Weighing system

Abstract

This system provides a weighing system that allows for precise setting of the weight value at which an item is discharged. [Solution] The weighing system comprises: a first gripping unit having a first gripping hand for gripping and discharging a portion of a group of articles contained in a container; a second gripping unit having a second gripping hand having a different shape from the first gripping hand for gripping and discharging another portion of the group of articles; an acquisition unit for acquiring at least one of the weight values ​​of the first articles gripped by the first gripping unit and the weight values ​​of the first articles discharged from the first gripping unit; and a control unit for controlling the discharge of the second articles from the second gripping unit based on the weight values.

Description

Technical Field

[0001] The present invention relates to a weighing system.

Background Art

[0002] As a device for weighing and distributing, for example, Patent Document 1 below discloses a device having a plurality of collection units each provided with gripping means for gripping and removing a part of an article and weighing means for recording the weight of a part of the article. The device further includes dispensing means and a computer pre-programmed for a predetermined total weight, measures the weight of the article gripped by the gripping means by the weighing means, and inputs it to a predetermined location.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above device described in Patent Document 1, there is a problem that the weight of the article to be input to a predetermined location falls outside the range of the target weight value preset due to various factors. In this case, at the subsequent stage of the above device, the weight adjustment of the article is carried out manually by an operator, which causes an increase in cost.

[0005] An object of one aspect of the present invention is to provide a weighing system capable of accurately setting the weight value at which an article is discharged.

Means for Solving the Problems

[0006] A weighing system according to one aspect of the present invention comprises: a first gripping unit having a first gripping hand for gripping and discharging a portion of a group of articles contained in a container; a second gripping unit having a second gripping hand having a different shape from the first gripping hand for gripping and discharging another portion of a group of articles; an acquisition unit for acquiring at least one of the weight values ​​of the first articles gripped by the first gripping unit and the weight values ​​of the first articles discharged from the first gripping unit; and a control unit for controlling the discharge of the second articles from the second gripping unit based on the weight values.

[0007] According to this weighing system, the control unit controls the discharge of the second item from the second gripping unit based on the weight value of the first item acquired by the acquisition unit and held by the first gripping unit. This allows the final weight value of the items discharged from the weighing system to be accurately set within the range of the target weight value, for example, if the weight value is less than the target weight value, by discharging the second item from the second gripping unit. In this way, by using the first and second gripping units, the weight value of the items discharged from the weighing system can be accurately set.

[0008] A weighing system according to another aspect of the present invention comprises: a first gripping unit having a first gripping hand for gripping and discharging a portion of a first group of first articles contained in a first container; a second gripping unit having a second gripping hand having a different shape from the first gripping hand for gripping and discharging a portion of a second group of second articles contained in a second container, or for taking out a portion of the first articles discharged from the first gripping unit; an acquisition unit for acquiring at least one of the weight value of the first articles gripped by the first gripping unit and the weight value of the first articles discharged from the first gripping unit; and a control unit for controlling the discharge of the second articles by the second gripping unit or the discharge of a portion of the first articles based on the weight value, wherein the second gripping unit is located after the first gripping unit. .

[0009] According to this weighing system, the control unit controls the discharge of the second item from the second gripping unit, or the discharge of a portion of the first item by the second gripping unit, based on the weight value of the first item acquired by the acquisition unit and held by the first gripping unit. As a result, for example, if the above weight value is outside the range of the target weight value, the second item will be discharged from the second gripping unit, or a portion of the first item will be discharged by the second gripping unit, thereby accurately setting the final weight value of the items discharged from the weighing system to the target weight value. In this way, by using the first gripping unit and the second gripping unit, the weight value of the items discharged from the weighing system can be set with high accuracy.

[0010] The first gripping unit may have multiple first gripping hands, the acquisition unit may acquire the weight value of the first item gripped by each of the multiple first gripping hands, and the control unit may perform a combination calculation of the weight values ​​acquired by the acquisition unit, select a combination of first gripping hands that is close to a preset target weight value, and perform control to release the grip of the selected first gripping hands. In this case, after the first gripping unit has gripped the first item once, the weighing system can discharge items with multiple target weight values. This can improve the production efficiency of items.

[0011] The first gripper may have three or more first gripping claws, and the second gripper may have two second gripping claws. In this case, the gripping of the second article by the second gripper can be set to a small amount, allowing for fine weight adjustment by the second gripper.

[0012] When the two second gripping claws of the second gripping hand are closed, a space may be provided between the two second gripping claws having a diameter of 0.5 to 1.5 times the diameter of the articles included in the article group. In this case, the gripping of the second article by the second gripping hand can be set to a smaller amount.

[0013] The second gripping hand may have a gripping detection unit that detects whether or not it has gripped the second article. In this case, the control unit can easily determine whether or not weight adjustment can be performed by the second gripping hand. [Effects of the Invention]

[0014] According to one aspect of the present invention, a weighing system capable of accurately setting the weight value of an article to be discharged can be provided.

Brief Description of the Drawings

[0015] [Figure 1] FIG. 1 is a front view of a weighing system according to the first embodiment. [Figure 2] FIG. 2 is a block diagram of the weighing system. [Figure 3] FIG. 3 is a schematic perspective view of the gripping unit. [Figure 4] FIGS. 4(a) to (c) are bottom views of the gripping claws of the gripper as viewed from below. [Figure 5] FIG. 5(a) is a bottom view of the gripper as viewed from below. FIGS. 5(b) and (c) are enlarged side views of the main part of the gripper. [Figure 6] FIG. 6 is a block diagram schematically showing the configuration of a weighing system according to the second embodiment. [Figure 7] FIG. 7 is a front view of the combination weighing device. [Figure 8] FIG. 8 is a schematic view showing the conveying device and the weight adjusting device. [Figure 9] FIG. 9 is an enlarged side view of the main part showing a modified example of the gripping mechanism.

