JP6693190B2 - Hand mechanism - Google Patents

Description

  The present invention relates to a hand mechanism for gripping an object to be gripped.

  Conventionally, a structure close to that of a human finger has been adopted for a robot hand, and attempts have been made to grasp various objects. For example, in a hand mechanism including a plurality of finger portions for stably gripping a large object to a small object, the plurality of finger portions respectively connect the distal phalanx portion and the middle phalanx portion adjacent to the distal phalanx portion. It may be composed of a plurality of bone parts including. Then, since the distal phalanx can be rotated in a predetermined angle range in two directions of the medial direction and the lateral direction from a state in which the distal phalanx is straight with respect to the middle phalanx, the human finger `` The operation close to the "pinching" operation is realized.

  On the other hand, in order to approximate the motion of the robot hand to the motion of a human finger, it is possible to adopt a configuration in which each finger is provided with a plurality of joints and each joint is driven by a corresponding actuator. However, contrary to this, the size of the robot hand is increased and the output of the actuator is restricted as a result of limiting the size of the robot hand. The technique of Patent Document 1 has been developed as a technique for eliminating such disadvantages. In the technique disclosed in Patent Document 1, an actuator is provided in the arm portion on the proximal end side of the robot hand, and a driving force transmission member that transmits the output of the actuator to the hand portion on the distal end side and the driving force transmitted by the driving force transmission member. The pulley member is disposed on the hand side. In this way, the driving source is provided in the arm portion apart from the hand portion, and the driving force is transmitted to the hand portion, whereby the size of the robot hand is reduced.

Japanese Patent No. 5482664

  In the hand mechanism of Patent Document 1, a driving unit such as an actuator is arranged on an arm portion apart from the hand main body for downsizing of the hand mechanism, and the driving force is transmitted to the hand unit side via various transmission mechanisms. It is transmitted to the fingers. Therefore, although the hand mechanism itself can be reduced in weight, the hand mechanism itself has a mechanically complicated structure due to the interposition of the transmission mechanism, which is not always preferable for maintenance. In constructing the hand mechanism, it is preferable to reduce the size of the entire mechanism including the actuator as well as the mechanical structure thereof, and the above Patent Document 1 provides an essential solution for reducing the size of the hand mechanism. I can't say.

  In addition, originally, in order to realize various gripping operations, preferably gripping operations similar to those of a human hand, the hand mechanism is provided with joints required for the fingers included in the hand mechanism, In order to realize the gripping action, it is necessary to supply a driving force around each joint, and as a result, it is necessary to mount a corresponding number of joints and actuators for supplying the driving force in the hand mechanism. However, in reality, the conventional technique has not shown a sufficient solution for enabling the miniaturization of the hand mechanism with the actuator mounted.

  The present invention has been made in view of the above problems, and an object of the present invention is to reduce the size of a hand mechanism that enables a gripping operation that is as close to a human gripping operation as possible.

  In the present invention, in order to solve the above-mentioned problems, an actuator for supplying a driving force and an arrangement of a drive transmitting portion of a finger driven by the driving force are provided in a limited area of a main body of a hand mechanism. I paid attention. In order to achieve both miniaturization of the hand mechanism and making the gripping motion as close as possible to the gripping motion of a human being, the combination of the minimum actuator and the drive transmission unit requires This is because it is essential to realize the gripping operation.

  More specifically, the present invention is a hand mechanism configured to be capable of gripping an object to be grasped by a plurality of fingers, and capable of supporting the object to be grasped when grasping the object to be grasped in a first grasping state. A first support part, and a second support part different from the first support part and capable of supporting the gripping target when gripping the gripping target in the second gripping state. Around the hand body portion, which is attached to the hand body portion and has a thumb portion between the holding position in the first holding state and the holding position in the second holding state by the first actuator. Attached to the hand main body portion, and a thumb portion having a second drive transmission portion that bends the thumb portion with respect to the hand main body portion by a second actuator, and a third actuator that is attached to the hand main body portion. The operating finger is the hand A third drive transmission portion that is bent with respect to the body portion, and a fourth drive transmission portion that is located on the tip side of the third drive transmission portion in the operating finger portion, the fourth drive transmission portion being provided by a fourth actuator. An operating finger portion having a fourth drive transmitting portion that bends a part of the operating finger portion on the more distal side with respect to a portion of the operating finger portion on the proximal end side of the fourth drive transmitting portion, and the hand. An auxiliary finger portion that is attached to the main body portion and has a fifth drive transmission portion that bends the auxiliary finger portion with respect to the hand main body portion by a fifth actuator.

