JP2019141957A - Robot hand and robot - Google Patents

Abstract

To provide a robot hand that can stably grip an object to be gripped and a robot.SOLUTION: The robot hand comprises: a first gripper having a first finger part and a second finger part that can move in a first direction; a first driving part that makes the first finger part and the second finger part to approach and separate from each other; a second gripper, arranged side in parallel with the first gripper in a second direction crossing the first direction, which has a third finger part and a fourth finger part that can move in the first direction; a second driving part that makes the third finger part and the fourth finger part to approach and separate from each other; and a third driving part that makes the first gripper and the second gripper to approach and separate from each other.SELECTED DRAWING: Figure 1

Description

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

  Conventionally, a robot hand described in Patent Document 1 is known. The robot hand described in Patent Document 1 includes an integrated first finger portion and a second finger portion, and an integrated third finger portion and a fourth finger portion, and the first finger portion The second finger part, the third finger part, and the fourth finger part can be approached and separated. In such a robot hand, the first finger part, the second finger part, the third finger part, and the fourth finger part can be brought close to each other to hold the object, and the first finger part, the second finger, By separating the part, the third finger part, and the fourth finger part, the object being held can be released.

Japanese Unexamined Patent Publication No. 2016-32865

  However, in the robot hand of Patent Document 1, since the first finger part and the second finger part are integrated, the first finger part and the second finger part cannot be approached or separated. Similarly, since the 3rd finger part and the 4th finger part are integrated, the 3rd finger part and the 4th finger part cannot be approached and separated. Therefore, depending on the shape of the object to be grasped, there is a problem that the four fingers (first to fourth fingers) cannot be fully utilized, and gripping by the four fingers becomes insufficient. there were.

A robot hand according to an application example of the present invention includes a first gripper having a first finger part and a second finger part movable in a first direction;
A first drive unit for approaching or separating the first finger unit and the second finger unit;
A second gripper that is arranged alongside the first gripper in a second direction intersecting the first direction and has a third finger part and a fourth finger part that are movable in the first direction;
A second drive unit for approaching or separating the third finger unit and the fourth finger unit;
And a third driving unit configured to approach or separate the first gripper and the second gripper.

1 is a perspective view showing a robot hand according to a first embodiment of the present invention. It is a top view of the robot hand shown in FIG. It is the sectional view on the AA line in FIG. It is a top view of the robot hand shown in FIG. It is a side view of the 1st gripper which the robot hand shown in Drawing 1 has. It is a side view of the 1st gripper which the robot hand shown in Drawing 1 has. FIG. 6 is a cross-sectional view of the first gripper shown in FIG. 5. It is a side view of the 2nd gripper which the robot hand shown in Drawing 1 has. It is a side view of the 2nd gripper which the robot hand shown in Drawing 1 has. It is a cross-sectional view of the second gripper shown in FIG. It is a top view which shows the robot hand of the state which hold | gripped the target object. It is a longitudinal cross-sectional view which shows the robot hand of the state which hold | gripped the target object. It is a cross-sectional view which shows the piezoelectric motor which comprises a drive part. It is a longitudinal cross-sectional view of the piezoelectric motor shown in FIG. It is a top view of the piezoelectric actuator which the piezoelectric motor shown in FIG. 13 has. It is a figure which shows the drive voltage applied to the piezoelectric actuator shown in FIG. It is a figure which shows the drive of a piezoelectric actuator when the drive voltage shown in FIG. 16 is applied. It is a figure which shows the drive voltage applied to the piezoelectric actuator shown in FIG. It is a figure which shows the drive of a piezoelectric actuator when the drive voltage shown in FIG. 18 is applied. It is a perspective view of the piezoelectric module which the piezoelectric motor shown in FIG. 13 has. It is a perspective view which shows the robot which concerns on 2nd Embodiment of this invention.

  Hereinafter, a robot hand and a robot according to the present invention will be described in detail based on an embodiment shown in the accompanying drawings.

<First Embodiment>
First, the robot hand according to the first embodiment of the present invention will be described.

  FIG. 1 is a perspective view showing a robot hand according to the first embodiment of the present invention. FIG. 2 is a plan view of the robot hand shown in FIG. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a plan view of the robot hand shown in FIG. 5 and 6 are side views of the first gripper of the robot hand shown in FIG. FIG. 7 is a cross-sectional view of the first gripper shown in FIG. 8 and 9 are side views of the second gripper of the robot hand shown in FIG. FIG. 10 is a cross-sectional view of the second gripper shown in FIG. FIG. 11 is a plan view showing the robot hand in a state of gripping an object. FIG. 12 is a longitudinal sectional view showing the robot hand in a state where the object is gripped. FIG. 13 is a cross-sectional view showing a piezoelectric motor constituting the drive unit. 14 is a longitudinal sectional view of the piezoelectric motor shown in FIG. FIG. 15 is a plan view of a piezoelectric actuator included in the piezoelectric motor shown in FIG. FIG. 16 is a diagram showing a drive voltage applied to the piezoelectric actuator shown in FIG. FIG. 17 is a diagram illustrating driving of the piezoelectric actuator when the driving voltage illustrated in FIG. 16 is applied. FIG. 18 is a diagram showing a drive voltage applied to the piezoelectric actuator shown in FIG. FIG. 19 is a diagram showing driving of the piezoelectric actuator when the driving voltage shown in FIG. 18 is applied. FIG. 20 is a perspective view of a piezoelectric module included in the piezoelectric motor shown in FIG.

  In the following, for convenience of explanation, the three axes orthogonal to each other are referred to as an X axis, a Y axis, and a Z axis, a direction parallel to the X axis is referred to as an “X axis direction”, and a direction parallel to the Y axis is referred to as a “Y axis direction. The direction parallel to the Z axis is also referred to as the “Z axis direction”. Further, the tip end side of each axis in the arrow direction is also referred to as “plus side”, and the opposite side is also referred to as “minus side”. Further, the Z axis direction plus side is also referred to as “upper”, and the Z axis direction minus side is also referred to as “lower”.