Modes for Carrying Out the Invention

[0016] Hereinafter, embodiments according to one aspect of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions are omitted.

[0017] (First Embodiment) FIG. 1 is a front view of a weighing system according to the first embodiment. The weighing system 110 shown in FIG. 1 is a combination weighing device that takes out some of the articles (first article group) stored in a container 50 (details will be described later) and discharges the articles to the outside. The weighing system 110 takes out and discharges some of the articles from the article group so that the weight falls within the target weight range. The articles discharged by the weighing system 110 are, for example, packaged in bags or stored in containers in subsequent processes of the weighing system 110 and shipped as products.

[0018] The weighing system 110 includes a unit drive unit 10, a gripping unit 15, a container 50, a container drive unit 54, a discharge chute 60, and a control unit 70.

[0019] The gripping unit 15 is attached to the unit drive unit 10. The gripping unit 15 is a robotic arm having one or more first gripping modules 20 (first gripping part) and one or more second gripping modules 21 (second gripping part).

[0020] The first gripping module 20 has a gripper 30 (first gripping hand) that grips and discharges some of the articles (first articles) in the article group stored in the container 50, and a weighing instrument 40 that measures the weight value of the articles. Each gripper 30 has gripping claws 30a that actually grip the articles. Further, a gripping member drive mechanism 30b for driving the gripping claws 30a is incorporated in the gripper 30. The weighing instrument 40 measures the weight value of the articles gripped by the gripper 30.

[0021] The second gripping module 21 has a gripper 31 (second gripping hand) that grips and discharges some of the other articles (second articles) in the article group stored in the container 50, and a weighing instrument 41 that measures the weight value of the articles. Each gripper 31 has a different shape from the gripper 30 of the first gripping module 20 (details will be described later). Further, a gripping member drive mechanism 32 is incorporated in the gripper 31. The weighing instrument 41 measures the weight value of the articles gripped by the gripper 31.

[0022] Container 50 is a component (first container) that contains a group of articles, and is movable between a first position and a second position by, for example, a container drive unit 54. When container 50 is in the first position, grippers 30 and 31 can grip articles from the group of articles inside container 50. When container 50 is in the second position, grippers 30 and 31 are in a position where they cannot grip articles from the group of articles inside container 50. Discharge chute 60 receives and discharges articles that have been released from gripper 30 and 31. The articles are, for example, noodles such as spaghetti, foods containing a lot of sugar, etc. The articles may also be foods with high viscosity.

[0023] Figure 2 is a block diagram of the weighing system. In Figure 2, the control unit 70 controls the operation of various components of the weighing system 110, such as the gripping member drive mechanisms 30b and 32, and the container drive unit 54. The control unit 70 performs combination calculations using the weight values ​​of the items weighed by the weighing instrument 40.

[0024] The control unit 70 moves the unit drive unit 10 and the container 50, bringing the grippers 30 and 31 closer to the container 50. The control unit 70 controls the gripping member drive mechanism 30b of the first gripping module 20 to cause a portion of the items in the group of items placed in the container 50 to be gripped by the gripping claws 30a of each gripper 30. The control unit 70 also controls the gripping member drive mechanism 32 of the second gripping module 21 to cause another portion of the items in the group of items placed in the container 50 to be gripped by each gripper 31.

[0025] Each weighing instrument 40 weighs the weight of the item gripped by the corresponding gripping device 30. The weight of the item gripped by each gripping device 30 is acquired, for example, by an acquisition unit (not shown) included in the control unit 70. The control unit 70 performs combination calculations based on the weight of the item gripped by each gripping device 30 weighed by each weighing instrument 40.

[0026] The combination calculation is a process that finds a combination of weight values ​​in which the sum of the weight values ​​of the items gripped by each gripper 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 claws 30a of the gripper 30 corresponding to the weight value combination that equals the target weight, and performs control to release the grip of the selected gripper 30. At this time, the control unit 70 releases the grip of the items by the grippers 30 above the discharge chute 60, thereby discharging the items with the target weight from the discharge chute 60. If it is impossible to find a combination of weight values ​​that equals the target weight, and the control unit 70 finds a gripping claws 30a of the gripper 30 corresponding to a weight value combination that is close to the target weight, the control unit 70 selects the gripper 30 corresponding to that combination, and performs control to release the grip of the selected gripper 30. This control is performed, for example, using the weight values ​​of grippers 30 other than the gripper 30 corresponding to the weight value combination that equals the target weight.

[0027] In the first embodiment, the target weight value is a predetermined weight range that includes the ideal weight value. For example, the lower limit of the target weight value is 90% or 95% of the ideal weight value, and the upper limit of the target weight value is 110% or 105% of the ideal weight value. 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 greater than 100% but 110% or less of the upper limit, or greater than 100% but 105% or less of the upper limit.

[0028] (2) Detailed configuration Figure 3 is a schematic perspective view of the gripping unit. Figures 4(a) to 4(c) are bottom views of the gripping claws of the gripper, viewed from below. The unit drive unit 10 and the gripping unit 15 will be described below using Figures 1, 3, and 4(a) to 4(c).

[0029] (2-1) Unit drive unit 10 As shown in Figure 1, the weighing system 110 comprises two unit drive units 10. The unit drive unit 10 on the left side in the front view of Figure 1 is designated as the first unit drive unit 10A, and the unit drive unit 10 on the right side in the front view of Figure 1 is designated as the second unit drive unit 10B. However, when describing common configurations and functions, they are simply referred to as the unit drive unit 10.

