Hand mechanism

Abstract

To provide a technology capable of achieving both grip of an object and attraction of the object suitably.SOLUTION: A hand mechanism includes a plurality of finger parts that include a first finger link part including a fingertip, a first joint part provided at the end on a finger root side of the first finger link part, a second finger link part connected to the first finger link part via the first joint part, and a second joint part provided at the end on the finger root side of the second finger link part. At least one prescribed finger part of the plurality of finger parts is provided with an attraction mechanism. The attraction mechanism is provided on a back surface of the first finger link part in the prescribed finger, and attracts and holds the object by generating negative pressure.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to a technique for picking up an object with a plurality of finger portions.

Background Art

[0002] Conventionally, a hand mechanism that is attached to a robot arm or the like and grips an object with a plurality of finger portions is known. In addition, a configuration in which a suction mechanism for sucking an object is combined with the hand mechanism is also known. For example, Patent Document 1 and Patent Document 2 disclose a configuration in which a suction rod is provided in a base portion that supports a plurality of finger portions so as to be able to advance and retreat. Patent Document 3 discloses a configuration in which a suction cup is attached to the abdomen of a finger portion. Patent Document 4 discloses a configuration in which a suction cup of a suction mechanism is attached to a portion closer to the fingertip side than the first joint in a finger portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described prior art, the way of placing the object may be restricted. For example, in the configurations of Patent Documents 1, 2, and 4, when the object is stored in a storage box with a narrow frontage, when there is a wall above the object, or when the object is placed at a corner of the storage box, etc., it may be difficult to approach the suction mechanism to a position suitable for sucking the object. Further, in the configuration of Patent Document 3, when gripping an object with a small thickness, etc., only a part of the suction cup may be sandwiched between the object and the finger portion, and it may be difficult to grip the object in a stable posture.

[0005] An object of the present invention is to provide a technique capable of suitably achieving both gripping of an object and suction of the object.

Means for Solving the Problems

[0006] The present invention is a hand mechanism including a plurality of finger portions each including a first finger link portion including a fingertip, a first joint portion provided at an end portion on the proximal side of the first finger link portion, a second finger link portion connected to the first finger link portion via the first joint portion, and a second joint portion provided at an end portion on the proximal side of the second finger link portion. The hand mechanism includes a suction mechanism provided on the back surface of the first finger link portion of at least one predetermined finger portion among the plurality of finger portions, and sucking and holding an object by generating a negative pressure.

Effects of the Invention

[0007] According to the present invention, it is possible to provide a technique capable of suitably achieving both gripping of an object and suction of the object.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14A

Figure 14B

Figure 15

Figure 16A

Figure 16B

Figure 17A

Figure 17B

Figure 17C

Figure 18

Figure 19

Figure 20

[0009] The hand mechanism according to the present invention includes a plurality of finger portions. Each of the plurality of finger portions includes a first finger link portion including a fingertip, a first joint portion provided at an end portion on the proximal side of the first finger link portion, a second finger link portion connected to the first finger link portion via the first joint portion, and a second joint portion provided at an end portion on the proximal side of the second finger link portion. That is, each of the plurality of finger portions has at least two joint portions. Thereby, the form of each finger portion can be flexibly changed according to the situation where the object is placed or the shape of the object. For example, when approaching the hand mechanism to a position suitable for gripping an object, it becomes easy to change the form of each finger portion so as not to interfere with an object or the like existing around the object. Also, it becomes easy to change the form of each finger portion according to the shape or size of the object.

[0010] By the way, in a site where objects suitable for picking up by gripping and objects suitable for picking up by suction are mixed, a mechanism capable of achieving both gripping and suction is desired. In contrast, a method of incorporating a suction mechanism into the hand mechanism can be considered. However, when approaching the hand mechanism to a position suitable for gripping or sucking the object, it may become difficult to change the shape of the finger part so as not to interfere with an object or the like existing around the object, or the control at that time may become complicated. Further, when gripping the object, the suction mechanism may interfere with the surrounding object or the object, or when sucking the object, the finger part may interfere with the surrounding object or the object, making it difficult to grip or suck the object in a stable posture.

[0011] Therefore, in the hand mechanism according to the present invention, among the plurality of finger parts, a suction mechanism is provided on the back surface of the first finger link part of at least one finger part (predetermined finger part). That is, the suction mechanism is provided on the back surface of the fingertip of the predetermined finger part. The suction mechanism is a mechanism that sucks and holds an object by generating negative pressure. Here, when gripping an object with a plurality of finger parts including the predetermined finger part, the object can be gripped by bringing the ventral surface of the first finger link part of the predetermined finger part into contact with the object. Thereby, it becomes possible to grip the object without the suction mechanism interfering with the object. Further, the object can also be gripped using finger parts other than the predetermined finger part. Therefore, it becomes possible to grip the object in a stable posture.