  A robot hand 1 shown in FIG. 1 is a hand that holds an object W, and includes a base 2 (third support portion), a first gripper 3, a second gripper 4, and a third gripper 5 supported by the base 2. Have. The first gripper 3 has two finger portions 31 and 32 that can be opened and closed in the X-axis direction, and the second gripper 4 has two finger portions 41 and 42 that can be opened and closed in the X-axis direction. . Further, the first and second grippers 3 and 4 can be approached and separated in the Y-axis direction. Since such a robot hand 1 can move the four finger portions 31, 32, 41, and 42 in the X-axis direction and the Y-axis direction, respectively, the relative positions of the finger portions 31, 32, 41, and 42 are as follows. The relationship can be controlled with a high degree of freedom, and the object W can be gripped in a stable state by the finger portions 31, 32, 41, and 42. In particular, in the robot hand 1, the third gripper 5 has a palm portion 51 that moves up and down in the Z-axis direction, and the object W is sandwiched between the four finger portions 31, 32, 41, 42 and the palm portion 51. Therefore, the object W can be gripped in a more stable state. Hereinafter, the robot hand 1 having such a configuration will be described in detail.

  As shown in FIG. 2, the base 2 is located at the center of the robot hand 1 and supports the first gripper 3, the second gripper 4, and the third gripper 5. As shown in FIG. 3, the base 2 includes a pair of support portions 21 and 22 arranged side by side in the Z-axis direction, and the support portions 21 and 22 so as to form a space S between the support portions 21 and 22. And a plurality of column portions 20 to be connected. The support part 21 located on the minus side in the Z-axis direction functions as an attachment part for attaching the robot hand 1 to a robot body 1100 described later, for example. In the space S between the support portions 21 and 22, the drive unit 8 (third drive unit) that moves the first and second grippers 3 and 4 closer to and away from each other in the Y-axis direction, and the palm unit 51 in the Z-axis direction A drive unit 9 (fourth drive unit) that moves up and down is provided. Moreover, the drive parts 8 and 9 are being fixed to the support part 21 in the state piled up in the Z-axis direction. Thus, by arranging the drive units 8 and 9 so as to overlap in the Z-axis direction, the installation space of the drive units 8 and 9 can be further reduced, and the robot hand 1 can be downsized.

  A pair of sliders 23 and 24 having a longitudinal shape extending in the Y-axis direction are disposed on the upper surface 221 of the support portion 22. The slider 23 is provided on the upper surface 221 of the support portion 22 via the slide guide 25 and is slidable in the Y-axis direction with respect to the support portion 22. A first gripper 3 is disposed on the negative side of the base 2 in the Y-axis direction, and the first gripper 3 is fixed to the tip of the slider 23 (end on the negative side in the Y-axis direction). On the other hand, the slider 24 is provided on the upper surface 221 of the support portion 22 via the slide guide 26 and is slidable in the Y-axis direction with respect to the support portion 22. A second gripper 4 is disposed on the Y axis direction plus side of the base 2, and the second gripper 4 is fixed to a tip end portion (an end portion on the Y axis direction plus side) of the slider 24.

  These sliders 23 and 24 are arranged side by side in the X-axis direction. A rack gear 231 is formed on the surface of the slider 23 facing the slider 24, and a rack gear 241 is formed on the surface of the slider 24 facing the slider 23. Further, a pinion gear 27 is provided between the sliders 23 and 24, and the pinion gear 27 meshes with the rack gears 231 and 241. Therefore, when the pinion gear 27 rotates, the sliders 23 and 24 move to the opposite sides in the Y-axis direction. As a result, as shown in FIGS. 2 and 4, the first and second grippers 3 and 4 Approach / separate. As described above, by using the rack gears 231 and 241 and the pinion gear 27, the first and second grippers 3 and 4 can be moved closer to and away from each other with a simple configuration.

  In the present embodiment, the movement amounts of the sliders 23 and 24 with respect to the rotation amount of the pinion gear 27 are substantially equal to each other. Thereby, the 1st, 2nd grippers 3 and 4 can be moved to the Y-axis direction with good balance. However, the movement amount of the sliders 23 and 24 relative to the rotation amount of the pinion gear 27 may be different from each other. That is, as the pinion gear 27 rotates, one of the sliders 23 and 24 may move more in the Y-axis direction than the other.

  The rotational drive of the pinion gear 27 is performed by the drive unit 8. The drive unit 8 is a piezoelectric motor, and includes a motor body 81 and a rotating shaft 82 that rotates by driving the motor body 81 as shown in FIG. The motor main body 81 is fixed to the support portion 21. The rotation shaft 82 penetrates the support portion 22 along the Z-axis direction and protrudes toward the upper surface 221 side of the support portion 22. The pinion gear 27 is fixed to the tip end portion of the rotating shaft 82 (the portion protruding from the support portion 22). According to such a drive unit 8, the pinion gear 27 can be rotationally driven with a simple configuration. In particular, in the present embodiment, since a piezoelectric motor is used as the drive unit 8, the drive unit 8 can be reduced in size and weight.

  By providing the drive unit 8 on the support unit 21, the pinion gear 27 can be directly attached to the rotating shaft 82. Therefore, the driving force of the driving unit 8 can be efficiently transmitted to the pinion gear 27. Further, since the pinion gear 27 can be directly attached to the rotating shaft 82, a driving force transmission mechanism (for example, a pulley, a belt, a gear, etc.) for transmitting the driving force of the driving unit 8 to the pinion gear 27 becomes unnecessary. . Therefore, the robot hand 1 can be downsized. In addition, by arranging the drive unit 8 in the space S between the support units 21 and 22, the space S can be used effectively, the robot hand 1 can be downsized, and the upper surface of the support unit 22 can be reduced. The arrangement of the sliders 23 and 24 and the pinion gear 27 provided on the robot hand 1 is not obstructed, and the design freedom of the robot hand 1 is increased.

