JP2016215374A - Robot hand and robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a small-sized robot hand capable of moving fingers in a plurality of directions at portions of joints but having a simple configuration.SOLUTION: A second member having a longitudinal shape is attached to a first member via a coupling member. The coupling member is caused to be rotatable about a first axis in a direction intersecting with a longitudinal direction of the second member with respect to the first member and to be rotatable about a second axis in a direction intersecting with both the longitudinal direction and the direction of the first axis with respect to the second member. Further, a first driving section rotationally driving the coupling member about the first axis is provided to the first member, and a second driving section rotationally driving the coupling member about the second axis is provided to the second member. Thus, it is possible to realize a small-sized robot hand causing the first member and the second member to be rotatable about the second axis as well as the first axis but having a simple configuration.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a robot hand and a robot.

  A robot hand capable of holding an object using a finger is known. In this robot hand, an object is held by bending a finger at a joint portion. Here, the “bending direction” is a direction in which a finger is bent when a person holds an object. In order to be able to grip various objects with the robot hand, it is desirable to have a joint that can move the finger not only in the bending direction at the joint but also in a direction different from the bending direction. .

  Therefore, a technique has been proposed in which a joint is formed by combining a second joint axis for moving a finger in the bending direction and a first joint axis for rotating the finger together with the second joint axis in a direction different from the bending direction ( Patent Document 1).

JP 2004-009281 A

  However, in the proposed technique, the main joint portion is fitted on the first joint shaft fixed to the apparatus main body side, and the arc-shaped second joint movable portion is rotatable on the outer peripheral portion of the main joint portion. It is pivotally supported. Then, the main joint portion is turned around the first joint axis using the first motor, and the second joint movable portion is turned using the linear step motor. For this reason, there has been a problem that the structure of the joint portion becomes complicated and the robot hand becomes large.

  The present invention has been made in order to solve the above-described problems of the prior art, and can be moved in a plurality of directions at a joint portion, but has a simple structure and a small robot. The purpose is to provide a technology capable of realizing a hand.

In order to solve at least a part of the problems described above, the robot hand of the present invention employs the following configuration. That is,
A first member;
A second member having a longitudinal shape;
A member that connects the first member and the second member, and is attached to the first member so as to be rotatable about a first axis in a direction intersecting a longitudinal direction of the second member. A connecting member attached to the second member so as to be rotatable about a second axis in a direction intersecting both the longitudinal direction and the direction of the first axis;
A first drive unit provided on the first member to rotate the coupling member around the first rotation axis;
A second drive unit provided on the second member for rotating the coupling member around the second rotation axis;
It is characterized by providing.

  In such a robot hand of the present invention, the second member having the shape in the longitudinal direction is attached to the first member via the connecting member. The connecting member is attached to the first member so as to be rotatable about a first axis in a direction intersecting the longitudinal direction of the second member, and a first drive provided on the first member. The connecting member can be rotated around the first axis by using the portion. Further, the connecting member is attached to the second member so as to be rotatable about the second axis in the direction intersecting both the longitudinal direction and the direction of the first axis, and is provided on the second member. The connecting member can be driven to rotate around the second axis by using the second driving unit. Therefore, the first member and the second member can be rotated not only in the direction around the first axis but also in the direction around the second axis. It can be realized.

  In the robot hand of the present invention described above, the longitudinal direction of the second member, the first axis, and the second axis may be orthogonal to each other.

  In this way, the movement direction of the second member when rotated about the first axis and the movement direction of the second member when rotated about the second axis are independent of each other, and The movement direction associated with the rotation does not include the component of the movement direction associated with the rotation around the second axis. For this reason, it is possible to simplify the control of the first drive unit that rotates the connecting member around the first axis and the second drive unit that rotates the connecting member around the second axis.

  In the robot hand of the present invention described above, one of the first axis and the second axis may be provided at a position offset from the center of gravity of the cross section taken by the plane perpendicular to the longitudinal direction of the second member.

  When the first axis and the second axis are not offset with respect to the center of gravity of the cross section taken by the plane perpendicular to the longitudinal direction of the second member, the cross section of the second member is the first axis and the second axis. In any case, the shape is uniform. For this reason, the movable range of the second member is almost the same regardless of the rotation direction for any of the axes. On the other hand, if one of the first axis and the second axis is offset from the center of gravity of the cross section of the second member, the cross-sectional shape is biased to one side with respect to the offset axis. For this reason, it is possible to expand the movable range of the second member in the offset direction for the offset shaft.

  In the robot hand of the present invention described above, the first member may also be a member having a shape having a longitudinal direction.

