallelepiped container that opens upwards. In a plan view, the container 50 is slightly larger than the area where the multiple gripping units 30 are arranged. In a plan view, the container 50 has a shape and size that can enclose the multiple gripping units 30. The container 50 has a shape and size that corresponds exactly to one robot hand 15.

When container 50 is in the first position P1, moving container 50 upwards and bringing it closer to the gripping portion 30 of the first robot hand 15A allows the gripping portion 30 to grasp items from the group of items X inside container 50. At this time, the gripping portion 30 of the second robot hand 15B cannot grasp items from the group of items X inside container 50. Similarly, when container 50 is in the second position P2, moving container 50 upwards and bringing it closer to the gripping portion 30 of the second robot hand 15B allows the gripping portion 30 to grasp items from the group of items X inside container 50. At this time, the gripping portion 30 of the first robot hand 15A cannot grasp items from the group of items X inside container 50.

When the quantity of articles X contained inside container 50 decreases, the container 50 with the reduced quantity of articles X is replaced by a person or machine with a new container 50 (containing a larger quantity of articles X). Alternatively, instead of replacing the container 50, the article transfer system 1 may be equipped with an article supply mechanism for supplying articles to the container 50.

The container drive unit 54 moves the container 50 vertically and horizontally, using a motor and fluid pressure as drive sources. The container drive unit 54 has a drive box 55 fixed to a frame (not shown) adjacent to the weighing device 120, a first main arm section 56A and a second main arm section 56B that are pivotable around two parallel first axes L1 and second axis L2 provided on the drive box 55, and a first sub-arm section 57A and a second sub-arm section 57B that are rotatably connected to the tip of the first main arm section 56A and the tip of the second main arm section 56B, respectively. The drive box 55 is fixed to another frame 200 (see Figure 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-rear direction (perpendicular to the plane of the paper in Figure 1 and horizontally). The tips of the first sub-arm portion 57A and the second sub-arm portion 57B are rotatably connected to the rear end of the holding portion 52. The holding portion 52 is supported by these link mechanisms.

The first main arm section 56A and the second main arm section 56B are each pivoted to face any direction by separate motors housed in the drive box 55. The pivot axes of the first sub-arm section 57A and the second sub-arm section 57B relative to the first main arm section 56A and the second main arm section 56B are parallel to the first axis L1 and the second axis L2. For example, the rotation angle of the second sub-arm section 57B relative to the second main arm section 56B is adjustable. The pivot axes of the first sub-arm section 57A and the second sub-arm section 57B relative to the holding section 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 section 56A, the first sub-arm section 57A, the second main arm section 56B, the second sub-arm section 57B, and the holding section 52 constitute five sides of a hexagon. The container drive unit 54 has a two-axis parallel link mechanism due to these configurations. The container drive unit 54, controlled by the control unit 70, rotates each arm, thereby moving the holding unit 52 in the vertical and horizontal directions. The orientation of the holding unit 52 is maintained horizontally by the rod 58.

Under the control of the control unit 70, the holding unit 52 is movable while maintaining a horizontal posture 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. This allows for adjustment of 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. Note that the configuration is not limited to the above; the container drive unit 54 may also have a left-right movement mechanism for moving the holding unit 52 in the left-right direction and a vertical movement mechanism for moving the holding unit 52 in the vertical direction. Such a two-axis drive mechanism also allows for adjustment of the position of the container 50.

The container drive unit 54 raises the holding unit 52 and the container 50, bringing the container 50 and the group of articles X closer to the robot hand 15. It then lowers the holding unit 52 and the container 50, separating the container 50 and the group of articles X from the robot hand 15. The container drive unit 54 inserts the gripping claws 30a into the group of articles X contained (placed) in the container 50, and then releases the gripping claws 30a that have grasped the articles from the container 50. In other words, the first robot hand 15A and the second robot hand 15B insert the gripping claws 30a of their respective gripping units 30 into the group of articles X within the container 50 and grasp a portion of the articles.

The item transfer system 1 is equipped with two discharge chutes 60. For example, two discharge chutes 60 of the same size and shape are arranged side-by-side on the left and right. In the following description, the discharge chute 60 located on the left side in the front view of Figure 1 may be referred to as the first discharge chute 60A, and the discharge chute 60 located on the right side in the front view may be referred to as the second discharge chute 60B. However, when describing common configurations and functions, the name "discharge chute 60" will simply be used.