  The hand mechanism according to the present invention includes a hand main body having a first support and a second support as its main body. The first support portion and the second support portion are portions where the gripping target object comes into contact and is stably supported when two different gripping states regarding gripping of the gripping target object are realized in the hand mechanism. Since the hand main body has the two different supporting portions in this manner, the hand mechanism can realize various object gripping operations, and thus the gripping operations can be approximated to human gripping operations as much as possible. It becomes possible. In addition, as an example, the first support portion is a front surface support portion located in a front surface portion of the hand body portion, and the second support portion is a side surface portion located in a side surface portion of the hand body portion. It may be a support.

  The hand mechanism includes a thumb portion, an operating finger portion, and an auxiliary finger portion. First, the thumb portion has a gripping position in which a first gripping state utilizing the support by the first supporting portion is formed and a gripping position in which a second gripping state utilizing the support by the second supporting portion is formed. And a first drive transmission unit that pivots the thumb portion is provided, and the drive around the first drive transmission unit is realized by the first actuator. Further, the thumb portion is further provided with a second drive transmission portion that enables a bending operation with respect to the hand body portion, and the drive around the second drive transmission portion is realized by the second actuator. By providing the two drive transmission parts on the thumb part in this way, the thumb part can realize the essential operation of the finger part necessary for forming two different gripping states. The two different gripping states may be formed by at least the thumb portion and the hand body portion, and may be formed by appropriately combining the operation finger portion and the auxiliary finger portion.

  The drive transmission unit in the present application is configured to include a drive shaft such as one or a plurality of joints forming a finger, which is driven by a corresponding actuator. For example, when the finger unit driven by one actuator has one drive shaft, the drive transmission unit corresponding to the one actuator includes that one drive shaft. In addition, when the drive shaft of the finger portion driven by the one actuator has a plurality of drive shafts by using, for example, a link mechanism, the drive transmission unit corresponding to the one actuator has the plurality of drive shafts. Will be included.

  Further, the operation finger portion has a third drive transmission portion and a fourth drive transmission portion regarding the bending operation. The third drive transmission unit is a drive transmission unit located on the proximal end side of the operating finger unit, and the fourth drive transmission unit is located on the distal end side. In the present application, the “tip side” of each finger means the free end side located at the fingertip, the “proximal side” is the opposite side of the “tip side”, and the finger is the hand body. It means the root side connected to the part, that is, the finger side. Further, the tip side of the hand body portion is substantially coincident with the tip side of each finger portion connected to the hand body portion, while the base end side of the hand body portion is opposite to the tip side. , The so-called wrist side.

  As described above, since the operation finger portion is provided with the two drive transmission portions regarding the bending operation, it is possible to contribute to the formation of the two different grasping states described above, and the operation finger portion can realize the more complicated bending operation. Becomes That is, since the tip position of the operating finger portion can be finely controlled by the complicated bending operation, for example, the holding operation of pinching the grasped object with the thumb portion and the operating finger portion can be performed, and the gripping of the hand mechanism can be performed. The motion can be made more similar to a human gripping motion. Therefore, it is preferable that the thumb portion and the operating finger portion are determined to have attachment positions of the respective finger portions with respect to the hand main body portion so that the two fingers can perform a joint gripping operation. For example, the thumb part and the operating finger part are arranged so that the thumb part and the operating finger part, which are in the gripping position in the first gripping state or the gripping position in the second gripping state, and the operating finger part can perform the pinching operation. May be attached to.

  Then, the auxiliary finger portion has a fifth drive transmission portion regarding the bending operation. Therefore, since the number of drive transmission parts is smaller than that of the operating finger portion, it is difficult for the finger portion to perform a finer bending operation than the operating finger portion. However, when the gripping target object is gripped together with the thumb portion and the operating finger part, the contact points with the gripping target object increase due to the addition of the auxiliary finger portion, and the stable gripping operation of the gripping target object can be realized. ..

  As described above, the hand mechanism according to the present invention has two drive transmission parts on the thumb part, two drive transmission parts on the operating finger part, and one drive transmission part on the auxiliary finger part. A configuration is adopted, and the configuration enables driving of each finger portion that is as close as possible to a human gripping operation with a minimum combination of an actuator and a drive transmission unit. Therefore, the hand mechanism can achieve both miniaturization and making the gripping motion as close to the human gripping motion as possible.

  It is possible to reduce the size of the hand mechanism that enables the gripping operation that is as close to the human gripping operation as possible.

It is a 1st perspective view of the hand mechanism which concerns on the Example of this invention. It is a 2nd perspective view of the hand mechanism which concerns on the Example of this invention. It is a figure which shows schematic structure in the state which removed the cover of the hand mechanism shown in FIG. It is a 1st figure which shows schematic structure of the thumb part of the hand mechanism shown in FIG. It is a 2nd figure which shows schematic structure of the thumb part of the hand mechanism shown in FIG. It is a 1st figure which shows the schematic structure of a part of operation finger part of the hand mechanism shown in FIG. It is a 2nd figure which shows the schematic structure of a part of operation finger part of the hand mechanism shown in FIG. It is a figure which shows schematic structure of the auxiliary | assistant finger part of the hand mechanism shown in FIG. It is a figure which shows arrangement | positioning of the actuator in the hand mechanism shown in FIG. It is a figure which shows the 1st holding | gripping state which is holding | gripping the holding | gripping target object which used the thumb part in the hand mechanism shown in FIG. It is a figure which shows the 2nd holding | gripping state which is holding the holding | gripping target object which used the thumb part in the hand mechanism shown in FIG. FIG. 3 is a diagram showing a state in which the hand mechanism shown in FIG. 1 pinches and grasps an object to be grasped by a thumb portion and an operating finger portion.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the technical scope of the invention thereto unless otherwise specified.