  In this way, it is possible to realize a robot hand that can be bent in a direction other than bending by a joint for bending the finger part of the robot hand.

  In the robot hand of the present invention described above, the first drive unit and the second drive unit may be a vibrating body that includes a piezoelectric material.

  In this way, the first drive unit and the second drive unit can be formed in a small size, and thus the robot hand can be downsized. Further, when the method of driving by vibrating the vibrating body is adopted, the connecting member does not rotate around the first axis and the second drive unit is not vibrated while the first drive unit is not vibrated. During this time, the connecting member does not rotate around the second axis. For this reason, the electric power for maintaining the same attitude becomes unnecessary, and power saving can be realized.

  The robot hand of the present invention described above may include a first reduction mechanism that decelerates the rotation of the first drive unit and transmits it to the connecting member.

  If it carries out like this, the drive force which the 1st drive part generated can be increased and transmitted to a connection member. Further, since the movement of the first drive unit is decelerated and transmitted to the connecting member, it is possible to control the fine movement of the connecting member.

  Further, the robot hand of the present invention described above may include a second speed reduction mechanism that decelerates the rotation of the second drive unit and transmits it to the connecting member.

  If it carries out like this, the drive force which the 2nd drive part generated can be increased and it can tell to a connection member. Moreover, since the movement of the second drive unit is decelerated and transmitted to the connecting member, it is possible to control the fine movement of the connecting member.

The robot hand of the present invention can be grasped in the following manner. That is,
A first member;
A second member having a longitudinal shape;
A connecting member that connects the first member and the second member;
Connecting the first member and the connecting member, a first shaft provided in a direction intersecting the longitudinal direction of the second member;
A second shaft that connects the second member and the connecting member, and is provided in a direction that intersects both the longitudinal direction and the direction of the first axis;
A first drive unit provided on the first member to rotate the coupling member around the first rotation axis;
A second drive unit provided on the second member for rotating the coupling member around the second rotation axis;
It is also possible to grasp in the form of a robot hand characterized by comprising

Alternatively, the robot hand of the present invention is
A first member;
A second member having a longitudinal shape;
A connecting member that connects the first member and the second member;
A first vibrating body provided on the first member and configured to vibrate in a bending direction and a stretching direction;
A first shaft that connects the first member and the connecting member, and is provided in a direction intersecting the expansion and contraction direction of the first vibrating body;
A second shaft that connects the second member and the connecting member, and is provided in a direction that intersects both the longitudinal direction and the expansion / contraction direction of the first vibrating body;
A second vibrating body provided on the second member for vibrating in a bending direction and an expansion / contraction direction, and provided in a direction in which the bending direction and the expansion / contraction direction intersect the second axis;
With
The first vibrating body rotates the connection member around the first rotation axis,
The second vibrating body can be grasped in the form of a robot hand in which the connecting member is driven to rotate about the second rotation axis.

  The robot hand of the present invention grasped in these aspects can also rotate the first member and the second member not only in the direction around the first axis but also in the direction around the second axis. Nevertheless, it is possible to realize a robot hand with a simple structure and a small size.

  Further, the robot hand of the present invention described above can be formed in a small size while being able to rotate the first member and the second member in the direction around the first axis and the direction around the second axis. . Therefore, a high-performance robot can be realized by mounting the robot hand of the present invention on the robot.

It is explanatory drawing which showed the external appearance shape of the robot hand of a present Example. It is explanatory drawing which showed the structure of the finger | toe part of the robot hand of a present Example. It is the perspective view which showed the structure of the piezoelectric motor which drives a finger | toe part. It is explanatory drawing which shows the operation principle of a piezoelectric motor. It is explanatory drawing which showed the operation | movement which the robot hand of a present Example bends and expand | extends a finger part. It is explanatory drawing which showed the operation | movement which the robot hand of a present Example inclines a finger | toe part to right and left. It is explanatory drawing which showed the structure of the joint part of the robot hand of a 1st modification. It is explanatory drawing which showed the structure of the finger | toe part of the robot hand of a 2nd modification. It is explanatory drawing which showed the structure of the finger | toe part of the robot hand of a 3rd modification. It is explanatory drawing which showed the structure of the finger | toe part of the robot hand of a 4th modification. It is explanatory drawing which illustrated the robot which mounted the robot hand of the Example and the modification on the front-end | tip of an arm.

