WO2017159504A1

WO2017159504A1 - Hand mechanism

Info

Publication number: WO2017159504A1
Application number: PCT/JP2017/009288
Authority: WO
Inventors: 正樹永塚; 文哉小泉
Original assignee: Thk株式会社
Priority date: 2016-03-14
Filing date: 2017-03-08
Publication date: 2017-09-21
Also published as: JP6693190B2; JP2017164831A

Abstract

A hand mechanism according to the present invention is configured to be able to grip an object to be gripped with a plurality of finger units, the hand mechanism comprising a hand main body unit that makes gripping in a first gripping state and gripping in a second gripping state possible, a thumb unit that comprises a first drive transmission unit that revolves the thumb unit about the hand main body unit between a gripping position in the first gripping state and a gripping position in the second gripping state with a first actuator and a second drive transmission unit that bends the thumb unit with respect to the hand main body unit with a second actuator, an operation finger unit that comprises a third drive transmission unit that performs bending with a third actuator and a fourth drive transmission unit that performs bending with a fourth actuator, and an auxiliary finger unit comprising a fifth drive transmission unit that bends the auxiliary finger unit with respect to the hand main body unit with a fifth actuator. As a result, the hand mechanism that enables a gripping operation approximated to a human gripping operation as much as possible is made smaller.

Description

Hand mechanism

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

Conventionally, a robot hand has a structure similar to a human finger, and attempts have been made to grip various objects. For example, in a hand mechanism having a plurality of fingers for stably grasping from a large object to a small object, the plurality of fingers are respectively connected to the distal phalanx and the middle phalanx adjacent to the distal phalanx. It may be composed of a plurality of bone parts. Then, the distal phalange portion can be rotated in a predetermined angular range in two directions, the inner direction and the outer direction, from the state in which the distal phalanx portion extends straight with respect to the middle phalanx portion. Operation close to the “pinch” operation is realized.

On the other hand, when trying to approximate the motion of the robot hand to the motion of a human finger, it is possible to employ a configuration in which each finger is provided with a plurality of joints and each joint is driven by a corresponding actuator. However, as a contradiction, the size of the robot hand is increased, and as a result of limiting the size of the robot hand, the output of the actuator is limited. As a technique for eliminating such disadvantages, the technique of Patent Document 1 has been developed. In the technique disclosed in Patent Document 1, an actuator is provided on the arm portion on the proximal end side of the robot hand, and a driving force transmitting member that transmits the output of the actuator to the hand portion on the distal end side is driven by the transmitted driving force. The pulley member is disposed on the hand side. As described above, the robot hand is reduced in size by providing the driving source on the arm part away from the hand part and transmitting the driving force to the hand part.

Japanese Patent No. 5482664

In the hand mechanism disclosed in Patent Document 1, a drive unit such as an actuator is disposed on an arm part away from the hand body in order to reduce the size of the hand mechanism, and the driving force is transmitted to the hand part side via various transmission mechanisms. Communicating to the finger. Therefore, although the hand mechanism itself can be reduced in weight, the hand mechanism itself has a mechanically complicated configuration due to the intervention of the transmission mechanism, and is not necessarily a preferable configuration for maintenance. In constructing the hand mechanism, it is preferable to reduce the entire size including the actuator and its mechanical structure. Patent Document 1 discloses that an essential solution regarding the miniaturization of the hand mechanism has been made. I can't say that.

In addition, when trying to realize various gripping operations, preferably a gripping operation similar to that of a human hand, in the hand mechanism, a joint required for a finger part included in the hand mechanism is provided, In order to realize the gripping operation, it is necessary to supply driving force around each joint. As a result, it is necessary to mount a corresponding number of joints and actuators for supplying driving force on the hand mechanism. However, in reality, the conventional technology does not show a sufficient solution means that allows the hand mechanism to be miniaturized with the actuator mounted.

