CN117120221A - Element holding device - Google Patents

Abstract

The element gripping device (10) of the present disclosure is provided with: a hand (30) having a plurality of grip parts (31) and gripping the element (P) as a magnetic body by the plurality of grip parts (31); a pick-up robot (20) for transferring the element (P) held by the hand (30); and a control unit (50) for adjusting the magnetic force of the hand (30). Since the magnetic force of the hand (30) can be adjusted by the control unit (50), a wide variety of objects can be accurately gripped.

Description

Element holding device

Technical Field

The present disclosure relates to an element gripping device.

Background

Conventionally, as a device for picking up and disposing a workpiece, a workpiece transfer device described in international publication No. 2017/094112 is known. The workpiece transfer apparatus includes a suction portion for sucking and picking up a workpiece of a magnetic material at a front end of a shaft member, and a holding portion for holding and supporting the workpiece in a posture after the suction portion sucks the workpiece. The shaft member of the attraction unit is connected to the electromagnet, and generates a plurality of levels of magnetic force (attraction force) in the attraction unit based on the electric power supplied to the electromagnet.

Prior art literature

Patent literature

Patent document 1: international publication No. 2017/094112

Disclosure of Invention

Problems to be solved by the invention

In the workpiece transfer apparatus described above, the suction portion and the holding portion are configured so that the holding portion itself for holding the workpiece cannot generate a magnetic force. Since the clamping portion is used for clamping the component, the clamping portion needs to be provided in accordance with the shape of the component, and a special clamping portion needs to be prepared for each component. In the workpiece transfer apparatus, since the number of workpieces that can be held by the holding portion is one, a plurality of workpieces cannot be held at a time. The ability to accurately hold a wide variety of objects to be held, such as different sizes, weights, and numbers, is not sufficient to cope with the versatility of various holding schemes.

Means for solving the problems

The device for holding an element of the present disclosure comprises: a hand part having a plurality of grip parts for gripping the element as a magnetic body; a pick-up robot that transfers the component held by the hand; and a control unit that adjusts the magnetic force of the hand.

Effects of the invention

According to the present disclosure, the magnetic force of the hand can be adjusted by the control unit, and thus a wide variety of objects can be accurately gripped.

Drawings

Fig. 1 is a front view of the component holding device.

Fig. 2 is a block diagram of the component holding device.

Fig. 3 is a front view of the hand.

Fig. 4 is a bottom view of the hand.

Fig. 5 is an operation explanatory view of the element gripping device of embodiment 1.

Fig. 6 is a flowchart of the device for gripping an element according to embodiment 1.

Fig. 7 is an operation explanatory view of the element gripping device of embodiment 2-1.

Fig. 8 is a flowchart of the device for holding an element according to embodiment 2-1.

Fig. 9 is an operation explanatory view of the element gripping device of embodiment 2-2.

Fig. 10 is a flowchart of the device for holding an element according to embodiment 2-2.

Fig. 11 is an operation explanatory view of the element gripping device of embodiment 3.

Fig. 12 is a flowchart of the device for gripping an element according to embodiment 3.

Detailed Description

[ description of embodiments of the present disclosure ]

First, embodiments of the present disclosure are exemplified and described.

(1) The component holding device of the present disclosure is a component holding device, comprising: a hand part having a plurality of grip parts for gripping the element as a magnetic body; a pick-up robot that transfers the component held by the hand; and a control unit that adjusts the magnetic force of the hand.

Since the magnetic force of the hand can be adjusted by the control unit, the magnetic force is used to attract or bounce the elements, and thereby an arbitrary number of elements can be gripped.

(2) Preferably, the control unit obtains the number information of the held elements, and associates the magnetic force with the number information.

By acquiring the number information of the held elements, the magnetic force can be correlated with the number information by the control unit.

(3) Preferably, the control unit adjusts a hand width, which is a distance between the grip units.

Since the hand width can be adjusted by the control unit, a plurality of types of elements having different sizes can be held by the same hand.

(4) Preferably, the control unit obtains information on the number of the held elements, and associates the magnetic force, the hand width, and the information on the number.

By acquiring the number information of the gripped elements, the magnetic force and the hand width can be correlated with the number information by the control unit.

(5) The hand width may be a distance between a pair of the grip portions facing each other.