  FIG. 1 is an explanatory diagram showing the external shape of the robot hand 10 of this embodiment. As shown in the figure, the robot hand 10 of this embodiment has a structure in which five finger parts 100 are provided on the palm part 150. Each finger part 100 includes a substantially cylindrical fingertip member 120, a substantially cylindrical intermediate member 110, and a connecting member 130 that connects the intermediate member 110 to the palm part 150. As will be described in detail later, one end of the fingertip member 120 is pivotally supported so as to be rotatable in a bending direction with respect to one end of the intermediate member 110, and a joint structure is formed between the fingertip member 120 and the intermediate member 110. Yes. Further, the other end of the intermediate member 110 is pivotally supported so as to be rotatable in a bending direction with respect to one end of another intermediate member 110, and a joint structure is also formed between the intermediate member 110 and the intermediate member 110. Yes. Further, the intermediate member 110 and the palm 150 are connected via a connecting member 130 to form a joint structure that can rotate in two directions.

  When it is necessary to distinguish between the two intermediate members 110 provided on the finger part 100, the intermediate member 110 that forms a joint structure with the fingertip member 120 is referred to as a distal end side intermediate member 110a. The intermediate member 110 that forms a joint structure with the intermediate member 110a may be referred to as a root-side intermediate member 110b. In addition, the direction in which the four fingers 100 are lined up (left and right direction on the paper surface of FIG. 1) is referred to as “side surface direction”, and the side displayed in FIG. 1 is referred to as “ventral side” and is displayed in FIG. The non-side is sometimes referred to as the “back side”. Furthermore, the direction connecting the “abdominal side” and the “back side” (the direction perpendicular to the paper surface on the paper surface of FIG. 1) may be referred to as the “front and back direction”. In this embodiment, the palm 150 corresponds to the “first member” in the present invention, and the root side intermediate member 110b corresponds to the “second member” in the present invention.

  FIG. 2 is an explanatory diagram showing the structure of the finger unit 100 mounted on the robot hand 10 of this embodiment. In FIG. 2, the index finger is used for explanation, but the same applies to the other four fingers. 2A shows a state in which the finger part 100 is viewed from the ventral side, and FIG. 2B shows a state in which the finger part 100 is viewed from the side surface direction.

  First, the joint structure formed between the fingertip member 120 and the distal end side intermediate member 110a will be described. As shown in the figure, a semicircular disk-shaped driven portion 112 is provided projecting toward the fingertip member 120 at the approximate center of the end surface of the distal end side intermediate member 110a. A joint shaft 116 is inserted through the center position of the plate shape. Further, from the fingertip member 120, shaft support portions 114 protrude from both sides of the driven portion 112, and both ends of the joint shaft 116 inserted through the driven portion 112 are supported by the shaft support portions 114. . For this reason, the fingertip member 120 and the distal end side intermediate member 110a are connected to be rotatable around the joint shaft 116 (bending direction). Furthermore, a piezoelectric motor 200 described later is housed inside the fingertip member 120. As will be described later, the piezoelectric motor 200 is provided with a convex portion 212 (see FIG. 3), and the convex portion 212 is pressed against the driven portion 112.

  The joint structure formed between the distal end side intermediate member 110a and the root side intermediate member 110b is the same as the joint structure described above. That is, the driven portion 112 protrudes from the end surface of the root side intermediate member 110 b, and the joint shaft 116 is inserted through the driven portion 112. Further, a shaft support portion 114 protrudes from the distal end side intermediate member 110 a, and both ends of the joint shaft 116 inserted through the driven portion 112 are supported by the shaft support portion 114. For this reason, the front end side intermediate member 110a and the root side intermediate member 110b are connected so as to be rotatable around the joint axis 116 (bending direction). Further, the piezoelectric motor 200 is housed inside the distal end side intermediate member 110a, and the convex portion 212 (see FIG. 3) of the piezoelectric motor 200 is pressed against the driven portion 112.

  The connecting member 130 is formed in a shape in which a first driven part 132 formed in a semicircular disk shape and a second driven part 134 formed in a semicircular disk shape are combined. Further, the first driven part 132 and the second driven part 134 have the first driven part in a state in which the arc-shaped part is directed in the opposite direction (therefore, the semicircular diameter side part is back to back). The positional relationship is such that the driving unit 132 and the second driven unit 134 are twisted 90 degrees.