<Schematic configuration of the hand mechanism 1>
1 and 2 are perspective views of the hand mechanism 1 according to the embodiment of the present invention. Specifically, FIG. 1 is a perspective view of the hand mechanism 1 as viewed from the palm side thereof, and FIG. 2 is a perspective view of the hand mechanism 1 as viewed from the back side of the hand. The hand mechanism 1 is configured such that the hand body portion 2 is provided with a four-finger structure. The hand body 2 has a generally rectangular parallelepiped shape. As shown in FIGS. 1 and 2, a thumb portion 3 is provided at a side portion of the hand body 2, and a tip portion of the hand body 2 is provided. An operating finger portion 4 and an auxiliary finger portion 5 are provided in the. The auxiliary finger portion 5 has a two-finger configuration, and each finger configuration is referred to as a first finger configuration 5a and a second finger configuration 5b. As will be described later, since the two-finger configuration of the auxiliary finger section 5 is configured to be simultaneously driven by one actuator, the two-finger configuration is collectively treated as one finger section.

  In the specification of the application, the “tip side” means the free end side located at the fingertip of the hand mechanism 1, and the “base end side” is the opposite side of the “tip side”. That is, the base end side of the hand main body 2 means the wrist side of the hand mechanism 1, and the base end side of each finger portion is the base side where the finger portion is connected to the hand main body portion 2, that is, the finger base. Means the side. The axis extending from the proximal end side to the distal end side of the hand mechanism 1 in the state shown in FIG. 1 is referred to as the “longitudinal axis” of the hand mechanism 1.

  Here, the hand mechanism 1 has a palm side support portion 2a, which is a relatively flat region, on the palm side of the hand body portion 2. When the hand mechanism 1 tries to grip the gripping target on the palm side (for example, when gripping the gripping target as shown in FIG. 11, which will be described later), the palm side support part 2a grips with the finger parts. It is a part that comes into contact with an object and supports the gripped state. The palm side support portion 2a corresponds to the front support portion according to the present invention. Further, the hand mechanism 1 has a side surface support portion 2b, which is a relatively flat region, on the side surface of the hand body portion 2. When the hand mechanism 1 tries to grip the gripping target on its side surface side (for example, when gripping the gripping target as shown in FIG. 10, which will be described later), the side surface support portion 2b holds the grip target together with the thumb portion 3. It is a part that comes into contact with an object and supports the gripped state. As described above, since the hand main body 2 has a substantially rectangular parallelepiped shape, the palm side support 2a and the side support 2b are not located on the same plane, and each support is generally They are orthogonal. A drive driver for an actuator that drives each finger portion is arranged on the back side of the hand of the hand mechanism 1 as described later, and a cover 2c for protecting the drive driver is provided.

Here, the thumb portion 3 can be driven so as to rotate around the hand main body portion 2 around the longitudinal axis of the hand mechanism 1. The specific configuration for driving will be described later. 1 and 2 show a state in which the grip surface 3a of the thumb portion 3 that comes into contact when gripping an object to be gripped faces the side surface support portion 2b. In the illustrated state, The gripping space formed between the gripping surface 3a and the side surface support portion 2b is in a substantially reduced state. As shown in FIG. 10, which will be described later, the thumb 3 is enlarged so that the gripping target can enter the gripping space, and then the gripping target is gripped between the gripping surface 3a and the side surface support 2b. In order to reduce the gripping space as described above, the gripping surface 3a can be driven so as to be spaced from and close to the side surface support portion 2b. As shown in FIGS. 1 and 2, the gripping surface 3a and the side surface support portion 2b are opposed to each other so that a gripping target is positioned between the gripping surface 3a and the side surface supporting portion 2b to grip the gripping object 3a. The position of the thumb portion 3 at this time is referred to as a first gripping position.

  Further, the thumb portion 3 pivots from the first gripping position around the hand main body portion 2 around the longitudinal axis of the hand mechanism 1, and as shown in FIG. 11, the gripping surface 3a faces the palm side support portion 2a. In this state, a gripping space is formed between the gripping surface 3a and the palm side support portion 2a. Even when the grip surface 3a faces the palm-side support portion 2a in this manner, the thumb portion 3 of the thumb portion 3 is separated from or close to the palm-side support portion 2a so that the grip space is expanded or contracted. Can also be driven. The state in which the gripping surface 3a and the palm side support portion 2a are opposed to each other to position the gripping target object between them and to grip the gripping object 3a corresponds to the second gripping state according to the present invention. The position of the thumb portion 3 is referred to as the second grip position.