  However, the arrangement of the drive unit 8 is not particularly limited. For example, the drive unit 8 may be arranged on the lower surface of the support unit 21 or the upper surface 221 of the support unit 22, or may be arranged on a portion other than the support units 21 and 22. May be. In the present embodiment, the pinion gear 27 is directly attached to the rotary shaft 82, but is not limited thereto. For example, a reduction gear or a driving force transmission mechanism (for example, between the drive unit 8 and the pinion gear 27) Pulleys, belts, etc.) may be arranged.

  As shown in FIG. 2, the first gripper 3 is disposed on the Y axis direction minus side of the base 2. Further, as shown in FIG. 5, the first gripper 3 includes a support portion 33 (first support portion) fixed to the tip portion of the slider 23 and a finger supported by the support portion 33 so as to be slidable in the X-axis direction. Parts 31 and 32. The support portion 33 has a plate shape whose thickness direction is the Y-axis direction, and is fixed to the slider 23 by, for example, screwing. And the finger parts 31 and 32 are supported by the surface 331 side of the support part 33 so that a slide to the X-axis direction is possible.

  The finger unit 31 is supported by the support unit 33 via the slide guide 34, and includes a slider 311 that can slide in the X-axis direction with respect to the support unit 33, and a finger body 312 that is fixed to the slider 311. Similarly, the finger portion 32 includes a slider 321 that is supported by the support portion 33 via the slide guide 35 and is slidable in the X-axis direction with respect to the support portion 33, and a finger main body 322 fixed to the slider 321. Have. The two finger bodies 312 and 322 are arranged side by side in the X-axis direction.

  The sliders 311 and 321 are arranged side by side in the Z-axis direction. A rack gear 311 a is formed on the surface of the slider 311 facing the slider 321, and a rack gear 321 a is formed on the surface of the slider 321 facing the slider 311. Further, a pinion gear 37 is provided between the sliders 311 and 321, and the pinion gear 37 meshes with the rack gears 311 a and 321 a. Therefore, when the pinion gear 37 rotates, the sliders 311 and 321 move to the opposite sides in the X-axis direction, and accordingly, the finger bodies 312 and 322 approach and separate as shown in FIGS. As described above, by using the rack gears 311a and 321a and the pinion gear 37, the finger bodies 312 and 322 can be approached and separated with a simple configuration.

  In the present embodiment, the movement amounts of the sliders 311 and 321 with respect to the rotation amount of the pinion gear 37 are substantially equal to each other. Thereby, the finger bodies 312 and 322 can be moved in the X-axis direction with good balance. However, the movement amount of the sliders 311 and 321 with respect to the rotation amount of the pinion gear 37 may be different from each other. That is, as the pinion gear 37 rotates, one of the sliders 311 and 321 may move more in the X-axis direction than the other.

  The rotation of the pinion gear 37 is performed by the drive unit 6 (first drive unit). The drive unit 6 is a piezoelectric motor, and includes a motor body 61 and a rotating shaft 62 that rotates by driving the motor body 61. As shown in FIG. 7, the motor main body 61 is fixed to the back surface 332 side of the support portion 33. The rotation shaft 62 extends along the Y-axis direction, penetrates the support portion 33, and protrudes toward the surface 331 side of the support portion 33. The pinion gear 37 is fixed to the tip end portion of the rotating shaft 62 (the portion protruding from the support portion 33). According to such a drive unit 6, the pinion gear 37 can be rotationally driven with a simple configuration. In particular, in this embodiment, since the piezoelectric motor is used as the drive unit 6, the drive unit 6 can be reduced in size and weight.

  By providing the drive unit 6 on the support unit 33, it becomes easy to directly attach the pinion gear 37 to the rotation shaft 62. Therefore, the driving force of the driving unit 6 can be efficiently transmitted to the pinion gear 37. Further, since the pinion gear 37 can be directly attached to the rotary shaft 62, a driving force transmission mechanism (for example, a pulley, a belt, a gear, etc.) for transmitting the driving force of the driving unit 6 to the pinion gear 37 becomes unnecessary. . Therefore, the robot hand 1 can be downsized. Further, by providing the drive unit 6 on the back surface 332 side of the support unit 33, the space between the base 2 and the support unit 33 can be effectively utilized, and the robot hand 1 can be reduced in size. The arrangement of the sliders 311 and 321 and the pinion gear 37 provided on the surface 331 side of the support portion 33 is not obstructed, and the degree of freedom in designing the robot hand 1 is increased.

  However, the arrangement of the drive unit 6 is not particularly limited. For example, the drive unit 6 may be arranged on the surface 331 side of the support unit 33, or may be arranged in a portion other than the support unit 33. In the present embodiment, the pinion gear 37 is directly fixed to the rotary shaft 62, but the present invention is not limited to this. For example, a speed reducer or a driving force transmission mechanism (for example, between the drive unit 6 and the pinion gear 37). , Pulleys, belts, and the like).

  As shown in FIG. 2, the second gripper 4 is disposed on the Y axis direction plus side of the base 2. In other words, the second gripper 4 is disposed to face the first gripper 3 in the Y-axis direction via the base 2. Such a second gripper 4 has the same configuration as the first gripper 3.

  As shown in FIG. 8, the second gripper 4 includes a support portion 43 (second support portion) fixed to the slider 24, and finger portions 41 and 42 supported by the support portion 43 so as to be slidable in the X-axis direction. Have. The support portion 43 has a plate shape with the Y-axis direction as the thickness direction, and is fixed to the distal end portion of the slider 24 by, for example, screwing. The finger portions 41 and 42 are supported on the surface 431 of the support portion 43 so as to be slidable in the X-axis direction. The finger portion 41 is supported by the support portion 43 via the slide guide 44, and includes a slider 411 that can slide in the X-axis direction with respect to the support portion 43, and a finger body 412 that is fixed to the slider 411. Similarly, the finger part 42 is supported by the support part 43 via the slide guide 45, and includes a slider 421 that can slide in the X-axis direction with respect to the support part 43, and a finger body 422 that is fixed to the slider 421. Have. The two finger bodies 412 and 422 are arranged side by side in the X-axis direction.