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

In the present invention, in order to solve the above-described problem, an arrangement for supplying a driving force and a driving transmission unit of a finger driven by the driving force in a limited region called a main body of the hand mechanism are provided. Pay attention. In order to achieve both miniaturization of the hand mechanism and approximating its gripping motion to human gripping motion as much as possible, the combination of the minimum number of actuators and the drive transmission unit can be used. It is considered essential to realize the gripping operation.

Specifically, the present invention is a hand mechanism configured to be able to grip a gripping object with a plurality of fingers, and can support the gripping object when gripping the gripping object in the first gripping state. A first support part, and a second support part that is different from the first support part and is capable of supporting the gripping object when gripping the gripping object in the second gripping state. A hand main body having a thumb portion between the gripping position in the first gripping state and the gripping position in the second gripping state by the first actuator. A first drive transmission section that pivots to the hand body, a thumb section that has a second drive transmission section that bends the thumb section with respect to the hand main body section by a second actuator, and is attached to the hand main body section. Move the operating finger to the hand A third drive transmission portion that is bent with respect to the main body, and a fourth drive transmission portion that is located on the distal side of the operation finger portion with respect to the third drive transmission portion. An operation finger portion having a fourth drive transmission portion that bends a part of the operation finger portion closer to the distal end than a portion of the operation finger portion closer to the proximal end than the fourth drive transmission portion; And an auxiliary finger portion having a fifth drive transmission portion that is attached to the main body portion and 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 the main body. The first support portion and the second support portion are portions that are stably supported by contact with the gripping object when two different gripping states relating to gripping of the gripping object are realized in the hand mechanism. Since the hand main body portion has two different support portions in this way, the hand mechanism can realize gripping operations of various objects, and thus approximate the gripping operation to a human gripping operation as much as possible. It becomes possible. As an example, the first support part is a front support part located at a front part of the hand body part, and the second support part is a side face located at a side part of the hand body part. It may be a support part.

The hand mechanism includes a thumb part, an operation finger part, and an auxiliary finger part. First, the thumb portion has a grip position where a first grip state using the support by the first support portion is formed, and a grip position where a second grip state using the support by the second support portion is formed. A first drive transmission unit for turning the thumb unit is provided between the first drive transmission unit and the first actuator. The drive around the first drive transmission unit is realized by the first actuator. In addition, the thumb portion is further provided with a second drive transmission portion that enables a bending operation with respect to the hand main body portion, and driving 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 an essential operation of the finger part necessary to form two different gripping states. The two different gripping states may be formed by at least the thumb part and the hand main body part, and may be formed by appropriately combining the operation finger part and the auxiliary finger part.

In addition, the drive transmission part in this application is a structure containing drive shafts, such as one or several joints which form a finger part driven by a corresponding actuator. For example, in the case where there is one finger drive shaft driven by one actuator, the drive transmission unit corresponding to the one actuator includes the one drive shaft. Further, when there are a plurality of finger drive shafts driven by one actuator 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 located on the proximal end side of the operation finger unit, and the fourth drive transmission unit is a drive transmission unit located on the distal end side. In addition, the “tip side” of each finger part in the present application means the free end side located at the fingertip, and the “base end side” is the opposite side to the “tip side”, and the finger part is the hand body. This means the root side connected to the part, that is, the finger side. Further, the distal end side of the hand main body portion substantially coincides with the distal end side of each finger portion connected to the hand main body portion, while the proximal end side of the hand main body portion is opposite to the distal end side thereof. , So-called wrist side.

As described above, the operation finger portion is provided with the two drive transmission portions for the bending operation, which contributes to the formation of the two different gripping states described above, and the operation finger portion can realize a more complicated bending operation. It becomes. That is, the tip position of the operation finger can be finely controlled by the complicated bending operation. For example, it is possible to grasp the object to be grasped by the thumb and the operation finger, and the gripping of the hand mechanism. The motion can be more approximated to a human gripping motion. Therefore, it is preferable that the attachment position of each finger part with respect to the hand main body part is determined so that the thumb part and the operation finger part can be jointly held by both finger parts. For example, the thumb portion and the operation finger portion are arranged so that the thumb portion and the operation finger portion at the holding position in the first holding state or the holding position in the second holding state can be pinched. It may be attached to.