Since the distance between the pair of opposed grip portions is only required to be adjusted, the adjustment of the hand width is easy.

(6) Preferably, the control unit includes: a magnetic force adjustment unit for adjusting the magnetic force of the hand; a hand width adjustment unit that adjusts the hand width; an operation unit that correlates the magnetic force, the hand width, and the number information; and a storage unit configured to store the magnetic force, the hand width, and the number information in which the magnetic force, the hand width, and the number information are associated.

The magnetic force and the hand width can be correlated with the number information by the arithmetic unit, and the correlated information can be stored in the storage unit, so that the magnetic force and the hand width with high gripping success rate can be controlled. Further, by doing so, the magnetic force and the hand width with higher gripping success rate can be learned and controlled.

(7) Preferably, the hand has the plurality of grip portions as magnetic bodies and a coil for magnetizing the grip portions.

The coil magnetizes the grip portion and the grip portion itself has a magnetic force, so that the element can be reliably gripped and transferred.

(8) Preferably, the control unit is configured to magnetize the grip portion with a strong magnetic force for the element having a large mass, and to magnetize the grip portion with a weak magnetic force for the element having a small mass.

If a strong magnetic force is used for the low-mass component, the low-mass component is attracted more than necessary by the strong magnetic force, and the component may be removed during the transfer of the component. Therefore, by using an appropriate magnetic force according to the mass of the elements as described above, the required number of elements can be attracted, and the gripping success rate can be improved.

(9) Preferably, the hand grips the element placed on the placement unit after attracting the element by magnetizing the plurality of grip portions.

For example, even when there is an element in a portion that is difficult to grip, such as an end portion of the mounting portion of the tray, the element can be sucked to a position where the element can be gripped and then gripped.

(10) Preferably, the hand is magnetized in an open state to attract the elements placed on the placement unit to the respective grip portions, and the plurality of grip portions are closed to collect the elements at one place and grip the elements.

For example, when the elements are arranged in a dispersed state on the mounting portion of the tray, the holding success rate may be low. Even in this case, the elements can be attracted to the respective grip portions, and the elements can be collected in one place by closing the plurality of grip portions, so that the grip success rate can be improved.

(11) Preferably, the hand holds a plurality of the elements with a magnetic force greater than a magnetic force for holding a single element.

The plurality of elements can be held without removing the elements without changing the hand.

[ detailed description of embodiment 1 of the present disclosure ]

[ Integrated Structure of element holding device ]

The overall structure of the element gripping device 10 will be described with reference to fig. 1. The component holding device 10 is a device for taking out a part of the components P from a box containing a large number of the components P and dividing the components P into small parts. The component gripping apparatus 10 includes a pickup robot 20 for gripping and transferring the component P, a camera 40 for capturing an image of an object such as the component P, and the like.

[ Structure of pickup robot ]

The pick-up robot 20 includes a vertical articulated robot arm 21 and a hand 30 attached to a distal end portion of the robot arm 21 and gripping the element P. The hand 30 is sometimes referred to as an end effector. The robot arm is not limited to the vertical articulated type, and may be a SCARA robot (horizontal articulated robot) or another robot.

The robot arm 21 includes a base portion 23 fixed to the bracket 22 and a plurality of links 24 for transmitting displacement and force, and the base portion 23 and the links 24 and the adjacent links 24 are connected to each other by joints 25 so as to be swingable or rotatable. In the present embodiment, the robot arm 21 includes joints 25 of three axes of swing and six axes of rotation, and a joint driving device (not shown) is incorporated in each joint 25.

[ Structure of hand ]

The hand 30 includes a plurality of grip portions 31 for gripping the element P, and in the present embodiment, the element P is gripped and held by a pair of grip portions 31. The hand 30 is mounted to the link 24 at an end portion opposite to the base portion 23. The pair of gripping portions 31 are capable of being displaced in the directions of approaching and separating from each other, the element P is gripped by the pair of gripping portions 31 being moved in parallel in the directions of approaching each other (closing operation), and the element P is released by the pair of gripping portions 31 being moved in parallel in the directions of separating from each other (actuating operation).