The discharge chute 60 is a funnel-shaped component. The discharge chute 60 is positioned below the robot hand 15. Specifically, the first discharge chute 60A is positioned below the first robot hand 15A, and the second discharge chute 60B is positioned below the second robot hand 15B. The first position P1 of the container 50 is located between the first robot hand 15A and the first discharge chute 60A, and the second position P2 of the container 50 is located between the second robot hand 15B and the second discharge chute 60B.

The first discharge chute 60A receives the article dropped by the gripping portion 30 of the first robot hand 15A when the container 50 is in the second position P2, and discharges it to the outside of the article transfer system 1. Similarly, the second discharge chute 60B receives the article dropped by the gripping portion 30 of the second robot hand 15B when the container 50 is in the first position P1, and discharges it to the outside of the article transfer system 1. In this way, the first robot hand 15A and the second robot hand 15B transfer the articles gripped by their respective gripping portions 30 to the destination position. That is, in this specification, "release of grip" by each robot hand 15 and the resulting "drop of article" mean the transfer of the article to the discharge chute 60.

In this embodiment, two discharge chutes are used, but the system is not limited to this. The first robot hand 15A and the second robot hand 15B may share a single discharge chute. In that case, the upper opening of the single discharge chute is set to a size and position that encompasses the entirety of the first position P1 and the second position P2 in a plan view. Alternatively, the items dropped from the robot hand 15 may be discharged directly to the outside without using a discharge chute.

Figure 2 is a block diagram of the item movement system 1. In Figure 2, the control unit 70 controls the operation of various components of the item movement system 1, such as the gripping member drive mechanism 30b and the container drive unit 54. The control unit 70 performs combination calculations using the weight values of the items weighed by the weighing scale 40. The control unit 70 is configured as a computer device including a processor such as a CPU, memory such as ROM and RAM, storage, and communication devices. The control unit 70 is electrically (or communicatively) connected to the hand drive unit 10, the gripping member drive mechanism 30b, the weighing scale 40, and the container drive unit 54. Ideal weight values and the like are input to the control unit 70 via the operation panel 100.

The control unit 70 controls the operation of various components of the article transfer system 1, such as the hand drive unit 10, the gripping member drive mechanism 30b, and the container drive unit 54, by executing a program stored in memory via the CPU. It also performs combination calculations using the weight values of the articles weighed by the weighing device 40. The various functions of the control unit 70 do not necessarily have to be implemented by software; they may be implemented by hardware, or through the cooperation of hardware and software.

The control unit 70 moves the hand drive unit 10 and the container 50, bringing the gripping unit 30 and the container 50 closer together. The control unit 70 controls the gripping member drive mechanism 30b to cause some of the items in the group of items X placed in the container 50 to be gripped by the gripping claws 30a of each gripping unit 30.

Each weighing device 40 weighs the weight of the 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 the process of finding a combination of weight values in which the sum of the weights of the items gripped by each gripping unit 30 equals the target weight. First, the control unit 70 acquires each weight value. Next, based on the result of the combination calculation, the control unit 70 selects the gripping claw 30a of the gripping unit 30 corresponding to the combination of weight values that equals the target weight, 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 from 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 is then discharged from the discharge chute 60. If a combination of weight values that results in the target weight is impossible, and the control unit 70 finds a gripping claw 30a of a gripping unit 30 that corresponds to a combination of weight values close to the target weight, the control unit 70 selects the gripping unit 30 corresponding 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 gripping units 30 other than the one corresponding to the combination of weight values that results in the target weight.

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, between 90% and 100% of the lower limit, or between 95% and 100% of the lower limit, or between 100% and 110% of the upper limit, or between 100% and 105% of the upper limit.

As described above, in the article transfer system 1 of this embodiment, the control unit 70 controls the gripping member drive mechanism 30b (gripping unit 30) and the container drive unit 54, performs combination calculations based on the calculation results from the weighing device 40, and selects a combination of gripping units 30 that results in a preset target weight value. The control unit 70 then discharges the articles into the selected plurality of gripping units 30.

