JP5970708B2 - Robot hand, robot, and gripping mechanism - Google Patents

Description

  The present invention relates to a robot hand, a robot, and a gripping mechanism.

  A robot hand that grips an object by moving a plurality of finger members in parallel to change the interval between them is known. The power for moving the finger member is transmitted from the power source to the finger member via the drive mechanism. As the drive mechanism, a gear mechanism in which a plurality of gears are combined or a link mechanism in which a plurality of link members are combined is often used.

  Here, there is always a gap in a portion where the gear of the gear mechanism meshes with the gear. In addition, a gap always exists in a portion where the link member and the link member of the link mechanism are combined. These gaps cause backlash in the drive mechanism. In the present application, for example, in the case of a gear mechanism, the backlash refers to a state in which the gear rotates idly for a period corresponding to the gap between the gears when the rotation direction of the gear is reversed, or a period in which the gear is in that state. Further, in the case of a link mechanism, it means a state in which the link member runs idle for a period corresponding to the gap between the link member and the link member when the moving direction of the link member is reversed, or a period in which the link member is in that state.

  During the backlash, even if the drive mechanism is moved, the finger member does not move, so that it is difficult to finely adjust the interval between the finger members. Therefore, by using a special mechanism called a harmonic drive speed reducer (Harmonic Drive is a registered trademark), the technology for avoiding the occurrence of backlash (Patent Document 1), the size of the backlash is monitored, and the backlash A technique (Patent Document 2) has been proposed that warns when the size exceeds an allowable amount.

JP 2007-152528 A JP-A-8-71966

  However, since the technique proposed in Patent Document 1 uses a special reduction gear, the structure becomes complicated and large. Further, with the technique proposed in Patent Document 2 described above, an increase in backlash due to wear can be detected, but the backlash cannot be eliminated.

  The present invention has been made in order to solve the above-described problems of the prior art, and is a robot capable of moving a finger member in parallel with a simple structure without causing backlash and gripping an object. An object is to provide a hand, a robot, and a gripping mechanism.

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,
Four finger blocks provided with finger members;
A drive mechanism for moving the finger block in a first direction or a second direction;
A plurality of peripheral blocks connected to the drive mechanism by a drive shaft;
A plurality of guide shafts slidably inserted into the sliding holes of the peripheral block;
With
The finger block is located at four corners of a quadrangle in plan view from the third direction, the peripheral block and the guide shaft are located along four sides of the quadrangle, and the center of the drive mechanism is the square , One of the two sides of the side part is parallel to the first direction and the other two sides of the side part are parallel to the second direction,
The first direction, the second direction, and the third direction are orthogonal to each other,
The gist of the present invention is to include a biasing member that biases the finger block in a moving direction in which the finger block moves.

  In the robot hand of the present invention having such a configuration, when the drive shaft is driven using the drive mechanism, the interval between the peripheral blocks can be changed. Further, in plan view, a finger block is disposed at a position of a square corner, and a finger member is attached to the finger block. For this reason, the finger member can be moved by driving the drive shaft, and various objects can be gripped. Further, the finger block is urged in the moving direction by the urging member. By doing so, it is possible to avoid the occurrence of backlash when the finger block is moved in the movement direction. The urging member may urge the finger block directly. However, since the finger block is connected to the peripheral block via the sliding shaft, the finger block is indirectly urged by urging the peripheral block. May be energized.

  In the robot hand of the present invention described above, the biasing member may be a coil spring.

  In this way, it is possible to realize the urging member with a small and simple structure.

  In the robot hand of the present invention described above, the coil spring that realizes the biasing member is in a state where the peripheral block is compressed more than the free length at the end point when the peripheral block approaches the center of the drive mechanism, and the peripheral block is driven by the drive mechanism. It is good also as a coil spring which will be in the state extended in the movement direction rather than the free length in the end point spaced apart from the center. The end point at which the peripheral block approaches the center of the drive mechanism is a position where the movement ends after the coil spring continues to move the peripheral block from the free length state, and the peripheral block is separated to the center of the drive mechanism. The end point is a position where the movement ends after the coil spring continues to move away from the peripheral blocks from the free length state.

  Since the coil spring that realizes the urging member can avoid the occurrence of backlash in the compressed state or in the extended state, in this way, the restriction due to the spring length when selecting the coil spring is limited. Can be greatly reduced. As a result, the degree of freedom in selecting the coil spring is increased, and a coil spring having more favorable characteristics can be used.

  In the robot hand of the present invention described above, the biasing member may be realized by a plurality of coil springs having different free lengths and biasing the finger block in the moving direction independently of each other.

  In this way, even if one of the coil springs that realize the biasing member becomes free length and does not generate a reaction force, another coil spring that realizes the biasing member generates a reaction force. Can always be avoided.

  In the robot hand of the present invention described above, the urging member may be realized by a coil spring provided with a drive shaft passing through the central axis.

  In this way, the coil spring can be provided in an overlapping manner at the position where the drive shaft is provided, so that the robot hand is not enlarged by providing the coil spring. Further, since the drive shaft passes through the central axis of the coil spring, it is possible to prevent the posture from being changed due to the coil spring falling and the reaction force generated from being changed.

  Alternatively, in the robot hand of the present invention described above, the urging member may be realized by a coil spring provided with a guide shaft passing through the central axis.

  Even in this case, since the coil spring can be provided at the position where the guide shaft is provided, the robot hand is not enlarged by providing the coil spring. In addition, since the guide shaft passes through the central axis of the coil spring, it is possible to prevent the generated reaction force from changing due to the posture of the coil spring falling and the like.

  In the robot hand of the present invention described above, a palm member that moves in a third direction (a direction orthogonal to the first direction and the second direction) is provided between the plurality of finger blocks, and the palm member moves in the third direction. An urging member may be provided that urges the palm member in the moving direction by erecting the drive shaft and connecting to the drive mechanism.

  In this case, the object can be firmly held between the plurality of finger members and the palm member by moving the palm member. Further, since the palm member is urged in the movement direction by the urging member, it is possible to avoid the backlash of the palm member in the third direction. This urging member may be realized using a coil spring. Further, the urging member may be realized by a coil spring provided with a drive shaft penetrating the central axis.

  In the robot hand of the present invention described above, the urging member may be realized by a piston / cylinder mechanism that expands and contracts by increasing / decreasing the pressure of the fluid chamber provided therein.

  In this way, it is possible to arbitrarily adjust the magnitude of the force for urging the moving member by adjusting the pressure of the fluid chamber.

Moreover, this invention can be grasped | ascertained with the aspect of a robot provided with the robot hand mentioned above. That is, the present invention grasped in the form of a robot
A robot equipped with a robot hand,
The robot hand is
Four finger blocks provided with finger members;
A drive mechanism for moving the finger block in a first direction or a second direction;
A plurality of peripheral blocks connected to the drive mechanism by a drive shaft;
A plurality of guide shafts slidably inserted into the sliding holes of the peripheral block;
With
The finger block is located at four corners of a quadrangle in plan view from the third direction, the peripheral block and the guide shaft are located along four sides of the quadrangle, and the center of the drive mechanism is the square , One of the two sides of the side part is parallel to the first direction and the other two sides of the side part are parallel to the second direction,
The first direction, the second direction, and the third direction are orthogonal to each other,
The gist of the present invention is to include a biasing member that biases the finger block in a moving direction in which the finger block moves.

  Also in the robot according to the present invention, it is possible to avoid the occurrence of backlash when the finger block is urged in the movement direction by the urging member and the movement member is moved in the movement direction.

  In the robot of the present invention described above, the biasing member may be a coil spring.

  In this way, it is possible to realize the urging member with a small and simple structure.

  In the above-described robot of the present invention, the coil spring that realizes the biasing member is in a state where the peripheral block is compressed more than the free length at the end point when the peripheral block approaches the center of the drive mechanism, and the peripheral block is the drive mechanism. It is good also as a coil spring which will be in the state extended in the direction of movement rather than free length at the end point separated from the center. The end point at which the peripheral block approaches the center of the drive mechanism is a position where the movement ends after the coil spring continues to move the peripheral block from the free length state, and the peripheral block is separated to the center of the drive mechanism. The end point is a position where the movement ends after the coil spring continues to move away from the peripheral blocks from the free length state.

  By doing so, the restriction due to the spring length when selecting the coil spring can be greatly reduced, so that it is possible to select a coil spring having more favorable characteristics.