  The sliders 411 and 421 are arranged side by side in the Z-axis direction. A rack gear 411 a is formed on the surface of the slider 411 facing the slider 421, and a rack gear 421 a is formed on the surface of the slider 421 facing the slider 411. Further, a pinion gear 47 is provided between the sliders 411 and 421, and the pinion gear 47 is engaged with the rack gears 411a and 421a. Therefore, when the pinion gear 47 rotates, the sliders 411 and 421 move to the opposite sides in the X-axis direction, and accordingly, the finger bodies 412 and 422 approach and separate as shown in FIGS. As described above, by using the rack gears 411a and 421a and the pinion gear 47, the finger bodies 412 and 422 can be approached and separated with a simple configuration.

  In the present embodiment, the movement amounts of the sliders 411 and 421 with respect to the rotation amount of the pinion gear 47 are substantially equal to each other. Thereby, the finger bodies 412 and 422 can be moved in the X-axis direction with good balance. However, the movement amount of the sliders 411 and 421 relative to the rotation amount of the pinion gear 47 may be different from each other. That is, as the pinion gear 47 rotates, one of the sliders 411 and 421 may move more in the X-axis direction than the other.

  The rotational drive of the pinion gear 47 is performed by the drive unit 7 (second drive unit). The drive unit 7 is a piezoelectric motor, and includes a motor main body 71 and a rotation shaft 72 that rotates by driving the motor main body 71. As shown in FIG. 10, the motor main body 71 is fixed to the back surface 432 side of the support portion 43. The rotating shaft 72 passes through the support portion 43 along the Y-axis direction and protrudes toward the surface 431 of the support portion 43. A pinion gear 47 is fixed to the tip end portion of the rotating shaft 72 (the portion protruding from the support portion 43). According to such a drive part 7, the pinion gear 47 can be rotationally driven with a simple configuration. In particular, in this embodiment, since a piezoelectric motor is used as the drive unit 7, the drive unit 7 can be reduced in size and weight.

  As described above, the drive unit 7 is provided on the support unit 43. Thus, by providing the drive unit 7 on the support unit 43, it becomes easy to directly attach the pinion gear 47 to the rotating shaft 72. Therefore, the driving force of the driving unit 7 can be efficiently transmitted to the pinion gear 47. Further, since the pinion gear 47 can be directly attached to the rotating shaft 72, a driving force transmission mechanism (for example, a pulley, a belt, a gear, etc.) for transmitting the driving force of the driving unit 7 to the pinion gear 47 becomes unnecessary. . Therefore, the robot hand 1 can be downsized. Further, by providing the drive unit 7 on the back surface 432 side of the support unit 43, the space between the base 2 and the support unit 43 can be effectively utilized, and the robot hand 1 can be reduced in size. The arrangement of the sliders 411 and 421 and the pinion gear 47 provided on the surface 431 side of the support portion 43 is not obstructed, and the degree of freedom in designing the robot hand 1 can be increased.

  However, the arrangement of the drive unit 7 is not particularly limited. For example, the drive unit 7 may be arranged on the surface 431 side of the support unit 43 or may be arranged in a portion other than the support unit 43. In the present embodiment, the pinion gear 47 is directly fixed to the rotating shaft 72, but the present invention is not limited to this. For example, a speed reducer or a driving force transmission mechanism (for example, between the drive unit 7 and the pinion gear 47). , Pulleys, belts, and the like).

  As shown in FIG. 2, the four finger bodies 312, 322, 412, and 422 included in the first and second grippers 3 and 4 are arranged such that the finger bodies 312 and 322 are aligned in the X-axis direction. 422 are arranged side by side in the X axis direction, the finger main bodies 312 and 422 are arranged side by side in the Y axis direction, and the finger main bodies 322 and 412 are arranged side by side in the Y axis direction. The four finger bodies 312, 322, 412, 422 are inclined toward the central axis H of the robot hand 1, and the separation distance D 1 between the finger bodies 312, 322 and the separation distance D 2 between the finger bodies 412, 422. The separation distance D3 of the finger bodies 312 and 422 and the separation distance D4 of the finger bodies 322 and 412 are gradually decreased from the proximal end side (Z-axis direction minus side) toward the distal end side (Z-axis direction plus side).

  When the four finger bodies 312, 322, 412, 422 are closed, the tips of the finger bodies 312, 322, 412, 422 are in contact with each other. A contact surface 312 a that contacts the finger body 322 and a contact surface 312 b that contacts the finger body 422 are provided at the tip of the finger body 312. In addition, a contact surface 322 a that contacts the finger body 312 (contact surface 312 a) and a contact surface 322 b that contacts the finger body 412 are provided at the tip of the finger body 322. Further, a contact surface 422a that contacts the finger main body 312 (contact surface 312b) and a contact surface 422b that contacts the finger main body 412 are provided at the tip of the finger main body 422. Further, a contact surface 412a that comes into contact with the finger body 322 (contact surface 322b) and a contact surface 412b that comes into contact with the finger body 422 (contact surface 422b) are provided at the distal end of the finger body 412. As described above, the tips of the finger bodies 312, 322, 412, and 422 are in contact with each other with the four finger bodies 312, 322, 412, 422 closed, and thus stable even if the object W is small. And can be gripped.

  As shown in FIG. 3, the third gripper 5 includes a palm 51 that can move (movable up and down) in the Z-axis direction with respect to the base 2, and a pair of ball screws 52 and 53. The ball screws 52 and 53 include nuts 522 and 532 and screw shafts 521 and 531 that are screwed into the nuts 522 and 532 and move in the Z-axis direction by the rotation of the nuts 522 and 532. The palm 51 is fixed to the upper ends of the screw shafts 521 and 531. According to such a configuration, when the nuts 522 and 532 are rotated, the screw shafts 521 and 531 move in the Z-axis direction, and accordingly, the palm portion 51 moves in the Z-axis direction.