  Thus, the thumb portion 3 has two degrees of freedom regarding driving. In other words, the degree of freedom of turning around the hand body 2 between the first grip position and the second grip position, and the drive for separating and approaching the palm side support 2a or the side support 2b. The thumb portion 3 has a degree of freedom, that is, a degree of freedom for the bending operation of the thumb portion 3. One or a plurality of joints or the like that compose the thumb portion 3 that is driven according to the former degree of freedom is referred to as a first drive transmission portion, and one or a plurality of joints that compose the thumb portion 3 that is driven according to the latter degree of freedom. The joint and the like are referred to as a second drive transmission unit. Details of each drive transmission unit will be described later.

  Further, the operating finger portion 4 is driven so that the fingertip thereof can be bent toward the palm side of the hand mechanism 1 (the side of the palm side support portion 2a), but two degrees of freedom are given to the bending. .. This is because it is possible to realize a fine grasping operation by the operation finger section 4. Then, one or a plurality of joints or the like constituting the operating finger section 4 which are driven in accordance with the respective degrees of freedom are referred to as a third drive transmission section and a fourth drive transmission section, respectively. On the other hand, the auxiliary finger portion 5 is also driven so that the fingertip thereof can be bent toward the palm side of the hand mechanism 1 (the side of the palm side support portion 2a), but only one degree of freedom is imparted during the bending. ing. This is because the auxiliary finger portion 5 is provided mainly for supporting the object to be grasped for stable grasping. Then, one or a plurality of joints or the like constituting the auxiliary finger portion 5 which is driven in accordance with the degree of freedom is referred to as a fifth drive transmission portion. Details of each drive transmission unit will be described later.

  Further, FIG. 3 shows a state in which the cover 2c provided on the back side of the hand is removed in the hand mechanism 1 in the state shown in FIG. Specifically, on the upper surface of the back side of the hand body 2, the drive driver 10a for driving and controlling the first actuator 30 corresponding to the first drive transmission portion of the thumb portion 3 described above and the first portion of the operation finger portion 4 are provided. A drive driver 10b for controlling the drive of a third actuator 45 (corresponding to reference numeral in FIG. 3 for reference because the third actuator 45 is hidden in the hand mechanism 1) corresponding to the three drive transmission units, and The drive driver 10c for driving and controlling the fourth actuator 40 corresponding to the fourth drive transmission portion of the operating finger portion 4, the fifth actuator 50 corresponding to the fifth drive transmission portion of the auxiliary finger portion 5 (the fifth actuator 50 is Since it is hidden in the hand mechanism 1, a drive driver 10d for driving and controlling the reference number is shown as a reference in FIG. Driver placement portion 10 is formed. By arranging the drivers together on the back side of the hand in this way, it is possible to secure a wide gripping area by the hand mechanism 1. It should be noted that the second actuator 35 corresponding to the second drive transmission portion of the thumb portion 3 (the reference numeral is shown for reference in FIG. 3 because the second actuator 35 is hidden in the hand mechanism 1) is drive-controlled. The drive driver 11 for this purpose is arranged in the housing 3c of the thumb 3 as shown in FIG. For the arrangement of all actuators in the hand mechanism 1, refer to FIG. 5, FIG. 9 and the like.

Here, the above-mentioned actuators 30, 35, 40, 4 mounted on the hand mechanism 1
5 and 50 are linear actuators having a direct acting output shaft. Each actuator has an actuator body having a substantially cylindrical shape, and an output shaft projecting from one end surface of the actuator body so as to be able to move forward and backward. Each actuator is electric and can adjust the amount of advance / retreat of the output shaft in accordance with a command from each corresponding drive driver.

Next, a detailed structure of each finger portion that constitutes the hand mechanism 1 will be described below.
<Thumb part 3>
The thumb part 3 will be described with reference to FIGS. 4 and 5. FIG. 4 is a perspective view of the thumb portion 3, and FIG. 5 is a view in which the configurations of the operating finger portion 4, the auxiliary finger portion 5 and the like in the hand mechanism 1 are omitted for understanding the internal structure of the thumb portion 3. As described above, the actuators associated with the thumb portion 3 are the first actuator 30 and the second actuator 35. The first drive transmission unit driven by the first actuator 30 will be described with reference to FIG. The output shaft 31 of the first actuator 30 fixed to the hand body portion 2 side is connected to the input portion 32 a of the swing link 32. The swing link 32 has an input section 32a and an output section 32b, and the driving force transmitted from the output shaft 31 swings the swing link 32, whereby the relative position of the output section 32b with respect to the input section 32a changes. The finger body 33 on the tip end side of the thumb portion 3 connected to the output portion 32b performs the above-described turning drive. Therefore, the drive force transmission structure from the output shaft 31 to the finger body 33, including the swing link 32, corresponds to the first drive transmission portion.