[0012] In addition, since the plurality of finger portions according to the present invention have at least two joint portions, when approaching the hand mechanism to a position suitable for gripping or adsorbing an object, it is easy to change the form of the plurality of finger portions so that the adsorption mechanism or the finger portions do not interfere with an object or the like existing around the object. For example, when an object is stored in a storage box with a narrow frontage, by making a predetermined finger portion into a substantially linear form and inserting it into the storage box, the adsorption mechanism can be approached to a position suitable for adsorbing the object. At that time, for the finger portions other than the predetermined finger portion, it can be formed in a form that can be inserted into the storage box without interfering with the wall of the storage box or the like, or it can be formed in a form that is not inserted into the storage box without interfering with the wall of the storage box or the like. Thereby, it becomes possible to adsorb the object stored in the storage box with a narrow frontage in a stable posture. Further, when an object is placed at a corner portion of the storage box, for example, by making a predetermined finger portion into a substantially crank shape, the adsorption mechanism can be approached to a position suitable for adsorbing the object. Thereby, it becomes possible to adsorb the object placed at the corner portion of the storage box in a stable posture.

[0013] Therefore, according to the hand mechanism of the present invention, it is possible to suitably achieve both gripping of an object and adsorption of the object.

[0014] The adsorption mechanism according to the present invention may include an adsorption nozzle extending from the base side to the tip side of the first finger link portion at a predetermined finger portion, and a pad attached to the tip of the adsorption nozzle and formed to be contractible from the tip side to the base side of the first finger link portion. At that time, in the axial direction of the first finger link portion, the adsorption mechanism may be attached to the first finger link portion so that the position of the tip of the adsorption nozzle is located on the base side rather than the tip side end of the first finger link portion.

[0015] Here, when gripping an object with a plurality of finger parts including a predetermined finger part, there is a possibility that the pad may interfere with the floor or the like on which the object is placed while approaching the predetermined finger part to a position suitable for gripping the object. On the other hand, if the pad is formed so as to be contractible from the fingertip side to the base side of the first finger link part, even if the pad interferes with the floor or the like during the above approach, by contracting the pad, the above approach can be properly continued. Further, since the position of the tip of the suction nozzle is retracted in the base direction from the end of the fingertip side of the first finger link part, it is also suppressed that the tip of the suction nozzle interferes with the floor or the like during the above approach. As a result, even when gripping an object with a plurality of finger parts including a predetermined finger part, it becomes possible to approach the predetermined finger part to a position suitable for gripping the object. Even in the case of gripping, it is possible to approach the predetermined finger part to a position suitable for gripping the object.

[0016] In addition, when the above-described pad is in a non-contracted state, the suction mechanism may be attached to the first finger link part so that the position of the front end surface of the pad in the axial direction of the first finger link part protrudes in the fingertip direction from the end of the fingertip side of the first finger link part. Thereby, when adsorbing an object by the suction mechanism, the front end surface of the pad can be brought into contact with the object prior to the tip of the first finger link part. That is, when approaching the suction mechanism to a position suitable for adsorbing the object, it is possible to suppress the fingertip portion of the predetermined finger part (the end portion on the fingertip side in the first finger link part) from interfering with the object. As a result, it becomes possible to adsorb the object in a more reliable and stable posture.

[0017] Here, when the pad is in a non - contracted state, the adsorption mechanism is attached to the first finger link portion such that the position of the tip surface of the pad in the axial direction of the first finger link portion protrudes in the fingertip direction from the end portion on the fingertip side of the first finger link portion. When an external force different from that during the adsorption of the object is applied to the pad, the pad may be formed such that the position of the tip surface of the pad in the axial direction of the first finger link portion contracts to a position equivalent to the end portion on the fingertip side of the first finger link portion. Thereby, when gripping an object with a plurality of finger portions including a predetermined finger portion, it is possible to suppress the pad from obstructing the approach while approaching the predetermined finger portion to a position suitable for gripping the object.

[0018] Here, the hand mechanism according to the present invention may be configured to be switchable between a first mode for adsorbing and picking up an object by an adsorption mechanism of a predetermined finger portion, and a second mode for gripping and picking up an object by at least two finger portions among a plurality of finger portions. Thereby, even at a site where objects suitable for picking up by gripping and objects suitable for picking up by adsorption are mixed, it becomes possible to efficiently pick up those objects.

[0019] In addition, in the above - described first mode, a predetermined finger portion functions as an adsorption finger portion for adsorbing the object after bringing the pad of the adsorption mechanism into contact with the object, and at least one finger portion among the finger portions other than the predetermined finger portion may function as a holding finger portion for holding the posture of the object adsorbed by the predetermined finger portion. Thereby, the posture of the object adsorbed by the adsorption mechanism can be stabilized. As a result, in the process of lifting the object and the process of moving the lifted object to a predetermined placement position, etc., it is possible to suppress the posture of the object from becoming unstable.

[0020] <Example> Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment are not intended to limit the technical scope of the invention only to these, unless otherwise specified.

[0021] Here, a case where the hand mechanism according to the present invention is applied to a robot arm will be described. FIG. 1 is a diagram showing a schematic configuration of the robot arm according to this embodiment. The robot arm 1 includes a hand mechanism 2, an arm mechanism 3, and a pedestal portion 4. The hand mechanism 2 is attached to one end of the arm mechanism 3. Further, the other end of the arm mechanism 3 is attached to the pedestal portion 4. The hand mechanism 2 includes a base portion 20 connected to the arm mechanism 3, and a plurality of finger portions 21 (in the example shown in FIG. 1, four finger portions 21) movably supported by the base portion 20. The detailed configuration of the hand mechanism 2 will be described later.