Specifically, the hand 30 includes a pair of grip portions 31, a coil 32, and a hand body portion 33 as shown in fig. 3 and 4. The pair of grip portions 31 are arranged in two rows from the hand body portion 33 and protrude downward, and are arranged so as to face each other in the opening/closing direction. The coil 32 is disposed at the end of the pair of grip portions 31 on the hand main body portion 33 side. The coil 32 is disposed so as to surround the two grip portions 31.

The grip 31 is made of a magnetic material, and is magnetized (has a magnetic force) by a magnetic field generated by flowing a current to the coil 32. The direction of the magnetic field can be controlled by the direction of the current flowing to the coil 32, and the intensity of the magnetic force can be controlled by the intensity of the current flowing to the coil 32. The adjustment of the intensity of the magnetic force and the adjustment of the hand width can be performed before, during and after the start of the picking operation. The pickup operation includes an operation of gripping the component P by the pair of gripping portions 31 and an operation of transferring the gripped component P by the pickup robot 20. The hand width is the distance between the pair of opposing grip portions 31 (the distance between the pair of opposing surfaces 34).

When the hand portion without the coil 32 is used to clamp the element P by the pair of clamp portions, the element P is fixed by friction force generated between the clamp portions and the element P. Therefore, if the contact area between the clamping portion and the element P is not sufficiently ensured, a sufficient friction force cannot be obtained. In this regard, since the hand 30 of the present disclosure includes the coil 32 and fixes the element P by magnetic force, the types of the element P that can be grasped by the same grasping portion 31 are increased.

The grip portion 31 is magnetized by a strong magnetic force to grip and transfer the element P for the element P having a relatively large mass, and the grip portion 31 is magnetized by a weak magnetic force to grip and transfer the element P for the element P having a relatively small mass. In this way, the relatively small-mass component P is not attracted more than necessary, and the component P fixed to the side surface of the grip 31 other than the opposing surface 34 by magnetic force alone, for example, can be prevented from falling off in the middle of transfer.

[ Structure of Camera ]

The camera 40 is a device for capturing an image of the element P, and includes a photoelectric conversion element such as a CCD or CMOS, a light source for illuminating the element P, and the like. The camera 40 outputs an image signal obtained by photoelectrically converting an image by a photoelectric conversion element to a control unit 50 described later. For example, when capturing an image of the component P held by the hand 30, the control unit 50 can acquire information on the type, number, and the like of the component P by performing image processing on the image signal. The camera 40 is mounted on a component (for example, a ceiling wall (not shown) disposed above the bracket 22) different from the pickup robot 20.

[ Electrical Structure of element holding device ]

Next, an electrical configuration of the element gripping device 10 will be described with reference to the block diagram of fig. 2. The component gripping apparatus 10 includes a control unit 50, and the control unit 50 comprehensively controls the entire component gripping apparatus. The control unit 50 includes a grip position estimating unit 51, a magnetic force adjusting unit 52, a hand width adjusting unit 53, a calculating unit 54, and a storage unit 55. The pick-up robot 20, the hand 30, and the camera 40 are connected to the control unit 50. The operation of the pick-up robot 20, the operation of the hand 30, and the operation of the camera 40 are controlled by the control unit 50.

The holding position estimating unit 51 estimates the position of the element P based on the image of the element P captured by the camera 40. For example, the center position of the image is preset as the position of the camera, which is known, and therefore the position of the element P is estimated by measuring the amount of shift of the element P from the center position of the image. Thus, the control unit 50 controls the operation of the robot arm 21 so that the centers of the pair of gripping units 31 move to the position of the element P.

The magnetic force adjustment unit 52 adjusts the intensity of the magnetic force generated in the coil 32 by adjusting the intensity of the current flowing to the coil 32. The intensity of the magnetic force is determined by the mass calculated based on the number information of the elements P. The magnetic force adjustment unit 52 adjusts the direction of the magnetic field generated in the coil 32 by adjusting the direction of the current flowing to the coil 32. By changing the orientation of the magnetic field, the element P can be attracted or sprung back.

The hand width adjustment unit 53 adjusts the hand width according to the type of the element P. The size of the element P is known, and thus the hand width can be determined according to the type of the element P.