  Second shafts 136 protrude from both sides of the second driven portion 134 in the diametrical direction, and each of the second shafts 136 is provided by two shaft support portions 114 protruding from the end surface of the root side intermediate member 110b. It is pivotally supported. For this reason, the connecting member 130 and the root side intermediate member 110b are rotatable around the second axis 136 (bending direction). Similarly, a first shaft 138 protrudes from both sides in the diameter direction of the first driven portion 132, and each first shaft 138 is pivoted by two shaft support portions 152 protruding from the palm portion 150. It is supported. For this reason, the connecting member 130 and the palm 150 can rotate around the first axis 138. Further, the piezoelectric motor 200 is housed inside the root side intermediate member 110b and the palm portion 150, respectively. Among these, the convex part 212 (refer FIG. 3) of the piezoelectric motor 200 accommodated in the root side intermediate member 110b is pressed against the first driven part 132, and the convex part of the piezoelectric motor 200 accommodated in the palm part 150. 212 is pressed against the second driven portion 134.

  In this embodiment, the piezoelectric motor 200 housed in the palm 150 corresponds to the “first drive unit”, “vibrating body”, and “first vibrating body” in the present invention, and the root side intermediate member 110b. The piezoelectric motor 200 housed in the “corresponding” corresponds to the “second drive unit”, the “vibrating body”, and the “second vibrating body” in the present invention. Further, since the first driven portion 132 and the second driven portion 134 are in a positional relationship such that the first driven portion 132 and the second driven portion 134 are twisted by 90 degrees, the first shaft that protrudes on both sides in the diameter direction of the first driven portion 132. 138 and the second shaft 136 projecting from both sides of the elder brother direction of the second driven portion 134 are orthogonal to each other. Furthermore, the first shaft 138 and the second shaft 136 are also orthogonal to the central axis L of the root side intermediate member 110b formed in a substantially cylindrical shape.

  FIG. 3 is a perspective view showing the structure of the piezoelectric motor 200 housed in the fingertip member 120, the intermediate member 110, and the palm 150. As shown in the figure, the piezoelectric motor 200 has a cubic shape, and a metal flat plate between two piezoelectric elements (a front piezoelectric element 220 and a back piezoelectric element 221) formed into a plate shape including a piezoelectric material. It has a laminated structure in which the shim plate 210 formed in the above is sandwiched. Hereinafter, the longitudinal direction of the piezoelectric motor 200 is referred to as an X direction. Further, as shown in the figure, the short direction of the piezoelectric motor 200 orthogonal to the X direction is referred to as the Y direction, and the thickness direction of the piezoelectric motor 200 orthogonal to the X direction and the Y direction is referred to as the Z direction. .

  A surface electrode 222 for applying a voltage to the surface piezoelectric element 220 is provided on the surface (upper surface) opposite to the surface in contact with the shim plate 210 of the surface piezoelectric element 220, as shown in FIG. As described above, four rectangular surface electrodes 222 are provided so that the upper surface of the surface piezoelectric element 220 is divided into four in a lattice shape. Further, although not shown in the drawing, the back surface of the four rectangular shapes is similarly formed on the surface (lower surface) opposite to the surface in contact with the shim plate 210 of the back piezoelectric element 221 so that the lower surface is divided into four grids. An electrode 223 is provided. The metal shim plate 210 not only reinforces the piezoelectric elements (the front piezoelectric element 220 and the back piezoelectric element 221), but also serves as a common electrode for applying a voltage to the front piezoelectric element 220 and the back piezoelectric element 221. It has a role and is grounded to the ground.

  A convex portion 212 is provided at an end portion of the piezoelectric motor 200 in the longitudinal direction (X direction). Further, a pair of support portions 214 for supporting the piezoelectric motor 200 in a state of being biased toward the side where the convex portions 212 are provided on both side surfaces of the piezoelectric motor 200 facing in the short direction (Y direction). Is provided. The convex portion 212 and the support portion 214 are formed integrally with the shim plate 210.

  FIG. 4 is an explanatory diagram showing the operating principle of the piezoelectric motor 200. The piezoelectric motor 200 operates by the elliptical movement of the convex portion 212 of the piezoelectric motor 200 when a voltage is applied to the front electrode 222 and the back electrode 223 of the piezoelectric motor 200 at a constant cycle. The convex portion 212 of the piezoelectric motor 200 moves elliptically for the following reason. The front electrode 222 provided on the front piezoelectric element 220 and the back electrode 223 provided on the back piezoelectric element 221 are plane-symmetric with respect to the XY plane and are basically the same. The front electrode 222 will be described as an example.