[0022] (Arm mechanism) The arm mechanism 3 includes a first arm link portion 31, a second arm link portion 32, a third arm link portion 33, a fourth arm link portion 34, a fifth arm link portion 35, and a connecting member 36. The base portion 20 of the hand mechanism 2 is connected to a first joint portion 30a formed at one end side of the first arm link portion 31 of the arm mechanism 3. A motor (not shown) for rotating the hand mechanism 2 with respect to the first arm link portion 31 around the axis of the first arm link portion 31 is provided at the first joint portion 30a. The other end side of the first arm link portion 31 is connected to one end side of the second arm link portion 32 at a second joint portion 30b. The first arm link portion 31 and the second arm link portion 32 are connected such that their central axes intersect perpendicularly. A motor (not shown) for rotating the first arm link portion 31 around the axis of the second arm link portion 32 with the other end side as the center with respect to the second arm link portion 32 is provided at the second joint portion 30b. Further, the other end side of the second arm link portion 32 is connected to one end side of the third arm link portion 33 at a third joint portion 30c. A motor (not shown) for relatively rotating the second arm link portion 32 with respect to the third arm link portion 33 is provided at the third joint portion 30c.

[0023] Similarly, the other end side of the third arm link portion 33 is connected to one end side of the fourth arm link portion 34 at the fourth joint portion 30d. Also, the other end side of the fourth arm link portion 34 is connected to the fifth arm link portion 35 at the fifth joint portion 30e. And, a motor (not shown) for relatively rotating the third arm link portion 33 with respect to the fourth arm link portion 34 is provided at the fourth joint portion 30d. Also, a motor (not shown) for relatively rotating the fourth arm link portion 34 with respect to the fifth arm link portion 35 is provided at the fifth joint portion 30e. Further, the fifth arm link portion 35 is connected to a connecting member 36 vertically arranged from the pedestal portion 4 at the sixth joint portion 30f. The fifth arm link portion 35 and the connecting member 36 are connected such that their respective central axes are coaxial. And, a motor (not shown) for rotating the fifth arm link portion 35 around the axes of the fifth arm link portion 35 and the connecting member 36 is provided at the sixth joint portion 30f. According to such a configuration, for example, the arm mechanism 3 can be made into a mechanism having six degrees of freedom.

[0024] (Hand mechanism) Next, the configuration of the hand mechanism 2 will be described with reference to FIGS. 2 to 11. The hand mechanism 2 in this example is configured to be switchable between a mode (first mode) of gripping and picking up an object such as a workpiece and a mode (second mode) of adsorbing and picking up the object.

[0025] FIG. 2 is a perspective view of the hand mechanism 2. FIG. 3 is a top view of the hand mechanism 2. Note that the arrows in FIG. 3 indicate the rotatable ranges of the respective finger portions 21. As shown in FIGS. 2 and 3, in the hand mechanism 2, four finger portions 21 are arranged on a circumference centered on the axis in the longitudinal direction of the hand mechanism 2 (the direction perpendicular to the paper surface in FIG. 3) at equal angular intervals (that is, at 90 deg intervals). In this example, among the four finger portions 21, adsorption mechanisms 600 are provided on two finger portions 21 (predetermined finger portions). Note that the structures other than the adsorption mechanisms 600 are common to all of the four finger portions 21. However, the operations of the four finger portions 21 are controlled independently of each other.

[0026] Figures 4 to 7 are diagrams for explaining the configuration of the finger portion 21. In Figures 4 to 7, the configuration of a predetermined finger portion 21 among the four finger portions 21 is described. Figure 4 is a side view of the predetermined finger portion 21. Note that in Figure 4, the base portion 20 is shown in a transparent state. Further, Figure 5 is a view of the tip end side of the finger portion 21 as seen from the direction of arrow A in Figure 4. Also, in Figures 4 and 5, a part of the second finger link portion 212 of the finger portion 21, which will be described later, is shown in a transparent state, and the internal structure of the second finger link portion 212 is also shown.

[0027] As shown in Figures 2 and 4, each finger portion 21 has a first finger link portion 211, a second finger link portion 212, and a base end portion 213. A first joint portion 22 is provided between the first finger link portion 211 and the second finger link portion 212 and is formed so as to be bendable and extendable. A second joint portion 23 is provided between the second finger link portion 212 and the base end portion 213 and is formed so as to be bendable and extendable. The base end portion 213 of the finger portion 21 is connected to the base portion 20 in a rotatable state about an axis in the longitudinal direction of the finger portion 21 (the direction perpendicular to the paper surface in Figure 3).

[0028] As shown in Figure 4, the base portion 20 incorporates a second motor 52 and a third motor 53. The second motor 52 is a motor for bending and extending the second joint portion 23, as shown in Figure 6. The third motor 53 is a motor for rotationally driving the entire finger portion 21 within the range indicated by the arrow in Figure 3. Also, as shown in Figure 5, the second finger link portion 212 incorporates a first motor 51. This first motor 51 is a motor for bending and extending the first joint portion 22, as shown in Figure 7.