  Here, in the robot hand 1, since the palm part 51 is supported by the two ball screws 52 and 53, the palm part 51 can be stably supported. In particular, since the two ball screws 52 and 53 are located on opposite sides of the central axis H and support both ends of the palm 51 in the X-axis direction, the palm 51 is supported more stably. can do. Further, by arranging the ball screws 52 and 53 in this way, the ball screws 52 and 53 can be arranged so as to be shifted from the central axis H (the rotation shaft 82 of the drive unit 8). Therefore, the arrangement of the drive unit 8 is not disturbed. However, it is not limited to this, For example, the number of ball screws may be one and may be three or more. The mechanism for moving the palm 51 in the Z-axis direction is not limited to a ball screw.

  The nuts 522 and 532 are rotationally driven by the drive unit 9 (fourth drive unit). The drive unit 9 is a piezoelectric motor, and includes a motor main body 91 and a rotating shaft 92 that rotates by driving the motor main body 91. The motor body 91 is fixed to the support portion 21 such that the rotation shaft 92 is along the Z-axis direction. The rotating shaft 92 is provided with pulleys 93 and 94, the nut 522 is provided with a pulley 95, and the nut 532 is provided with a pulley 96. Furthermore, the pulleys 93 and 95 are connected by a belt 97, and the pulleys 94 and 96 are connected by a belt 98. The pulleys 93, 94, 95, 96 and the belts 97, 98 constitute a driving force transmission mechanism for transmitting the driving force of the driving unit 9 to the nuts 522, 532. Therefore, when the rotating shaft 92 rotates, the nuts 522 and 532 rotate, and accordingly, the palm 51 moves (lifts) in the Z-axis direction. According to such a drive unit 9, the palm 51 can be moved in the Z-axis direction with a simple configuration. In particular, in this embodiment, since the piezoelectric motor is used as the drive unit 9, the drive unit 9 can be reduced in size and weight.

  The overall configuration of the robot hand 1 has been described above. According to such a robot hand 1, the four fingers 31, 32, 41, 42 can be moved in the X-axis direction and the Y-axis direction, respectively. The positional relationship can be controlled with a high degree of freedom, and the object W can be gripped in a stable state by the finger portions 31, 32, 41, and 42.

  As shown in FIG. 11, the case where the object W having the thick part W1 and the part W2 narrower than the part W1 is gripped will be described as a representative example. The finger bodies 412 and 422 of the second gripper 4 The separation distance D2 is adjusted to the distance that can grip the portion W1, the separation distance D1 of the finger bodies 312 and 322 of the first gripper 3 is adjusted to the distance that can hold the portion W2, and the first gripper 3 (finger bodies 312 and 322) The four finger bodies 312, 322, 412, and 422 are brought into contact with the object W by adjusting the distance D 5 between the second gripper (the finger bodies 412 and 422) and the length of the object W, respectively. The object W can be gripped with good balance by the four finger bodies 312, 322, 412, 422.

  Furthermore, as shown in FIG. 12, after gripping the object W with the four finger bodies 312, 322, 412, and 422, the palm 51 is moved to the Z axis direction plus side (object W side). By contacting the object W, the object W can be held by the four finger bodies 312, 322, 412, 422 and the palm 51. Therefore, the object W can be gripped in a more stable state. In addition, the object W having various sizes and shapes can be gripped with a sufficient gripping force.

  In the above description, the palm 51 is brought into contact with the object W after the object W is gripped by the four finger bodies 312, 322, 412, and 422. However, the present invention is not limited to this. After the part 51 is brought into contact with the object W, the object W may be gripped by the four finger bodies 312, 322, 412, 422, and the operation of bringing the palm part 51 into contact with the object W and 4 The operation of gripping the object W with the finger bodies 312, 322, 412, 422 may be performed simultaneously.

  Next, the drive units 6, 7, 8, and 9 will be briefly described. The drive units 6, 7, 8, and 9 are piezoelectric motors and have the same configuration as each other. Therefore, the drive unit 6 will be described below as a representative, and the other drive units 7, 8, 9 The description of is omitted.

  As shown in FIG. 13, the drive unit 6 includes a motor main body 61 and a rotation shaft 62. The motor body 61 includes a base 63, a rotor 64 that can rotate around the central axis O with respect to the base 63, a driven member 65 provided on the rotor 64, and a plurality of piezoelectric modules fixed to the base 63. 66. The driven member 65 has an annular shape and is disposed concentrically with the central axis O on the main surface of the rotor 64. A rotating shaft 62 along the central axis O is fixed to the rotor 64.

  Each piezoelectric module 66 is fixed to the base 63 while being housed in the internal space 631 of the base 63. As shown in FIG. 14, in a state of being fixed to the base 63, each piezoelectric module 66 is urged toward the driven member 65 and abuts against the driven member 65 with an appropriate frictional force. Yes. When each piezoelectric module 66 is stopped, the rotor 64 is held by the base 63 by the frictional force generated between the driven module 65 and the movement of the rotor 64 relative to the base 63 is suppressed. Therefore, when the drive of the drive part 6 has stopped, the relative positional relationship of the finger parts 31 and 32 is maintained. Therefore, for example, if the object W is being held, the state can be more reliably maintained. On the contrary, when each piezoelectric module 66 is driven, the driving force of each piezoelectric module 66 is transmitted to the driven member 65, and the rotor 64 rotates about the central axis O with respect to the base 63. Therefore, the finger parts 31 and 32 can be opened and closed by driving each piezoelectric module 66.

  Each piezoelectric module 66 includes a plurality of stacked piezoelectric actuators 67 and a biasing portion 68 that biases the piezoelectric actuator 67 toward the driven member 65. As illustrated in FIG. 15, the piezoelectric actuator 67 includes a vibration unit 671, a support unit 672 that supports the vibration unit 671, a pair of connection units 673 that connect the vibration unit 671 and the support unit 672, and the vibration unit 671. And a transmission portion 674 that is provided at the distal end portion and transmits the driving force of the vibration portion 671 to the driven member 65.