  In the robot of the present invention described above, the biasing member may be realized by a plurality of coil springs having different free lengths and biasing the moving member in the first direction independently of each other.

  In this way, even if one of the coil springs that realize the biasing member becomes free length and does not generate a reaction force, another coil spring that realizes the biasing member generates a reaction force. Can always be avoided.

  In the robot of the present invention described above, the urging member may be realized by a coil spring provided with a drive shaft passing through the central axis.

  In this way, the coil spring can be provided in an overlapping manner at the position where the drive shaft is provided, so that the robot is not enlarged by providing the coil spring. Further, since the drive shaft passes through the central axis of the coil spring, it is possible to prevent the posture from being changed due to the coil spring falling and the reaction force generated from being changed.

  Alternatively, in the robot of the present invention described above, the urging member may be realized by a coil spring provided with a guide shaft passing through the central axis.

  Even if it does in this way, since a coil spring can be provided in the position where the guide sliding shaft was provided, the robot will not be enlarged by providing the coil spring. In addition, since the guide shaft passes through the central axis of the coil spring, it is possible to prevent the generated reaction force from changing due to the posture of the coil spring falling and the like.

  In the robot of the present invention described above, a palm member that moves in a third direction (a direction orthogonal to the first direction and the second direction) is provided between the plurality of finger blocks, and the palm member is driven in the third direction. A biasing member that biases the palm member in the moving direction by connecting the shaft to the drive mechanism may be provided.

  In this case, the object can be firmly held between the plurality of finger members and the palm member by moving the palm member. Further, since the palm member is urged in the movement direction by the urging member, it is possible to avoid backlash in the movement direction of the palm member. The urging member may be realized using a coil spring. Further, the urging member may be realized by a coil spring provided with a drive shaft penetrating the central axis.

  In the robot of the present invention described above, the urging member may be realized by a piston / cylinder mechanism that expands and contracts by increasing / decreasing the pressure of the fluid chamber provided therein.

  In this way, it is possible to arbitrarily adjust the magnitude of the force for urging the moving member by adjusting the pressure of the fluid chamber.

Furthermore, the present invention can be grasped as a mechanism (that is, a gripping mechanism) for the above-described robot hand to grip an object. That is, the present invention grasped in the aspect of the gripping mechanism
Four finger blocks provided with finger members;
A drive mechanism for moving the finger block in a first direction or a second direction;
A plurality of peripheral blocks connected to the drive mechanism by a drive shaft;
A plurality of guide shafts slidably inserted into the sliding holes of the peripheral block;
With
The finger block is located at four corners of a quadrangle in plan view from the third direction, the peripheral block and the guide shaft are located along four sides of the quadrangle, and the center of the drive mechanism is the square , One of the two sides of the side part is parallel to the first direction and the other two sides of the side part are parallel to the second direction,
The first direction, the second direction, and the third direction are orthogonal to each other,
The gist of the present invention is to include a biasing member that biases the finger block in a moving direction in which the finger block moves.

  According to such a gripping mechanism of the present invention, it is possible to avoid the occurrence of backlash when the finger block is urged in the movement direction by the urging member and the finger block is moved in the movement direction.

  In the above-described gripping mechanism of the present invention, the biasing member may be a coil spring.

  In this way, it is possible to realize the urging member with a small and simple structure.

  In the gripping mechanism of the present invention described above, the coil spring that realizes the urging member is in a state of being compressed more than the free length in the moving direction at the end point where the peripheral block approaches the center of the drive mechanism, and the peripheral block is driven by the drive mechanism. It is good also as a coil spring which will be in the state extended in the movement direction rather than the free length in the end point spaced apart from the center. The end point at which the peripheral block approaches the center of the drive mechanism is a position where the movement ends after the coil spring continues to move the peripheral block from the free length state, and the peripheral block is separated to the center of the drive mechanism. The end point is a position where the movement ends after the coil spring continues to move away from the peripheral blocks from the free length state.

  By doing so, the restriction due to the spring length when selecting the coil spring can be greatly reduced, so that it is possible to select a coil spring having more favorable characteristics.

  In the above-described gripping mechanism of the present invention, the biasing member may be realized by a plurality of coil springs having different free lengths and biasing the moving member in the moving direction independently of each other.

  In this way, even if one of the coil springs that realize the biasing member becomes free length and does not generate a reaction force, another coil spring that realizes the biasing member generates a reaction force. Can always be avoided.

It is a perspective view which shows the structure of the robot hand of a present Example. It is a perspective view which shows the structure of the robot hand of a present Example. It is explanatory drawing which shows operation | movement of the robot hand of a present Example. It is explanatory drawing which shows the structure of the transmission shaft unit of the robot hand of a present Example. It is explanatory drawing which showed operation | movement of the transmission shaft unit of a present Example. It is explanatory drawing which showed the mechanism in which the 2nd coil spring avoids generation | occurrence | production of the backlash of a 2nd direction. It is explanatory drawing which showed the mechanism in which the 1st coil spring avoids generation | occurrence | production of the backlash of a 1st direction. It is explanatory drawing which showed the mechanism in which the robot hand of a 1st modification avoids generation | occurrence | production of a backlash. It is explanatory drawing which showed the mechanism in which the robot hand of a 2nd modification avoids generation | occurrence | production of a backlash. It is explanatory drawing which illustrated the robot hand of the 3rd modification. It is explanatory drawing which illustrated the robot hand of the 4th modification. It is explanatory drawing which illustrated the robot hand of the 5th modification. It is explanatory drawing which illustrated the single arm robot provided with the robot hand. It is explanatory drawing which illustrated the robot of the multiple arms provided with the robot hand.

A. The structure of the robot hand of this embodiment:
1 and 2 are explanatory views showing the structure of the robot hand 10 of this embodiment. As shown in FIG. 1, the robot hand 10 of this embodiment includes a plurality of blocks, a rack for connecting the blocks, a guide member, and the like. First, the configuration of the block will be described. In FIG. 1, the blocks are displayed with diagonal lines. The robot hand 10 according to the present embodiment includes two first peripheral blocks 110A and 110B provided so as to sandwich the drive mechanism 100 provided on the base case 160 from the first direction, and the drive mechanism 100 in the second direction. Two second peripheral blocks 120A and B provided so as to be sandwiched between the four finger blocks 130A to 130D.

  Of these, the finger block 130A is provided in a position that is in the first direction with respect to the second peripheral block 120B and in the second direction with respect to the first peripheral block 110A. The finger block 130B is provided at a position that is in the first direction with respect to the second peripheral block 120A and in the second direction with respect to the first peripheral block 110A. The finger block 130C is provided at a position that is in the first direction with respect to the second peripheral block 120A and in the second direction with respect to the first peripheral block 110A. Furthermore, the finger block 130D is provided at a position that is in the first direction with respect to the second peripheral block 120B and in the second direction with respect to the first peripheral block 110A. In addition, finger members 140A to 140D are attached to the upper surfaces of the finger blocks 130A to 130D.

  In this embodiment, since the peripheral block and the guide shaft are connected between the four finger blocks, respectively, when viewed in plan from the third direction, the finger block is located at the four corners of the quadrangle, The block and the guide shaft are located along the four sides of the square. The center of the drive mechanism is located at the center of the quadrangle, the two sides of the side are parallel to the first direction, and the other two sides of the side are parallel to the second direction. .

  The finger blocks 130A to 130D are each provided with a guide shaft extending in the first direction and a guide shaft extending in the second direction. That is, the finger block 130A is provided with a first guide shaft 131A extending in the first direction and a second guide shaft 132A extending in the second direction. Of these, the first guide shaft 131A is slidably inserted into a first guide hole 123B formed through the second peripheral block 120B in the first direction, and the second guide shaft 132A is inserted into the first peripheral block. 110A is slidably inserted into a second guide hole 114A formed through the second direction. The finger block 130B is provided with a first guide shaft 131B extending in the first direction and a second guide shaft 132B extending in the second direction. The first guide shaft 131B moves the second peripheral block 120A in the second direction. The second guide shaft 132B is slidably inserted into the first guide hole 123A formed so as to penetrate in one direction, and the second guide shaft 132B is formed in the second guide hole 114A formed so as to penetrate the first peripheral block 110A in the second direction. It is slidably inserted in. Similarly, the finger block 130C is provided with a first guide shaft 131C extending in the first direction and a second guide shaft 132C extending in the second direction, and the first guide shaft 131C extends the second peripheral block 120A. The second guide shaft 132C is slidably inserted into the first guide hole 123A formed through the first direction, and the second guide shaft 132C is formed through the first peripheral block 110A in the second direction. 114B is slidably inserted. Furthermore, the finger block 130D is provided with a first guide shaft 131D extending in the first direction and a second guide shaft 132D extending in the second direction. The first guide shaft 131D moves the second peripheral block 120B to the second position. The second guide shaft 132D is slidably inserted into the first guide hole 123B formed through the one direction, and the second guide shaft 132D is formed through the first peripheral block 110A in the second direction. It is slidably inserted in.