[0030] The unit drive unit 10 has two parallel frames 12 and a forward / backward movement mechanism 11 that moves the gripping unit 15 horizontally along the frames 12. The unit drive unit 10 can move the block 111 that holds the gripping unit 15 forward or backward when viewed from the front using the forward / backward movement mechanism 11. The unit drive unit 10 has, for example, a servo motor, an air cylinder, etc., for moving the block 111.

[0031] In the weighing system 110, the first gripping unit 15A and the second gripping unit 15B are arranged horizontally. The first gripping unit 15A can be moved horizontally in the front-rear direction by the first unit drive unit 10A, and the second gripping unit 15B can be moved horizontally in the back-rear direction by the second unit drive unit 10B. The position of the group of articles in the container 50 can be matched with the article gripping position set for each gripping unit 15.

[0032] (2-2) Gripping unit 15 As shown in Figure 1, the weighing system 110 is equipped with two gripping units 15. The gripping unit 15 on the left side in the front view of Figure 1 is designated as the first gripping unit 15A, and the gripping unit 15 on the right side in the front view of Figure 1 is designated as the second gripping unit 15B. However, when describing the common configuration and function, they are simply referred to as gripping unit 15.

[0033] The gripping unit 15 includes a plate-shaped connecting member 16 connected to the block 111 of the unit drive unit 10, one or more first gripping modules 20, and one or more second gripping modules 21.

[0034] (2-2-1) Connecting member 16 The connecting member 16 is connected to the block 111 of the unit drive unit 10, for example, by screw fastening.

[0035] (2-2-2) First gripping module 20 As shown in Figure 3, the first gripping module 20 is a device in which the gripper 30 and the weighing device 40 are assembled as a single unit. The top surface of the weighing device 40 is fixed to the connecting member 16 via a mounting bracket 400, and the gripper 30 is fixed to the bottom surface of the weighing device 40.

[0036] (2-2-2-1) Grip device 30 The gripping device 30 is a device for gripping an article. Each gripping device 30 has a gripping claw 30a and a gripping member driving mechanism 30b which is a driving mechanism for driving the gripping claw 30a. The gripping member driving mechanism 30b drives the gripping claw 30a using, for example, a motor or fluid pressure as a driving source.

[0037] In the first embodiment, as shown in Figure 3, the gripping claw 30a has a rod-shaped or finger-shaped member with a claw formed at its tip that is bent inward to hook onto an article. Each gripper 30 has multiple (for example, three or more) gripping claws 30a (first gripping claw portion). Note that the number and shape of the gripping claws 30a depicted in Figure 3 etc. are merely examples and can be changed as appropriate.

[0038] As shown in Figures 4(a) and 4(b), when each gripping device 30 is viewed from the gripping claw 30a side (bottom side), the multiple gripping claws 30a are arranged in a circumferential direction. Also, when viewed from the gripping claw 30a side of each gripping device 30, the multiple gripping claws 30a are arranged at approximately equal intervals in the circumferential direction. Furthermore, when viewed from the gripping claw 30a side of each gripping device 30, the gripping claws 30a are movable in the radial direction. The gripping device 30 grips an article by moving the gripping claws 30a, which are separated from each other, radially inward by the gripping member drive mechanism 30b to bring them closer together, thereby gripping the article between the multiple gripping claws 30a. The gripping device 30 releases the grip from the article by moving the gripping claws 30a, which are close together, radially outward by the gripping member drive mechanism 30b to separate them. In other words, the multiple gripping claws 30a of the gripping unit 15 can be switched between at least one of a first state and a second state. The first state is a state in which the relative distance between the gripping claws 30a is reduced to a first distance to grip the article. The second state is a state in which the relative distance between the gripping claws 30a is increased to a second distance greater than the first distance to release the grip on the article. In the second state, for example, the gripping claws 30a of the gripper 30 may be closed to the position of the virtual circle C1 shown in Figure 4(c). The second state may be considered as the initial state of the gripping claws 30a.

[0039] However, if a gripping force limiting function is provided to prevent the article from being crushed by the gripping claws 30a or for the purpose of overload protection, the gripping force will stop due to an external force from the article before the relative distance between the gripping claws 30a is reduced to the first distance. Therefore, the first state does not necessarily have to be the state in which the relative distance between the gripping claws 30a is reduced to the first distance; the first state may be the state in which the distance is reduced to a distance at which the article can be gripped.

[0040] (2-2-2-2) Measuring instrument 40 In the first gripping module 20, one weighing device 40 is provided for each gripping device 30. The weighing device 40 measures the weight of the item being gripped by the gripping claws 30a of the corresponding gripping device 30.

[0041] Each measuring instrument 40 includes a sensor unit 40a (see Figure 3) and an internal control unit (not shown). The sensor unit 40a includes 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 MEMS-type miniature acceleration sensor is used as the acceleration sensor.

[0042] The internal control unit of the weighing device 40 measures the mass of the object being gripped by the gripper 30 based on the force and acceleration measured by the sensor unit 40a when the gripper 30, which is gripping the object, is moved in conjunction with the movement of the unit drive unit 10. Specifically, the internal control unit of the weighing device 40 measures the mass of the object being gripped by the gripper 30 by dividing the force measured by the force sensor by the acceleration measured by the acceleration sensor.

[0043] However, the weighing device 40 is not limited to a method that measures the mass of an item based on the force and acceleration measured when the gripper 30 is moving. The weighing device 40 may also use a load cell or the like to measure the weight of an item being gripped by the gripper 30 while it is stationary.

[0044] (2-2-3) Second gripping module 21 As shown in Figure 3, the second gripping module 21 is a device in which the gripper 31 and the weighing device 41 are assembled as a single unit. The top surface of the weighing device 41 is fixed to the connecting member 16 via a mounting bracket 400, and the gripper 31 is fixed to the bottom surface of the weighing device 41.