  The vibrating portion 671 is provided with five piezoelectric elements 671a, 671b, 671c, 671d, and 671e. The piezoelectric element 671c is disposed along the longitudinal direction of the vibration part 671 at the center in the width direction of the vibration part 671. Piezoelectric elements 671a and 671b are arranged along the longitudinal direction of the vibration part 671 on one side in the width direction of the vibration part 671 with respect to the piezoelectric element 671c, and piezoelectric elements 671d and 671e are arranged on the other side of the vibration part 671. Arranged along the longitudinal direction. Each of these piezoelectric elements 671a, 671b, 671c, 671d, 671e expands and contracts in the longitudinal direction of the vibration part 671 by applying a voltage.

  In such a piezoelectric actuator 67, for example, when the voltage V1 shown in FIG. 16 is applied to the piezoelectric elements 671a and 671e, the voltage V2 is applied to the piezoelectric elements 671c, and the voltage V3 is applied to the piezoelectric elements 671b and 671d, As 671 expands and contracts in the longitudinal direction and bends in the width direction and bends and vibrates in an S shape, the transmission portion 674 moves elliptically counterclockwise in the drawing as shown in FIG. Conversely, when the voltage V1 ′ in FIG. 18 is applied to the piezoelectric elements 671a and 671e, the voltage V2 ′ is applied to the piezoelectric elements 671c, and the voltage V3 ′ is applied to the piezoelectric elements 671b and 671d, the vibrating portion 671 is moved in the longitudinal direction. In addition to expanding and contracting in the width direction, it bends in the width direction and bends and vibrates in an S-shape. As a result, the transmitting portion 674 moves elliptically in the clockwise direction in FIG. As the elliptical motion of the transmission portion 674 is transmitted to the driven member 65, the rotor 64 rotates forward / reversely with respect to the base 63.

  A biasing portion 68 is attached to such a piezoelectric actuator 67, and the piezoelectric actuator 67 is fixed to the base 63 via the biasing portion 68. The urging unit 68 has a function of urging the piezoelectric actuator 67 toward the driven member 65, and includes a pair of substrates 680 that sandwich the piezoelectric actuator 67 as shown in FIG. Each of the pair of substrates 680 includes a base portion 681, a fixing portion 682, and a spring portion 683 that connects the base portion 681 and the fixing portion 682. And the support part 672 of the piezoelectric actuator 67 is being fixed to the base 681 via the adhesive agent. The fixing portion 682 is a portion fixed to the base 63, and two through holes 682 a for fixing to the base 63 are provided.

  Although the drive unit 6 has been described above, the configuration of the drive unit 6 is not particularly limited as long as it uses expansion and contraction of a piezoelectric element. For example, in the configuration described above, five piezoelectric modules 66 are provided, but the number of piezoelectric modules 66 is not particularly limited, and may be four or less, or may be six or more. . In the above-described configuration, each piezoelectric module 66 includes four piezoelectric actuators 67 stacked. However, the number of piezoelectric actuators 67 is not particularly limited, and may be three or less. There may be five or more.

  The robot hand 1 has been described above. As described above, the robot hand 1 includes the first gripper 3 having the finger part 31 (first finger part) and the finger part 32 (second finger part) movable in the X-axis direction (first direction). And a drive unit 6 (first drive unit) for approaching or separating the finger unit 31 and the finger unit 32, and a first gripper 3 arranged in the Y-axis direction (second direction) intersecting the X-axis direction, A second gripper 4 having a finger part 41 (third finger part) and a finger part 42 (fourth finger part) movable in the X-axis direction, and a drive part 7 (approaching or separating the finger part 41 and finger part 42) 2nd drive part) and the drive part 8 (3rd drive part) which makes the 1st gripper 3 and the 2nd gripper 4 approach or space apart. According to such a structure, the space | interval of the finger parts 31 and 32 of the 1st gripper 3 and the space | interval of the finger parts 41 and 42 of the 2nd gripper 4 can each be controlled independently. That is, since the four finger portions 31, 32, 41, and 42 can be moved in the X-axis direction and the Y-axis direction, respectively, the relative positional relationship between the finger portions 31, 32, 41, and 42 is highly flexible. Can be controlled. Therefore, the objects W of various sizes and shapes can be gripped with sufficient gripping force by the finger portions 31, 32, 41, and 42 in a stable state.

  In addition, as described above, the first gripper 3 includes the support portion 33 (first support portion) that supports the finger portion 31 and the finger portion 32 so as to be movable in the X-axis direction. 33. The second gripper 4 has a support portion 43 (second support portion) that supports the finger portion 41 and the finger portion 42 so as to be movable in the X-axis direction, and the drive portion 7 is provided on the support portion 43. Yes. Thus, by providing the drive unit 6 on the support unit 33, the drive unit 6 can be disposed near the finger units 31 and 32, and the driving force of the drive unit 6 is efficiently applied to the finger units 31 and 32. Can communicate. Similarly, by providing the drive unit 7 on the support unit 43, the drive unit 7 can be disposed near the finger units 41 and 42, and the driving force of the drive unit 7 is efficiently transmitted to the finger units 41 and 42. can do.

  Further, as described above, the support portion 33 and the support portion 43 are arranged side by side in the Y-axis direction, and the drive portion 6 is provided on the support portion 43 side (back surface 332 side) of the support portion 33. The drive unit 7 is provided on the support unit 33 side (back surface 432 side) of the support unit 43. The space on the back surface 332 side of the support portion 33 can be effectively used as a space for disposing the drive portion 6, and the space on the back surface 432 side of the support portion 43 is effective as a space for disposing the drive portion 7. Can be used. Therefore, the robot hand 1 can be downsized.

  Further, as described above, the first gripper 3 is provided with the pinion gear 37 (first pinion gear) that rotates by the drive of the drive unit 6 and the rack gear 311 a (provided with the pinion gear 37 and provided with the finger unit 31). A first rack gear) and a rack gear 321a (second rack gear) provided on the finger 32 and meshing with the pinion gear 37. Thereby, by rotating the pinion gear 37, the finger parts 31, 32 can be approached / separated, and the mechanism for approaching / separating the finger parts 31, 32 becomes simple. Similarly, the second gripper 4 is provided with a pinion gear 47 (second pinion gear) that rotates by driving of the drive unit 7, and a rack gear 411 a (third rack gear) that is provided on the finger 41 and meshes with the pinion gear 47. And a rack gear 421a (fourth rack gear) provided on the finger portion 42 and meshing with the pinion gear 47. Thereby, by rotating the pinion gear 47, the finger parts 41 and 42 can be approached / separated, and the mechanism for approaching / separating the finger parts 41, 42 becomes simple.