  The first guide holes 123A, B and the second guide holes 114A, B of this embodiment correspond to “sliding holes” in the present invention.

  Further, as shown in FIG. 2, a first drive shaft 111B is erected from the first peripheral block 110B in the first direction. The first drive shaft 111 </ b> B has a gear tooth profile on the side surface, and constitutes a rack and pinion mechanism together with a pinion gear provided in the drive mechanism 100. Further, a first coil spring 115B having an inner diameter larger than the outer diameter of the first drive shaft 111B is mounted on the outer periphery of the first drive shaft 111B. The first coil spring 115B is mounted in a state of being compressed between the drive mechanism 100 and the first peripheral block 110B. Similarly, from the first peripheral block 110 </ b> A, a first drive shaft 111 </ b> A having a gear tooth profile formed on the side surface is erected in the first direction. The first drive shaft 111 </ b> A also constitutes a rack and pinion mechanism together with a pinion gear provided in the drive mechanism 100. Further, a first coil spring 115A having an inner diameter larger than the outer diameter of the first drive shaft 111A is mounted on the outer periphery of the first drive shaft 111A. The first coil spring 115A is mounted in a state of being compressed between the drive mechanism 100 and the first peripheral block 110A. These first coil springs 115A and 115B correspond to “biasing members” in the present invention. The internal structure of the drive mechanism 100 will be described later.

  A second drive shaft 122A is erected from the second peripheral block 120A in the second direction. The second drive shaft 122 </ b> A also has a gear tooth profile on the side surface, and constitutes a rack and pinion mechanism together with a pinion gear provided in the drive mechanism 100. Similarly, from the second peripheral block 120B, a second drive shaft 122B having a gear tooth profile formed on the side surface is erected in the second direction, and the second drive shaft 122B is also provided in the drive mechanism 100. Together with this, the rack and pinion mechanism is configured. Further, a second coil spring 126A having an inner diameter larger than the outer diameter of the second drive shaft 122A is mounted on the outer periphery of the second drive shaft 122A, and the second drive shaft 122B is mounted on the outer periphery of the second drive shaft 122B. A second coil spring 126B having an inner diameter larger than the outer diameter is attached. The second coil spring 126A is mounted in a state of being compressed between the drive mechanism 100 and the second peripheral block 120A, and the second coil spring 126B is pressed between the drive mechanism 100 and the second peripheral block 120B. It is installed in a contracted state. These second coil springs 126A and 126B also correspond to “biasing members” in the present invention.

  From the center of the upper surface of the drive mechanism 100, a screw shaft 150a having a screw formed on the outer peripheral side surface is erected, and a flat palm member 150 is attached to the tip of the screw shaft 150a. Further, the screw shaft 150 a is connected to the drive mechanism 100. A third coil spring 150c having an inner diameter larger than the outer diameter of the screw shaft 150a is attached to the outer periphery of the screw shaft 150a. The third coil spring 150c is mounted in a state of being compressed between the drive mechanism 100 and the palm member 150. Further, on the upper surface of the drive mechanism 100, a guide shaft 150b is slidable from positions on both sides of the screw shaft 150a, and the tip of the guide shaft 150b is attached to the palm member 150. Further, the palm member 150 is formed in a rectangular shape in which the width in the second direction is narrower than the width in the first direction. Further, the base case 160 is attached to the link portion 312 of the robot arm. In this embodiment, the screw shaft 150a also corresponds to the “drive shaft” in the present invention, and the direction in which the screw shaft 150a connects the palm member 150 and the drive mechanism 100 is the “third direction” in the present invention. Correspond. Furthermore, the third coil spring 150c also corresponds to the “biasing member” in the present invention.

B. Holding operation of the robot hand of this embodiment:
FIG. 3 is an explanatory diagram illustrating an operation in which the robot hand 10 of the present embodiment grips an object. When gripping an object, the size of the robot hand 10 in the width direction is changed according to the size of the object to be gripped. Although the description here assumes that the width direction is the second direction, the first direction may be the width direction. FIG. 3A shows how the size of the robot hand 10 in the width direction is changed. As described above, the second guide shafts 132A to 132D standing from the finger blocks 130A to 130D in the second direction can slide in the second guide holes 114A and 114 formed in the first peripheral blocks 110A and 110B. Inserted in a state (see FIG. 1). For this reason, if the interval between the second peripheral block 120A and the second peripheral block 120B is changed, the interval between the finger block 130A and the finger block 130B and the interval between the finger block 130D and the finger block 130C are simultaneously changed accordingly. can do. And since finger member 140A-D is attached to the upper surface of finger block 130A-D, by moving these finger blocks 130A-D, finger member 140A-D attached to each can be moved. it can. The drive mechanism 100 for changing the interval between the second peripheral block 120B and the second peripheral block 120A will be described later. FIG. 3A illustrates how the interval is narrowed.

  If the size of the robot hand 10 in the width direction is adjusted, the size of the robot hand 10 in the holding direction is reduced in accordance with the size of the object to be held. Although the description here assumes that the gripping direction is the first direction, the second direction may be the gripping direction. FIG. 3B shows how the size of the robot hand 10 in the gripping direction is reduced. As described above, the first guide shafts 131A to 131D standing in the first direction from the finger blocks 130A to 130D are slidable in the first guide holes 123A and 123B formed in the second peripheral blocks 120A and 120B. (See FIG. 1). For this reason, if the interval between the first peripheral block 110A and the first peripheral block 110B is reduced, the interval between the finger block 130A and the finger block 130D and the interval between the finger block 130B and the finger block 130C are accordingly reduced. As a result, the distance between the finger member 140A and the finger member 140D and the distance between the finger member 140B and the finger member 140C can be simultaneously narrowed, and the object can be gripped. A mechanism for reducing the distance between the first peripheral block 110A and the first peripheral block 110B will be described later.

  Furthermore, in the robot hand 10 of the present embodiment, the palm member 150 can be moved in the third direction so that the upper surface of the palm member 150 is brought into contact with the object. In this way, the object can be grasped using the four finger members 140A to 140D and the palm member 150, so that even a small object can be grasped stably. FIG. 3C shows a state in which the palm member 150 is moved upward in the drawing. In the above description, the interval between the four finger members 140A to 140D in the width direction is changed first, then the interval in the next gripping direction is changed, and the last palm member 150 is moved in the third direction. It was supposed to be. However, the four finger members 140A to 140D may be moved simultaneously in the width direction and the holding direction, or the four finger members 140A to 140D and the palm member 150 may be moved simultaneously.

  Next, the drive mechanism 100 for changing the size of the robot hand 10 in the first direction or the second direction and moving the palm member 150 in the third direction will be described.

  FIG. 4 is an explanatory diagram showing the transmission shaft unit 200 mounted on the robot hand 10 of the present embodiment. In FIG. 4, only the transmission shaft unit 200 and the piezoelectric motor that drives the transmission shaft unit 200 are indicated by solid lines, and only a rough outline is indicated by broken lines in order to avoid the complexity of the drawing. It is shown.

  The transmission shaft unit 200 of the present embodiment has a triple tube structure in which three transmission shafts are coaxially incorporated. A hollow circular tube-shaped first transmission shaft 212 is provided on the outermost transmission shaft of the transmission shaft unit 200, and a first pinion gear 206 is formed on the outer periphery of the upper end of the first transmission shaft 212. A drive gear 212 </ b> G is attached to the lower end of the first transmission shaft 212.

  Inside the first transmission shaft 212, a hollow transmission-shaped second transmission shaft 210 (see FIG. 5B) (not shown) is housed so as to be rotatable with respect to the first transmission shaft 212. The second transmission shaft 210 is formed longer than the first transmission shaft 212, a second pinion gear 204 is formed on the outer periphery of the upper end of the second transmission shaft 210, and a drive gear is formed on the lower end of the second transmission shaft 210. 210G is attached. Further, the first pinion gear 206 and the second pinion gear 204 are formed to have the same outer diameter.