[0045] (2-2-3-1) Grip device 31 The gripper 31 is a device for gripping articles. The gripper 31 grips a smaller amount of article compared to the gripper 30. The weight value of the article discharged from the weighing system 110 is adjusted by the discharge of some or all of the article gripped by the gripper 31. As shown in Figure 3, each gripper 31 has a gripping member drive mechanism 32, a plurality of gripping mechanisms 33, and a disc portion 34. The gripping member drive mechanism 32 is, for example, a main part having a cylindrical shape, and drives the gripping mechanisms 33 and the disc portion 34 using, for example, a motor housed in a casing as a drive source.

[0046] Figure 5(a) is a bottom view of the gripper as seen from below. Figures 5(b) and (c) are enlarged side views of the main part of the gripper. As shown in Figure 5(a), when the gripper 31 is viewed from below, the multiple gripping mechanisms 33 are arranged in a line in the circumferential direction. Also, when the gripper 31 is viewed from below, the multiple gripping mechanisms 33 are arranged at approximately equal intervals in the circumferential direction. In the first embodiment, the gripper 31 is provided with four gripping mechanisms 33, but is not limited to this. Each gripping mechanism 33 may be driven synchronously with each other, or may be driven independently of each other. Each of the multiple gripping mechanisms 33 has a cylindrical portion 35 and a first claw portion 36 and a second claw portion 37 (second gripping claw portion).

[0047] The cylindrical portion 35 is a part that has a frustoconical shape when viewed from the side and is located within the opening 34a provided in the disc portion 34. At least a part of the cylindrical portion 35 is located below the disc portion 34. The diameter of the cylindrical portion 33a decreases towards the bottom.

[0048] The first claw portion 36 and the second claw portion 37 are the parts of the gripper 31 that actually grip the articles. In the first embodiment, the first claw portion 36 is fixed, while the second claw portion 37 can be moved horizontally by the gripping member driving mechanism 32. As shown in Figures 5(b) and (c), when the second claw portion 37 moves horizontally (radially inward) toward the first claw portion 36, the first claw portion 36 and the second claw portion 37 become closed. Conversely, when the second claw portion 37 moves horizontally (radially outward) toward the first claw portion 36, the first claw portion 36 and the second claw portion 37 become open. For example, when the gripping mechanism 33 is in contact with a group of articles, the gripping mechanism 33 grips the articles when the first claw portion 36 and the second claw portion 37 become closed.

[0049] The first claw portion 36 has a base portion 36a, a tip portion 36b, and a groove portion 36c. The base portion 36a is a rod-shaped portion fixed to the cylindrical portion 35. A part of the base portion 36a protrudes downward from the tip of the cylindrical portion 35. The tip portion 36b is the portion that protrudes downward from the tip of the base portion 36a. The tip portion 36b extends away from the second claw portion 37. The surface of the tip portion 36b facing the second claw portion 37 is a curved surface, but is not limited to this. This surface may be an inclined surface. The length of the tip portion 36b is, for example, about 4 mm. The tip of the tip portion 36b is located inside the opening 34a of the disc portion 34.

[0050] The groove 36c is a recess provided in the base 36a into which an article enters when the first claw portion 36 and the second claw portion 37 are closed. In the first embodiment, the groove 36c is provided on the surface of the base 36a facing the second claw portion 37 and is recessed away from the second claw portion 37. In the direction perpendicular to the direction in which the first claw portion 36 and the second claw portion 37 face each other, and in the direction perpendicular to the vertical direction, the groove 36c extends from one end to the other of the base 36a. In a side view, the groove 36c has, for example, a semicircular shape, a semielliptical shape, etc.

[0051] The second claw portion 37 has a base portion 37a, a tip portion 37b, and a groove portion 37c. The base portion 37a is a rod-shaped portion that can move within a groove 35a provided in the cylindrical portion 35. Although not shown, the base portion 37a is connected to the gripping member driving mechanism 32. A part of the base portion 37a protrudes downward from the tip of the cylindrical portion 35. The tip portion 37b is the portion that protrudes downward from the tip of the base portion 37a. The tip portion 37b extends away from the first claw portion 36, similar to the tip portion 36b of the first claw portion 36. The surface of the tip portion 37b facing the first claw portion 36 is a curved surface, but is not limited to this. This surface may be an inclined surface. The length of the tip portion 37b is, for example, about 4 mm. Regardless of whether the first claw portion 36 and the second claw portion 37 are in an open or closed state, the tip of the tip portion 37b is located inside the opening 34a of the disc portion 34.

[0052] The groove 37c is a recess provided in the base 37a into which an article enters when the first claw portion 36 and the second claw portion 37 are closed. In the first embodiment, the groove 37c is provided on the surface of the base 37a facing the first claw portion 36 and is recessed away from the first claw portion 36. In the direction perpendicular to the direction in which the first claw portion 36 and the second claw portion 37 face each other, and in the direction perpendicular to the vertical direction, the groove 37c extends from one end to the other of the base 37a. In a side view, the groove 37c has, for example, a semicircular shape, a semielliptical shape, etc.

[0053] When the first claw portion 36 and the second claw portion 37 are closed, the base portions 36a and 37a are in contact with each other, while the tip portions 36b and 37b are separated from each other. Therefore, in the closed state, gripping an article with the tip portions 36b and 37b is impossible or difficult. On the other hand, when the first claw portion 36 and the second claw portion 37 are closed, the groove portions 36c and 37c come together to create a substantially cylindrical space S between the first claw portion 36 and the second claw portion 37. The diameter D of the space S is, for example, 0.5 times or more and 1.5 times or less the diameter of the articles included in the group of articles. By having the first claw portion 36 and the second claw portion 37 have the above configuration, the articles gripped by each gripping mechanism 33 can be limited to only those articles contained within the space S.