  Next, the second drive transmission unit driven by the second actuator 35 will be described with reference to FIGS. 4 and 5. As shown in FIG. 5, the second actuator 35 is arranged in the housing 3c, and the drive driver 11 thereof is also arranged in the housing 3c. Then, the output shaft 36 of the second actuator 35 is connected to the input portion of the swing link (not shown in FIG. 5), and further from the output portion, the rotary shaft 37 on the finger body 33 side (see FIG. 4). The rotation torque for is output. The through hole into which the rotary shaft 37 is inserted is shown as 37a in FIG. As a result, when the second actuator 35 is driven, the finger body 33 drives the hand body 2 to rotate for the above-described bending operation. Therefore, the structure for transmitting the driving force from the output shaft 36 to the rotary shaft 37, including the swing link, corresponds to the second drive transmission portion.

  As described above, since the second actuator 35 adopts the structure arranged in the housing 3c, the bending operation of the thumb portion 3 by the second actuator is changed to the state by the swing drive of the thumb portion 3 by the first actuator 30. It is viable regardless. That is, regardless of whether the thumb portion 3 is in the first grip position, the second grip position, or between the both grip positions, the bending operation of the thumb portion 3 by the second actuator 35 does not occur. It is feasible.

  Here, the finger body 33 has a gripping surface 3a and a housing 3c, and the thumb portion 3 shown in FIG. 5 is in a state in which the gripping surface 3a is removed, so that the thumb portion 3 The inside is visualized. Here, as shown in FIG. 1, the housing 3c of the thumb portion 3 is provided with a protruding portion 3b having a shape protruding toward the side surface support portion 2b when the thumb portion 3 is attached to the hand body portion 2. Has been. Therefore, the grip surface 3a does not have a relatively flat shape following the side surface support portion 2b, but a grip assist surface 3d formed so as to straddle the grip space between the thumb portion 3 and the side surface support portion 2b. I will have it in the department. As a result, even when the thumb portion 3 is driven to be bent by the second actuator 35, the grip assist surface 3d prevents the gripping target object from entering the rotation part, which contributes to the realization of stable gripping. Is.

When the grip surface 3a of the thumb portion 3 is located close to the side surface support portion 2b, a part of the hand body portion 2 is cut out so that the protrusion portion 3b does not interfere with the hand body portion 2. The notch 2d is formed so that the protrusion 3c can be housed (see FIG. 1). Further, when the thumb portion 3 is located at or near the second gripping position, the cutout portion is provided so that the protrusion portion 3b does not interfere with the hand body portion 2 even when the thumb portion 3 is bent and driven by the second actuator 35. 2d is formed.

<About the operating finger section 4>
Next, the operating finger portion 4 will be described based on FIGS. 6 and 7. The operation finger section 4 is composed of two sub finger sections 4a and 4b, a schematic configuration of the sub finger section 4a is shown in FIG. 6, and a schematic configuration of another sub finger section 4b is shown in FIG. .. As described above, the actuators associated with the operating finger unit 4 are the third actuator 45 and the fourth actuator 40. The third drive transmission section is driven by the third actuator 45, and the drive transmission section is included in the sub-finger section 4a shown in FIG. Further, the fourth drive transmission unit is driven by the fourth actuator 40, and the drive transmission unit is included in the sub finger portion 4b shown in FIG.

  First, the sub finger portion 4a will be described. The output shaft 46 of the third actuator 45 fixed to the hand body portion 2 side is connected to the input portion 47 a of the swing link 47. The swing link 47 has an input portion 47a and an output portion 47b, and the relative position of the output portion 47b with respect to the input portion 47a fluctuates as the swing link 47 swings due to the driving force transmitted from the output shaft 46. Then, the first finger portion 48 of the operating finger portion 4 is connected to the output portion 47b. The first finger portion 48 is the most proximal finger portion of the three finger portions 44, 43, and 48 forming the finger configuration of the operating finger portion 4 (see FIG. 3). Therefore, in accordance with the swing of the swing link 47, the entire three finger portions 44, 43, and 48 including the first finger portion 48 drive the hand main body 2 to rotate for the above-described bending operation. It will be. Therefore, the drive force transmitting structure from the output shaft 46 to the first finger portion 48 including the swing link 47 corresponds to the third drive transmitting portion.