  Further, a hollow transmission-shaped third transmission shaft 208 (see FIG. 5C) is accommodated inside the second transmission shaft 210 so as to be rotatable with respect to the second transmission shaft 210. Yes. The third transmission shaft 208 is formed to be longer than the second transmission shaft 210, and a screw portion 202 that is internally threaded is provided on the outer periphery of the upper end of the third transmission shaft 208. A drive gear 208 </ b> G is formed at the lower end of the transmission shaft 208. The screw portion 202 is screwed with a screw shaft 150 a connected to the palm member 150.

  The upper half of the transmission shaft unit 200 having such a structure is housed in the drive mechanism 100, and the lower half of the transmission shaft unit 200 is housed in the base case 160. Further, in the base case 160, a drive motor (not shown) for driving the drive gear 212G of the first transmission shaft 212, a drive motor (not shown) for driving the drive gear 210G of the second transmission shaft 210, and a third A drive motor (not shown) for driving the drive gear 208G of the transmission shaft 208 is accommodated. In this embodiment, the transmission shaft unit 200 corresponds to the drive mechanism 100 in the present invention.

  FIG. 5 is an explanatory diagram showing an operation in which the robot hand 10 of the present embodiment changes the size in the first direction or the second direction or moves the palm member 150 in the third direction. FIG. 5A shows how the drive gear 212G of the first transmission shaft 212 is driven. In FIG. 5A, only the relevant part is represented by a thick solid line and the other parts are represented by a thin broken line in order to avoid complicated illustration.

  As illustrated, when the drive gear 212G is driven, the first transmission shaft 212 rotates, and the first pinion gear 206 at the upper end of the first transmission shaft 212 rotates. The first pinion gear 206 is engaged with the first drive shafts 111A and 111B, the first drive shaft 111A is connected to the first peripheral block 110A, and the first drive shaft 111B is connected to the first peripheral block 110B. ing. Therefore, when the first pinion gear 206 rotates, the interval between the first peripheral block 110A and the first peripheral block 110B (the interval in the first direction (here, the gripping direction)) is changed. For example, when the first pinion gear 206 is rotated clockwise in FIG. 5A, the first peripheral block 110A and the first peripheral block 110B move in a direction in which the distance increases. Conversely, when the first pinion gear 206 is rotated counterclockwise, the first peripheral block 110A and the first peripheral block 110B move in the direction of narrowing.

  FIG. 5B shows how the drive gear 210G of the second transmission shaft 210 is driven. In FIG. 5B, only the relevant part is represented by a thick solid line and the other parts are represented by a thin broken line in order to avoid complicated illustration. When the drive gear 210G is driven, the second transmission shaft 210 rotates and the second pinion gear 204 at the upper end of the second transmission shaft 210 rotates. The second pinion gear 204 is engaged with the second drive shafts 122A and 122B, the second drive shaft 122A is connected to the second peripheral block 120A, and the second drive shaft 122B is connected to the second peripheral block 120B. ing. Therefore, when the second pinion gear 204 is rotated, the interval between the second peripheral block 120A and the second peripheral block 120B (interval in the second direction (here, the width direction)) is changed. For example, when the second pinion gear 204 is rotated clockwise in FIG. 5B, the second peripheral block 120A and the second peripheral block 120B move in a direction in which the distance increases. Conversely, when the second pinion gear 204 is rotated counterclockwise, the second peripheral block 120A and the second peripheral block 120B move in a direction in which the interval is reduced.

  FIG. 5C shows a state where the drive gear 208G of the third transmission shaft 208 is driven. In FIG. 5C, only the relevant part is represented by a thick solid line, and the other part is represented by a thin broken line. When the drive gear 208G is driven, the third transmission shaft 208 rotates and the screw portion 202 at the upper end of the third transmission shaft 208 rotates. The screw portion 202 is screwed with the screw shaft 150a, and the palm member 150 is attached to the upper end of the screw shaft 150a. Further, a guide shaft 150 b is erected from the upper surface of the drive mechanism 100 and attached to the palm member 150. For this reason, the palm member 150 can move in the direction of the younger brother 3 (vertical direction in the drawing) with respect to the drive mechanism 100, but cannot rotate. Therefore, when the screw portion 202 is rotated, the screw shaft 150a screwed to the screw portion 202 moves in the direction of the younger brother 3 (up and down direction in the drawing), and accordingly, the palm member 150 moves in the direction of the younger brother 3 (up and down in the drawing). Direction). For example, in the example shown in FIG. 5C, when the screw portion 202 is rotated clockwise, the palm member 150 moves in the downward direction, and conversely, when the screw portion 202 is rotated counterclockwise, the palm portion 150 moves. The member 150 moves in the upward direction.

C. Action of various coil springs:
The transmission shaft unit 200 described above is configured by a plurality of rack and pinion mechanisms, and there is always a gap between the rack-side gear teeth and the pinion-side gear teeth. In addition, there is always a gap between the gear teeth of the drive gears 208G, 210G, and 212G of the transmission shaft unit 200 and the gear teeth of the motor (not shown). These gaps generate so-called backlash (a state where the driving force is not transmitted to the finger members 140A to 140D even when the motor is rotated, or such a period). As a result, it is difficult to finely adjust the interval between the finger members 140A to 140D, and it is difficult to grip an object (particularly a small object or a thin object). However, in the robot hand 10 of the present embodiment, it is possible to avoid the occurrence of backlash only by providing the first coil springs 115A and 115B and the second coil springs 126A and 126B.

  FIG. 6 is an explanatory diagram showing a mechanism by which the second coil springs 126A and 126B avoid the occurrence of backlash. Note that, when the robot hand 10 is viewed from the side, many parts overlap and obscure understanding. Therefore, description will be given by taking a cross section of the robot hand 10 at an appropriate position. FIG. 6A shows the cross-sectional position of the robot hand 10. As shown in the drawing, the cross section is a plane passing between the finger block 130D and the second peripheral block 120B, between the first peripheral block 110B and the driving mechanism 100, and between the finger block 130C and the second peripheral block 120A. Then, when the robot hand 10 is viewed from the direction of the arrow P in the drawing, a cross-sectional view as shown in FIG. 6B or FIG. 6C is obtained.

  FIG. 6B shows a state in which the interval between the finger members 140A to 140D is narrowed in the second direction. As described above, in order to narrow the interval between the finger members 140A to 140D in the second direction, the second peripheral blocks 120A and 120B are moved closer to the drive mechanism 100 (see FIG. 5B). Then, the second coil springs 126A and 126B are compressed, and the second peripheral blocks 120A and 120B receive a reaction force from the second coil springs 126A and 126B. As a result, the second peripheral blocks 120A and 120B are pressed in a direction away from the drive mechanism 100 in the second direction, so that backlash in the second direction can be eliminated.

  FIG. 6C shows a state in which the interval between the finger members 140A to 140D is widened in the second direction. As described above, the second peripheral blocks 120 </ b> A and 120 </ b> B are moved away from the drive mechanism 100 in order to increase the interval between the finger members 140 </ b> A to 140 </ b> D in the second direction. Here, the spring lengths of the second coil springs 126A and 126B (free) so that the second coil springs 126A and 126B are compressed even when the interval between the finger members 140A to 140D is maximized in the second direction. Long) is set. In this way, even when the interval between the finger members 140A to 140D is widened in the second direction, the second peripheral blocks 120A and 120B can always be pressed in the direction away from the drive mechanism 100. Can eliminate the backlash.

  FIG. 7 is an explanatory diagram showing a mechanism by which the first coil springs 115A and 115B avoid the occurrence of backlash. Also in FIG. 7, description will be made using a cross-sectional view of the robot hand 10. As shown in FIG. 7A, in FIG. 7, between the finger block 130D and the first peripheral block 110B, between the second peripheral block 120B and the drive mechanism 100, and further between the finger block 130A and the first peripheral block. A cross-section is taken at a position passing between 110A. When the robot hand 10 is viewed from the direction of the arrow Q in the figure, a cross-sectional view as shown in FIG. 7B or FIG. 7C is obtained.