[0054] The disc portion 34 is a plate member that can move vertically by the gripping member drive mechanism 32. By moving the disc portion 34 downward, it is possible to drop any items attached to the gripping mechanism 33. This makes it less likely for there to be a difference between the weight value of the items weighed by the weighing device 41 and the weight value of the items discharged from the gripper 31.

[0055] Although not shown in the figures, in the first embodiment, the gripper 31 has a grip detection unit that detects whether each gripping mechanism 33 has gripped an article. The grip detection unit is, for example, a component that detects whether or not an article is present in space S. The grip detection unit is, for example, a photosensor, a capacitive sensor, etc.

[0056] (2-2-3-2) Measuring instrument 41 In the second gripping module 21, one weighing device 41 is provided for each gripping device 31. The weighing device 41 measures the weight of the item being gripped by the corresponding gripping device 31. In the first embodiment, the structure of each weighing device 41 is the same as the structure of the weighing device 40 included in the first gripping module 20, but is not limited to this.

[0057] (2-4) Container 50 The container 50 contains a group of articles. The container 50 is placed on a mounting surface 52 that moves horizontally and vertically. In the first embodiment, the container 50 is a rectangular parallelepiped container with an open top. The container 50 is configured so that when the amount of articles contained inside decreases, a person or machine can replace the container 50 with a new container 50 (which contains more articles). Alternatively, instead of the container 50 being replaceable, it may have an article supply mechanism for supplying articles to the container 50. The container 50 moves between a first position and a second position by a container drive unit 54.

[0058] The first position is the position directly below the gripper 30 of the first gripping unit 15A, and is the position in which the gripper 30 of the first gripping unit 15A can grip the articles inside the container 50. When the container 50 is in the first position, the grippers 30 and 31 of the second gripping unit 15B cannot grip the articles inside the container 50.

[0059] On the other hand, the second position of the container 50 is a position directly below the gripper 30 of the second gripping unit 15B, and a position in which the gripper 30 of the second gripping unit 15B can grip the articles inside the container 50. When the container 50 is in the second position, the grippers 30 and 31 of the first gripping unit 15A cannot grip the articles inside the container 50.

[0060] (2-5) Container drive unit 54 The container drive unit 54 can move the container 50 horizontally using a motor or fluid pressure as a drive source. The container drive unit 54 has, for example, a rectangular parallelepiped-shaped drive body 540. In Figure 1, when the front is considered to be the front in a front view, the drive body in front of the two discharge chutes 60 is called the first drive body 541, and the drive body behind is called the second drive body (not shown). Two horizontal support columns are provided in front of the two discharge chutes 60, parallel to each other vertically, and two horizontal support columns are also provided in parallel to each other vertically behind. In a front view, the lower horizontal support column is the first horizontal support column 551, and the upper horizontal support column is the second horizontal support column 552.

[0061] The first drive unit 541 of the container drive unit 54 has, for example, a left-right movement mechanism 56 (see Figure 2), and can move horizontally along the first horizontal support column 551 and the second horizontal support column 552. Although not shown, the second drive unit of the container drive unit 54 also has a left-right movement mechanism 57 (see Figure 2), and can move horizontally along a horizontal support column different from the first horizontal support column 551 and the second horizontal support column 552. The first drive unit 541 and the second drive unit move synchronously.

[0062] Thus, in the weighing system 110, the first gripping unit 15A and the second gripping unit 15B are arranged horizontally, and the container 50 can be moved horizontally in the left-right direction by the left-right movement mechanism, so that the position of the group of articles inside the container 50 can be matched with the article gripping position set for each gripping unit 15.

[0063] The mounting surface 52 has four vertical supports extending vertically downward from the four corners of its underside. In a front view, the left support is designated as the first vertical support 521, and the right support is designated as the second vertical support 522. Although not shown in the diagram, a third vertical support is provided behind the first vertical support 521, and a fourth vertical support is provided behind the second vertical support 522.

[0064] The first drive unit 541 has a vertical movement mechanism (not shown) that can move the first vertical support column 521 and the second vertical support column 522 in the vertical direction. The second drive unit also has a similar vertical movement mechanism that can move the third vertical support column and the fourth vertical support column in the vertical direction. The first drive unit 541 and the second drive unit can move the first vertical support column 521 and the second vertical support column 522, and the third vertical support column and the fourth vertical support column in the vertical direction in a synchronous manner.

[0065] Thus, in the weighing system 110, the container 50 can be moved vertically by the vertical movement mechanism, so even if the container 50 is positioned vertically apart from each gripping unit 15, the position of the group of items inside the container 50 can be matched with the item gripping position set for each gripping unit 15. Furthermore, in the weighing system 110, the vertical movement mechanism does not need to raise or lower the left-right movement mechanism; only the container 50 needs to be raised or lowered, thus reducing the load when raising or lowering the container 50. In addition, in the weighing system 110, the left-right movement mechanism 56 is not positioned in the space above the entrance of the discharge chute 60, so foreign matter contamination into the discharge chute 60 is avoided. Similarly, since the vertical movement mechanism is not positioned in the space above the entrance of the discharge chute 60, foreign matter contamination into the discharge chute 60 is avoided.

[0066] (2-6) Discharge chute 60 As shown in Figure 1, the weighing system 110 is equipped with two discharge chutes 60. The discharge chute 60 on the left side in the front view of Figure 1 is designated as the first discharge chute 60A, and the discharge chute 60 on the right side in the front view of Figure 1 is designated as the second discharge chute 60B. However, when describing the common configuration and function, they will simply be referred to as the discharge chute 60.