The calculation unit 54 correlates the magnetic force, the hand width, and the number information, and stores the correlated information in the storage unit 55. The calculation unit 54 calculates the total mass of the elements P based on the mass of each element P and the number information of the elements P. The computing unit 54 accesses the storage unit 55 to acquire information such as magnetic force and hand width corresponding to the number information (total mass) of the elements P.

The storage unit 55 stores a table 56 that associates the element name of the element P with the hand width (hereinafter referred to as "hand width and element table"), a table 57 that associates the element name of the element P with the mass (hereinafter referred to as "element mass"), and a table 58 that associates the mass with the magnetic force (electric power) (hereinafter referred to as "magnetic force and mass table").

[ description of operation of the element holding device ]

Next, the operation of the element gripping device 10 will be described with reference to the operation explanatory diagram of fig. 5. Fig. 5 (a) shows a case where the element SP with a small mass is gripped as the element P placed in the placement portion 61 of the tray 60, and fig. 5 (B) shows a case where the element LP with a large mass is gripped as the element P placed in the placement portion 61 of the tray 60. Both the small element SP and the large element LP are magnetic bodies. The small element SP is smaller and lighter than the large element LP. The hand width when gripping the small element SP is smaller than the hand width when gripping the large element LP. The magnetic force used when gripping the small element SP is weaker than the magnetic force used when gripping the large element LP.

For example, when the small element SP is an M3 bolt and the large element LP is an M6 bolt, the hand width when the small element SP is gripped may be set to 5mm and the hand width when the large element LP is gripped may be set to 8mm. When the mass of the small element SP is 1g and the mass of the large element LP is 5g and the magnetic force (electric power) when gripping the small element SP is 20W, the magnetic force (electric power) when gripping the large element LP may be 100W or more than that.

Specifically, the computing unit 54 may determine the hand width by accessing the storage unit 55 and referring to the hand width and the element chart 56. The calculation unit 54 may determine the mass of each element by accessing the storage unit 55 and referring to the element mass 57, and calculate the total mass of the elements P based on the number information of the elements P and the mass of each element. The computing unit 54 may determine the magnetic force corresponding to the entire mass of the element P by accessing the storage unit 55 and referring to the magnetic force and mass chart 58.

As described above, by adjusting the hand width according to the type of the element P (small element SP, large element LP, etc.), a plurality of types of elements P can be held by the same hand 30. It is needless to say that the present invention is not limited to the small element SP and the large element LP described above, and the small element SP and the large element LP may be used in a range where the hand width can be adjusted. Further, by using magnetic force in combination when gripping the component P, the component P can be held more reliably, and the probability of dropping the component P when transferring the component P can be reduced.

However, in the case of using a strong magnetic force when holding a small component SP, a plurality of small components SP may be held more than necessary when holding one small component SP, and therefore, it is preferable to use a weak magnetic force.

[ operation procedure of element holding device ]

Next, the operation steps of the element gripping device 10 will be described with reference to the flowchart of fig. 6. First, the camera 40 captures an image of the component P mounted on the mounting portion 61, and the grip position estimating portion 51 estimates the grip position of the component P, and moves the hand 30 to the grip position (step S1). Next, the operation unit 54 accesses the storage unit 55 and refers to the hand width and the element chart 56 to determine the hand width (step S2). Next, the hand width adjustment unit 53 moves the two clamping units 31 so that the distance between the pair of clamping units 31 becomes the hand width determined in step S2. Next, the computing unit 54 accesses the storage unit 55 and refers to the element mass 57 (step S4), and similarly refers to the magnetic force and mass chart 58 (step S5), and the computing unit 54 determines the magnetic force based on the reference results of steps S4 and S5 (step S6).

Next, the magnetic force adjustment unit 52 turns on the magnetic force determined in step S6 (step S7). Next, the two gripping portions 31 grip the component P (step S8), and the robot arm 21 picks up the component P (step S9). Next, the magnetic force is turned off or reversed by the magnetic force adjusting unit 52 (step S10), and the element P that is not capable of being held (the element P fixed only by the magnetic force on the surface other than the facing surface 34) falls by its own weight. Then, the magnetic force stronger than that in step S6 is turned on by the magnetic force adjusting unit 52 (step S11), and the component P is hardly removed at the time of component transfer.