As shown in Figures 1, 3, and 4, multiple sensors 9 are provided above the movable area of the holding portion 52, arranged in the front-to-back direction (perpendicular to the plane of the paper in Figure 1). In this embodiment, four sensors 9 are mounted corresponding to the number of rows (N, specifically 4 rows) of the gripping portion 30 in that direction. The four sensors 9 are fixed, for example, to the main body frame 121, and emit light vertically downwards while detecting the reflected 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 (up-down direction) of the gripping claws 30a within the group of articles X in the container 50.

As shown in Figures 1 and 4, each sensor 9 transmits and receives light at the central position between the first robot hand 15A and the second robot hand 15B. Each sensor 9 detects the position and number of gripping parts 30 in the left-right direction (M above; specifically, four), and the height of the item, while the holding part 52 and the container 50 are being moved between the first position P1 and the second position P2 by the container drive unit 54. The timing of the detection may be adjusted by the control unit 70 considering the left-right movement speed of the container drive unit 54 (for example, to synchronize with the movement of the container drive unit 54). As a result, each time the container 50 moves (passes through) from the first position P1 to the second position P2, or from the second position P2 to the first position P1, a height detection signal is output for 16 points (multiple points corresponding to the planar arrangement of the multiple gripping parts 30) that are distributed in a grid pattern in the left-right direction (direction of movement) and front-back direction within the container 50. In other words, the sensor 9 is located above the container 50 and detects the height of the items in the group of items X in the direction into which the gripping claws 30a are inserted by irradiating the items X with light.

The control unit 70 is electrically (or communicatively) connected to 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 claws 30a for each gripping unit 30 relative to the group of articles X. The height of the articles varies within the container 50. Meanwhile, the container 50 (holding unit 52) is positioned horizontally and brought close to the robot hand 15. Therefore, the insertion amount of the gripping claws 30a for each gripping unit 30 relative to a container 50 at a certain height is not constant (uniform).

The control unit 70 stores, for example, the correspondence between the insertion amount and opening angle for gripping an item of a desired gripping amount. Upon receiving height detection signals from each sensor 9, the control unit 70 sets the vertical position of the container 50 and the item group X, and calculates the corresponding insertion amount for each gripping unit 30. Furthermore, the control unit 70 refers to the stored correspondence and calculates the opening angle of the gripping claws 30a corresponding to the insertion amount for 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 one is to grip the item) so that the calculated insertion amount and opening angle are achieved. In other words, the control unit 70 controls the gripping operation of the robot hand 15 based on the item height detected by the sensor 9.

Returning to Figure 1, the item moving system 1 includes a mechanism to reduce the influence of external disturbances such as steam, for example, when dealing with items that generate steam. As shown in Figure 1, the item moving system 1 includes a fan 80 that blows air into the weighing device 120. The fan 80 is located, for example, behind the sensor 9. The configuration of the fan 80 is not particularly limited, and a known blower can be used. The fan 80 has, for example, a motor built into the casing and an impeller attached to the casing. Power is supplied to the fan 80. The control unit 70 is electrically (or communicatively) connected to the fan 80.

Furthermore, potential disturbances for sensor 9 include not only steam generated from heated objects, but also fragments of easily dispersed foods (e.g., foods containing shredded kelp, dried bonito flakes, or seaweed). If the object is not food, other disturbances may be targeted.

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

Referring to Figure 5, the fan 80 will be described from a different perspective. As shown in Figure 5, the fan 80 is mounted, for example, on another frame 200 adjacent to the weighing device 120. The fan 80 is directed, for example, diagonally downward, and supplies a predetermined strength (amount) of wind (airflow) towards space S. The space S through which the fan 80 blows air is the space between the first gripping region RA, which includes the area of the first robot hand 15A, and the second gripping region RB, which includes the area of the second robot hand 15B. In other words, the space through which the fan 80 blows air is the space that avoids the positions of the first robot hand 15A and the second robot hand 15B.

The control unit 70 controls the operation and stopping of the fan 80 in relation to the space S. In particular, the control unit 70 blows air into the space S at times other than the weight calculation period during which the weight of the item is calculated in the weighing instrument 40. More specifically, the control unit 70 controls the fan 80 to turn on and blow air into the space S while the height of the item is detected by the sensor 9. More specifically, the control unit 70 may drive the fan 80 to include the period during which the height of the item is detected by the sensor 9, or it may drive the fan 80 only during the period during which the height of the item is detected by the sensor 9. Alternatively, the control unit 70 may drive the fan 80 to include, or only during, the period during 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. This is to prevent the airflow from the fan 80 from hitting the item that is being held by the gripping claws 30a and affecting the weighing process.