[0067] The discharge chute 60 is a funnel-shaped component. The discharge chute 60 is positioned directly below the gripping unit 15. Specifically, the first discharge chute 60A is positioned directly below the first gripping unit 15A, and the second discharge chute 60B is positioned directly below the second gripping unit 15B.

[0068] The container 50 is positioned between the first gripping unit 15A and the first discharge chute 60A, or between the second gripping unit 15B and the second discharge chute 60B.

[0069] The first discharge chute 60A receives the item that the gripper 30 of the first gripping unit 15A releases and drops when the container 50 is positioned between the second gripping unit 15B and the second discharge chute 60B, and discharges it outside the weighing system 110.

[0070] Similarly, the second discharge chute 60B receives the item that the gripper 30 of the second gripping unit 15B releases and drops when the container 50 is positioned between the first gripping unit 15A and the first discharge chute 60A, and discharges it outside the weighing system 110.

[0071] In this embodiment, two discharge chutes are used, but the invention is not limited to this, and the first gripping unit 15A and the second gripping unit 15B may share a single discharge chute. It is also possible to discharge the material directly to the outside without using a discharge chute.

[0072] (2-7) Control Unit 70 The control unit 70 has memory such as ROM and RAM in addition to a CPU (not shown in the figure). As shown in Figure 2, the control unit 70 is electrically connected to the unit drive unit 10, the gripping member drive mechanisms 30b and 32, the weighing instruments 40 and 41, and the container drive unit 54. The control unit 70 receives input such as the ideal weight value via the operation panel 101.

[0073] The control unit 70 controls the operation of various components of the weighing system 110, such as the unit drive unit 10, the gripping member drive mechanisms 30b and 32, and the container drive unit 54, by executing a program stored in memory by the CPU, and also performs combination calculations using the weight values ​​of items weighed by the weighing instruments 40 and 41. The various functions of the control unit 70 do not necessarily have to be implemented in software, they may be implemented in hardware, or they may be implemented through the cooperation of hardware and software.

[0074] The control unit 70 drives the gripping claws 30a via the gripping member driving mechanism 30b to grip an article with the gripping claws 30a, and then releases the grip from the article. Here, "gripping" means that the multiple gripping claws 30a, which are at a distance from each other as shown in Figure 4(a), move radially inward to a position where they are closer to each other as shown in Figure 4(b), and "releasing the grip" means that after gripping, they return to their distanced positions as shown in Figure 4(a).

[0075] The control unit 70 drives the gripping mechanism 33 of the gripper 31 via the gripping member drive mechanism 32. This causes the first claw portion 36 and the second claw portion 37 to grip the article, and then releases the grip on the article. The control unit 70 controls the gripping member drive mechanism 32 based on the weight value obtained from the gripper 30. For example, if the weight value obtained from the gripper 30 is the target weight value, the grip on the article by the gripper 31 is maintained. On the other hand, if the weight value obtained from the gripper 30 is less than the target weight value but close to the target weight value, the grip on the article by part or all of the gripper 31 is released. As a result, the control unit 70 brings the total weight of the article discharged from both the grippers 30 and 31 to the target weight value. Here, "gripping" means that multiple gripping claws 30a, which are positioned far apart from each other as shown in Figure 5(b), move radially inward to a position where they are closer together as shown in Figure 5(c), and "releasing the grip" means that after gripping, they return to their far apart positions as shown in Figure 5(b).

[0076] According to the weighing system 110 of the first embodiment described above, the control unit 70 controls the discharge of the second item from the gripper 31 based on the weight value of the first item obtained by the weighing instrument 40 and gripped by the gripper 30. As a result, for example, if the weight value is less than the target weight value, the second item is discharged from the gripper 31 of the second gripping module 21, thereby accurately setting the final weight value of the items discharged from the weighing system 110 within the range of the target weight value. In this way, by using the grippers 30 and 31, the weight value of the items discharged from the weighing system 110 can be set with high accuracy.

[0077] In the first embodiment, the first gripping module 20 has multiple grippers 30, and the control unit 70, which also functions as an acquisition unit, acquires the weight value of the first article gripped by each of the multiple grippers 30, performs a combination calculation of the weight values ​​acquired by the acquisition unit, selects a combination of grippers 30 that is either a preset target weight or close to the target weight, and performs control to release the grip of the selected grippers 30. As a result, after the grippers 30 have temporarily gripped some of the articles from the group of articles in the container 50, the weighing system 110 can discharge articles with the target weight multiple times. This improves the production efficiency of articles by the weighing system 110.

[0078] In the first embodiment, the gripper 30 has three or more gripping claws 30a, and the gripper 31 has two claw portions, a first claw portion 36 and a second claw portion 37. Therefore, the gripping of the article by the gripper 30 can be set to a small amount, and fine weight adjustment can be performed by the gripper 30.

[0079] In the first embodiment, when the first claw portion 36 and the second claw portion 37 are closed, a space S is provided between the first claw portion 36 and the second claw portion 37, having a diameter D of 0.5 to 1.5 times the diameter of the articles included in the group of articles. Therefore, the amount of articles gripped by the gripper 31 can be set to be smaller.

[0080] In the first embodiment, the gripper 31 has a grip detection unit that detects whether or not it has gripped an article. Therefore, the control unit 70 can easily determine whether or not weight adjustment is possible using the gripper 31.

[0081] (Second Embodiment) The weighing system according to the second embodiment will be described below. In the description of the second embodiment, descriptions that overlap with the first embodiment will be omitted, and only the parts that differ from the first embodiment will be described. In other words, to the extent that it is technically possible, descriptions of the first embodiment may be used in the second embodiment as appropriate.

