JP4100622B2 - Robot hand - Google Patents

Description

  The present invention relates to a multi-finger articulated robot hand that resembles the shape of a human hand.

  As such a multi-finger multi-joint type robot hand, for example, one disclosed in Patent Document 1 is generally known. In the robot hand disclosed in this document 1, five fingers are connected to the palm, and each finger has a base joint portion, a middle joint portion, and a terminal joint portion sequentially from each other via joint axes. It is a connected structure. Then, each node is rotated and driven around the joint axis by a motor so that the fingers are bent and stretched. In addition, the joint shaft that connects the palm and the base joint portion is configured to be swingable about an axis orthogonal to the joint axis, and is driven by a motor. Is configured to swing.

Motors that drive each joint of the finger around the joint axis are mounted on adjacent joints. Specifically, the motor that drives the end joint is the middle joint, and the motor that drives the middle joint is Motors for driving the base joints are respectively mounted on the palms of the base joints, and the rotational driving force of each motor is transmitted to the respective joints via a gear transmission mechanism.
Japanese Patent Laid-Open No. 11-156778

  The robot hand disclosed in Patent Document 1 has room for improvement in the following points.

  That is, in the multi-finger multi-joint type robot hand, it is preferable that a torque as high as possible can be generated in each node portion in order to improve fingertip responsiveness or to secure a gripping force.

  However, in the configuration of Patent Document 1 in which a motor for driving the middle joint and the last joint is mounted on the finger itself (that is, the base joint and the middle joint) and the finger is driven, due to restrictions on strength and size. The motor that can be mounted is subject to restrictions, and the freedom of motor selection is low. For this reason, there are cases where sufficient torque cannot be secured due to restrictions due to the size and weight of the motor. In particular, in a robot hand having a size close to that of a human hand, a motor that can be mounted on each node is limited to a very small one, and it is difficult to secure torque.

  Therefore, in recent years, it has been considered that all motors for bending and extending the fingers are mounted on the palm, and the middle and end nodes are driven using wires. However, the mechanism for driving a finger with a wire cannot be said to be sufficient in terms of rigidity, and there is a problem that the wire is easily stretched and cut during driving and has low reliability. In addition, when all the motors that perform bending and stretching and swinging of fingers are mounted on the palm, considering the practicality, the drive mechanism for bending and stretching and swinging of each finger needs to be compactly housed in the palm. Therefore, it is necessary to solve this point.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to appropriately drive a finger with high torque in a multi-finger multi-joint robot hand similar to the shape of a human hand. It is to provide a highly reliable robot hand that can be made, and more preferably, to make a multi-finger multi-joint robot hand compact.

To solve the above problem,
The invention according to claim 1 comprises a palm and a plurality of fingers connected to the palm, wherein the fingers are connected to the palm so as to be turnable sequentially via a joint shaft. In the robot hand configured to be able to bend and extend by being configured to be able to bend and extend by using the connecting portion with the palm as a fulcrum in the arrangement direction thereof, of the unit nodes constituting the finger A bending and stretching drive mechanism for bending and stretching the finger by rotating and driving the first unit node directly connected to the palm and the second unit node connected to the first unit node around a joint axis; a shall a swing drive mechanism for oscillating the finger by rotating the joint shaft for connecting the palm and the first unit knuckles around an axis orthogonal to the articulation axis, before Symbol this said joint shaft connecting the palms and the first unit knuckles A cross-shaped joint member connected to a swing shaft extending in a direction orthogonal to the first and second bevel gears is provided on the swing shaft of the joint member so as to be rotatable on both sides of the joint shaft. while being mounted, together with the third bevel gear to the joint axis of the joint member is rotatably mounted in a state of meshing with the first bevel gear, the opposite of the third bevel gear across the oscillation axis of said joint axis the fourth bevel gear is rotatably mounted in a state of meshing with the second bevel gear to the portion of the side, while the front Symbol third Beberua is connected to said first unit knuckles, the fourth bevel gear is said second It is connected to the link mechanism components for transmitting a rotational driving force to the two units knuckles, further rotation the first unit knuckles so as to bend and stretch the fingers and the second unit knuckles each of the joint axis Drive First for a second motor, and a third motor for rotating the joint shaft for connecting the palm and the first unit knuckles to pivot the fingers around an axis perpendicular to the articulation axis Is mounted on the palm, the rotational driving force of the first motor is applied to the first bevel gear, the rotational driving force of the second motor is applied to the second bevel gear, and the rotational driving force of the third motor is applied to the swing shaft of the joint member. The bending and stretching drive mechanism and the swinging drive mechanism are configured so as to be transmitted to each other.