  First, as is well known, piezoelectric elements including a piezoelectric material (the front piezoelectric element 220 and the back piezoelectric element 221) have a property of expanding when a positive voltage is applied. Accordingly, as shown in FIG. 4A, when a positive voltage is applied to all four front electrodes 222 and then the applied voltage is released, the piezoelectric motor 200 (front piezoelectric element 220) is moved in the longitudinal direction. The operation of expanding and contracting in the (X direction) is repeated. The operation in which the piezoelectric motor 200 repeats expansion and contraction in the longitudinal direction (X direction) in this way is referred to as “stretch vibration”. Hereinafter, the direction (± X direction in the figure) in which the piezoelectric motor 200 expands and contracts is referred to as the “stretching direction”. Further, when the frequency at which the positive voltage is applied is changed, the amount of expansion / contraction suddenly increases when a certain frequency is reached, and a kind of resonance phenomenon occurs. The frequency at which resonance occurs due to stretching vibration (resonance frequency) is determined by the physical properties of the surface piezoelectric element 220 and the dimensions (width W, length L, thickness T) of the surface piezoelectric element 220.

  Further, as shown in FIG. 4B or FIG. 4C, two table electrodes 222 that are diagonal to each other are paired (a set of the table electrode 222a and the table electrode 222d, or the table electrode 222b and the table electrode 222c). A positive voltage is applied at a constant cycle. Then, the piezoelectric motor 200 (the front piezoelectric element 220) operates such that the front end portion (the portion provided with the convex portion 212) in the longitudinal direction (X direction) swings the head in the left-right direction (Y direction) on the drawing. repeat. For example, as shown in FIG. 4B, when a positive voltage is applied to the set of the front electrode 222a and the front electrode 222d at a constant period, the piezoelectric motor 200 performs an operation in which the longitudinal tip moves to the right. repeat. Further, as shown in FIG. 4C, when a positive voltage is applied to the set of the front electrode 222b and the front electrode 222c at a constant period, the piezoelectric motor 200 moves in the left direction in the longitudinal direction. repeat. Such an operation of the piezoelectric motor 200 is referred to as “bending vibration”. Hereinafter, the direction (± Y direction in the figure) in which the piezoelectric motor 200 undergoes bending vibration is referred to as “bending direction”. Regarding such bending vibration, there is a resonance frequency determined by the physical properties of the surface piezoelectric element 220 and the dimensions (width W, length L, thickness T) of the surface piezoelectric element 220. Therefore, when a positive voltage is applied at the resonance frequency to the two front electrodes 222 located diagonally to each other, the piezoelectric motor 200 vibrates with a large swing in the right or left direction (Y direction).

  Here, both the resonance frequency of the stretching vibration shown in FIG. 4 (a) and the resonance frequency of the bending vibration shown in FIG. 4 (b) or FIG. It is determined by the dimensions of 220 (width W, length L, thickness T). Therefore, if the dimensions (width W, length L, thickness T) of the surface piezoelectric element 220 are appropriately selected, the two resonance frequencies can be matched. When a voltage in the form of bending vibration as shown in FIG. 4B or FIG. 4C is applied to such a surface piezoelectric element 220 at a resonance frequency, FIG. 4B or FIG. At the same time as the bending vibration shown in c) occurs, the stretching vibration of FIG. 4A is also induced by resonance. As a result, when a voltage is applied to the set of the front electrode 222a and the front electrode 222d in the mode shown in FIG. 4B, the tip of the piezoelectric motor 200 (the portion where the convex portion 212 is provided) is shown on the drawing. Performs an operation that draws an ellipse clockwise (elliptic motion). 4C, when a voltage is applied to the set of the front electrode 222b and the front electrode 222c, the tip of the piezoelectric motor 200 performs an elliptical motion counterclockwise on the drawing. In the above description, a positive voltage is applied to the front electrode 222. However, as is well known, the piezoelectric material is also deformed by applying a negative voltage. Therefore, bending vibration (and stretching vibration) may be generated by applying a negative voltage to the surface electrode 222, or bending vibration (and stretching and contracting) by applying an alternating voltage that repeats a positive voltage and a negative voltage. (Vibration) may be generated. In the above description, it is assumed that a voltage having a resonance frequency is applied. However, it is sufficient to apply a voltage having a waveform including the resonance frequency. For example, a pulse voltage may be used. Further, similarly to the front piezoelectric element 220, the back piezoelectric element 221 can generate bending vibration and stretching vibration by applying a voltage to the back electrode 223.

  The piezoelectric motor 200 drives the driven body using such elliptical motion. That is, the elliptical motion is generated in a state where the convex portion 212 of the piezoelectric motor 200 is pressed against the driven body. Then, when the piezoelectric motor 200 expands, the convex portion 212 moves from the left to the right (or from the right to the left) while being pressed against the driven body, and when the piezoelectric motor 200 contracts. The operation of returning to the original position while being away from the driven body is repeated. As a result, the driven body is driven in one direction by the frictional force received from the convex portion 212.