[0082] Figure 6 is a schematic block diagram showing the configuration of the weighing system according to the second embodiment. As shown in Figure 6, the weighing system 300 according to the second embodiment includes a combination weighing device 110A, a conveying device 310, and a weight adjustment device 320. In the weighing system 300, the combination weighing device 110A is located at the upstream end. Therefore, the conveying device 310 and the weight adjustment device 320 are located after the combination weighing device 110A.

[0083] Figure 7 is a front view of the combination weighing device. The combination weighing device 110A shown in Figure 7 differs from the weighing system 110 of the first embodiment in that it does not have a second gripping module 21. In other words, the combination weighing device 110A has gripping units 15C and 15D as gripping units 15, which do not include the second gripping module 21. Therefore, the control unit included in the combination weighing device 110A performs a combination calculation of the weight values ​​of the articles to be gripped by each of the multiple grippers 30. After that, the control unit selects a combination of grippers 30 that is close to a preset target weight value, and performs control to release the grip of the selected grippers 30. After this control, the articles removed from the grippers 30 are discharged outside the combination weighing device 110A through the discharge chute 60. The articles are then stored, for example, in a storage container prepared in advance at the outlet of the discharge chute 60.

[0084] Figure 8 is a schematic diagram showing a conveying device and a weight adjustment device. As shown in Figure 8, the conveying device 310 is a device that conveys a container SC containing articles G1 discharged from the combined weighing device 110A, and is, for example, a belt conveyor. The conveying device 310 may have a weight measuring device for measuring the weight of the container SC. For example, if the weight of the articles G1 contained in the container SC deviates from the target weight, the conveying device 310 may be temporarily stopped. In this case, the conveying device 310 may be temporarily stopped after the container SC has been conveyed to a position where weight adjustment can be performed by the weight adjustment device 320. After weight adjustment by the weight adjustment device 320 has been performed, the conveying of the container SC by the conveying device 310 may be resumed.

[0085] The weight adjustment device 320 is a device (second gripping part) that adjusts the weight of articles in the storage container SC, and is, for example, a robot arm. The weight adjustment device 320 has a main body 321, an arm 322, a control unit 323, and a container 324 (second container) that stores the article group G2 (second article group). The main body 321 is the part that supports the arm 322 and is fixed to the factory floor or the like. The main body 321 may have a user interface such as a display, touch panel, or keyboard.

[0086] The arm 322 is the part that grasps or discharges the group of articles G2 contained in the container 324, or the articles G1 in the container SC. A gripping module 21A having a gripper 31A (second gripping hand) and a weighing device 41A is attached to the tip of the arm 322. The gripping module 21A of the weight adjustment device 320 has the same structure as the second gripping module 21 of the first embodiment described above, and therefore has a different shape from the first gripping module 20 of the combined weighing device 110A. The gripper 31A is capable of the same operation as the second gripping module 21 of the first embodiment described above. By the movement of the arm 322, the gripping module 21A can move directly above the conveying device 310 and directly above the container 324. In addition, the gripping module 21A can approach the vicinity of the conveying device 310 and the vicinity of the container 324. Therefore, the gripper 31A included in the gripping module 21A is capable of gripping both a portion of the articles G1 in the storage container SC on the conveying device 310 and a portion of the group of articles G2 to be stored in the container 324. In addition, the gripper 31A is capable of discharging a portion or all of the gripped articles G1 into the container 324, and discharging a portion of the gripped group of articles G2 into the storage container SC. The weighing device 41A included in the gripping module 21A weighs the portion of the articles G1 or group of articles G2 gripped by the gripper 31A.

[0087] The control unit 323 has a CPU (not shown in the figure) as well as memory such as ROM and RAM. The control unit 323 is electrically connected to the combined weighing device 110A and the conveying device 310. The control unit 323 controls the operation of various configurations of the arm 322 and the gripping module 21A by executing a program stored in memory via the CPU, acquires the weight value measured by the weighing instrument 41A, acquires the weight value transmitted from the combined weighing device 110A and / or the conveying device 310, and calculates the weight value that the gripping module 21A should grip or release. The various functions of the control unit 323 do not necessarily have to be implemented in software; they may be implemented in hardware, or they may be implemented through the cooperation of hardware and software.

[0088] The control unit 323 controls the movement of the arm 322 to position the gripping module 21A near one of the container 324 and the storage container SC. At this time, the gripper 31A comes into contact with the article G1 or the group of articles G2. Subsequently, the control unit 323 drives each part included in the gripper 31A, similar to the control unit 70 in the first embodiment, to cause the gripper 31A to grip the article. Subsequently, the control unit 323 controls the movement of the arm 322 to position the gripping module 21A near the other of the container 324 and the storage container SC. Then, based on the weight value obtained from the combined weighing device 110A and / or the conveying device 310, it performs control to release the grip of the gripping module 21A.

[0089] For example, if the weight value of item G1 transmitted from the combined weighing device 110A is the target weight value, weight adjustment by the weight adjustment device 320 is not required, or weight adjustment may be performed to achieve the ideal weight value. For example, if the weight value of item G1 transmitted from the combined weighing device 110A is less than the target weight value but close to the target weight value, the gripper 31A grasps a portion of the item group G2 from the container 324 and then discharges that portion into the containment container SC. For example, if the weight value of item G1 transmitted from the combined weighing device 110A is greater than the target weight value but close to the target weight value, the gripper 31A grasps a portion of item G1 from inside the containment container SC and then discharges that portion into the container 324. Through these operations, the control unit 323 brings the total weight value of the items discharged from the weighing system 300 to the target weight value.