The invention according to claim 2
The robot hand according to claim 1, wherein the third unit knuckles via a joint shaft to the tip of the second unit knuckles pivotally coupled to further second unit knuckles against the first unit knuckles In conjunction with this rotation, an interlocking mechanism is provided for rotating the third unit node relative to the second single node about the joint axis.

The invention according to claim 3
The robot hand according to claim 1 or 2, while the first and second motors are arranged in the thickness direction in the palm, the third to these first and second motors A motor is arranged side by side in the longitudinal direction of the finger.

According to the robot hand according to claim 1, a first motor mounted on the palm, bending driving Organization to drive the second unit knuckles are configured, the second unit not only the first unit knuckles A motor for driving the joint is also mounted on the palm. Therefore, the degree of freedom in selecting the motor that drives the second unit node is also increased, and both the first and second unit nodes can be driven by a high-output (high torque) motor. Moreover, since the driving Organization for driving the second unit knuckles and a link mechanism, without involving trouble such elongation and disconnection, such as the drive mechanism using the wire, to ensure the power second unit Can be transmitted to the node. Therefore, it is possible to provide a highly reliable robot hand that can appropriately drive a finger with higher torque. In addition, since it is possible to reduce the weight of the finger, there is an effect that the finger can be moved more quickly.

Further, according to this robot hand, the rotational driving force of the first motor is first transmitted to the first unit knuckles through the third bevel gear, whereby the first unit knuckles against the palm of the joint member It is driven to rotate around the joint axis. Further, the rotational driving force of the second motor is transmitted to the second unit node via the second and fourth bevel gears and the link mechanism constituent member, whereby the second unit node is articulated with respect to the first unit node. It is driven to rotate around the axis. Furthermore, the joint member (swing shaft) is driven by the third motor, so that the finger (first unit node) swings with respect to the palm. According to this configuration, it is possible to transmit the driving force of each motor to the first unit node portion or the like with a compact configuration in which the joint member and the gear are combined. Therefore, it is possible to suppress the area occupied by the bending drive motor Kamao and swing drive mechanism per one finger, it is possible to construct a robot hand more compact.

According to the robot hand of the second aspect , even if the finger further has the third unit joint, a dedicated motor for driving the third unit joint is not required. Therefore, it is possible to reduce the weight of the finger, and it is possible to move the finger more quickly. Further, compared with a conventional robot hand of this type in which the third unit node is driven by a dedicated motor, the robot unit can be manufactured at a lower cost because a dedicated motor is not required for the third unit node. There is also a merit.

According to the robot hand according to claim 3, the motors of the bending drive motor Kamao and swing drive mechanism it is possible to mount a compact for each finger with respect to the palm, the robot hand a compact structure It becomes possible. In other words, it is possible to keep the respective motors determined palm size bending drive motor Kamao and swing drive mechanism into a compact for each finger.