  In addition, the front end side of the first finger portion 48 is provided with a pair of front end side wall surface portions 48a arranged narrower than the base end side in the vicinity of the connection portion with the output portion 47b. The pair of tip side wall surface portions 48a has a width dimension that fits into the space between the pair of wall surfaces forming the second finger portion 43 included in the sub finger portion 4b shown in FIG. The base end side of the first finger portion 48 is designed so as not to fit between the pair of wall surfaces of the second finger portion 43, as shown in FIG. The tip side wall surface portion 48a is provided with a through hole into which the fixed shaft 43b is inserted, as shown in FIGS. The first finger portion 48 and the second finger portion 43 are connected to each other by this fixed shaft 43b, but both finger portions can be rotationally driven with respect to each other about the fixed shaft 43b. Further, a through hole into which the support shaft 43c shown in FIG. 7 is inserted is formed on the tip side of the tip side wall surface portion 48a with respect to the through hole into which the fixed shaft 43b is inserted. The first finger portion 48 is rotatably connected to the support shaft 43c. As will be described later, a connecting link 43d is rotatably attached to the support shaft 43c. Further, a recessed portion 48b is formed at an edge portion of the tip side wall surface portion 48a which is closer to the base end side than the through hole into which the fixed shaft 43b is inserted. The recess 48b is formed to receive the support shaft 43a on the second finger portion 43 side when the first finger portion 48 is connected to the second finger portion 43.

  Next, the sub finger portion 4b will be described with reference to FIG. The output shaft 41 of the fourth actuator 40 fixed to the hand body portion 2 side is connected to the input portion 42a of the swing link 42. The swing link 42 has an input portion 42a and an output portion 42b, and the driving force transmitted from the output shaft 41 swings the swing link 42, whereby the relative position of the output portion 42b with respect to the input portion 42a changes. Then, the second finger portion 43 of the operating finger portion 4 is connected to the output portion 42b via the connecting link 42c. Specifically, in the second finger portion 43, the connection link 42c is rotatably connected to the support shaft 43a. The second finger portion 43 is a middle finger portion among the three finger portions 44, 43, and 48 that form the finger configuration of the operating finger portion 4 (see FIG. 3).

  Further, the fixed shaft 43b is arranged in the second finger portion 43, and the support shaft 43e is further provided on the tip side of the second finger portion 43, which constitutes the finger configuration of the operating finger portion 3. Of the two finger portions 44, 43, 48, the third finger portion 44 on the tip side is connected to the second finger portion 43 via the support shaft 43e so as to be rotatable relative to the second finger portion 43. Further, the connecting link 43d is arranged between the second finger portion 43 and the third finger portion 44. The connection link 43d is rotatably connected to a support shaft 43c rotatably inserted in the through hole of the first finger portion 48 and a support shaft on the third finger portion 44 side (not shown). There is. With the above configuration, the third finger portion 44 rotationally drives the second finger portion 43 for the bending operation in accordance with the swing of the swing link 42 driven by the fourth actuator 40. Therefore, the structure for transmitting the driving force from the output shaft 41 to the third finger portion 44 including the swing link 42 and the connecting link 43d corresponds to the fourth drive transmitting portion.

  Then, in the hand mechanism 1, the sub-finger portions 4a and 4b having the above-described configuration are combined with each other through the fixed shaft 43b and the support shaft 43c to be in the state shown in FIG. Will be formed. As the operating finger unit 4, the third operating unit 45 drives the entire operating finger unit 4 to bend the hand body unit 2, and the fourth actuator 40 drives the operating finger unit 4. Of the four, the third finger portion 44 performs a bending operation relative to the second finger portion 43.

<About the auxiliary finger section 5>
Next, the auxiliary finger section 5 will be described with reference to FIG. The auxiliary finger portion 5 includes a first finger configuration 5a and a second finger configuration 5b, which are two finger configurations. As described above, the auxiliary finger section 5 is a finger section for stably gripping an object to be grasped, and it is sufficient that the auxiliary finger section 5 bends at least with respect to the hand body section 2. The specific structure of can take any structure. As an example, as shown in FIG. 8, each finger configuration may have three finger portions similar to the operating finger portion 4. Then, each finger portion may employ a suitable link mechanism so as to mechanically bend in association with the bending operation of the auxiliary finger portion 5 with respect to the hand body portion 2. The important point is that the actuator associated with the auxiliary finger portion 5 is only the fifth actuator 50 for performing the bending operation. As long as it is driven by the driving force of the fifth actuator 50, the first finger configuration 5a and the second finger configuration 5b can adopt any link structure for bending. The fifth drive transmission unit is driven by the fifth actuator 50, and the drive transmission unit is shown in FIG.