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 that are irradiated with light. Even if steam or parts of the articles are generated from the group of articles X, the airflow can remove or reduce the steam or parts of the articles from the space S. The airflow does not affect the detection operation of the sensor 9 due to light irradiation (or if it does, the effect is slight and negligible). Therefore, the influence of disturbances on the sensor 9 can be reduced.

Conventionally, if no countermeasures were taken against disturbances that could occur on the group of items X, for example, the sensor 9 could misdetect the height of the items. The control unit 70 controls the height of the container 50 by, for example, calculating the average of the detection results (detected values) of the 16 points (M x N) mentioned above. If a detection result higher than the actual height of the items is output, the position of the container 50 raised by the container drive unit 54 will be too low, potentially resulting in insufficient insertion of the gripping claws 30a (or even a complete miss). If a detection result lower than the actual height of the items is output, the position of the container 50 raised by the container drive unit 54 will be too high, potentially resulting in excessive insertion of the gripping claws 30a. According to this embodiment, such problems are avoided.

When combined weighing is performed, the sensor 9 accurately detects the height of the items. The control unit 70 can accurately control the insertion amount of the gripping claws 30a for the group of items X during combined weighing. Therefore, the weighing accuracy and efficiency of combined weighing are improved.

If airflow hits an item gripped by the gripping claws 30a, the calculation of the item's weight may be affected. By configuring the system to blow air into the surrounding space at times other than the weight calculation period, the influence of airflow on the weight calculation can be reduced.

When airflow hits an item grasped by the robot hand 15, it can affect the quality or weight of the item being transferred. Such effects can be reduced by blowing air into the space S that avoids the robot hand 15.

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

The embodiments of this disclosure have been described above, but the present invention is not limited to these embodiments. For example, in the above embodiments, a configuration was illustrated in which the robot hand 15 grasps an article by moving the container 50 (holding portion 52) closer to the robot hand 15. However, a different configuration may be adopted in which the robot hand 15 or gripping portion 30 grasps an article by moving (for example, lowering) the robot hand 15 or gripping portion 30 closer to the container 50. In that case, the robot hand 15 or gripping portion 30 is provided with an appropriate known movement mechanism. By moving (for example, raising) the robot hand 15 or gripping portion 30, the gripping claws 30a that are gripping the article can be separated from the container 50.

The transfer of items by a robotic hand is not limited to "releasing the grip" and the subsequent "dropping of the item into the discharge chute." The robotic hand, while gripping an item, may move horizontally or vertically to transfer the item to another container, another hopper, or a conveying device such as a conveyor.

The robot hand may have only one gripping part. The sensor for detecting the height of the object group X may be omitted.

The item transfer system does not need to perform combined weighing. The item transfer system may not have a weight calculation unit for calculating the weight of the item gripped by the gripping unit; the weight may be calculated after the item has been transferred.

The fan may be a fan that exhausts (or draws in) air into space S, rather than a fan 80 that blows air into space S. A known exhaust fan or suction fan having a motor and impeller may be used. Such a fan can exhaust air from the space S between the sensor 9 and the container 50 (group of articles X) irradiated with light from the sensor 9, thereby achieving the same effect as described above. Furthermore, the fan may be capable of both blowing and exhausting air. The fan may perform blowing and exhausting air, for example, in alternating combinations.

As shown in Figure 6, the fan 80 may be attached to the main frame 121 of the weighing device 120. In this case as well, the fan 80 is positioned behind the sensor 9. Compared to the above embodiment, by blowing or exhausting air from a position closer to the space S, the target space can be narrowed, and the impact on the gripping and weighing operations can be further reduced.

The fan may be mounted horizontally and perform airflow or exhaust horizontally. Alternatively, the fan may perform airflow or exhaust diagonally upwards. A fan installed at a lower position (approximately the same position as the container 50 that moves left and right) may also perform airflow or exhaust upwards.