The auxiliary finger portion has a fifth drive transmission portion with respect to the bending operation. Therefore, since there are few drive transmission parts compared with an operation finger part, as for a finger part, bending operation | movement finer than an operation finger part is difficult. However, when the gripping object is gripped together with the thumb part or the operation finger part, the contact point with the gripping object is increased by adding the auxiliary finger part, and a stable gripping operation of the gripping object can be realized. .

As described above, the hand mechanism according to the present invention has two drive transmission portions in the thumb portion, two drive transmission portions in the operation finger portion, and one drive transmission portion in the auxiliary finger portion. A configuration is employed, and this configuration enables driving of each finger unit as close as possible to a human gripping operation with a minimum combination of actuator and drive transmission unit. Therefore, the hand mechanism can achieve both miniaturization and approximating the gripping operation to a human gripping operation as much as possible.

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

It is a 1st perspective view of the hand mechanism concerning the example of the present 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 of 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 schematic structure of a part of operation finger | toe part of the hand mechanism shown in FIG. FIG. 4 is a second diagram illustrating a schematic configuration of a part of the operation finger portion of the hand mechanism illustrated in FIG. 1. It is a figure which shows schematic structure of the auxiliary 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. In the hand mechanism shown in FIG. 1, it is a figure which shows the 1st holding state which is holding the holding target object using the thumb part. In the hand mechanism shown in FIG. 1, it is a figure which shows the 2nd holding state which is holding the holding target object using the thumb part. In the hand mechanism shown in FIG. 1, it is a figure which shows the state which has pinched and hold | gripped the holding | grip target object by the thumb part and the operation finger part.

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 the present embodiment are not intended to limit the technical scope of the invention to those unless otherwise specified.

<Schematic configuration of hand mechanism 1>
1 and 2 are perspective views of a hand mechanism 1 according to an embodiment of the present invention. Specifically, FIG. 1 is a perspective view when the hand mechanism 1 is viewed from the palm side, and FIG. 2 is a perspective view when viewed from the back side of the hand. The hand mechanism 1 is configured by providing a hand body 2 with a four finger configuration. The hand main body 2 has a substantially rectangular parallelepiped shape, and as shown in FIGS. 1 and 2, a thumb portion 3 is provided at a side portion of the hand main body 2, and a tip end portion of the hand main body 2. The operation finger part 4 and the auxiliary finger part 5 are provided. The auxiliary finger unit 5 has a two-finger configuration, and the respective finger configurations are 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 unit 5 is configured to be driven simultaneously by one actuator, the two-finger configuration is collectively handled as one finger unit.

In the present specification, the “front end side” means a free end side located at the fingertip of the hand mechanism 1, and the “proximal end side” is an opposite side to the “front end 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 unit is the base side where the finger unit is connected to the hand main body unit 2, that is, the finger base. Means 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 2 a that is a relatively flat region on the palm side of the hand main body portion 2. The palm-side support unit 2a grips with each finger when the hand mechanism 1 tries to grip a gripping object on its palm side (for example, when gripping the gripping object as shown in FIG. 11 described later). It is a part that contacts the object and supports the grip state. This palm side support portion 2a corresponds to a front support portion according to the present invention. Furthermore, the hand mechanism 1 has a side support portion 2 b that is a relatively flat region on the side surface of the hand main body portion 2. The side surface support portion 2b is to be grasped together with the thumb portion 3 when the hand mechanism 1 tries to grasp the object to be grasped on the side surface side (for example, when grasping the object to be grasped as shown in FIG. 10 described later). It is a part that contacts an object and supports its gripping state. As described above, since the hand main body 2 has a substantially rectangular parallelepiped shape, the palm side support portion 2a and the side surface support portion 2b are not located on the same plane, and the support portions are generally Orthogonal. Further, on the back side of the hand of the hand mechanism 1, an actuator driver for driving each finger is disposed as will be described later, and a cover 2c for protecting the driver is provided.