  The output shaft 51 of the fifth actuator 50 fixed to the hand body portion 2 side is connected to the input portion 52 a of the swing link 52. The swing link 52 has an input portion 52a and an output portion 52b, and the swinging of the swing link 52 by the driving force transmitted from the output shaft 51 changes the relative position of the output portion 52b with respect to the input portion 52a. The second finger structure 5b is directly connected to the output section 52b, and the first finger structure 5a is further connected via the connecting link 53. Therefore, in accordance with the swing of the swing link 52, the first finger configuration 5a and the second finger configuration 5b interlock with each other to rotationally drive the hand body 2 for the above-described bending operation. .. Further, the link mechanism in each finger structure causes the finger portions in each finger structure to rotate relative to each other in association with the bending operation. From the above, the drive force transmission structure from the output shaft 51 to the first finger configuration 5a and the second finger configuration 5b including the swing link 52 corresponds to the fifth drive transmission unit. In addition, as another form of the auxiliary finger portion 5, instead of simply rotating the first finger configuration 5a and the second finger configuration 5b in conjunction with each other, the fifth actuator 50 uses the first finger configuration 5a and the second finger configuration 5a. Each of 5b may be rotationally driven according to the shape of the grasped object. As for each finger configuration for conforming to the shape of the object to be grasped, for example, the technique disclosed in JP-A-2015-112650 can be adopted.

<Arrangement of Actuators in Hand Mechanism 1>
In the hand mechanism 1 having the finger portions configured as described above, the arrangement of the actuators corresponding to the finger portions is determined from the viewpoint of downsizing the hand mechanism 1. Therefore, the arrangement will be described based on FIG. FIG. 9 shows the positional relationship between each finger part and the corresponding actuator when the hand mechanism 1 is viewed from the back side of the hand. First, the fourth actuator 40 corresponding to the operating finger portion 4 is arranged near the base of the finger configuration. Further, the third actuator 45, which is another actuator corresponding to the operation finger portion 4, is arranged near the base of the first finger configuration 5a of the auxiliary finger portion 5. As described above, even if the third actuator 45 is displaced from the position of the operating finger portion 4, the operating finger portion is arranged by arranging the first finger portion 48 beside the swing link 47 as shown in FIG. 4 can be configured without any trouble. Since the fifth actuator 50 is not located near the root of the first finger configuration 5a as shown in FIG. 8, it is possible to place the third actuator 45 at that location. The fifth actuator 50 corresponding to the auxiliary finger portion 5 is arranged near the base of the second finger configuration 5b of the auxiliary finger portion 5.

  Next, with respect to the thumb portion 3, the second actuator 35 is arranged inside the thumb portion 3, and the first actuator 30 is arranged in the hand main body portion 2 more than the third actuator 45, the fourth actuator 40 and the fifth actuator 50. It is located on the proximal side. In consideration of the fact that the thumb portion 4 has the configuration shown in FIG. 4, the first actuator 30 among the actuators related to the hand mechanism 1 is arranged at the most proximal end side in this way, so that the hand body portion 2 The attachment position of the thumb portion 4 can be set to the most proximal side. Therefore, the holding space by the thumb portion 3 in the hand mechanism 1 can be secured as large as possible, which results in the miniaturization of the hand mechanism 1. Further, when the thumb portion 3 performs a bending operation on the hand body portion 2, the grasping target surface 3d is formed on the thumb portion 3, so that the grasped object does not enter the turning portion of the bending operation. This can be prevented, and stable gripping can be achieved.

<Exemplary gripping form by the hand mechanism 1>
Here, FIGS. 10 to 12 exemplify a gripping form of the gripping target 100 by the hand mechanism 1. First, in the gripping form shown in FIG. 10, the gripping target 100 is gripped between the thumb portion 3 and the side surface support portion 2b. In order to form such a grasped state, for example, the first actuator 30 moves the thumb portion 3 to the first grasping position, and the second actuator 35 separates the thumb portion 3 from the hand body portion 2. Then, the grip target 100 is positioned in the grip space between the thumb portion 3 and the side surface support portion 2b, and the thumb portion 3 is brought close to the hand body portion 2 by the second actuator 35. As a result, the grasped object 100 is sandwiched between the thumb portion 3 and the side surface support portion 2b, and the grasped state shown in FIG. 10 is formed.

  Next, in the gripping form shown in FIG. 11, the gripping target 100 is gripped between the thumb portion 3 and the palm side support portion 2a. In order to form such a grasped state, for example, the thumb portion 3 is moved to the second grasp position by the first actuator 30, and the thumb portion 3 is separated from the hand body portion 2 by the second actuator 35. Then, the gripping target 100 is positioned in the gripping space between the thumb portion 3 and the palm side support portion 2a, and the thumb portion 3 is brought close to the hand body portion 2 by the second actuator 35. As a result, the grasped object 100 is sandwiched between the thumb portion 3 and the palm side support portion 2a, and the grasped state shown in FIG. 11 is formed.