  FIG. 5 is an explanatory diagram showing an operation of bending the finger 100 when the finger 100 is viewed from the side. For example, since the convex portion 212 of the piezoelectric motor 200 housed in the fingertip member 120 is pressed against the driven portion 112, when the piezoelectric motor 200 is driven, the fingertip member 120 is moved to the driven portion 112 with a thick arrow. It can be rotated around the joint axis 116 in the direction indicated by. Similarly, by driving the piezoelectric motor 200 housed in the front end side intermediate member 110a, the front end side intermediate member 110a is moved toward the direction indicated by the thick arrow with respect to the driven part 112. It can be rotated around the joint axis 116. Further, similarly for the piezoelectric motor 200 housed in the root side intermediate member 110b, by driving the piezoelectric motor 200, the direction indicated by the bold arrow with respect to the base side intermediate member 110b with respect to the first driven portion 132. Toward the second axis 136. As a result, when each piezoelectric motor 200 is driven, the entire finger part 100 can be bent as shown by a broken line in the drawing. Further, if the piezoelectric motor 200 is driven in the opposite direction, the bent finger part 100 can be extended.

  In FIG. 5, it has been described that all the piezoelectric motors 200 housed in the fingertip member 120, the distal end side intermediate member 110a, and the root side intermediate member 110b are driven simultaneously and in the same direction. 200 may be driven, or some of the piezoelectric motors 200 may be driven in the opposite direction with respect to other piezoelectric motors 200.

  FIG. 6 is an explanatory diagram showing an operation of tilting the finger part 100 left and right when the finger part 100 is viewed from the ventral side. When the finger unit 100 is tilted to the left or right, the first driven shaft 134 of the connecting member 130 is moved in the direction indicated by the thick arrow using the piezoelectric motor 200 housed in the palm unit 150. Rotate around 138. In this way, the entire finger part 100 can be tilted as indicated by a thick broken line in the figure. Further, if the piezoelectric motor 200 is driven in the reverse direction, the finger part 100 can be tilted in the reverse direction as shown by a thin broken line in the drawing. Furthermore, after the piezoelectric motor 200 is driven in any direction to incline the finger part 100, the inclined finger part 100 can be returned to the original state by driving the piezoelectric motor 200 in the opposite direction. Further, FIG. 6 shows a state in which the finger part 100 is tilted to the left and right without being bent. Of course, as shown in FIG. 5, the finger part 100 is bent (or while being bent). ), It is also possible to tilt the finger part 100 left and right.

  As described above, the robot hand 10 according to the present embodiment has the second axis as shown in FIG. 5 at the joint portion between the finger portion 100 (specifically, the root side intermediate member 110b) and the palm portion 150. A rotation around 136 (bending direction) and a rotation around the first axis 138 (left-right direction) as shown in FIG. 6 are possible. For this reason, it becomes possible to move each finger | toe part 100 more flexibly and to hold | grip a complicated target object. Nevertheless, the finger part 100 (specifically, the root-side intermediate member 110b) and the palm part 150 are connected via the connecting member 130, and the finger part 100 (specifically, the root-side intermediate member 110b) and the palm part 150 are respectively connected. It has a simple structure in which the piezoelectric motor 200 is accommodated. For this reason, a joint part can be reduced in size, As a result, it becomes possible to avoid that the robot hand 10 enlarges.

  In the above-described embodiment, the second shaft 136 of the connecting member 130 has been described as being provided on the substantially central axis L of the root side intermediate member 110b formed in a substantially cylindrical shape. However, the second shaft 136 may be provided at a position offset with respect to the central axis L of the root side intermediate member 110b. In this way, the movable range of the joint can be expanded in the direction in which the second shaft 136 is offset. Hereinafter, this point will be described with reference to the drawings.

  FIG. 7 is an explanatory diagram of a first modified example in which the second shaft 136 of the connecting member 130 is offset. 7A shows a state in which the palm portion 150, the connecting member 130, and the root-side intermediate member 110b are viewed from the side, and the tip-side intermediate member 110a and the fingertip member 120 are shown. Is omitted in FIG. Moreover, the state seen from the direction of arrow P in the drawing is shown in FIG. In FIG. 7B, the illustration of the distal end side intermediate member 110a and the fingertip member 120 is omitted. As shown in FIG. 7 (b), the second shaft 136 of the first modified example extends from the center-of-gravity position G of the cross section taken on the plane orthogonal to the central axis L of the root side intermediate member 110b in the ventral direction. It is offset by a distance F. In the state where the second shaft 136 is offset in this way, the movable limit of the root side intermediate member 110b in the bending direction is a position indicated by a one-dot chain line in FIG.