Here, the thumb portion 3 can be driven so as to turn 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 gripping surface 3a of the thumb portion 3 that contacts the gripping target object is opposed to the side support portion 2b. In the illustrated state, FIG. The gripping space formed between the gripping surface 3a and the side support portion 2b is generally reduced. As shown in FIG. 10 described later, the thumb portion 3 is enlarged so that the grasped object can enter the grasping space, and then the grasped object is grasped between the grasping surface 3a and the side support portion 2b. In order to reduce the gripping space as described above, the gripping surface 3a can be driven so as to be separated 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 face each other, so that the gripping object is positioned between the gripping surface 3a and the side surface support portion 2b. The position of the thumb part 3 at this time is referred to as a first gripping position.

Further, the thumb portion 3 pivots around the hand body portion 2 around the longitudinal axis of the hand mechanism 1 from the first gripping position, and the gripping surface 3a faces the palm side support portion 2a as shown in FIG. As a result, a gripping space is formed between the gripping surface 3a and the palm-side support portion 2a. Thus, even when the gripping surface 3a faces the palm-side support portion 2a, the thumb portion 3 is separated and close to the palm-side support portion 2a so that the gripping space expands and contracts. Can also be driven. The state in which the gripping surface 3a and the palm-side support portion 2a face each other and the gripping object is positioned between the gripping surface 3a and the palm-side support portion 2a is equivalent to the second gripping state according to the present invention. The position of the thumb 3 is referred to as a second grip position.

Thus, with regard to the thumb part 3, two degrees of freedom related to driving are given. That is, it is driven for the degree of freedom of turning around the hand main body 2 between the first gripping position and the second gripping position, and separation and proximity to the palm-side support part 2a or the side support part 2b. The thumb part 3 has a degree of freedom, that is, a degree of freedom for the bending operation of the thumb part 3. One or a plurality of joints or the like constituting the thumb part 3 driven according to the former degree of freedom is referred to as a first drive transmission part, and one or a plurality of parts constituting the thumb part 3 driven according to the latter degree of freedom. These joints are referred to as a second drive transmission unit. Details of each drive transmission unit will be described later.

Further, the operation finger unit 4 is driven so that the fingertip can be bent to the palm side of the hand mechanism 1 (the palm-side support unit 2a side), but two degrees of freedom are given for the bending. . This is because a fine gripping operation can be realized by the operation finger unit 4. One or a plurality of joints or the like constituting the operation finger unit 4 driven according to each degree of freedom are referred to as a third drive transmission unit and a fourth drive transmission unit, respectively. On the other hand, the auxiliary finger portion 5 is also driven so that its fingertip can be bent to the palm side (the palm-side support portion 2a side) of the hand mechanism 1, but only one degree of freedom is given for the bending. ing. This is because the auxiliary finger part 5 is provided mainly for supporting a grasped object for stable grasping. And the 1 or several joint etc. which comprise the auxiliary finger part 5 driven according to the said freedom degree are called a 5th drive transmission part. Details of each drive transmission unit will be described later.

FIG. 3 shows a state in which the cover 2c provided on the back side of the hand is removed from the hand mechanism 1 in the state shown in FIG. Specifically, a 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 on the upper surface on the back side of the hand of the hand main body portion 2 and the second of the operation finger portion 4 are provided. A drive driver 10b for driving and controlling a third actuator 45 corresponding to the three drive transmission units (the third actuator 45 is hidden in the hand mechanism 1 and therefore the reference number is shown in FIG. 3 for reference); A drive driver 10c for driving and controlling the fourth actuator 40 corresponding to the fourth drive transmission unit of the operation finger unit 4, and a fifth actuator 50 corresponding to the fifth drive transmission unit of the auxiliary finger unit 5 (the fifth actuator 50 is Since it is hidden in the hand mechanism 1, a drive driver 10 d for driving and controlling the drive driver 10 d is collectively placed in FIG. 3. Driver placement portion 10 is formed. Thus, by arranging the drivers together on the back side of the hand, it is possible to secure a wide grip area by the hand mechanism 1. The second actuator 35 corresponding to the second drive transmission portion of the thumb portion 3 is driven and controlled (the second actuator 35 is hidden in the hand mechanism 1 and therefore the reference number is shown for reference in FIG. 3). For this purpose, the drive driver 11 is disposed 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 and FIG.