[0029] The structure described so far is not specific to a predetermined finger portion 21 but is common to the four finger portions 21.

[0030] Next, FIGS. 8 to 11 are diagrams for explaining the configuration of the suction mechanism 600 provided on a predetermined finger portion 21. FIGS. 8 and 9 are side views of the suction mechanism 600. Note that in FIG. 8, the nozzle body 601 described later is shown in a transparent state. Further, in FIG. 9, in addition to the nozzle body 601, the pad 603 described later is also shown in a transparent state.

[0031] As shown in FIG. 4, the suction mechanism 600 is attached to the back surface of the fingertip (the back surface 216 of the first finger link portion 211) of a predetermined finger portion 21. Thus, when gripping an object with a plurality of finger portions 21 including the predetermined finger portion 21, it is possible to grip the object using the ventral surface of the fingertip (the ventral surface 215 of the first finger link portion 211) of the predetermined finger portion 21. The suction mechanism 600 is a mechanism for sucking an object using negative pressure. Such a suction mechanism 600 is configured to include a nozzle body 601, a suction nozzle 602, and a pad 603, as shown in FIGS. 8 and 9. The nozzle body 601 is a housing in which a negative pressure passage 601A is formed inside, and is attached to the back surface 216 of the first finger link portion 211. The suction nozzle 602 is a cylindrical nozzle protruding from the nozzle body 601, and the inside of the suction nozzle 602 communicates with the negative pressure passage 601A. The suction nozzle 602 in this example is formed to extend from the base side toward the fingertip side along the axial direction of the first finger link portion 211. The suction nozzle 602 may be integrally formed with the nozzle body 601, or may be fixed to the nozzle body 601 by a screw mechanism or the like. Further, a pad 603 is placed on the suction nozzle 602. The pad 603 is a cylindrical body formed in a bellows shape, and is manufactured from a flexible material such as silicone rubber. Thereby, when the suction mechanism 600 sucks an object, the tip surface of the pad 603 can be brought into close contact with the object. Such a pad 603 is detachable from the suction nozzle 602, as shown in FIG. 8.

[0032] The adsorption mechanism 600 configured as described above is connected to a vacuum pump via a vacuum pipe 610 as shown in FIG. 4. Specifically, the negative pressure passage 601A of the nozzle body 601 is connected to the vacuum pump via the vacuum pipe 610. The vacuum pump is a pump for sucking gas. The vacuum pump may be provided separately from the robot arm 1 or may be provided on the pedestal portion 4 or the like. When such a vacuum pump is operated, the air inside the negative pressure passage 601A, inside the suction nozzle 602, and inside the pad 603 can be sucked into the vacuum pump via the vacuum pipe 610. As a result, a negative pressure can be generated at the tip of the pad 603. Therefore, by generating a negative pressure at the tip of the pad 603 with the tip surface of the pad 603 in close contact with the object, the object can be adsorbed to the tip of the pad 603. Note that An electromagnetic valve (hereinafter sometimes referred to as a "negative pressure electromagnetic valve") 620 for conducting (opening) or blocking (closing) the internal passage of the vacuum pipe 610 may be provided in the middle of the vacuum pipe 610. Thereby, by opening and closing the negative pressure electromagnetic valve 620 while maintaining the state in which the vacuum pump is operated, the generation and cancellation of the negative pressure at the tip of the pad 603 can be quickly switched.

[0033] Figures 10 and 11 are diagrams for explaining the positional relationship between each part of the suction mechanism 600 and the first finger link part 211. FIG. 10 is a diagram showing the case where the pad 603 of the suction mechanism 600 is not contracted. FIG. 11 is a diagram showing the case where the pad 603 of the suction mechanism 600 is in a predetermined contracted state. The "state where the pad 603 is not contracted" referred to here means a state where no external force acts on the pad 603 and the axial length of the pad 603 is the free length. Further, the "predetermined contracted state" referred to here means the state where the pad 603 can be most contracted when adsorbing and holding an object, and is a state where the degree of contraction is smaller than the state where the pad 603 is contracted to the limit according to the physical properties of the pad 603. Note that C1 in FIGS. 10 and 11 is the center when the first finger link part 211 is rotated in the bending direction and the extending direction as shown in FIG. 7 described above. Further, Pc1 in FIGS. 10 and 11 is a virtual circle centered on C1 and having a radius equal to the distance from C1 to the tip (the end on the fingertip side) of the first finger link part 211.