  The best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 schematically shows a robot hand according to the present invention in a plan view. A robot hand 10 shown in the figure is a multi-finger multi-joint type robot hand including a palm 12 and fingers connected to the palm 12, and includes four fingers 14a to 14d in the illustrated example. Each finger 14a-14d consists of a base joint part 16, a middle joint part 17, and a terminal joint part 18, and these unit joint parts are sequentially connected to the palm 12 in that order via the joint shaft so as to be rotatable. It is configured to be able to bend and stretch, and is configured to be swingable in the left-right direction (the direction in which the fingers 14a to 14d are arranged) with respect to the palm 12, as indicated by the arrows in FIG. Each is driven. Hereinafter, the fingers 14a to 14d and the driving mechanism thereof will be described in detail. Since the fingers 14a to 14d have a common configuration, in the following description, the rightmost finger 14a in FIG. 1 will be described as an example.

  2 to 5 show the configuration of the finger 14a and its driving mechanism in a side view, a longitudinal sectional view, a perspective view (simplified view), and a plan sectional view, respectively.

As shown in these figures, the base portion 16, the middle portion 17 and the end portion 18 constituting the finger 14a are formed in a U-shaped cross section that opens on the ventral side of the hand (the right side in FIGS. 2 and 3). In addition, the joints on the fingertip side are rotatably connected via the joint shafts 19a and 19b in a state where the joints are sequentially inserted into the joints on the palm 12 side. Specifically, the proximal end portion of the middle joint portion 17 is inserted into the distal end portion of the proximal joint portion 16, and both joint portions are rotatably connected to each other via the joint shaft 19 a at the insertion portion. The proximal end portion of the end node portion 18 is inserted into the distal end portion of each of the two nodes, and both the node portions are connected to each other via the joint shaft 19b at the insertion portion.

  A side wall 16a of the base joint portion 16 extends downward, and a joint shaft 20 provided in parallel with the joint shafts 19a and 19b is rotatably inserted over the side walls 16a. The joint shaft 20 penetrates the drive shaft 21 (oscillation shaft) extending in the direction orthogonal to this, that is, in the thickness direction of the palm 12 (the left-right direction in FIGS. And connected so as to be relatively rotatable. In this embodiment, the joint member of the present invention is constituted by the joint shaft 20 and the drive shaft 21 thus connected in a cross shape.

  The drive shaft 21 is connected to an output shaft of a motor 22 (third motor) fixed to a frame (not shown) of the palm 12, and is driven to rotate by the motor 22. As the motor 22 and the motors 32 and 34 described later, for example, a servo motor incorporating a speed reduction mechanism is applied.

As shown in FIG. 5, two large and small bevel gears 24 and 26 are mounted on the joint shaft 20 on both sides of the drive shaft 21 so as to face each other and to be rotatable relative to the joint shaft 20. Yes. One of these gears 24, 26 (the larger one) bevel gear 24 (third bevel gear) is fixed to the side wall 16 a of the base portion 16. Further, the bevel gear 26 on the other side (the fourth bevel gear) link 46 (link mechanism component) is assembled integrally. On the other hand, two large and small bevel gears 28 and 30 are mounted on the drive shaft 21 on both sides of the joint shaft 20 so as to face each other and to be rotatable relative to the drive shaft 21. The bevel gear 28 (first bevel gear) on one side (the larger one) of these gears 28 and 30 is connected to the bevel gear 24 inserted into the joint shaft 20, and the bevel gear 30 (second bevel gear) on the other side is The bevel gears 26 are meshed with each other.

  Below the joint shaft 20 and the drive shaft 21, the two motors 32, 34 for bending and extending the fingers 14 a are arranged upward and along the drive shaft 21. It is fixed to.

A bevel gear 38 is fixed to the tip of the output shaft 36 of the motor 32 (second motor) on one side (the right side in FIGS. 2 and 3) of these motors 32, 34, and this bevel gear 38 is inserted into the drive shaft 21. Meshed with the bevel gear 30. A pulley-integrated bevel gear 44 is inserted into a middle portion of the output shaft 36 of the motor 32 (a portion between the bevel gear 38 and the motor main body) in a relatively rotatable state, and the bevel gear 44 is driven. It meshes with the bevel gear 28 inserted into the shaft 21. A drive belt 41 is stretched over a pulley 44a (pulley portion) of the bevel gear 44 between a pulley 42 fixed to the output shaft 40 of the motor 34 (first motor) on the other side. Thus, the bevel gear 44 is configured to be rotationally driven around the output shaft 36.