Here, each of the

actuators

30, 35, 40, 45, 50 mounted on the hand mechanism 1 is a linear actuator having a linear motion output shaft. Each actuator has an actuator body having a substantially cylindrical shape and an output shaft that protrudes forward and backward from one end face of the actuator body. Each actuator is electrically driven and can adjust the amount of advancement / retraction of the output shaft in accordance with a command from each of the corresponding drive drivers.

Next, the detailed structure of each finger part which comprises the hand mechanism 1 is demonstrated below.
<About thumb part 3>
The thumb part 3 is demonstrated based on FIG.4 and FIG.5. 4 is a perspective view of the thumb portion 3, and FIG. 5 is a view in which the configuration of the operation finger portion 4, the auxiliary finger portion 5 and the like in the hand mechanism 1 is omitted in order to understand the internal structure of the thumb portion 3. As described above, the two actuators associated with the thumb portion 3 are the first actuator 30 and the second actuator 35. The 1st drive transmission part driven by the 1st actuator 30 is demonstrated based on FIG. An output shaft 31 of the first actuator 30 fixed to the hand main body 2 side is connected to an input portion 32 a of the swing link 32. The swing link 32 has an input part 32a and an output part 32b, and the relative position of the output part 32b with respect to the input part 32a varies as the swing link 32 swings by the driving force transmitted from the output shaft 31. The finger body 33 on the distal end side of the thumb portion 3 connected to the output portion 32b performs the above-described turning drive. Therefore, the transmission structure of the driving force from the output shaft 31 to the finger body 33 including the swing link 32 corresponds to the first drive transmission unit.

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

As described above, since the second actuator 35 employs a structure arranged in the housing 3c, the bending operation of the thumb portion 3 by the second actuator is brought into a state by the turning drive of the thumb portion 3 by the first actuator 30. It is feasible regardless. That is, regardless of whether the thumb portion 3 is in the first gripping position or the second gripping position, or between the two gripping positions, the bending operation of the thumb portion 3 by the second actuator 35 is performed. It is feasible.

Here, the finger part body 33 has a gripping surface 3a and a housing 3c, and the thumb part 3 shown in FIG. 5 is in a state in which the gripping surface 3a is removed. The inside is visualized. Here, the housing 3c of the thumb portion 3 is provided with a protruding portion 3b having a shape protruding to the side support portion 2b side when the thumb portion 3 is attached to the hand main body portion 2 as shown in FIG. It has been. For this reason, the gripping surface 3a does not have a relatively flat shape that follows the side support portion 2b, but has a grip assisting surface 3d formed so as to straddle the gripping space between the thumb portion 3 and the side support portion 2b. Will have in the part. As a result, even when the thumb 3 is bent and driven by the second actuator 35, the grip assisting surface 3d prevents the gripping object from entering the rotating portion, which contributes to the realization of stable gripping. It is.

When the gripping surface 3a of the thumb 3 is in a position close to the side support 2b, a part of the hand main body 2 is cut away so that the projection 3b does not interfere with the hand main body 2. A notch 2d is formed so that the protrusion 3b can be accommodated (see FIG. 1). Further, when the thumb portion 3 is located at or near the second gripping position, the notch portion is arranged so that the projection portion 3b does not interfere with the hand main body portion 2 even when it is bent and driven by the second actuator 35. 2d is formed.

<About the operation finger unit 4>
Next, the operation finger part 4 will be described with reference to FIGS. 6 and 7. The operation finger unit 4 includes two

sub-finger units

4a and 4b. FIG. 6 shows a schematic configuration of the sub-finger unit 4a, and FIG. 7 shows a schematic configuration of another sub-finger unit 4b. . As described above, the actuators associated with the operation finger unit 4 are the third actuator 45 and the fourth actuator 40. The third actuator 45 is driven by the third actuator 45, and the drive transmission unit is included in the sub-finger 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 unit 4b shown in FIG.