[0034] As shown in FIGS. 10 and 11, the size of each part of the suction mechanism 600 and / or the attachment position to the first finger link part 211 in this example are determined such that the tip of the suction nozzle 602 is located inside the circle Pc1. Thereby, the position of the tip of the suction nozzle 602 in the axial direction of the first finger link part 211 is a position retracted toward the base end side from the tip of the first finger link part 211. Also, as shown in FIG. 10, the size of each part of the suction mechanism 600 and / or the attachment position to the first finger link part 211 in this example are determined such that the front end surface of the pad 603 is located outside the circle Pc1 when the pad 603 is not contracted. Thereby, when the pad 603 is not contracted, the position of the front end surface of the pad 603 in the axial direction of the first finger link part 211 is a position protruding from the tip of the first finger link part 211. Further, as shown in FIG. 11, the size of each part of the suction mechanism 600 and / or the attachment position to the first finger link part 211 in this example are determined such that the front end surface of the pad 603 is located on the circumference of the circle Pc1 or outside the circle Pc1 when the pad 603 is in a predetermined contracted state. Thereby, when the pad 603 is in a predetermined contracted state, the position of the front end surface of the pad 603 in the axial direction of the first finger link part 211 is a position equivalent to the tip of the first finger link part 211 or a position protruding in the fingertip direction. Here, the “predetermined contracted state” is a state in which the degree of contraction is smaller than the state of being contracted to the limit according to the physical properties of the pad 603 as described above. Therefore, even when the size of each part of the suction mechanism 600 and / or the attachment position to the first finger link part 211 are determined such that the front end surface of the pad 603 is located outside the circle Pc1 when the pad 603 is in a predetermined contracted state, when an external force different from that during suction of the object is applied to the pad 603, the pad 603 can contract until the position of the front end surface of the pad 603 becomes a position on the circumference of the circle Pc1 (a position where the position of the front end surface of the pad 603 in the axial direction of the first finger link part 211 becomes equivalent to the tip of the first finger link part 211).

[0035] (Base part) The pedestal portion 4 is a pedestal for supporting the arm mechanism 3. The pedestal portion 4 incorporates various control devices such as a control device for controlling the arm mechanism 3, a control device for controlling the hand mechanism 2, and a control device for controlling the suction mechanism 600. By these control devices, a motor for driving each joint portion of the arm mechanism 3, a motor for driving each joint portion of the hand mechanism 2, a negative pressure solenoid valve 620 of the hand mechanism 2, etc. are controlled. Note that the pedestal portion 4 may incorporate the above-described vacuum pump.

[0036] (Operational effects of the present embodiment) Here, the operation and effect of the present embodiment will be described with reference to FIGS. 12 to 19. FIG. 12 is a diagram for explaining a basic operation example of the hand mechanism 2 when adsorbing an object. In the example shown in FIG. 12, an object 10 having a rectangular cross section is placed on the bottom 70 of the storage box 80. In such a case, first, the first motor 51, the second motor 52, and the third motor 53 of each of the two predetermined finger portions 21 are controlled so that the front end surfaces of the pads 603 in each finger portion 21 are parallel to the upper surface of the object 10. Next, the arm mechanism 3 is controlled so that the adsorption mechanism 600 descends to a position suitable for adsorbing the object 10 (for example, a position where the front end surface of the pad 603 is in close contact with the upper surface of the object 10). When these controls are performed, as shown in FIG. 12, the front end surface of the pad 603 of the adsorption mechanism 600 contacts the upper surface of the object 10 before the predetermined finger portion 21. This is because, as shown in FIG. 10 described above, the position of the front end surface of the pad 603 in a state where the pad 603 is not contracted protrudes in the fingertip direction from the tip of the first finger link portion 211. Then, when the adsorption mechanism 600 moves to a position suitable for adsorbing the object 10, the negative pressure solenoid valve 620 is opened. As a result, the air inside the pad 603 is sucked into the vacuum pump through the negative pressure passage 601A in the adsorption nozzle 602 and the vacuum pipe 610. As a result, a negative pressure is generated at the tip of the pad 603. When a negative pressure is generated at the tip of the pad 603, the object 10 is sucked toward the base side of the first finger link portion 211, and accordingly, the pad 603 contracts, but such a suction operation is not inhibited by the predetermined finger portion 21. This is because, as shown in FIG. 11 described above, the position of the front end surface of the pad 603 when the pad 603 is in a predetermined contracted state is at a position equivalent to the tip of the first finger link portion 211 or a position protruding in the fingertip direction. As a result, the adsorption mechanism 600 can be approached to a position suitable for adsorbing the object 10. Therefore, the object 10 can be adsorbed and held in a stable posture.