  FIG.7 (b) has shown the state which narrowed the space | interval of finger member 140A-D to the 1st direction. When the first peripheral blocks 110A and 110B are moved closer to the driving mechanism 100 in order to narrow the interval between the finger members 140A to 140D in the first direction, the first coil springs 115A and 115B are compressed, and the first peripheral blocks 110A and 110B The reaction force is received from the first coil springs 115A and 115B. As a result, the first peripheral blocks 110A and 110B are pressed in a direction away from the drive mechanism 100 in the first direction, so that backlash in the first direction can be eliminated.

  Moreover, FIG.7 (c) has shown the state which expanded the space | interval of finger member 140A-D to the 1st direction. Even when the distance between the finger members 140A to 140D is maximized in the first direction (the second peripheral blocks 120A and 120B are the farthest away from the drive mechanism 100), the first coil springs 115A and 115B are compressed. As shown, the spring lengths (free lengths) of the first coil springs 115A and 115B are set in advance. In this way, even when the interval between the finger members 140A to 140D is widened in the first direction, the first peripheral blocks 110A and 110B can always be pressed in the direction away from the drive mechanism 100. Can eliminate the backlash.

  As described above, the first coil springs 115A and 115B have a function of eliminating backlash in the first direction, and the second coil springs 126A and 126B have a function of eliminating backlash in the second direction. The same applies to the third coil spring 150c attached to the screw shaft 150a. That is, the spring length (free length) of the third coil spring 150c is set to such a length that the third coil spring 150c is compressed even when the palm member 150 is raised most. In this way, the palm member 150 can always be pressed away from the drive mechanism 100 by the third coil spring 150c, so backlash in the moving direction of the palm member 150 can be eliminated.

  In the robot hand 10 of the above-described embodiment, the first coil springs 115A and 115B, the second coil springs 126A and 126B, and the third coil spring 150c are simply configured to be mounted in the first direction and the second direction. In addition, backlash in the moving direction of the palm member 150 can be eliminated.

  In the above-described embodiment, the first coil springs 115A and 115B, the second coil springs 126A and 126B, and the third coil spring 150c are described as being always used in a compressed state. On the other hand, it is also possible to use these coil springs in an always extended state. That is, one end face of the first coil spring 115A is fixed to the drive mechanism 100, and the other end face is fixed to the first peripheral block 110A. Moreover, about the 1st coil spring 115B, one end surface is fixed to the drive mechanism 100, and the other end surface is fixed to the 1st peripheral block 110B. Similarly, for the second coil springs 126A and 126B, one end face is fixed to the drive mechanism 100, and the other end face is fixed to the second peripheral block 120A and the second peripheral block 120B. Further, with respect to the third coil spring 150 c, one end face is fixed to the drive mechanism 100 and the other end face is fixed to the palm member 150. The spring lengths (free lengths) of the respective coil springs are the same even when the finger members 140A to 140D are brought closest to each other or the palm member 150 is lowered most (closest to the drive mechanism 100). Set the length to By doing so, the first peripheral block 110A, 100B, the second peripheral block 120A, 120B, and the palm member 150 are pulled in the direction of the normal drive mechanism 100, so the first direction, the second direction , And backlash in the moving direction of the palm member 150 can be eliminated.

  When the first coil springs 115A and 115B, the second coil springs 126A and 126B, and the third coil spring 150c are always used in a compressed state, the reaction force of each coil spring is in a direction that increases the interval between the finger members 140A to 140D. Works. For this reason, the space | interval of finger member 140A-D can be expanded rapidly. Moreover, the reaction force of each coil spring becomes large, so that the space | interval of finger member 140A-D is narrowed. For this reason, when a small object or a thin object is gripped, the moving speed of the finger members 140A to 140D is reduced, so that the object can be gripped without being damaged.

  On the other hand, when the first coil springs 115A and 115B, the second coil springs 126A and 126B, and the third coil spring 150c are used in an always extended state, the reaction force of each coil spring reduces the interval between the finger members 140A to 140D. Act on. For this reason, it becomes possible to narrow the space | interval of finger member 140A-D rapidly.

  In the embodiment described above, the first coil springs 115A and 115B, the second coil springs 126A and 126B, and the third coil spring 150c are all used in the same manner. For example, if the first coil springs 115A and 115B are compressed and used, the second coil springs 126A and 126B and the third coil spring 150c are also compressed and used. However, a coil spring that is used by being compressed and a coil spring that is used by being extended may be combined. For example, the first coil springs 115A and 115B and the third coil spring 150c may be used after being compressed, and the second coil springs 126A and 126B may be used after being expanded.

  In the above-described embodiment, the first coil springs 115A and 115B are attached to the first drive shafts 111A and 111B, the second coil springs 126A and 126B are attached to the second drive shafts 122A and 122B, and the third coil spring 150c is a screw. It is attached to the shaft 150a. These coil springs are not necessarily attached to the first drive shafts 111A and 111B, the second drive shafts 122A and 122B, and the screw shaft 150a. However, if the first drive shafts 111A and 111B, the second drive shafts 122A and 122B, and the screw shaft 150a are attached, the following effects can be obtained.

  First, the first peripheral block 110A will be described. The first peripheral block 110A is moved by the driving force received from the first drive shaft 111A. Here, if the first coil spring 115A is attached to the first drive shaft 111A, the drive force by the first drive shaft 111A and the reaction force by the first coil spring 115A act on the first peripheral block 110A at the same position. To do. For this reason, a moment for rotating the first peripheral block 110A due to the driving force and the reaction force being applied at different positions does not occur. The same applies to the first peripheral block 110B. For this reason, when the first peripheral blocks 110A and 110B are moved in the first direction, the first guide shafts 131A to 131D are not caught in the first guide holes 123A and 123B, and can be moved smoothly.

  Similarly, for the second peripheral blocks 120A and 120B and the palm member 150, the position where the driving force acts on the second peripheral blocks 120A and 120B and the palm member 150 and the position where the reaction force of each coil spring acts are the same. Can be made. Therefore, no moment is applied to the second peripheral blocks 120A and 120B and the palm member 150, and these can be moved smoothly.

  In addition, the first coil springs 115A and 115B, the second coil springs 126A and 126B, and the third coil spring 150c are attached to the first drive shafts 111A and 111B, the second drive shafts 122A and 122B, and the screw shaft 150a. In this case, each coil spring is guided by the shaft, so that each coil spring does not fall or bend, and the magnitude of the reaction force does not change.

D. Modified example:
There are several variations of the robot hand 10 of the present embodiment described above. Hereinafter, the robot hand 10 of these modified examples will be briefly described focusing on the differences from the above-described embodiments. In the modified example described below, the same components as those in the above-described embodiment are denoted by the same reference numerals as those in the embodiment, and detailed description thereof is omitted.

D-1. First modification:
In the above-described embodiments, the first coil springs 115A and 115B, the second coil springs 126A and 126B, and the third coil spring 150c have been described as being used in a constantly compressed state or a constantly expanded state. That is, for example, if the first coil springs 115A and 115B are always used in a compressed state, the first coil springs 115A and 115B are in a compressed state even when the finger members 140A to 140D are expanded most in the first direction. Set the spring length (free length) of the coil spring. On the other hand, if the first coil springs 115A and 115B are always used in an extended state, the first coil springs 115A and 115B are in an extended state even when the finger members 140A to 140D are most narrowed in the first direction. Set the spring length (free length) of the coil spring.

  On the other hand, the first coil spring 115A is in an expanded state when the finger members 140A-D are expanded most in the first direction, and in a compressed state when the finger members 140A-D are most narrowed in the first direction. , 115B spring length (free length) may be set. Similarly, the second coil springs 126A and 126B are expanded when the finger members 140A to 140D are expanded most in the second direction, and are compressed when the finger members 140A to D are narrowed most in the second direction. Alternatively, the spring length (free length) of the second coil springs 126A and 126B may be set. Further, the third coil spring 150c is also in an expanded state when the palm member 150 is moved up most (away from the drive mechanism 100), and compressed when the palm member 150 is moved down most (closest to the drive mechanism 100). You may set the spring length (free length) of the 3rd coil spring 150c so that it may be in a state.

  FIG. 8 is an explanatory view showing a mechanism by which the robot hand 10 of the first modified example eliminates backlash. FIG. 8A shows a state in which the finger members 140A to 140D are most expanded in the second direction. In this state, since the second coil springs 126 </ b> A and 126 </ b> B are in an extended state, the second peripheral blocks 120 </ b> A and 120 </ b> B receive a reaction force in a direction approaching the drive mechanism 100. The white arrows shown in the figure indicate that the second peripheral blocks 120A and 120B receive a reaction force from the extended second coil springs 126A and 126B.