As shown in FIGS. 2 to 4, a link 48 is connected by a pin between the middle node portion 17 and the link 46 among the unit node portions constituting the finger 14 a. More specifically, the position of the proximal end portion of the middle joint portion 17 on the ventral side of the hand relative to the joint shaft 19 a and the link 46 are connected to a linear link 48. Further, the distal end portion of the base joint portion 16 and the proximal end portion of the end joint portion 18 are connected by a link 50 with a pin. The link 50 is formed in a substantially Z-shape and is connected to a position on the back side of the hand relative to the joint axis 19a in the base node 16 and a position on the ventral side of the hand relative to the joint axis 19b in the end node 18. Has been.

  Next, the operation of the robot hand 10 will be described.

  As shown in FIG. 2 and the like, in the extended state of the finger 14a in which the respective nodes 16 to 18 extend straight, first, the finger 14a is swung with respect to the palm 12 (see the white arrow in FIG. 1). The drive shaft 21 is rotationally driven by the motor 22. When the drive shaft 21 is rotationally driven in this way, the joint shaft 20 swings with the intersection point with the drive shaft 21 as a fulcrum, and as a result, the finger 14a swings with respect to the palm 12. .

On the other hand, to bend the finger 14a from the extended state, the bevel gear 44 is rotationally driven by the motor 34. When the bevel gear 44 is driven in this way, the rotational driving force is transmitted to the base joint portion 16 (side wall 16a) via the bevel gear 28 and the bevel gear 24. As a result, as shown in FIG. The part 16 rotates and the finger 14a tilts to the ventral side of the hand. In this case, the link 46 (bevel gear 26) is rotated by rotationally driving the bevel gear 38 together with the driving of the bevel gear 44 . That is, as described above, since the base joint portion 16 and the middle joint portion 17 of the finger 14a are connected by the link 48, if only the base joint portion 16 is rotated around the joint axis 20, the link 48 Movement is hindered. Therefore, in order to avoid this, the link 46 is rotated as indicated by an arrow in the drawing in accordance with the rotation amount (angle) of the base portion 16. Specifically, the bevel gear 38 is rotationally driven by the motor 32. When the bevel gear 38 is driven in this way, the rotational driving force is transmitted to the bevel gear 26 via the bevel gear 30, and as a result, the link 46 integrally assembled with the bevel gear 26 rotates.

  The above operation is a case where the finger 14a is bent to the ventral side of the hand with respect to the palm 12 in the extended state. However, when the finger 14a is bent from the middle portion thereof, the link 46 (bevel gear 26) is moved from the above position. Rotate further. When the link 46 is thus rotated, the middle node portion 17 is pulled to the ventral side of the hand via the link 48 as shown in FIG. 7, and as a result, the middle node portion 17 rotates with the joint shaft 19a as a fulcrum. Then, the middle joint portion 17 is bent to the palm side with respect to the base joint portion 16. Then, when the middle joint portion 17 is bent with respect to the base joint portion 16 in this way, the distal joint portion 18 is pulled through the link 50, and as a result, the distal joint portion 18 rotates about the joint shaft 19b as a fulcrum. The end node 18 is bent to the ventral side of the hand with respect to the node 17.

  Here, the operation of bending the entire finger 14a with respect to the palm 12 with the joint shaft 20 as a fulcrum and the operation of bending the middle joint portion 17 and the base joint portion 16 with the joint shafts 19a and 19b as fulcrums are described separately. However, the refraction operation of the finger 14a can be smoothly performed by performing these operations in parallel. Moreover, the finger | toe 14a can be returned to an expansion | extension state by performing operation | movement contrary to the above operations.