Next, the robot arm 21 transfers the component P to another mounting unit (step S12). Next, the hand 30 opens (step S13) to release the component P, and the magnetic force adjusting unit 52 turns off the magnetic force or reverses the magnetic force when the component P is placed on the robot arm 21 (step S14), whereby the component P can be reliably released from the grip 31.

[ Effect of embodiment 1 ]

As described above, the element gripping device 10 of the present disclosure includes: a hand 30 having a plurality of grip portions 31, and gripping the element P as a magnetic body by the plurality of grip portions 31; a pick-up robot 20 for transferring the component P held by the hand 30; and a control unit 50 for adjusting the magnetic force of the hand 30.

Since the magnetic force of the hand 30 can be adjusted by the control unit 50, the components P can be attracted or sprung back by the magnetic force, and thus an arbitrary number of components P can be gripped.

In this way, a variety of gripping schemes can be handled, and a variety of gripping objects having different numbers can be accurately gripped.

Preferably, the control unit 50 obtains the number information of the held elements P to correlate the magnetic force with the number information.

By acquiring the number information of the held elements P, the control unit 50 can correlate the magnetic force with the number information.

Preferably, the control unit 50 adjusts the hand width, which is the distance between the grip units 31.

Since the hand width can be adjusted by the control unit 50, the small component SP and the large component LP can be held by the same hand 30.

In this way, versatility of the hand 30 can be improved, and a wide variety of gripping objects having different sizes can be accurately gripped.

Preferably, the control unit 50 obtains the number information of the gripped elements P to correlate the magnetic force, the hand width, and the number information.

By acquiring the number information of the gripped elements P, the control unit 50 can correlate the magnetic force, the hand width, and the number information.

The hand width may be the spacing of the pair of opposing grips 31.

Since the distance between the pair of opposed grip portions 31 is only required to be adjusted, the adjustment of the hand width is easy.

The control unit 50 includes: a magnetic force adjustment unit 52 for adjusting the magnetic force of the hand 30; a hand width adjustment unit 53 for adjusting the hand width; an arithmetic unit 54 for associating the magnetic force, the hand width, and the number information; and a storage unit 55 for storing the magnetic force, the hand width, and the number information associated with each other.

The calculation unit 54 can correlate the magnetic force and the hand width with the number information, and the correlated information is stored in the storage unit 55, so that the magnetic force and the hand width with high gripping success rate can be controlled. Further, by doing so, the magnetic force and the hand width with higher gripping success rate can be learned and controlled.

The hand 30 includes a plurality of grip portions 31 as magnetic bodies and a coil 32 for magnetizing the grip portions 31.

The holding portion 31 is magnetized by the coil 32, and the holding portion 31 itself has a magnetic force, so that the element P can be held and transferred reliably.

The magnetic force adjusting unit 52 of the control unit 50 is configured to magnetize the grip portion 31 by using a strong magnetic force for the element LP having a large mass, and magnetize the grip portion 31 by using a weak magnetic force for the element SP having a small mass.

If a strong magnetic force is used for the component SP having a small mass, the component SP having a small mass is attracted more than necessary by the strong magnetic force, and the small component SP may be removed during the transfer of the component. Therefore, by using an appropriate magnetic force corresponding to the mass of the elements P as described above, the required number of elements P can be attracted, and the gripping success rate can be improved.

By performing the process as in embodiment 1, a wide variety of gripping objects having different sizes, weights, or numbers can be accurately gripped.

[ detailed description of embodiment 2-1 of the present disclosure ]

Next, embodiment 2-1 of the present disclosure will be described with reference to fig. 7 and 8. Embodiment 2-1 describes a method of magnetizing the hand 30 and moving and discharging the component P by attracting the component P to a position where the component P can be held by the hand 30 when the component P is present at a corner (end of the placement portion 61) of the tray 60 and the component P cannot be grasped by the hand 30 and cannot be discharged.