  As described above, the robot hand 1 has the base 2 (third support portion) that supports the first gripper 3 and the second gripper 4 so as to be movable in the Y-axis direction. Thereby, since the first gripper 3 and the second gripper 4 can be connected via the base 2, the first gripper 3 and the second gripper 4 can be easily moved (approached / separated) in the Y-axis direction. Become.

  Further, as described above, the first gripper 3 is disposed on the Y axis direction minus side (one side in the Y axis direction) with respect to the base 2, and the second gripper 3 is disposed on the Y axis direction plus side (the other side in the Y axis direction). A gripper 4 is arranged. Thereby, the first and second grippers 3 and 4 can be supported by the base 2 in a balanced manner.

  As described above, the robot hand 1 is supported by the base 2 so as to be movable in the Y-axis direction, and the slider 23 (first slider) to which the first gripper 3 is connected, and the base 2 in the Y-axis direction. A slider 24 (second slider) that is movably supported and connected to the second gripper 4, a pinion gear 27 (third pinion gear) that rotates by driving of the drive unit 8, and a slider 23 are provided. A rack gear 231 (fifth rack gear) meshed with the gear 27 and a rack gear 241 (sixth rack gear) provided on the slider 24 and meshed with the pinion gear 27 are included. According to such a configuration, the first and second grippers 3 and 4 can be moved closer to and away from each other by rotating the pinion gear 27 by driving the drive unit 8. The mechanism that moves the two closer to and away from each other becomes simple.

  Further, as described above, the drive unit 8 is provided on the base 2. Thus, by providing the drive unit 8 on the base 2, the drive unit 8 can be disposed near the sliders 23 and 24. Therefore, the driving force of the driving unit 8 can be efficiently transmitted to the sliders 23 and 24.

  As described above, the robot hand 1 is disposed between the first gripper 3 and the second gripper 4 and is movable in the Z-axis direction (third direction) intersecting the X-axis direction and the Y-axis direction. It has a palm part 51 and a drive part 9 (fourth drive part) that moves the palm part 51 in the Z-axis direction. Thereby, the object W can be clamped by the four finger parts 31, 32, 41, 42 and the palm part 51, and the object W can be gripped more stably.

  Further, as described above, the drive unit 6 includes the piezoelectric elements 671a, 671b, 671c, 671d, and 671e, and the vibration unit 671 (vibrating body) that vibrates by driving the piezoelectric elements 671a, 671b, 671c, 671d, and 671e. , And a rotor 64 that is rotated by the vibration of the vibration part 671. The drive units 7, 8, and 9 are also piezoelectric motors having the same configuration. Thus, by using a piezoelectric motor as the drive units 6, 7, 8, and 9, for example, the drive units 6, 7, 8, and 9 can be reduced in size and weight as compared with the case of using an electromagnetic motor. be able to. In particular, since the robot hand 1 is provided with four drive units 6, 7, 8, and 9, all the drive units 6, 7, 8, and 9 are reduced in size and weight. 1 significantly contributes to miniaturization and weight reduction.

Second Embodiment
Next, a robot according to a second embodiment of the present invention will be described.

FIG. 21 is a perspective view showing a robot according to the second embodiment of the present invention.
The robot 1000 shown in FIG. 21 can perform operations such as feeding, removing, transporting, and assembling precision instruments and parts constituting the precision equipment. The robot 1000 includes a robot body 1100 and a robot hand 1 attached to the robot body 1100.

  The robot body 1100 is a six-axis robot, and includes a base 1110 (first member) fixed to a floor or a ceiling, an arm 1120 (second member) rotatably connected to the base 1110, and a pivot to the arm 1120. An arm 1130 (third member) that is freely connected, an arm 1140 that is rotatably connected to the arm 1130, an arm 1150 that is rotatably connected to the arm 1140, and a arm 1150 that is rotatably connected An arm 1160, an arm 1170 rotatably connected to the arm 1160, and a control device 1180 for controlling driving of the arms 1120, 1130, 1140, 1150, 1160, and 1170. Further, the arm 1170 is provided with a hand connection unit, and the robot hand 1 is attached to the hand connection unit as an end effector corresponding to an operation to be executed by the robot body 1100.

  As described above, the robot 1000 includes the robot body 1100 and the robot hand 1 attached to the robot body 1100. Then, as described in the first embodiment, the robot hand 1 includes a finger part 31 (first finger part) and a finger part 32 (second finger part) that are movable in the X-axis direction (first direction). A first gripper 3 having the first gripper 3 in the Y-axis direction (second direction) intersecting the X-axis direction, and a drive unit 6 (first drive unit) for moving the finger part 31 and the finger part 32 closer to or away from each other. The second gripper 4 having the finger part 41 (third finger part) and the finger part 42 (fourth finger part) that are arranged side by side and movable in the X-axis direction, and the finger part 41 and the finger part 42 are approached or A drive unit 7 (second drive unit) that separates and a drive unit 8 (third drive unit) that approaches or separates the first gripper 3 and the second gripper 4 are provided. According to such a configuration, since the four finger portions 31, 32, 41, 42 can be moved in the X-axis direction and the Y-axis direction, respectively, the relative positions of the finger portions 31, 32, 41, 42 are as follows. The relationship can be controlled with a high degree of freedom. Therefore, the objects W of various sizes and shapes can be gripped with sufficient gripping force by the finger portions 31, 32, 41, and 42 in a stable state.

  Note that the configuration of the robot 1000 is not limited to the configuration of the present embodiment, and may be, for example, a horizontal articulated robot (scalar robot) or a double-arm robot.