[0037] Next, a basic operation example of the hand mechanism 2 when gripping an object will be described with reference to FIG. 13. In the example shown in FIG. 13, an object 10 having a rectangular cross section is placed on the bottom 70 of the storage box 80. In such a case, first, the first motor 51, the second motor 52, and the third motor 53 in each of the two predetermined finger portions 21 are controlled so that the distance between the ventral surfaces (the ventral surface 215 of the first finger link portion 211) at the fingertips of the two predetermined finger portions 21 is wider than the width of the object 10 and the heights of those fingertips are the same. Next, the arm mechanism 3 is controlled so that the positions of the fingertips of the two predetermined finger portions 21 are lowered to positions suitable for gripping the object 10. Then, when the positions of the fingertips of the two predetermined finger portions 21 are lowered to positions suitable for gripping the object 10, the first motor 51, the second motor 52, and the third motor 53 in each finger portion 21 are controlled so that the distance between the fingertips of the two predetermined finger portions 21 is narrowed. When these controls are performed, as shown in FIG. 13, the ventral surfaces (the ventral surface 215 of the first finger link portion 211) of the fingertips in the two predetermined finger portions 21 come into contact with the opposing side surfaces of the object 10, respectively. Here, the suction mechanism 600 in this example is attached to the back surface (the back surface 216 of the first finger link portion 211) of the fingertip in the predetermined finger portion 21. Therefore, in the above-described gripping operation, the suction mechanism 600 does not interfere with the object 10. In the case where the thickness of the object 10 is thin or the like, the pad 603 of the suction mechanism 600 may contact the bottom 70 of the storage box on the way of lowering the hand mechanism 2 to a position suitable for gripping the object 10. However, since the pad 603 in this example is configured to be contractible to a position where the position of the tip surface of the pad 603 in the axial direction of the first finger link portion 211 becomes equivalent to the tip of the first finger link portion 211, the pad 603 does not inhibit the above-described lowering operation. Also, as shown in FIGS. 10 and 11 described above, since the position of the tip of the suction nozzle 602 is retracted in the direction of the base of the finger from the tip of the first finger link portion 211, the suction nozzle 602 does not interfere with the bottom 70 of the storage box. As a result, even when gripping the object 10 using the predetermined finger portion 21 to which the suction mechanism 600 is attached, the finger portion 21 can be approached to a position suitable for gripping the object 10. Therefore, it is possible to grip the object 10 in a stable posture.

[0038] Next, an operation example of the hand mechanism 2 when picking up an object from a storage box with an outlet provided on the side will be described with reference to FIG. 14A. In the example shown in FIG. 14A, the object 10 is stored in a storage box 80 having an outlet provided on the side. In such a case, first, the arm mechanism 3 is controlled so that the base portion 20 becomes horizontal (lateral). Also, the first motor 51, the second motor 52, and the third motor 53 of the predetermined finger portion 21 are controlled so that the second finger link portion 212 becomes horizontal and the first finger link portion 211 becomes vertically downward. That is, the first motor 51, the second motor 52, and the third motor are controlled so that the predetermined finger portion 21 assumes a substantially L-shaped form. Subsequently, the arm mechanism 3 is controlled to move the hand mechanism 2 horizontally. As a result, the fingertips of the predetermined finger portion 21 are inserted into the storage box 80, and the front end surface of the pad 603 is moved above the object 10. After moving the front end surface of the pad 603 above the object 10, the arm mechanism 3 is controlled so that the hand mechanism 2 descends along the vertical direction. When these controls are performed, as shown in FIG. 14A, the suction mechanism 600 is moved to a position suitable for sucking the object 10 (a position where the front end surface of the pad 603 is in close contact with the upper surface of the object 10). When the front end surface of the pad 603 moves to a position in close contact with the upper surface of the object 10, the negative pressure solenoid valve 620 is opened. As a result, the object 10 can be adsorbed to the suction mechanism 600. Thereafter, the arm mechanism 3 is controlled so that the hand mechanism 2 rises, and then the arm mechanism 3 is controlled so that the hand mechanism 2 moves horizontally in the direction opposite to the above, whereby the object 10 is taken out from the storage box 80. Therefore, even when the object 10 is stored in the storage box 80 having an outlet provided on the side, the suction mechanism 600 can be approached to a position suitable for sucking the object 10.

[0039] In addition, after the object 10 is taken out from the storage box 80 as shown in FIG. 14A, the finger portions 21 other than the predetermined finger portion 21 may function as holding finger portions for stabilizing the posture of the object 10. For example, as shown in FIG. 14B, the fingertips (the first finger link portions 211) of the finger portions 21 other than the predetermined finger portion 21 may be brought into contact with the lower surface of the object 10. Thereby, during the movement of the picked-up object 10 to the placement position, it is possible to suppress the posture of the object 10 from becoming unstable.

[0040] Next, an operation example of the hand mechanism 2 when picking up an object placed along the wall inside the storage box will be described with reference to FIG. 15. In the example shown in FIG. 15, the object 10 is stored in a state of being in contact with the side wall surface inside the storage box 80. In such a case, first, the first motor 51, the second motor 52, and the third motor 53 of the predetermined finger portion 21 are controlled so that the front end surface of the pad 603 becomes horizontal and the predetermined finger portion 21 forms a substantially V-shaped configuration. Subsequently, the arm mechanism 3 is controlled so that the front end surface of the pad 603 moves above the object 10. After moving the front end surface of the pad 603 above the object 10, the arm mechanism 3 is controlled so that the hand mechanism 2 descends along the vertical direction. When these controls are performed, as shown in FIG. 15, the suction mechanism 600 is moved to a position suitable for sucking the object 10 (a position where the front end surface of the pad 603 is in close contact with the upper surface of the object 10). When the front end surface of the pad 603 moves to a position in close contact with the upper surface of the object 10, the negative pressure solenoid valve 620 is opened. Thereby, the object 10 can be adsorbed to the suction mechanism 600. Thereafter, by controlling the arm mechanism 3 so that the hand mechanism 2 ascends, the object 10 placed along the wall of the storage box 80 is taken out from the storage box 80. Therefore, even when the object 10 is placed along the wall inside the storage box 80, the suction mechanism 600 can be approached to a position suitable for sucking the object 10. In addition, after the object 10 is taken out from the storage box 80, similar to FIG. 14B, the finger portions 21 other than the predetermined finger portion 21 may function as holding finger portions for stabilizing the posture of the object 10.