  In the above description, the configuration and driving mechanism of one finger 14a among the fingers 14a to 14d of the robot hand 10 have been described, but the other fingers 14b to 14d are configured in the same manner as the finger 14a. ing. Accordingly, it is possible to realize a movement close to a human hand by swinging and bending the fingers 14a to 14d.

According to the configuration of the robot hand 10 as described above, the drive mechanism is configured to drive not only the base joint portion 16 but also the middle joint portion 17 by the motor 32 mounted on the palm 12. There is no restriction on the size and weight of the motor 32 depending on the size and strength of the base portion 16, unlike the conventional robot hand of this type in which a motor for driving is mounted on the base portion. In other words, the degree of freedom in selecting a motor for driving the middle joint portion 17 can be increased. Accordingly, not only the base joint part 16 but also the middle joint part 17 can be driven by a motor with higher output (high torque), and as a result, each finger of the robot hand 10 can be driven with higher torque. Become.

  In addition, since the middle joint portion 17 is driven using a link mechanism (links 46, 48, etc.), there is no trouble such as extension or disconnection of the power transmission medium as in a drive mechanism using a wire. The rotational driving force can be reliably transmitted to the middle joint portion 17. Therefore, the finger 14a can be appropriately driven with higher torque, and a highly reliable robot hand can be provided.

  Further, in the robot hand 10, the end node portion 18 is linked to the movement of the middle node portion 1 using a link mechanism (that is, by providing a linkage mechanism), so that no motor is applied to the fingers 14 a (˜14 d). Since the finger 14a (˜14d) can be driven without being mounted, the finger 14a (˜14d) can be significantly reduced in weight compared to this type of conventional ballot hand. Accordingly, there is an effect that the finger 14a (˜14d) can be moved more quickly. In addition, there is a feature that the robot hand 10 can be manufactured at low cost and the control configuration can be simplified because a motor for driving the end joint 18 is not necessary.

  Further, as described above, a cross-shaped joint member in which the joint shaft 20 and the drive shaft 21 are orthogonal to each other is provided, and by rotating the drive shaft 21 by the motor 22, the fingers 14a (˜14d) are swung. The bevel gears 24, 26, 28 and 30 are attached to the shafts 20, 21 of the joint members, and the rotational drive force of the motor 34 is transmitted to the base joint portion 16 via the bevel gears 28, 24, thereby the base joint portion 16. Since the drive mechanism is configured to drive the middle joint 17 by transmitting the rotational driving force of the motor 32 to the middle joint 17 via the bevel gears 30, 26, etc., as described above. The robot hand 10 can be configured to be compact by allowing the finger 14a (˜14d) to swing and bend and stretch with a compact mechanism that combines a simple joint member and a bevel gear. It can be.

  In particular, the motor 22 for swinging the finger among the motors 22, 32, 34 is directed in the thickness direction of the palm 12 (that is, the output shaft 21 extends in the thickness direction), and the lower side of the motor 22 (the finger The motors 32 and 34 for finger bending and extending are arranged in the longitudinal direction of 14a, and the motors 32 and 34 are arranged side by side in the thickness direction, so that a large motor having a relatively high output (high torque) can be obtained. Even when used, the motors 22, 32, and 34 can be efficiently mounted on the palm 12 for each finger. Accordingly, in combination with the configuration for transmitting the driving force as described above, the entire robot hand can be configured compactly.

The robot hand 10 described above is the best mode for carrying out the present invention, and the specific configuration thereof can be changed as appropriate without departing from the gist of the present invention .

For example, in the above example, the end joint 18 is configured to be driven by interlocking with the movement of the middle joint 17 using a link mechanism, but it is configured to be driven by a dedicated motor as in the prior art. May be. For example, as shown in FIG. 8, a bevel gear 52 that can rotate around the joint shaft 19 a is provided and fixed to the end node 18, and the gear 52 is attached to the output shaft of the motor 54 mounted on the middle node 17. The bevel gear 56 may be engaged, and the end node 18 may be driven by the motor 54. According to this structure, since the end node part 18 can be driven independently, there exists an advantage that the freedom degree of a motion of a fingertip part increases. In the case of this configuration, the motor 54 is mounted on the middle joint portion 17. However, since the motor 32 that drives the middle joint portion 17 is mounted on the palm 12, regarding the size and weight of the motor 32. Are not constrained .