First, the sub finger part 4a will be described. An output shaft 46 of the third actuator 45 fixed to the hand main body 2 side is connected to an 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 varies as the swing link 47 swings by the driving force transmitted from the output shaft 46. And the 1st finger part 48 of the operation finger part 4 is connected to the output part 47b. The first finger portion 48 is the most proximal finger portion among the three

finger portions

44, 43, and 48 that constitute the finger configuration of the operation finger portion 4 (see FIG. 3). Accordingly, the entire three

finger portions

44, 43, 48 including the first finger portion 48 perform rotational driving for the bending operation described above on the hand main body 2 in accordance with the swing of the swing link 47. It will be. Therefore, the drive force transmission structure from the output shaft 46 to the first finger portion 48 including the swing link 47 corresponds to the third drive transmission unit.

In addition, the front end side of the 1st finger part 48 is provided with a pair of front end side wall surface parts 48a arranged narrower than the base end side in the vicinity of the connection part with the output part 47b. The pair of front end side wall surface portions 48a have a width dimension that fits into a space between a pair of wall surfaces forming the second finger portion 43 included in the sub finger portion 4b shown in FIG. In addition, the base end side of the 1st finger part 48 is designed so that it may not fit between a pair of wall surfaces of the 2nd finger part 43, as shown in FIG. Further, as shown in FIGS. 6 and 7, the distal end side wall surface portion 48 a is provided with a through hole into which the fixed shaft 43 b is inserted. The first finger portion 48 and the second finger portion 43 are connected to each other by the fixed shaft 43b, but the two finger portions can be driven to rotate around the fixed shaft 43b. Furthermore, a through hole into which the support shaft 43c shown in FIG. 7 is inserted is formed on the distal end side of the distal 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. In addition, a recessed portion 48b is formed at the edge portion of the distal end side wall surface portion 48a and on the edge portion on the proximal end side from the through hole into which the fixed shaft 43b is inserted. The recess 48 b is formed to receive the support shaft 43 a 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 4b will be described with reference to FIG. An output shaft 41 of the fourth actuator 40 fixed to the hand body 2 side is connected to an input portion 42 a of the swing link 42. The swing link 42 has an input part 42a and an output part 42b, and the relative position of the output part 42b with respect to the input part 42a varies as the swing link 42 swings by the driving force transmitted from the output shaft 41. And the 2nd finger part 43 of the operation finger part 4 is connected to the output part 42b via the connection 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 finger portion located in the middle of the three

finger portions

44, 43, and 48 constituting the finger configuration of the operation finger portion 4 (see FIG. 3).

The second finger portion 43 is provided with the fixed shaft 43b, and further provided with a support shaft 43e on the distal end side of the second finger portion 43, which constitutes the finger structure of the operation finger portion 4. The third finger portion 44 on the distal end side of the two

finger portions

44, 43, 48 is connected to be rotatable relative to the second finger portion 43 via a support shaft 43e. Further, a connecting link 43 d is disposed between the second finger portion 43 and the third finger portion 44. The connecting link 43d is rotatably connected to a support shaft 43c that is rotatably inserted into the through hole of the first finger portion 48 and a support shaft on the third finger portion 44 side (not shown). Yes. With the above configuration, the third finger portion 44 performs rotational driving for the bending operation with respect to the second finger portion 43 in accordance with the swing of the swing link 42 driven by the fourth actuator 40. Therefore, the drive force transmission structure from the output shaft 41 to the third finger portion 44 including the swing link 42 and the connection link 43d corresponds to the fourth drive transmission unit.

Then, as the hand mechanism 1, the

sub finger portions

4a and 4b having the above-described configuration are combined through the fixed shaft 43b and the support shaft 43c, so that the state shown in FIG. Will be formed. And as the operation finger part 4, when the 3rd actuator 45 drives, the operation finger part 4 whole bends with respect to the hand main-body part 2, and when the 4th actuator 40 drives, the operation finger part 4, the third finger portion 44 performs a bending operation relative to the second finger portion 43.