[0041] Next, the case of picking up an object placed at a corner portion inside the storage box will be described with reference to FIGS. 16A and 16B. FIG. 16A is a side view of the state of the hand mechanism 2 when picking up the object 10. FIG. 16B is a top view of the state of the hand mechanism 2 when picking up the object 10. In FIGS. 16A and 16B, the object 10 is assumed to have an upper surface with a relatively large area. Also, although the object 10 in FIGS. 16A and 16B has a circular cross section, it may have a rectangular cross section. In the example shown in FIGS. 16A and 16B, the object 10 is placed at a corner portion inside the storage box 80. In such a case, first, for each of the two predetermined finger portions 21, similar to the example shown in FIG. 15 described above, the first motor 51, the second motor 52, and the third motor 53 of each finger portion 21 are controlled so that the tip surface of the pad 603 becomes horizontal and the predetermined finger portion 21 takes a substantially V-shaped form. Subsequently, the arm mechanism 3 is controlled so that the tip surfaces of the pads 603 of the two predetermined finger portions 21 move above the object 10. After moving the tip surfaces of the two pads 603 above the object 10, the arm mechanism 3 is controlled so that the hand mechanism 2 descends along the vertical direction. When these controls are performed, as shown in FIG. 16A, the suction mechanisms 600 of the two predetermined finger portions 21 are moved to a position suitable for sucking the object 10 (a position where the tip surfaces of both of the two pads 603 are in close contact with the upper surface of the object 10). When both of the two pads 603 move to a position in close contact with the upper surface of the object 10, the negative pressure solenoid valve 620 is opened. Thereby, the object 10 can be sucked by the two suction mechanisms 600 attached to the two predetermined finger portions 21. Thereafter, by controlling the arm mechanism 3 so that the hand mechanism 2 ascends, the object 10 placed at the corner portion of the storage box 80 is taken out from the storage box 80. Therefore, even when the object 10 is placed at a corner portion inside the storage box 80, the suction mechanism 600 can be approached to a position suitable for sucking the object 10.

[0042]

[0043] ​Next, an operation example of the hand mechanism 2 when picking up an object placed obliquely in the storage box will be described with reference to FIGS. 17A to 17C. FIG. 17A is a diagram showing a state in which the object 10 is adsorbed by the adsorption mechanism 600. FIG. 17B is a diagram showing a state in which the object 10 taken out from the storage box is held only by the adsorption mechanism 600. FIG. 17C is a diagram showing a state in which the object 10 taken out from the storage box is held by the adsorption mechanism 600 and the holding fingers.

[0044] In the example shown in FIG. 17A, the plate-shaped object 10 is stored in the storage box 80 in an obliquely inclined state. In such a case, first, the arm mechanism 3 and the hand mechanism 2 (the first motor 51, the second motor 52, and the third motor 53 of the predetermined finger portion 21) are controlled so that the front end surface of the pad 603 in the predetermined finger portion 21 is parallel to the upper surface of the object 10 and the front end surface contacts the upper surface of the object 10. When such control is performed, as shown in FIG. 17A, the adsorption mechanism 600 is moved to a position suitable for adsorbing the object 10 (a position where the front end surface of the pad 603 is in close contact with the upper surface of the object 10). When the front end surface of the pad 603 moves to a position in close contact with the upper surface of the object 10, the negative pressure solenoid valve 620 is opened. Thereby, the object 10 can be adsorbed to the adsorption mechanism 600. Thereafter, the arm mechanism 3 is controlled so that the hand mechanism 2 rises, and as shown in FIG. 17B, the object 10 is taken out from the storage box 80. After the object 10 is taken out from the storage box 80, as shown in FIG. 17C, the hand mechanism 2 is controlled so that the fingertips (the first finger link portion 211) of the finger portions 21 other than the predetermined finger portion 21 contact the surface of the object 10 opposite to the adsorption surface of the pad 603. Thereby, the object 10 can be held by the adsorption by the adsorption mechanism 600 and the gripping by the finger portions 21 other than the predetermined finger portion 21 and the pad 603. As a result, even when the object 10 is stored in the storage box 80 in an obliquely inclined state, the adsorption mechanism 600 can be approached to a position suitable for adsorbing the object 10, and the object 10 taken out from the storage box 80 can be more reliably held continuously.

[0045] Next, the case of picking up a spherical object will be described with reference to FIG. 18. In the example shown in FIG. 18, the object 10 has a spherical shape. In such a case, the first motor 51, the second motor 52, and the third motor 53 of each finger portion 21 are controlled so that each of the two predetermined finger portions 21 forms a substantially V-shaped configuration. At this time, the first motor 51, the second motor 52, and the third motor 53 of each finger portion 21 are controlled such that the fingertip (first finger link portion 211) of one finger portion 21 bends toward the other finger portion 21, and the fingertip (first finger link portion 211) of the other finger portion 21 bends toward one finger portion 21. When the pad 603 of a predetermined finger portion 21 is brought into contact with the surface of the object 10 in the state controlled in the above-described configuration, the two pads 603 can be brought into close contact with the surface of the object 10. Then, when the negative pressure solenoid valve 620 of each finger portion 21 is opened in a state where the two pads 603 are in close contact with the surface of the object 10, the object 10 is adsorbed by the adsorption mechanism 600 of the two predetermined finger portions 21. Thereby, even a spherical object 10 can be picked up in a stable posture.