Also, in the above example, each finger 14a~14d are all Motobushi unit 16, has the 3-joint of the finger structure with the middle section 17 and the end joint portion 18, second joint or 4, It may be a finger structure having a joint larger than the joint. Also, the number of fingers is not limited to four, and may be three or five or more.

It is a top view (schematic diagram) showing a robot hand concerning the present invention. It is a side view (A arrow line view of FIG. 1) which shows the structure of a finger | toe and its drive mechanism. It is a longitudinal cross-sectional view of FIG. It is a perspective view (simplified figure) which shows a part of finger | toe and its drive mechanism. FIG. 3 is a cross-sectional view taken along the line BB in FIG. 2 showing a part of the drive mechanism. It is a side view explaining the bending | flexion and extension operation | movement of a finger | toe. It is a side view explaining the bending | flexion and extension operation | movement of a finger | toe. It is principal part sectional drawing of the finger | toe which shows the modification of a robot hand.

Explanation of symbols

10 Robot Hand 12 Palm 14a-14d Finger (Finger)
16 Base section (first unit section)
17 Middle section (second unit section)
18 End section (third unit section)
22, 32, 34 Motor 19a, 19b, 20 Joint shaft

Claims (3)

A palm and a plurality of fingers connected to the palm, and the fingers can bend and stretch by being composed of a plurality of unit joints that are sequentially connected to the palm via a joint axis. And a robot hand configured to be able to swing in the direction of their alignment with the connecting portion with the palm as a fulcrum,
By rotating and driving the first unit node directly connected to the palm and the second unit node connected to the first unit node among the unit nodes constituting the finger, about the joint axis, respectively. A bending / stretching drive mechanism for bending and stretching a finger; and a swinging drive mechanism for swinging the finger by rotationally driving a joint shaft connecting the first unit node and the palm around an axis orthogonal to the joint axis; a shall include a,
A cross-shaped joint member is provided in which a swing shaft extending in a direction orthogonal to the joint shaft connecting the palm and the first unit node is connected, and a first joint is provided on the swing shaft of the joint member. And the second bevel gear is rotatably mounted on both sides of the joint shaft, while the third bevel gear is rotatably mounted on the joint shaft of the joint member while meshing with the first bevel gear. A fourth bevel gear is rotatably mounted on a portion of the joint shaft on the opposite side of the third bevel gear across the swing shaft so that the fourth bevel gear is engaged with the second bevel gear. The fourth bevel gear is connected to a link mechanism component for transmitting a rotational driving force to the second unit node, and further, the first unit is bent to extend and contract the finger. Nodal part and number First and second motors for rotationally driving the unit joints around the joint axis, and a joint axis for connecting the first unit joint and the palm to swing the finger are orthogonal to the joint axis. And a third motor for rotationally driving around the rotating shaft, the rotational drive force of the first motor being applied to the first bevel gear, the rotational drive force of the second motor being applied to the second bevel gear, and the third motor. The robot hand is characterized in that the bending / stretching drive mechanism and the swinging drive mechanism are configured such that the rotational driving force is transmitted to the swinging shaft of the joint member . The robot hand according to claim 1, wherein
A third unit node is rotatably connected to a tip of the second unit node via a joint shaft, and the third unit node is rotated with the rotation of the second unit node relative to the first unit node. robot hand, characterized in that the interlocking mechanism has been found provided that parts to pivot the joint axis of the second single knuckles. The robot hand according to claim 1 or 2,
The first and second motors are arranged side by side in the thickness direction of the palm, while the third motor is arranged side by side in the longitudinal direction of the finger with respect to the first and second motors. Characteristic robot hand.