  As described above, the robot hand and the robot according to the present invention have been described based on the illustrated embodiment. However, the present invention is not limited to this, and the configuration of each unit is an arbitrary configuration having the same function. Can be substituted. In addition, any other component may be added to the present invention. In the above-described embodiment, the X axis, the Y axis, and the Z axis are orthogonal to each other. However, the X axis, the Y axis, and the Z axis may be crossed or may not be orthogonal.

  DESCRIPTION OF SYMBOLS 1 ... Robot hand, 2 ... Base, 20 ... Column part, 21, 22 ... Support part, 221 ... Upper surface, 23, 24 ... Slider, 231, 241 ... Rack gear, 25, 26 ... Slide guide, 27 ... Pinion gear, 3 ... 1st gripper, 31, 32 ... Finger part, 311, 321 ... Slider, 311a, 321a ... Rack gear, 312, 322 ... Finger body, 312a, 312b, 322a, 322b ... Contact surface, 33 ... Supporting part, 331 ... Surface 332 ... Back side, 34, 35 ... Slide guide, 37 ... Pinion gear, 4 ... Second gripper, 41, 42 ... Finger part, 411, 421 ... Slider, 411a, 421a ... Rack gear, 412, 422 ... Finger body, 412a 412b, 422a, 422b ... contact surface, 43 ... support, 431 ... front surface, 432 ... back surface, 44, 45 ... slurry Guide, 47 ... pinion gear, 5 ... third gripper, 51 ... palm, 52, 53 ... ball screw, 521, 531 ... screw shaft, 522, 532 ... nut, 6 ... driving unit, 61 ... motor body, 62 ... Rotating shaft, 63 ... base, 631 ... internal space, 64 ... rotor, 65 ... driven member, 66 ... piezoelectric module, 67 ... piezoelectric actuator, 671 ... vibrating part, 671a, 671b, 671c, 671d, 671e ... piezoelectric element, 672 ... Supporting portion, 673 ... Connection portion, 674 ... Transmission portion, 68 ... Biasing portion, 680 ... Substrate, 681 ... Base portion, 682 ... Fixing portion, 682a ... Through hole, 683 ... Spring portion, 7, 8, 9 ... Drive unit, 71, 81, 91 ... motor body, 72, 82, 92 ... rotating shaft, 93, 94, 95, 96 ... pulley, 97, 98 ... belt, 1000 ... robot, DESCRIPTION OF SYMBOLS 100 ... Robot main body, 1110 ... Base, 1120, 1130, 1140, 1150, 1160, 1170 ... Arm, 1180 ... Control device, D1, D2, D3, D4, D5 ... Separation distance, H ... Center axis, O ... Center axis , S ... space, V1, V1 ', V2, V2', V3, V3 '... voltage, W ... object, W1 ... part, W2 ... part

Claims (11)

A first gripper having a first finger and a second finger movable in a first direction;
A first drive unit for approaching or separating the first finger unit and the second finger unit;
A second gripper that is arranged alongside the first gripper in a second direction intersecting the first direction and has a third finger part and a fourth finger part that are movable in the first direction;
A second drive unit for approaching or separating the third finger unit and the fourth finger unit;
A robot hand, comprising: a third drive unit that moves the first gripper and the second gripper toward or away from each other. The first gripper has a first support portion that supports the first finger portion and the second finger portion so as to be movable in the first direction;
The first drive unit is provided in the first support unit,
The second gripper has a second support part that supports the third finger part and the fourth finger part so as to be movable in the first direction,
The robot hand according to claim 1, wherein the second drive unit is provided on the second support unit. The first support part and the second support part are arranged side by side in the second direction,
The first drive part is provided on the second support part side of the first support part,
The robot hand according to claim 2, wherein the second drive unit is provided on the first support unit side of the second support unit. The first gripper includes a first pinion gear that is rotated by driving the first driving unit, a first rack gear that is provided on the first finger unit and meshes with the first pinion gear, and the second finger unit. And a second rack gear meshed with the first pinion gear,
The second gripper includes a second pinion gear that is rotated by driving of the second driving unit, a third rack gear that is provided on the third finger unit and meshes with the second pinion gear, and the fourth finger unit. 4. The robot hand according to claim 1, further comprising: a fourth rack gear provided at a portion and meshing with the second pinion gear.   5. The robot hand according to claim 1, further comprising a third support portion that supports the first gripper and the second gripper so as to be movable in the second direction. 6.   The robot hand according to claim 5, wherein the first gripper is disposed on one side in the second direction with respect to the third support portion, and the second gripper is disposed on the other side in the second direction. A first slider supported by the third support portion so as to be movable in the second direction and connected to the first gripper;
A second slider supported by the third support portion so as to be movable in the second direction and connected to the second gripper;
A third pinion gear that rotates by driving of the third driving unit;
A fifth rack gear provided on the first slider and meshing with the third pinion gear;
The robot hand according to claim 5, further comprising: a sixth rack gear provided on the second slider and meshing with the third pinion gear.   The robot hand according to claim 5, wherein the third driving unit is provided in the third support unit.   The first driving unit, the second driving unit, and the third driving unit each include a piezoelectric element, and a vibrating body that vibrates by driving the piezoelectric element, and a rotor that rotates by the vibration of the vibrating body, The robot hand according to claim 1, wherein the robot hand has a piezoelectric motor. A palm portion disposed between the first gripper and the second gripper and movable in a third direction intersecting the first direction and the second direction;
The robot hand according to claim 1, further comprising: a fourth driving unit that moves the palm unit in the third direction. The robot body,
A robot hand mounted on the robot body,
The robot hand is
A first gripper having a first finger and a second finger movable in a first direction;
A first drive unit for approaching or separating the first finger unit and the second finger unit;
A second gripper that is arranged alongside the first gripper in a second direction intersecting the first direction and has a third finger part and a fourth finger part that are movable in the first direction;
A second drive unit for approaching or separating the third finger unit and the fourth finger unit;
A robot comprising: a third driving unit that moves the first gripper and the second gripper toward or away from each other.

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