  When the finger members 140A to 140D are moved so that the interval in the second direction is narrowed, the lengths of the extended second coil springs 126A and 126B are restored, so that the second peripheral blocks 120A and 120B are moved to the second coil springs 126A and 126B. The reaction force received from becomes smaller. As shown in FIG. 8B, at the moment when the lengths of the second coil springs 126A and 126B become free, the reaction force received by the second peripheral blocks 120A and 120B from the second coil springs 126A and 126B is 0. However, when the finger members 140A to 140D are further moved, the second coil springs 126A and 126B are compressed. As a result, as shown in FIG. 8C, the second peripheral blocks 120 </ b> A and 120 </ b> B now receive a reaction force in a direction away from the drive mechanism 100. The hatched arrows shown in FIG. 8C indicate that the second peripheral blocks 120A and 120B receive a reaction force from the compressed second coil springs 126A and 126B.

  For this reason, in the robot hand 10 of the first modified example, except for the moment when the second coil springs 126A and 126B are free length, the reaction force on either the side approaching the drive mechanism 100 or the side moving away from the drive mechanism 100 is It can always be added to the second peripheral block 120A, 120B. For this reason, it is possible to substantially avoid the occurrence of backlash in the second direction.

  The same applies to the first coil springs 115A and 115B and the third coil spring 150c. That is, except for the moment when the first coil springs 115A and 115B and the third coil spring 150c have a free length, a reaction force can always be applied to the first peripheral blocks 110A and 110B and the palm member 150. The occurrence of backlash in one direction and the occurrence of backlash in the moving direction of the palm member 150 can be substantially avoided.

  In the robot hand 10 of the above-described embodiment, the first coil springs 115A and 115B, the second coil springs 126A and 126B, and the third coil spring 150c are used in either a constantly compressed state or a constantly expanded state. . Therefore, if the coil springs are used in a compressed state, these coil springs have a spring length (free length) so that they are still compressed even when the distance between the finger members 140A to 140D is maximized. Must be a sufficiently long coil spring. On the other hand, if it is used in an extended state, it is a coil spring whose spring length (free length) is sufficiently short so that it is still in an extended state even if the interval between the finger members 140A to 140D is reduced to a minimum. There must be. In any case, the degree of freedom in selecting the coil spring is reduced.

  On the other hand, in the robot hand 10 of the first modified example described above, there is no restriction on the spring length (free length) of the coil spring. For this reason, the freedom degree of selection of a coil spring becomes large, and it becomes possible to select the appropriate coil spring which can obtain the reaction force of a more preferable magnitude | size.

D-2. Second modification:
In the first modification described above, the first coil spring 115A and the first coil spring 115B have been described as having the same spring length (free length). The second coil spring 126A and the second coil spring 126B have been described as being set to the same spring length. However, the first coil spring 115A and the first coil spring 115B may be set to different spring lengths (free lengths), and the second coil spring 126A and the second coil spring 126B may be set to different spring lengths (free lengths).

  FIG. 9 is an explanatory view showing a mechanism by which the robot hand 10 of the second modified example eliminates backlash. In the example shown in FIG. 9, the second coil spring 126B is a coil spring having a longer spring length (free length) than the second coil spring 126A, but the second coil spring 126A may be a longer coil spring. Good. FIG. 9A shows a state in which the finger members 140A to 140D are most expanded in the second direction. In this state, since the second coil springs 126 </ b> A and 126 </ b> B are in an extended state, the second peripheral blocks 120 </ b> A and 120 </ b> B receive a reaction force in a direction approaching the drive mechanism 100. In addition, the white arrow shown in the drawing represents that the second coil springs 126A and 126B are extended to generate a reaction force.

  When the finger members 140A to 140D are moved so that the interval in the second direction is narrowed, the lengths of the extended second coil springs 126A and 126B are restored, so that the second peripheral blocks 120A and 120B are moved to the second coil springs 126A and 126B. The reaction force received from becomes smaller. As shown in FIG. 9B, the second coil spring 126B having the longer spring length first becomes a free length and the reaction force becomes zero. However, since the second coil spring 126A has a shorter spring length than the second coil spring 126B, even if the second coil spring 126B has a free length, the second coil spring 126A does not have a free length and still generates a reaction force.

  Further, when the finger members 140A to 140D are moved so that the interval in the second direction is narrowed, the second coil spring 126A having the shorter spring length (free length) is now free as shown in FIG. 9C. The reaction force becomes zero as the length increases. However, the second coil spring 126B having the longer spring length is already compressed and generates a reaction force. In addition, the hatched arrow shown in FIG. 9C indicates that the compressed second coil spring 126B generates a reaction force. Further, when the finger members 140A to 140D are moved so that the interval in the second direction is narrowed, the second coil springs 126A and 126B are both compressed as shown in FIG. Generate power.

  As described above, in the robot hand 10 of the second modified example, one of the second coil springs 126A and 126B always generates a reaction force. For this reason, it is possible to avoid the occurrence of backlash in the second direction at any moment. The above description applies to the first coil springs 115A and 115B in exactly the same manner. Therefore, by making the spring lengths (free lengths) of the first coil spring 115A and the first coil spring 115B different, it is possible to cause one of the first coil springs 115A and 115B to always generate a reaction force. it can. As a result, it is possible to avoid the occurrence of backlash in the first direction at any moment.

D-3. Third modification:
In the above-described embodiment or modification, the first coil springs 115A and 115B for eliminating backlash in the first direction are the first drive shafts 111A and 111B for moving the finger members 140A to 140D in the first direction. It was described as being attached to However, the first coil springs 115A and 115B are not necessarily attached to the first drive shafts 111A and 111B. That is, since the first guide shafts 131A to 131D are erected from the finger members 140A to 140D in the first direction, backlash in the first direction is eliminated from these first guide shafts 131A to 131D. For this purpose, a coil spring may be attached. Similarly, with respect to the coil spring for eliminating the backlash in the second direction, the backlash in the second direction is applied to the second guide shafts 132A to 132D erected in the second direction from the finger members 140A to 140D. A coil spring may be attached to eliminate the problem. Further, with respect to the coil spring for eliminating the backlash in the movement direction of the palm member 150, two guide shafts 150b are erected from the palm member 150 in the movement direction of the palm member 150. A coil spring for eliminating backlash may be attached to 150b.

  FIG. 10 shows the robot hand 10 of the third modified example. As illustrated, in the robot hand 10 of the third modified example, the first coil springs 135A to 135D are mounted on the first guide shafts 131A to 131D standing in the first direction from the finger blocks 130A to 130D. Further, second coil springs 136A to 136D are mounted on second guide shafts 132A to 132D that are erected in the second direction from the finger blocks 130A to 130D. Further, a third coil spring 150d is mounted on each of the two guide shafts 150b provided upright from the palm member 150 in the moving direction of the palm member 150.

  If the first coil springs 135A to 135D, the second coil springs 136A to 136D, and the third coil spring 150d are always compressed so that they are sufficiently long, the finger block 130A Reaction force can always be applied to ~ D and the palm member 150. Alternatively, the finger block can also be obtained by using a coil spring having a sufficiently short spring length (free length) so that the first coil springs 135A to 135D, the second coil springs 136A to 136D, and the third coil spring 150d are always stretched. A reaction force can always be applied to 130A to D and the palm member 150.

  Further, the spring lengths (free lengths) of the first coil springs 135A to 135D and the second coil springs 136A to 136D are expanded when the interval between the finger members 140A to 140D is widened, and the interval between the finger members 140A to 140D is increased. You may set to the spring length which will be in the state compressed when narrowed most. Alternatively, the spring length (free length) of the third coil spring 150d is in an extended state when the palm member 150 is raised most (farther away from the drive mechanism 100), and when the palm member 150 is lowered most (the drive mechanism 100 has the largest length). The spring length may be set so that it is in a compressed state as it approaches. At this time, the first coil spring 135A and the first coil spring 135D have different spring lengths (free lengths), the first coil spring 135B and the first coil spring 135C have different spring lengths (free lengths), and the second coil springs. The spring lengths (free lengths) of 136A and the second coil spring 136B are made different, the spring lengths (free lengths) of the second coil spring 136C and the second coil spring 136D are made different, and the spring lengths of the two third coil springs 150d ( The free length may be different.