Next, in the gripping form shown in FIG. 12, the gripping target 100 is pinched and gripped by the tip part of the thumb part 3 and the tip part of the operating finger part 4. In order to form such a grasped state, for example, the thumb portion 3 is moved to the second grasp position by the first actuator 30, and the thumb portion 3 is separated from the hand body portion 2 by the second actuator 35. Then, the gripping target 100 is positioned in the gripping space between the thumb portion 3 and the operating finger portion 4, and the second actuator 35
Thus, the thumb portion 3 is brought close to the hand main body portion 2, and the third actuator 45 and the fourth actuator 40 perform the bending operation so that the tip portion of the operating finger portion 4 overlaps the tip portion of the thumb portion 3. As a result, the grasped object 100 is sandwiched between the tip portion of the thumb portion 3 and the tip portion of the operating finger portion 4, and the grasped state shown in FIG. 12 is formed.

  In addition, when the grasped object 100 is relatively thick, the graspable object 100 may be stably supported by appropriately bending each finger configuration of the auxiliary finger section 5.

  As described above, in the hand mechanism 1 according to the present invention, the thumb portion 3 is provided with two degrees of freedom of the turning operation and the bending operation, and the operating finger portion 4 is provided with the two degrees of freedom regarding the bending operation. 5 has one degree of freedom regarding the bending operation. These degrees of freedom are the degrees of freedom of each finger portion required to approximate the gripping operation by the hand mechanism 1 to the gripping operation of a human. By setting such a degree of freedom for each finger portion, it is possible to realize a suitable gripping operation that is closer to a human gripping operation in the hand mechanism 1 with a minimum configuration, and thus to reduce the size of the hand mechanism 1. It is possible to plan.

DESCRIPTION OF SYMBOLS 1 ... Hand mechanism, 2 ... Hand main body part, 3 ... Thumb part, 3a ... Gripping surface, 3b ... Projection part, 3c ... Housing, 4 ... Operation finger part 5 ... Auxiliary finger portion, 10 ... Driver placement portion, 30 ... First actuator, 35 ... Second actuator, 45 ... Third actuator, 40 ... Fourth actuator, 50 ... Fifth actuator

Claims (7)

A hand mechanism configured to be capable of gripping an object to be gripped by a plurality of fingers,
A first support part capable of supporting the gripping target when gripping the gripping target in the first gripping state, and a second supporting part different from the first supporting part. A hand body part having a second support part capable of supporting the object to be gripped when gripping in a gripping state;
A first drive transmission that is attached to the hand body portion and that pivots a thumb portion around the hand body portion between a holding position in the first holding state and a holding position in the second holding state by a first actuator. And a thumb portion having a second drive transmission portion that bends the thumb portion with respect to the hand body portion by a second actuator,
A third drive transmission portion that is attached to the hand body portion and that bends the operating finger portion with respect to the hand body portion by a third actuator, and a fourth drive transmission portion that is located on the tip side of the third drive transmission portion in the operating finger portion. A part of the operation finger portion on the tip side of the fourth drive transmission portion is moved to a part of the operation finger portion on the base end side of the fourth drive transmission portion by the fourth actuator. An operation finger portion having a fourth drive transmission portion that is bent with respect to each other;
An auxiliary finger portion that is attached to the hand body portion and has a fifth drive transmission portion that bends the auxiliary finger portion with respect to the hand body portion by a fifth actuator;
A hand mechanism. The first support part is a front support part located at a front part of the hand body part,
The second support portion is a side surface support portion located at a side surface portion of the hand body portion,
The hand mechanism according to claim 1. The first actuator, the third actuator, the fourth actuator, and the fifth actuator are arranged in a portion of the hand body portion that does not interfere with the front support portion,
Each of the third actuator and the fourth actuator is a linear actuator, and each output shaft is connected to the operating finger portion via a first operating finger link mechanism and a second operating finger link mechanism,
The fifth actuator is a linear actuator, the output shaft of which is connected to the auxiliary finger portion via an auxiliary finger link mechanism,
The first actuator is a linear actuator, and its output shaft is connected to the thumb portion via a thumb link mechanism, and the first actuator includes the third actuator and the fourth actuator in the hand body portion. Disposed on the base end side of the hand body portion with respect to the actuator and the fifth actuator,
The hand mechanism according to claim 2. The second actuator is disposed within the casing of the thumb portion,
The hand mechanism according to claim 3. When the thumb portion is driven around the second drive transmission portion by the second actuator, the grip space formed between the thumb portion and the side surface support portion of the hand body portion is A protrusion formed by protruding from the thumb is provided on the thumb,
The protrusion has a gripping surface facing the gripping space,
The hand mechanism according to claim 4. The thumb portion is driven around the second drive transmission portion by the second actuator, so that the protrusion portion of the thumb portion is housed inside the hand body portion in a state where the gripping space is reduced. Configured as
The hand mechanism according to claim 5. A driver placement section is provided at the back surface of the hand body section, in which drive drivers for the first actuator, the third actuator, the fourth actuator, and the fifth actuator are placed.
The drive driver of the second actuator is disposed in the casing of the thumb portion,
The hand mechanism according to any one of claims 4 to 6.

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