  FIG. 7C shows the present embodiment in which the second shaft 136 of the connecting member 130 is not offset as a reference. Moreover, the state seen from the direction of arrow Q in FIG.7 (c) is shown by FIG.7 (d). As shown in FIG. 7D, the second shaft 136 of this embodiment shown as a reference is not offset from the central axis of the root side intermediate member 110b. In this case, the movable limit of the root side intermediate member 110b in the bending direction is a position indicated by a one-dot chain line in FIG. Then, as apparent from comparing the movable limit of FIG. 7A and the movable limit of FIG. 7C, the movable limit to the offset side is widened by offsetting the second shaft 136. It becomes possible.

  In the above-described embodiment, the piezoelectric motor 200 housed in the root-side intermediate member 110b is driven to bend or extend the root-side intermediate member 110b (see FIG. 5), and the piezoelectric housed in the palm 150. It has been described that the entire finger unit 100 is tilted in the left-right direction by driving the motor 200 (see FIG. 6). However, as shown in FIG. 8, by driving the piezoelectric motor 200 housed in the palm 150, the root-side intermediate member 110b is bent or extended to drive the piezoelectric motor 200 housed in the root-side intermediate member 110b. By doing so, it is possible to tilt the entire finger part 100 in the left-right direction.

  That is, in the second modified example shown in FIG. 8, the first shaft 138 that rotates the connecting member 130 with respect to the palm 150 is the left-right direction on the side surface direction of the finger 100 (FIG. 8A). In (b), it is provided in a direction perpendicular to the paper surface. Further, the second shaft 136 that rotates the base intermediate member 110b with respect to the connecting member 130 is the front and back direction of the finger portion 100 (in FIG. 8A, the direction perpendicular to the paper surface; in FIG. 8B, the left-right direction). It is provided for. Accordingly, the shaft support portion 114, the shaft support portion 152, the first driven portion 132, and the second driven portion 134 of the second modified example of FIG. The positional relationship is changed such that the member 110b is rotated 90 degrees around the central axis L.

  In the above-described embodiments and modifications, the piezoelectric motor 200 has been described as directly driving the first driven portion 132 and the second driven portion 134 of the connecting member 130. However, the piezoelectric motor 200 may drive the first driven unit 132 and the second driven unit 134 via a speed reduction mechanism.

  FIG. 9 is an explanatory diagram illustrating a third modification in which the piezoelectric motor 200 drives the first driven unit 132 and the second driven unit 134 via a speed reduction mechanism. In FIG. 9, the palm part 150, the connecting member 130, the root side intermediate member 110 b, and the tip side intermediate member 110 a are enlarged and displayed for the finger part 100 of the third modified example. As shown in the figure, in the third modification, a first speed reduction mechanism 140 is provided between the piezoelectric motor 200 housed in the palm 150 and the second driven part 134 of the connecting member 130. The first reduction mechanism 140 is configured by coaxially assembling a small rotor 140a and a large rotor 140b having a larger radius than the small rotor 140a. When the piezoelectric motor 200 drives the large rotor 140b, the movement is transmitted to the second driven portion 134 in a state where the movement is decelerated via the small rotor 140a. For this reason, the force of the piezoelectric motor 200 is increased, and the root side intermediate member 110b (and the front end side intermediate member 110a and the fingertip member 120) can be rotated around the first axis 138 (bending direction).

  In addition, a second speed reduction mechanism 142 is provided between the piezoelectric motor 200 housed in the root side intermediate member 110 b and the first driven portion 132 of the connecting member 130. The second reduction mechanism 142 is configured by coaxially assembling a small rotor 142a and a large rotor 142b having a larger radius than the small rotor 142a. When the piezoelectric motor 200 drives the large rotor 142b, the movement is transmitted to the first driven portion 132 in a state where the movement is decelerated via the small rotor 140a. For this reason, the force of the piezoelectric motor 200 is increased, and the root side intermediate member 110b (and the front end side intermediate member 110a and the fingertip member 120) can be rotated around the second axis 136 (left and right direction).