[ description of operation of the element holding device ]

Fig. 7 (a) shows a case where the component P is placed at the corner of the tray 60. When the component P is placed on the end of the placement portion 61, even if the hand 30 is moved to the end of the tray 60 and the pair of holding portions 31 are opened, the component P cannot be held by the pair of holding portions 31. Therefore, fig. 7 (B) shows a case where the element P is attracted to the grip portion 31 only by the magnetic force by flowing the current to the coil 32 and turning on the magnetic force of the grip portion 31. Fig. 7 (C) shows a case where the pair of grip portions 31 is closed and the hand 30 is moved to the center of the tray 60 in a state where the element P is attracted to the grip portions 31. Fig. 7 (D) shows a state in which after the magnetic force of the grip portion 31 is turned off and the element P is released, the hand 30 is moved upward and the pair of grip portions 31 is opened to a hand width corresponding to the type of the element P.

[ operation procedure of element holding device ]

Next, the operation steps of the element gripping device 10 will be described with reference to the flowchart of fig. 8. First, the component P that is difficult to hold by the hand 30 is specified by imaging the component P with the camera 40 (step S210). Next, the pair of grip portions 31 of the hand 30 are opened to bring one of the grip portions 31 into a state as close as possible to the element P (step S211). Next, the computing unit 54 accesses the storage unit 55 and refers to the magnetic force and the quality chart 58 to determine the magnetic force (step S212).

Next, the magnetic force adjustment unit 52 turns on the magnetic force determined in step S212 (step S213). Thereby, the element P is attracted to the grip portion 31 from the end of the placement portion 61 by the magnetic force. After the element P is brought into contact with the grip portions 31, the pair of grip portions 31 of the hand 30 are closed or the robot arm 21 is moved to a position where the element P can be gripped (for example, a central portion of the placement portion 61) (step S214). Then, the magnetic force is turned off by the magnetic force adjusting unit 52, and the element P is released from the grip unit 31 (step S215).

Next, the hand 30 is moved upward of the component P (step S216), and the component P is imaged by the camera 40, whereby the grip position estimating unit 51 estimates the grip position of the component P (step S217). Next, the pair of gripping portions 31 of the hand 30 are opened so as to be able to grip the hand width of the element P, and the hand 30 is moved to the height position of the placement portion 61. When the element P is disposed between the pair of gripping portions 31, the element P is gripped by closing the pair of gripping portions 31 (step S218). Next, the hand 30 is moved upward to pick up the component P (step S219).

[ Effect of embodiment 2-1 ]

As described above, the hand 30 of the present disclosure grips the component P placed on the placement unit 61 after attracting the component P by magnetizing the plurality of grip units 31.

For example, even when the component P is present at a portion difficult to grip, such as the end of the placement portion 61 of the tray 60, the component P can be sucked to a position where the component P can be gripped and then gripped.

[ detailed description of embodiment 2-2 of the present disclosure ]

Next, embodiment 2-2 of the present disclosure will be described with reference to fig. 9 and 10. Embodiment 2-2 illustrates a method as follows: when the plurality of elements P are arranged to be thin and flat, the hand 30 is closed in a state where the grip width is larger than the grip width of the elements P and the magnetic force is also strong, and the stack of the elements P is manufactured by concentrating the plurality of elements P at one place, so that the gripping success rate is increased.

[ description of operation of the element holding device ]

Fig. 9 (a) shows a case where a plurality of components P are placed in a thin and flat manner in the placement portion 61 of the tray 60. It is found that if the hand 30 is used to grip the element P in this state, the element P may not be gripped, and the gripping success rate may be low. Therefore, fig. 9 (B) shows a case where the plurality of elements P are attracted to the pair of grip portions 31 by only the magnetic force by flowing the current to the coil 32 and turning on the magnetic force of the pair of grip portions 31. Fig. 7 (C) shows a case where a plurality of elements P are gathered to one place by closing a pair of grip portions 31. Fig. 7 (D) shows a case where a stack of components P is manufactured by moving the hand 30 upward after the magnetic force of the grip portion 31 is turned off and the components P are released.

[ operation procedure of element holding device ]

Next, the operation steps of the element gripping device 10 will be described with reference to the flowchart of fig. 10. First, by capturing images of a plurality of elements P with the camera 40, a state in which the elements P are difficult to hold by the hand 30 is determined. As the camera 40, a 3D camera is preferably used to capture an image of the element P in a bulk state. The computing unit 54 calculates the surface roughness based on the image captured by the camera 40, determines whether or not the element P stack is formed, and determines that the gripping is difficult if the element P stack is not formed (step S220). Next, the pair of grip portions 31 of the hand 30 are opened. The width of the hand at that time is set to be the largest width within the range where the pair of holding portions 31 do not interfere with the tray 60 (step S221). Next, the magnetic force adjustment unit 52 determines the magnetic force to be strong (step S222), and turns on the magnetic force (step S223). Thereby, the plurality of elements P are attracted to the pair of holding portions 31 by the magnetic force, respectively. In this state, the pair of grip portions 31 is closed, thereby bringing the plurality of elements P together (step S224). Next, the magnetic force is turned off by the magnetic force adjustment unit 52 to form a stack of components P (step S225).