D-4. Fourth modification:
In the above-described embodiment or modification, it has been described that any coil spring is attached to the drive shaft, the guide shaft, or the screw shaft. However, the coil spring does not necessarily have to be mounted on any of these shafts. For example, as shown in FIG. 11, four finger blocks 130 </ b> A to 130 </ b> D may be connected by a coil spring between finger blocks adjacent in the first direction, and may be connected by a coil spring between finger blocks adjacent in the second direction. . That is, in the example shown in FIG. 11, in the first direction, the finger block 130A and the finger block 130B are connected by the first coil spring 137AB, and the finger block 130C and the finger block 130D are connected by the first coil spring 137CD. Yes. In the second direction, the finger block 130A and the finger block 130D are connected by the second coil spring 137AD, and the finger block 130B and the finger block 130C are connected by the second coil spring 137BC.

  Even in this case, the finger blocks 130A to 130D receive a reaction force in a direction approaching the drive mechanism 100 or a direction away from the drive mechanism 100, so that backlash occurs in the first direction and the second direction. Can be avoided.

  In the example shown in FIG. 11, the case where the first coil springs 137AB, BC, CD, and DA are provided between the four finger blocks 130A to 130D has been described. Between the mechanism 100, between the first peripheral block 110B and the drive mechanism 100, between the second peripheral block 120A and the drive mechanism 100, and between the second peripheral block 120B and the drive mechanism 100, respectively. It is also possible to provide a coil spring.

D-5. Fifth modification:
In the above-described embodiment or modification, in order to eliminate backlash of the finger members 140A to D and the palm member 150, the first peripheral blocks 110A and 110B (or finger blocks 130A to 130D) and the palm are used by using a coil spring. It has been described that the member 150 is energized. However, if the first peripheral blocks 110A and 110B (or finger blocks 130A to 130D) and the palm member 150 can be urged, it is not always necessary to use a coil spring. For example, it can be energized using a piston / cylinder mechanism that operates using a gas such as air or a liquid such as oil.

  FIG. 12 is an explanatory view exemplifying a robot hand 10 of a fifth modification that eliminates backlash of the finger members 140A to 140D using a piston / cylinder mechanism (air cylinder 170) that operates using air. In the illustrated example, the air cylinder 170 is attached between the finger blocks 130A to 130D. However, the present invention is not limited to this, and the air cylinder 170 is attached between the finger blocks 130A to 130D and the drive mechanism 100. Also good. Of course, the air cylinder 170 may be attached between the palm member 150 and the drive mechanism 100.

  In the robot hand 10 of the fifth modification shown in FIG. 12, the air cylinder 170 tries to widen the interval between the finger blocks 130 </ b> A to 130 </ b> D according to the pressure of the air supplied from the air tube 172. For this reason, the backlash of finger member 140A-D can be eliminated. Further, since the force generated by the air cylinder 170 is determined by the pressure of air supplied from the air tube 172, in the robot hand 10 of the fifth modified example, what state is the interval between the finger members 140A to 140D? Regardless, it is possible to always apply an appropriate amount of force to the finger blocks 130A-D.

E. Application example:
The robot hand 10 according to the present embodiment and the modification described above can be applied to the following robots.

  FIG. 13 is an explanatory view illustrating a single arm robot 300 including the robot hand 10. As illustrated, the robot 300 has an arm 310 including a plurality of link portions 312 and a joint portion 320 that connects the link portions 312 in a bendable state. The robot hand 10 is connected to the tip of the arm 310. For this reason, it is possible to drive the arm 310 to bring the robot hand 10 close to the position of the target and to grip the target with the robot hand 10.

  FIG. 14 is an explanatory diagram illustrating a multi-arm robot 350 including the robot hand 10. As illustrated, the robot 350 includes a plurality of arms 310 (two in the illustrated example) including a plurality of link portions 312 and joint portions 320 that connect the link portions 312 in a bendable state. ) The robot hand 10 and the tool 301 are connected to the tip of the arm 310. In addition, a plurality of cameras 353 are mounted on the head 352, and a control unit 356 that controls the overall operation is mounted inside the main body 354. Further, it can be conveyed by a caster 358 provided on the bottom surface of the main body 354. The robot 350 can also hold the object with the robot hand 10 by driving the arm 310 to bring the robot hand 10 close to the position of the object.

  As described above, the robot hand and the robot according to various embodiments have been described. However, the present invention is not limited to all the embodiments and modifications described above, and can be implemented in various modes without departing from the gist thereof. is there.

10 ... Robot hand, 100 ... Drive mechanism,
110A, B ... first peripheral block, 111A, B ... first drive shaft,
114A, B ... second guide hole, 115A, B ... first coil spring,
120A, B ... second peripheral block, 122A, B ... second drive shaft,
123A, B ... 1st guide hole, 126A, B ... 2nd coil spring,
130A to D: finger block, 131A to D: first guide shaft,
132A to D: second guide shaft, 135A to D: first coil spring,
136A-D ... 2nd coil spring, 137AB ... 1st coil spring,
137AD ... second coil spring, 137BC ... second coil spring,
137CD: first coil spring, 140A to D: finger member,
150 ... Palm member, 150a ... Screw shaft, 150b ... Guide shaft,
150c, d ... third coil spring, 160 ... base case,
170 ... Air cylinder, 172 ... Air tube,
200 ... Transmission shaft unit, 202 ... Screw part, 204 ... Second pinion gear,
206 ... 1st pinion gear, 208 ... 3rd transmission shaft, 208G ... Drive gear,
210 ... second transmission shaft, 210G ... drive gear, 212 ... first transmission shaft,
212G ... Drive gear, 300 ... Robot, 301 ... Tool,
310 ... arm, 312 ... link part, 320 ... joint part,
350 ... Robot, 352 ... Head, 353 ... Camera,
354 ... Main unit, 356 ... Control unit, 358 ... Caster

Claims (19)