<About the auxiliary finger 5>
Next, the auxiliary finger part 5 is demonstrated based on FIG. The auxiliary finger unit 5 includes a first finger configuration 5a and a second finger configuration 5b which are two finger configurations. As described above, the auxiliary finger unit 5 is a finger unit for stably holding the object to be grasped, and it is sufficient that the auxiliary finger unit 5 bends at least with respect to the hand main body unit 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 in the same manner as the operation finger portion 4. Each finger portion may employ a suitable link mechanism so as to be mechanically bent in conjunction with the bending operation of the auxiliary finger portion 5 with respect to the hand main body portion 2. The important point is that the actuator associated with the auxiliary finger 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 actuator 50 is driven by the fifth drive transmission unit, and the drive transmission unit is shown in FIG.

The output shaft 51 of the fifth actuator 50 fixed to the hand body 2 side is connected to the input portion 52 a of the swing link 52. The swing link 52 has an input part 52a and an output part 52b, and the relative position of the output part 52b with respect to the input part 52a varies as the swing link 52 swings by the driving force transmitted from the output shaft 51. The second finger configuration 5 b is directly connected to the output unit 52 b, and the first finger configuration 5 a is further connected via the connecting link 53. Therefore, according to the swing of the swing link 52, the first finger configuration 5a and the second finger configuration 5b perform the rotational drive for the bending operation described above on the hand main body 2 in conjunction with each other. . Further, the finger parts in each finger structure are relatively rotated by the link mechanism in each finger structure in conjunction with the bending operation. From the above, the drive force transmission structure including the swing link 52 from the output shaft 51 to the first finger configuration 5a and the second finger configuration 5b corresponds to the fifth drive transmission unit. Further, as another form of the auxiliary finger unit 5, instead of the first finger configuration 5a and the second finger configuration 5b being simply rotated in conjunction with each other, the first finger configuration 5a and the second finger configuration are driven by the fifth actuator 50. Each of 5b may be driven to rotate following the shape of the object to be grasped. For example, the technique disclosed in Japanese Patent Application Laid-Open No. 2015-112650 can be adopted as each finger configuration for conforming to the shape of the grasped object.

<Arrangement of each actuator in the hand mechanism 1>
In the hand mechanism 1 having each finger portion configured as described above, the arrangement of the actuator corresponding to each finger portion is determined from the viewpoint of miniaturization of the hand mechanism 1. Therefore, the arrangement will be described with reference to FIG. FIG. 9 shows the positional relationship between each finger portion and the corresponding actuator when the hand mechanism 1 is viewed from the back side of the hand. First, the 4th actuator 40 corresponding to the operation finger part 4 is arrange | positioned in the base vicinity of the finger structure. Further, a third actuator 45, which is another actuator corresponding to the operation finger portion 4, is disposed in the vicinity of the root of the first finger configuration 5 a of the auxiliary finger portion 5. Even when the third actuator 45 is thus displaced from the position of the operation finger portion 4, the first finger portion 48 is arranged beside the swing link 47 as shown in FIG. 4 can be configured without hindrance. In addition, since the 5th actuator 50 is not located in the base vicinity of the 1st finger structure 5a as shown in FIG. 8, it is possible to arrange | position the 3rd actuator 45 in the said place. And the 5th actuator 50 corresponding to the auxiliary finger part 5 is arrange | positioned in the base vicinity of the 2nd finger structure 5b of the auxiliary finger part 5. FIG.