  Further, in the above-described embodiments and modifications, the connecting member 130 is not provided between the fingertip member 120 and the front end side intermediate member 110a or between the front end side intermediate member 110a and the root side intermediate member 110b. Therefore, it has been described that these portions can rotate in the bending direction but cannot rotate in the left-right direction. However, as in the fourth modified example illustrated in FIG. 10, the fingertip member 120 and the distal end side intermediate member 110 a and the distal end side intermediate member 110 a and the root side intermediate member 110 b are also coupled via the coupling member 130. You may do it. If it carries out like this, it will become possible to rotate in the bending direction and the left-right direction also in the joint part between the fingertip member 120 and the front end side intermediate member 110a, or between the front end side intermediate member 110a and the root side intermediate member 110b. . In the third modification described above, the root side intermediate member 110b corresponds to the “first member” in the present invention, and the tip side intermediate member 110a corresponds to the “second member” in the present invention.

  FIG. 11 is an explanatory view illustrating a robot 400 in which the robot hand 10 according to the embodiment or the modification is mounted on the tip of the arm 300. As described above, the robot hand 10 according to the present embodiment and the modified example can downsize the robot hand 10 while being able to move the finger unit 100 flexibly. For this reason, a high-performance robot 400 can be realized.

  Although the robot hand and the robot of the present invention have been described above, the present invention is not limited to the above-described embodiments and modifications, and can be implemented in various modes without departing from the scope of the invention. .

10 ... Robot hand, 100 ... Finger part, 110 ... Intermediate member,
112: Driven part, 114 ... Shaft support part, 116 ... Joint axis,
120 ... fingertip member, 130 ... connecting member, 132 ... first driven part,
140: first reduction mechanism, 142: second reduction mechanism, 134: second driven part,
136 ... second axis, 138 ... first axis, 150 ... palm,
152 ... shaft support part, 200 ... piezoelectric motor, 212 ... convex part,
220 ... front piezoelectric element, 221 ... back piezoelectric element, 222 ... front electrode,
223 ... back electrode, 300 ... arm, 400 ... robot.

Claims (10)

A first member;
A second member having a longitudinal shape;
A member that connects the first member and the second member, and is attached to the first member so as to be rotatable about a first axis in a direction intersecting a longitudinal direction of the second member. A connecting member attached to the second member so as to be rotatable about a second axis in a direction intersecting both the longitudinal direction and the direction of the first axis;
A first drive unit provided on the first member to rotate the coupling member around the first rotation axis;
A second drive unit provided on the second member for rotating the coupling member around the second rotation axis;
A robot hand characterized by comprising: The robot hand according to claim 1, wherein
The robot hand, wherein the longitudinal direction of the second member, the first axis, and the second axis are set in directions orthogonal to each other. In the robot hand according to claim 1 or 2,
One of the first axis and the second axis is provided at a position offset from the center of gravity of a cross section taken by the plane perpendicular to the longitudinal direction of the second member. In the robot hand according to any one of claims 1 to 3,
The robot hand, wherein the first member is a member having a longitudinal direction. In the robot hand according to any one of claims 1 to 4,
The robot hand, wherein the first drive unit and the second drive unit are vibrators formed by including a piezoelectric material. In the robot hand according to any one of claims 1 to 5,
A robot hand, comprising: a first reduction mechanism that decelerates the rotation of the first drive unit and transmits the rotation to the connecting member. In the robot hand according to any one of claims 1 to 6,
A robot hand, comprising: a second speed reduction mechanism that decelerates the rotation of the second drive unit and transmits it to the connecting member. A first member;
A second member having a longitudinal shape;
A connecting member that connects the first member and the second member;
Connecting the first member and the connecting member, a first shaft provided in a direction intersecting the longitudinal direction of the second member;
A second shaft that connects the second member and the connecting member, and is provided in a direction that intersects both the longitudinal direction and the direction of the first axis;
A first drive unit provided on the first member to rotate the coupling member around the first rotation axis;
A second drive unit provided on the second member for rotating the coupling member around the second rotation axis;
A robot hand characterized by comprising: A first member;
A second member having a longitudinal shape;
A connecting member that connects the first member and the second member;
A first vibrating body provided on the first member and configured to vibrate in a bending direction and a stretching direction;
A first shaft that connects the first member and the connecting member, and is provided in a direction intersecting the expansion and contraction direction of the first vibrating body;
A second shaft that connects the second member and the connecting member, and is provided in a direction that intersects both the longitudinal direction and the expansion / contraction direction of the first vibrating body;
A second vibrating body provided on the second member for vibrating in a bending direction and an expansion / contraction direction, and provided in a direction in which the bending direction and the expansion / contraction direction intersect the second axis;
With
The first vibrating body rotates the connection member around the first rotation axis,
The robot hand, wherein the second vibrating body rotationally drives the connecting member about the second rotation axis.   A robot comprising the robot hand according to any one of claims 1 to 9.

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