Four finger blocks provided with finger members;
A drive mechanism for moving the finger block in a first direction or a second direction;
A plurality of peripheral blocks connected to the drive mechanism by a drive shaft;
A plurality of guide shafts slidably inserted into the sliding holes of the peripheral block;
With
The finger block is located at four corners of a quadrangle in plan view from the third direction, the peripheral block and the guide shaft are located along four sides of the quadrangle, and the center of the drive mechanism is the square , One of the two sides of the side part is parallel to the first direction and the other two sides of the side part are parallel to the second direction,
The first direction, the second direction, and the third direction are orthogonal to each other,
A biasing member that biases the finger block in a moving direction of moving the finger block ;
The biasing member moves at the end point when the peripheral block approaches the center of the drive mechanism.
And the peripheral block is separated from the center of the drive mechanism.
Robot hand, characterized in Oh Rukoto with a coil spring in a state of being stretched than the free length in the moving direction at the end point of between. The robot hand according to claim 1 ,
The robot hand according to claim 1, wherein the biasing members are a plurality of coil springs having different free lengths and biasing the finger block in the moving direction independently of each other. The robot hand according to claim 1 or 2 ,
The robot hand according to claim 1, wherein the biasing member is a coil spring provided on the central axis so that the drive shaft passes therethrough. Four finger blocks provided with finger members;
  A drive mechanism for moving the finger block in a first direction or a second direction;
  A plurality of peripheral blocks connected to the drive mechanism by a drive shaft;
  A plurality of guide shafts slidably inserted into the sliding holes of the peripheral block;
  With
  The finger blocks are located at four corners of a quadrangle in plan view from the third direction, and the peripheral block is
The guide and the guide shaft are located along the four sides of the square, and the center of the drive mechanism is the front
Located at the center of the square, one of the two sides of the side is parallel to the first direction and the side
The other two sides of the part are parallel to the second direction,
  The first direction, the second direction, and the third direction are orthogonal to each other,
  A biasing member that biases the finger block in a moving direction of moving the finger block;
  The urging member is a coil spring provided on the central axis with the guide shaft penetrating therethrough.
Robot hand characterized by The robot hand according to claim 4,
  The biasing member moves at the end point when the peripheral block approaches the center of the drive mechanism.
And the peripheral block is separated from the center of the drive mechanism.
It is a coil spring that is in an extended state in the moving direction beyond the free length at the end point
Robot hand characterized by The robot hand according to claim 5,
  The urging members have different free lengths and urge the finger blocks in the moving direction independently of each other.
A robot hand characterized by a plurality of coil springs. Four finger blocks provided with finger members;
A drive mechanism for moving the finger block in a first direction or a second direction;
A plurality of peripheral blocks connected to the drive mechanism by a drive shaft;
A plurality of guide shafts slidably inserted into the sliding holes of the peripheral block;
A biasing member that biases the finger block in a moving direction of moving the finger block;
A palm member provided between the plurality of finger blocks and moving in a third direction;
A drive shaft erected in the third direction from the palm member and connected to the drive mechanism;
A biasing member that biases the palm member in a moving direction;
With
The finger block is positioned at four corners of a quadrangle in plan view from the third direction, the peripheral block and the guide shaft are positioned along four sides of the quadrangle, and the center of the drive mechanism is the center Located in the center of the quadrangle, one of the two sides of the side is parallel to the first direction and the other two sides of the side are parallel to the second direction;
The robot hand, wherein the first direction, the second direction, and the third direction are orthogonal to each other . Four finger blocks provided with finger members;
A drive mechanism for moving the finger block in a first direction or a second direction;
A plurality of peripheral blocks connected to the drive mechanism by a drive shaft;
A plurality of guide shafts slidably inserted into the sliding holes of the peripheral block;
With
The finger blocks are located at four corners of a quadrangle in plan view from the third direction, and the peripheral block is
The guide and the guide shaft are located along the four sides of the square, and the center of the drive mechanism is the front
Located at the center of the square, one of the two sides of the side is parallel to the first direction and the side
The other two sides of the part are parallel to the second direction,
The first direction, the second direction, and the third direction are orthogonal to each other,
A biasing member that biases the finger block in a moving direction of moving the finger block;
The robot hand according to claim 1, wherein the biasing member is a piston / cylinder mechanism that expands and contracts by increasing / decreasing the pressure of a fluid chamber provided therein. A robot equipped with a robot hand,
The robot hand is
Four finger blocks provided with finger members;
A drive mechanism for moving the finger block in a first direction or a second direction;
A plurality of peripheral blocks connected to the drive mechanism by a drive shaft;
A plurality of guide shafts slidably inserted into the sliding holes of the peripheral block;
With
The finger block is located at four corners of a quadrangle in plan view from the third direction, the peripheral block and the guide shaft are located along four sides of the quadrangle, and the center of the drive mechanism is the square , One of the two sides of the side part is parallel to the first direction and the other two sides of the side part are parallel to the second direction,
The first direction, the second direction, and the third direction are orthogonal to each other,
A biasing member that biases the finger block in a moving direction of moving the finger block ;
The biasing member moves at the end point when the peripheral block approaches the center of the drive mechanism.
And the peripheral block is separated from the center of the drive mechanism.
Robot, characterized in Oh Rukoto with a coil spring in a state of being stretched than the free length in the moving direction at the end point of between. The robot according to claim 9 ,
The robot is characterized in that the biasing members are a plurality of coil springs having different free lengths and biasing the finger block in the moving direction independently of each other. The robot according to claim 9 or 10 , wherein
The robot according to claim 1, wherein the urging member is a coil spring provided with a drive shaft passing through a central axis. A robot equipped with a robot hand,
  The robot hand is
  Four finger blocks provided with finger members;
  A drive mechanism for moving the finger block in a first direction or a second direction;
  A plurality of peripheral blocks connected to the drive mechanism by a drive shaft;
  A plurality of guide shafts slidably inserted into the sliding holes of the peripheral block;
  With
  The finger blocks are located at four corners of a quadrangle in plan view from the third direction, and the peripheral block is
The guide and the guide shaft are located along the four sides of the square, and the center of the drive mechanism is the front
Located at the center of the square, one of the two sides of the side is parallel to the first direction and the side
The other two sides of the part are parallel to the second direction,
  The first direction, the second direction, and the third direction are orthogonal to each other,
  A biasing member that biases the finger block in a moving direction of moving the finger block;
  The urging member is a coil spring provided on the central axis with the guide shaft penetrating therethrough.
Robot characterized by. The robot according to claim 12, wherein
  The biasing member moves at the end point when the peripheral block approaches the center of the drive mechanism.
And the peripheral block is separated from the center of the drive mechanism.
It is a coil spring that is in an extended state in the moving direction beyond the free length at the end point
Robot characterized by. The robot according to claim 13,
  The urging members have different free lengths and urge the finger blocks in the moving direction independently of each other.
A robot characterized by a plurality of coil springs. A robot equipped with a robot hand,
The robot hand is
Four finger blocks provided with finger members;
A drive mechanism for moving the finger block in a first direction or a second direction;
A plurality of peripheral blocks connected to the drive mechanism by a drive shaft;
A plurality of guide shafts slidably inserted into the sliding holes of the peripheral block;
A biasing member that biases the finger block in a moving direction of moving the finger block;
A palm member provided between the plurality of finger blocks and moving in a third direction;
A drive shaft erected in the third direction from the palm member and connected to the drive mechanism;
A biasing member that biases the palm member in the third direction;
With
The finger block is positioned at four corners of a quadrangle in plan view from the third direction, the peripheral block and the guide shaft are positioned along four sides of the quadrangle, and the center of the drive mechanism is the center Located in the center of the quadrangle, one of the two sides of the side is parallel to the first direction and the other two sides of the side are parallel to the second direction;
The robot according to claim 1, wherein the first direction, the second direction, and the third direction are orthogonal to each other . A robot equipped with a robot hand,
The robot hand is
Four finger blocks provided with finger members;
A drive mechanism for moving the finger block in a first direction or a second direction;
A plurality of peripheral blocks connected to the drive mechanism by a drive shaft;
A plurality of guide shafts slidably inserted into the sliding holes of the peripheral block;
With
The finger blocks are located at four corners of a quadrangle in plan view from the third direction, and the peripheral block is
The guide and the guide shaft are located along the four sides of the square, and the center of the drive mechanism is the front
Located at the center of the square, one of the two sides of the side is parallel to the first direction and the side
The other two sides of the part are parallel to the second direction,
The first direction, the second direction, and the third direction are orthogonal to each other,
A biasing member that biases the finger block in a moving direction of moving the finger block;
The robot according to claim 1, wherein the urging member is a piston / cylinder mechanism that expands and contracts by increasing / decreasing a pressure of a fluid chamber provided therein. Four finger blocks provided with finger members;
A drive mechanism for moving the finger block in a first direction or a second direction;
A plurality of peripheral blocks connected to the drive mechanism by a drive shaft;
A plurality of guide shafts slidably inserted into the sliding holes of the peripheral block;
With
The finger blocks are located at four corners of a quadrangle in plan view from the third direction, and the peripheral block is
The guide and the guide shaft are located along the four sides of the square, and the center of the drive mechanism is the front
Located at the center of the square, one of the two sides of the side is parallel to the first direction and the side
The other two sides of the part are parallel to the second direction,
The first direction, the second direction, and the third direction are orthogonal to each other,
A biasing member that biases the finger block in a moving direction of moving the finger block;
The biasing member is in a state of being compressed more than a free length in the moving direction when the peripheral block approaches the center of the drive mechanism, and the moving direction when the peripheral block is separated from the center of the drive mechanism. A gripping mechanism characterized in that it is a coil spring that is in an extended state with respect to the free length. Four finger blocks provided with finger members;
A drive mechanism for moving the finger block in a first direction or a second direction;
A plurality of peripheral blocks connected to the drive mechanism by a drive shaft;
A plurality of guide shafts slidably inserted into the sliding holes of the peripheral block;
With
The finger blocks are located at four corners of a quadrangle in plan view from the third direction, and the peripheral block is
The guide and the guide shaft are located along the four sides of the square, and the center of the drive mechanism is the front
Located at the center of the square, one of the two sides of the side is parallel to the first direction and the side
The other two sides of the part are parallel to the second direction,
The first direction, the second direction, and the third direction are orthogonal to each other,
A biasing member that biases the finger block in a moving direction of moving the finger block;
The gripping mechanism, wherein the biasing member is a plurality of coil springs having different free lengths and biasing the finger block in the moving direction independently of each other.   The gripping mechanism according to claim 17,
  The urging members have different free lengths and urge the finger blocks in the moving direction independently of each other.
A gripping mechanism comprising a plurality of coil springs.

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