Next, the hand 30 is moved upward from the plurality of elements P (step S226), and the plurality of elements P are imaged by the camera 40. The computing unit 54 calculates the surface roughness based on the image captured by the camera 40, and determines whether or not the element P stack is formed (step S227). Next, the pair of gripping portions 31 of the hand 30 are opened so as to be able to grip the hand width of the element P, and the hand 30 is moved to the vicinity of the vertex of the element P stack. When the element P is disposed between the pair of gripping portions 31, the element P is gripped by closing the pair of gripping portions 31 (step S228). Next, the hand 30 is moved upward to pick up the component P (step S229).

[ Effect of embodiment 2-2 ]

As described above, the hand 30 of the present disclosure is magnetized in the opened state by the plurality of grip portions 31, and is configured to attract the components P placed on the placement portion 61 to the respective grip portions 31, and is configured to grip the components P after closing the plurality of grip portions 31 and gathering the components P.

For example, when the components P are arranged in a dispersed state on the mounting portion 61 of the tray 60, the holding success rate may be lowered. Even in this case, since the element P can be sucked to each grip portion 31 and the plurality of grip portions 31 are closed to collect the element P at one place, the gripping success rate can be improved.

By performing the process as in embodiment 2-1 or embodiment 2-2, it is possible to accurately grip a wide variety of gripping objects in different loading states.

[ embodiment 3 of the present disclosure ]

Next, embodiment 3 of the present disclosure will be described with reference to fig. 11 and 12. Embodiment 3 describes a method of magnetizing the hand 30 so as to have a magnetic force larger than a magnetic force for holding one element P when a plurality of (two or more) elements P are to be held, and holding the plurality of elements P.

[ description of operation of the element holding device ]

Fig. 11 (a) shows a case where the holding position of the component P by the hand 30 is determined by imaging the mounting portion 61 of the tray 60 with the camera 40, and the hand 30 is moved to the holding position. Fig. 11 (B) shows a case where a plurality of elements P are held by magnetizing the hand 30 with a strong magnetic force and closing the pair of holding portions 31. Fig. 11 (C) shows a case where the hand 30 is moved upward of the tray 60. Fig. 11 (D) shows a case where the component P that cannot be held (the component P that is attracted to the hand 30 only by the magnetic force) falls down to the placement portion 61 of the tray 60 by breaking the magnetic force generated in the hand 30.

For example, the magnetic force (electric power) when gripping the element P having a mass of 1g may be set to 50W, and the magnetic force (electric power) when gripping the element P having a mass of 5g may be set to 250W. This magnetic force is 2.5 times that of embodiment 1, and therefore, a plurality of elements P can be reliably held.

[ operation procedure of element holding device ]

Next, the operation steps of the component gripping apparatus 10 will be described with reference to the flowchart of fig. 12. First, the computing unit 54 picks up an image of the mounting unit 61 of the tray 60 with the camera 40, determines which position the components P are more gathered on the basis of the picked-up image, and determines the position where the components P are most gathered as the holding position (step S30). Next, the computing unit 54 inquires the mass of the gripped element P from the storage unit 55, refers to the element mass 57 (step S31), refers to the magnetic force and mass chart 58 (step S32), and determines the magnetic force based on the reference results of steps S31 and S32 and the number information of gripped elements P (step S33).

Next, the computing unit 54 accesses the storage unit 55, and refers to the hand width and the element chart 56, thereby determining the hand width corresponding to the gripped element P (step S34). The hand width adjustment unit 53 moves the pair of holding units 31 so as to become the hand width determined in step S34.