Furthermore, the configuration in which the fan 80 is positioned behind the sensor 9 is not limited. For example, as shown in Figure 7, a weighing device 120A (article moving system 1A) may be employed in which fans 80A and 80B, capable of switching between blowing and exhausting air, are provided on the right and left sides of the main frame 121, respectively. These fans 80A and 80B may be fixed, for example, to the left and right doors (not shown) attached to the main frame 121. At least one fan 80A and 80B are fixed to the inner surface of each door. The fans 80A and 80B are, for example, oriented horizontally and facing each other. The left fan 80A is provided to the left (outside horizontally) of the first gripping area RA, and the right fan 80B is provided to the right (outside horizontally) of the second gripping area RB. That is, the positions of the fans 80A and 80B are outside the first gripping area RA and the second gripping area RB. Fans 80A and 80B are positioned in the center of the first gripping region RA and the second gripping region RB in the front-rear direction.

The control unit 70 controls the right fan 80B to blow air and the left fan 80A to exhaust air while the container 50 is moving from the first position P1 to the second position P2 (moving to the right). Similarly, the control unit 70 controls the left fan 80A to blow air and the right fan 80B to exhaust air while the container 50 is moving from the second position P2 to the first position P1 (moving to the left). In other words, in control using a pair of left and right fans, air is blown by the fan located in front of the moving container 50 (the fan facing the approaching container 50), and exhaust air is exhausted by the fan located behind the moving container 50.

In this case, the space in which air is blown and exhausted by fans 80A and 80B includes the first gripping area RA and the second gripping area RB. 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 times other than the weight calculation period in which the weight of the item is calculated in the weighing device 40. The control unit 70 may drive fans 80A and 80B to include the period in which the height of the item is detected by the sensor 9, or it may drive fans 80A and 80B only during the period in which the height of the item is detected by the sensor 9. The driving timing of fans 80A and 80B can be determined in the same way as the driving timing of fan 80 in the above embodiment. According to the item moving system 1A, which combines blowing and exhausting air according to the direction of movement of the container 50, the influence of disturbances on the sensor 9 can be suitably reduced, similar to the item moving system 1.

The timing of fan-assisted airflow or exhaust may coincide with the weight calculation period in the weighing device 40 (weight calculation unit). The space S where fan-assisted airflow or exhaust occurs may coincide with the position of the robot hand 15, i.e., either the first gripping region RA or the second gripping region RB.

1, 1A…Article transfer 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 device (weight calculation unit), 50…Container (placement 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 (4)

A robot hand having at least one gripping portion for gripping articles, inserting the gripping member of the gripping portion into a group of articles placed on a mounting portion to grip a portion of the articles, and transferring the gripped articles to a destination position,
A sensor is provided above the aforementioned mounting section and detects the height of the articles in the direction into which the gripping member is inserted, by irradiating the group of articles with light,
A control unit controls the gripping operation of the robot hand based on the height of the item detected by the sensor ,
A fan located below the sensor and used to blow or exhaust air into the space between the sensor and the group of articles to which the light is irradiated,
Equipped with ,
The control unit controls the blowing or exhausting of air into the space and stopping the fan, and blows or exhausts air into the space at times other than the weight calculation period during which the weight of the article is calculated in the weight calculation unit, in an article transfer device. A robot hand having at least one gripping portion for gripping articles, inserting the gripping member of the gripping portion into a group of articles placed on a mounting portion to grip a portion of the articles, and transferring the gripped articles to a destination position,
A sensor is provided above the aforementioned mounting section and detects the height of the articles in the direction into which the gripping member is inserted, by irradiating the group of articles with light,
A control unit controls the gripping operation of the robot hand based on the height of the item detected by the sensor,
A fan located below the sensor and used to blow or exhaust air into the space between the sensor and the group of articles to which the light is irradiated,
Equipped with,
An article transfer device in which the space where air is blown or exhausted by the fan is a space that avoids the position of the robot hand . The aforementioned at least one gripping portion is a plurality of gripping portions,
The system further comprises a weight calculation unit that calculates the weight of the article gripped by each of the gripping members of the plurality of gripping units,
The article transfer device according to claim 1, wherein the control unit controls the gripping unit, performs combination calculations based on the calculation results in the weight calculation unit, selects a combination of the gripping units that results in a preset target weight value, and discharges the article to the selected gripping unit. The aforementioned at least one gripping portion is a plurality of gripping portions,
The system further includes a weight calculation unit that calculates the weight of the article gripped by each of the gripping members of the plurality of gripping units.
The article transfer device according to claim 2, wherein the control unit controls the gripping unit, performs combination calculations based on the calculation results in the weight calculation unit, selects a combination of the gripping units that results in a preset target weight value, and discharges the article to the selected gripping unit.