[0046] Next, the case of picking up two objects 10 simultaneously will be described with reference to FIG. 19. In the example shown in FIG. 19, two objects 10 are arranged side by side. In such a case, first, the arm mechanism 3 and the hand mechanism 2 are controlled such that the pad 603 of one finger portion 21 among the two predetermined finger portions 21 is positioned above one object 10, and the pad 603 of the other finger portion 21 is positioned above the other object 10. Next, the arm mechanism 3 is controlled so that the hand mechanism 2 descends to a position where the front end surface of one pad 603 is in close contact with the upper surface of one object 10 and the front end surface of the other pad 603 is in close contact with the upper surface of the other object 10. When the front end surface of each of the two pads 603 is in close contact with the upper surface of the object 10 to be adsorbed, the negative pressure solenoid valve 620 of each finger portion 21 is opened. As a result, the adsorption mechanisms 600 of the two predetermined finger portions 21 can adsorb different objects from each other. As a result, it becomes possible to pick up two objects 10 simultaneously.

[0047] As described above, each of the various operations is realized by determining the size and mounting position of the suction mechanism 600 as shown in FIGS. 10 and 11 described above, and by having a predetermined finger portion 21 with two or more degrees of freedom.

[0048] Therefore, according to the hand mechanism 2 in the present embodiment, it is possible to suitably achieve both the gripping of the object and the suction of the object.

[0049] <Other embodiments> In the above-described embodiment, an example in which the suction mechanism 600 is provided on two predetermined finger portions 21 out of the four finger portions 21 provided in the hand mechanism 2 has been described. However, as shown in FIG. 20, the suction mechanism 600 may be provided on all of the four finger portions 21. Thereby, the degree of freedom when sucking the object can be increased. For example, when picking up a relatively heavy object, it is also possible to pick up the object 10 by using the suction mechanisms 600 of three or more finger portions 21. At that time, among the four finger portions 21, it is also possible to suck the suction mechanism 600 of a part of the finger portions 21 onto the upper surface of the object 10 and suck the suction mechanism 600 of the remaining finger portions 21 onto the side surface of the object 10. In addition, it is also possible to pick up three or more objects 10 at the same time. Therefore, the method of picking up the object 10 can be flexibly changed according to various conditions including the above-described examples.

[0050] In the above-described embodiment, a hand mechanism having four finger portions has been exemplified. However, the number of finger portions is not limited to four, and can be appropriately changed according to the usage conditions of the hand mechanism or the like as long as it is two or more. Further, in the above-described embodiment, a configuration in which the suction mechanism is provided on two of the four finger portions has been exemplified. However, the number of finger portions on which the suction mechanism is provided can be appropriately changed according to the usage conditions of the hand mechanism or the like as long as it is one or more.

Explanation of reference numerals

[0051] 1 ··· Robot arm, 2 ··· Hand mechanism, 20 ··· Base portion, 21 ··· Finger portion, 22... the first joint part, 23... the second joint part, 211... the first finger link part, 212... the second finger link part, 213... the base end part, 215... the ventral surface, 216... the dorsal surface, 3... the arm mechanism, 4... the pedestal part, 51... the first motor, 52... the second motor, 53... the third motor, 600... the suction mechanism, 601... the nozzle body, 601A... the negative pressure passage, 602... the suction nozzle, 603... the pad, 610... the vacuum pipe, 620... the negative pressure solenoid valve

Claims

1. A first finger link portion including a fingertip, A first joint portion provided at the proximal end of the first finger link portion, A second finger link portion connected to the first finger link portion via the first joint portion, A second joint portion provided at the proximal end of the second finger link portion, A hand mechanism including a plurality of finger portions, An adsorption mechanism is provided on the back surface of the first finger link portion of at least one predetermined finger portion among the plurality of finger portions, and adsorbs and holds an object by generating negative pressure. The adsorption mechanism is An adsorption nozzle extending from the proximal end side to the fingertip side of the first finger link portion, A pad attached to the tip of the adsorption nozzle and formed to be contractible from the fingertip side to the proximal end side of the first finger link portion, Comprising In the axial direction of the first finger link portion, the adsorption mechanism is attached to the first finger link portion such that the position of the tip of the adsorption nozzle is located on the proximal end side rather than the fingertip side end of the first finger link portion. Hand mechanism.

2. When the pad is in a non-contracted state, the adsorption mechanism is attached to the first finger link portion such that the position of the front end surface of the pad in the axial direction of the first finger link portion protrudes in the fingertip direction rather than the fingertip side end of the first finger link portion. The hand mechanism according to Claim 1.

3. When an external force different from the time of adsorbing an object is applied to the pad, the pad is formed such that the position of the front end surface of the pad in the axial direction of the first finger link portion contracts to a position equivalent to the fingertip side end of the first finger link portion. The hand mechanism according to Claim 2.

Images