[0090] Container 324 is a component that contains the group of articles G2 and is fixed in a predetermined position. The group of articles G2 is identical to the articles G1 in the storage container SC. Container 324 is located on the opposite side of the main body 321, with the transport device 310 in between, but is not limited to this location. The group of articles G2 in container 324 can be replenished in the same manner as container 50.

[0091] The weighing system 300 according to the second embodiment described above also provides the same effects and advantages as the first embodiment. In addition, according to the second embodiment, even if the weight value of the item G1 transmitted from the combined weighing device 110A is greater than the target weight value, the weight value of the item discharged from the weighing system 300 can be adjusted to the target weight value. As a result, the item is discharged more easily from the combined weighing device 110A, and the production efficiency of the item can be further improved.

[0092] The present invention has been described in detail above based on the above embodiments and modifications. However, the present invention is not limited to the above embodiments and modifications. The present invention can be further modified without departing from its spirit.

[0093] Figure 9 is an enlarged side view of a modified gripping mechanism. As shown in Figure 9, the gripping mechanism 33A may also have a cylindrical portion 35, a first claw portion 36A, and a second claw portion 37A. The first claw portion 36A differs from the first claw portion 36 of the first embodiment in that it has an outer circumferential curved surface 36d instead of a tip portion 36b. The outer circumferential curved surface 36d is a side surface that extends from the tip of the base portion 36a away from the second claw portion 37A and is convex downwards. Similarly, the second claw portion 37A differs from the second claw portion 37 of the first embodiment in that it has an outer circumferential curved surface 37d instead of a tip portion 37b. The outer circumferential curved surface 37d is a side surface that extends from the tip of the base portion 37a away from the first claw portion 36A and is convex downwards. Even when such a gripping mechanism 33A is used, the same effects and advantages as in the above embodiment can be achieved.

[0094] In the first embodiment described above, the need to release the grip of the second gripping module is determined based on the weight of the article measured by the first gripping module, but the invention is not limited to this. For example, the control unit may control the removal of an article from the second gripping module based on the weight of the article discharged by the first gripping module. In this case, the control unit obtains the weight of the article discharged by the first gripping module from a weighing device provided in, for example, a discharge chute. Alternatively, the control unit may control the removal of an article from the second gripping module based on both the weight of the article measured by the first gripping module and the weight of the article discharged by the first gripping module. In this case, the control unit may also utilize, for example, the difference between the above weight values.

[0095] In the second embodiment described above, the control unit controls the removal of an article from the gripper of the weight adjustment device or the retrieval of an article from the storage container, based on the weight value of the article weighed by the first gripping module included in the combined weighing device, but is not limited to this. For example, the control unit may perform weight adjustment by the weight adjustment device based on the weight value of the article weighed by a weight measuring device included in the conveying device, etc. Alternatively, weight adjustment by the weight adjustment device may be performed based on both the weight value of the article weighed by the first gripping module included in the combined weighing device and the weight value of the article weighed by a weight measuring device included in the conveying device, etc.

[0096] In the second embodiment described above, when the weight adjustment device grips an article from the container, it releases the grip on the article on the container, but is not limited to this. For example, it may release the gripped article on a chute for disposal. Also, when the weight adjustment device grips an article from the container, it may return part or all of the article to the container according to the weight value of the container. [Explanation of Symbols]

[0097] 10...Unit drive unit, 15...Gripping unit, 20...First gripping module (first gripping part), 21...Second gripping module (second gripping part), 21A...Gripping module, 30...Gripper (first gripping hand) , 30a...gripping claw (first grasping claw part), 30b, 32...gripping member drive mechanism, 31, 31A... grasper (second grasping hand), 33, 33A... grasping mechanism, 35... cylinder part, 36, 36A... first claw part, 36a, 3 7a...base, 36b,37b...tip, 36c,37c...groove, 36d,37d...outer curved surface, 37,37A...second claw, 40,41,41A...weighing device, 50...container (first container), 70,323...control unit, 110,300...weighing system, 110A...combined weighing device, 310...conveying device, 320...weight adjustment device, 324...container (second container), G1...article, G2...group of articles, S...space.

Claims

1. A first gripping unit having a first gripping hand that grasps and discharges some of the first items from a group of items contained in a container, A second gripping unit having a second gripping hand that grips and discharges a portion of the other second articles from the group of articles, and which has a different shape from the first gripping hand, wherein the gripping of the second articles is set to be less than that of the first gripping hand, An acquisition unit that acquires at least one of the weight value of the first article gripped by the first gripping unit and the weight value of the first article discharged from the first gripping unit, A control unit that controls the discharge of the second article from the second gripping portion based on the weight value, Equipped with, A weighing system in which the first gripping portion and the second gripping portion are connected by a plate-shaped connecting member.

2. The first gripping section has a plurality of first gripping hands, The acquisition unit acquires the weight value of the first article held by each of the plurality of first gripping hands. The control unit, The acquisition unit performs a calculation of the combination of weight values ​​acquired, Select a combination of the first grips that is either a pre-set target weight or close to that target weight, The weighing system according to claim 1, further comprising the implementation of control to release the grip of the selected first gripper.

3. The first gripping hand has three or more first gripping claw portions, The weighing system according to claim 1 or 2, wherein the second gripping hand has two second gripping claw portions.

4. The weighing system according to claim 3, wherein when the two second gripping claws of the second gripping hand are closed, a space is provided between the two second gripping claws having a diameter of 0.5 to 1.5 times the diameter of the articles included in the group of articles.

5. The weighing system according to any one of claims 1 to 4, wherein the second gripping hand has a gripping detection unit for detecting whether or not it has gripped the second article.

Images