Next, with respect to the thumb portion 3, the second actuator 35 is disposed therein, and the first actuator 30 is more of the hand main body portion 2 than the third actuator 45, the fourth actuator 40, and the fifth actuator 50. It is arranged on the base end side. Considering that the thumb portion 3 has the configuration shown in FIG. 4, the hand main body portion 2 can be obtained by disposing the first actuator 30 on the most proximal side among the actuators related to the hand mechanism 1 in this way. The attachment position of the thumb part 3 can be the most proximal side. Therefore, it is possible to secure as large a gripping space as possible by the thumb portion 3 in the hand mechanism 1, which contributes to downsizing of the hand mechanism 1 as a result. Further, when the thumb part 3 performs the bending operation on the hand main body part 2, the gripping auxiliary surface 3d is formed on the thumb part 3, so that the object to be grasped enters the turning part of the bending operation. This can be prevented, and stable gripping can be realized.

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

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

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

In addition, when the gripping target object 100 is relatively thick, the gripping target object 100 may be stably supported by appropriately bending each finger configuration of the auxiliary finger portion 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 operation finger portion 4 is provided with two degrees of freedom regarding the bending operation, and the auxiliary finger portion. 5 is given one degree of freedom with respect to the bending operation. These degrees of freedom are the degrees of freedom of each finger necessary to approximate the gripping operation by the hand mechanism 1 by a human gripping operation. By setting such degrees of freedom for each finger, a suitable gripping operation approximated by a human gripping operation in the hand mechanism 1 is realized with a minimum configuration, and thus the hand mechanism 1 can be downsized. It becomes possible to plan.

DESCRIPTION OF SYMBOLS 1 ... Hand mechanism, 2 ... Hand main-body part, 3 ... Thumb part, 3a ... Holding surface, 3b ... Projection part, 3c ... Case, 4 ... Operating finger part 5 ... auxiliary finger part, 10 ... driver placement part, 30 ... first actuator, 35 ... second actuator, 45 ... third actuator, 40 ... fourth actuator, 50 ... Fifth actuator

Claims

A hand mechanism configured to be able to grip a gripping object with a plurality of fingers,
When gripping the gripping object in the first gripping state, the first support part can support the gripping object, and the support part is different from the first support part, and the gripping object is A hand main body having a second support that can support the object to be gripped when gripping in a gripping state;
A first drive transmission that is attached to the hand main body and causes the thumb to pivot about the hand main body between a gripping position in the first gripping state and a gripping position in the second gripping state by a first actuator. And a thumb part having a second drive transmission part that bends the thumb part with respect to the hand body part by a second actuator,
A third drive transmission unit that is attached to the hand body unit and bends the operation finger unit with respect to the hand body unit by a third actuator; A drive transmission unit, wherein a fourth actuator causes a part of the operation finger part on the distal end side from the fourth drive transmission part to be a part of the operation finger part on the proximal side from the fourth drive transmission part. An operation finger portion having a fourth drive transmission portion that bends against
An auxiliary finger portion having a fifth drive transmission portion attached to the hand main body portion and bending the auxiliary finger portion with respect to the hand main body portion by a fifth actuator;
Comprising 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 part is a side support part located at a side part of the hand main body part.
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 that does not interfere with the front support portion in the hand body portion,
Each of the third actuator and the fourth actuator is a linear actuator, and each output shaft is coupled to the operation finger portion via a first operation finger link mechanism and a second operation finger link mechanism,
The fifth actuator is a linear actuator, and an output shaft thereof is connected to the auxiliary finger part via an auxiliary finger link mechanism,
The first actuator is a linear actuator, and an output shaft of the first actuator is coupled to the thumb portion via a thumb link mechanism. The first actuator includes the third actuator and the fourth actuator in the hand body portion. Arranged on the proximal end side of the hand main body from the actuator and the fifth actuator,
The hand mechanism according to claim 2.
The second actuator is disposed in a housing of the thumb part.
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 support portion of the hand main body portion, 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 protruding portion of the thumb portion is accommodated inside the hand main body portion with the gripping space reduced. Configured as
The hand mechanism according to claim 5.
A driver arrangement portion is provided on the back portion of the hand main body portion, in which drive drivers for the first actuator, the third actuator, the fourth actuator, and the fifth actuator are arranged,
A driving driver of the second actuator is disposed in a housing of the thumb portion;
The hand mechanism according to any one of claims 4 to 6.