Next, the magnetic force adjustment unit 52 turns on the magnetic force determined in step S33 (step S35). Next, the two gripping portions 31 grip the component P (step S36), and the robot arm 21 picks up the component P (step S37). Next, the magnetic force is turned off or reversed by the magnetic force adjusting unit 52 (step S38), and the component P that cannot be held (the component P fixed only by the magnetic force on the surface other than the opposing surface 34) falls by its own weight. Then, the magnetic force stronger than that in step S33 is turned on by the magnetic force adjusting unit 52 (step S39), making the element P difficult to be removed. Next, the robot arm 21 transfers the component P to another mounting unit (step S40).

[ Effect of embodiment 3 ]

As described above, the hand 30 of the present disclosure holds the plurality of elements P with a magnetic force larger than the magnetic force for holding the single element P.

The plurality of components P can be held without removing the components without changing the hand 30.

By performing the process as in embodiment 3, the transfer performance of the hand 30 can be improved.

Other embodiments

(1) In the above embodiment, the camera 40 is illustrated as being mounted on a component different from the pick-up robot 20, but the camera 40 may be mounted on the hand 30 of the pick-up robot 20.

(2) In the above embodiment, the hand 30 has been illustrated as having the pair of grip portions 31, but may be a hand having three or more grip portions, and the adjustment of the hand width is only required to be able to adjust the intervals between the plurality of grip portions.

(3) In the above embodiment, the element P is exemplified as being quadrangular in side view, but may be circular in side view.

(4) In the above embodiment, the coil 32 is used to magnetize the grip portion 31, but a permanent magnet may be used to magnetize the grip portion. In this case, the magnetic force can be adjusted by moving the permanent magnet toward or away from the grip portion.

Description of the reference numerals

10: element holding device

20: the pickup robot 21: robot arm 22: support 23: base portion 24: connecting rod 25: joint

30: hand 31: gripping portion 32: coil 33: hand body 34: opposite surface

40: camera with camera body

50: the control unit 51: a holding position estimating unit 52: magnetic force adjustment unit 53: hand width adjustment unit 54: the arithmetic unit 55: storage unit 56: : hand width and element chart 57: element mass 58: magnetic force and mass diagram

60: tray 61: mounting part

P: element SP: small element LP: large elements.

Claims (11)

1. An element gripping device is provided with:

a hand part having a plurality of grip parts for gripping the element as a magnetic body;

a pick-up robot that transfers the component held by the hand; and

and a control unit for adjusting the magnetic force of the hand.

2. The component holding device according to claim 1, wherein,

the control unit obtains the number information of the held elements to correlate the magnetic force with the number information.

3. The element holding device according to claim 1 or 2, wherein,

the control unit adjusts a hand width, which is a distance between the grip units.

4. The component holding device according to claim 3, wherein,

the control unit obtains the number information of the held elements, and associates the magnetic force, the hand width, and the number information.

5. The component holding device according to claim 3 or 4, wherein,

the hand width is a distance between a pair of the holding parts facing each other.

6. The component holding device according to any one of claims 3 to 5, wherein,

the control unit includes: a magnetic force adjustment unit for adjusting the magnetic force of the hand; a hand width adjustment unit that adjusts the hand width; an operation unit that correlates the magnetic force, the hand width, and the number information; and a storage unit configured to store the magnetic force, the hand width, and the number information in which the magnetic force, the hand width, and the number information are associated.

7. The element gripping device according to any one of claims 1 to 6, wherein,

the hand has the plurality of grip portions as magnetic bodies and a coil for magnetizing the grip portions.

8. The component holding device according to claim 7, wherein,

the control unit is configured to magnetize the grip portion with a strong magnetic force for the element having a large mass, and magnetize the grip portion with a weak magnetic force for the element having a small mass.

9. The element gripping device according to any one of claims 1 to 8, wherein,

the hand holds the element placed on the placement unit after attracting the element by magnetizing the plurality of holding units.

10. The element gripping device according to any one of claims 1 to 9, wherein,

the hand is magnetized in an open state by the plurality of grip portions, and the hand is configured to attract the elements placed on the placement portion to the grip portions, and to grip the elements after the elements are gathered at one place by closing the plurality of grip portions.

11. The element gripping device according to any one of claims 1 to 10, wherein,

the hand holds a plurality of the elements with a magnetic force greater than the magnetic force used to hold a single element.