1. Technical Field
The present invention relates to a robot.
2. Related Art
In related art, in robots having driven arms, generally, cable routings including cables for power supply to motors for driving the arms, communication lines for various sensors and controls, and pipes for driving using fluids are present inside and outside of the arms. As a configuration in which the cable routings are drawn out from the inside to the outside of the arm and used, a technology disclosed in Patent Document 1 (Japanese Patent No. 3746244) is known. That is, in the technology disclosed in Patent Document 1, a configuration in which cable routings inside of an arm are drawn out in a direction perpendicular to the casing of the arm and the cable routings are bent nearly perpendicularly and routed toward the next arm is disclosed. Further, Patent Document 2 (Japanese Patent No. 5159994) discloses a configuration in which cable routings are routed inside of an arm.
As in the technology disclosed in Patent Document 1, in the case where the direction in which the cable routings inside of the arm are drawn out is perpendicular to the rotation axis of the arm, the cable routings easily reach a region farther from the rotation axis with the rotation of the arm. Further, a fixing part for bending and directing the cable routings extending perpendicularly to the rotation axis toward an end effector (a cable routing fixing part 11′ of Patent Document 1 or the like) is necessary, and the fixing part enlarges the circle of movement of the arm. Accordingly, in related art disclosed in Patent Document 1, the drive range of the arm may be restricted for avoidance of the cable routings in contact with another part or the like. Furthermore, in the technology disclosed in Patent Document 2, the size of the outer shape of the arm becomes larger and the drive range of the arm may be restricted.
An advantage of some aspects of the invention is to provide a structure in which cable routings are harder to cause restriction on a drive range of an arm.
A robot according to an aspect of the invention includes an arm that rotates about a predetermined rotation axis as a rotation center, and a cable routing connecting part that can connect a cable routing inside of the arm and a cable routing outside of the arm, wherein the cable routing connecting part is provided in the arm, and present within a circle having a radius as a distance between a part of the arm farthest from the rotation axis and the rotation axis and centered at the rotation axis.
That is, as seen from the axis direction of the rotation axis, the circle having the radius as the distance between the part of the arm farthest from the rotation axis and the rotation axis and centered at the rotation axis is a circle of movement as the maximum range that the arm reaches when the arm rotates about the rotation axis (the other parts are fixed). Further, when the cable routing connecting part is present within the circle of movement (with in a cylinder formed by a locus of movement of the circle of movement along the rotation axis), the cable routing connecting part does not reach the outside of the circle of movement regardless of the rotation state of the arm. Therefore, when the arm is driven by a rotation or the like, the likelihood of the interference of the cable routing connecting part with objects around (the other parts of the robot, members present around the robot, etc.) is not higher. Accordingly, the robot has the structure in which the cable routing is harder to cause the restriction on the drive range of the arm.
Here, it is sufficient that the arm is a part that rotates around the predetermined rotation axis as the rotation center and the robot has one or more of the arms. Further, the shape of the arm is not limited. The arm may extend in the rotation axis direction or the arm extend in a direction different from the rotation axis (e.g. a direction perpendicular to the rotation axis). Note that the arm extending in the rotation axis direction, e.g., the so-called twistable arm having a cylindrical casing with the rotation axis inside of the cylinder is a preferable configuration example because the cable routing connected to the cable routing connecting part rotates with the rotation of the arm and the cable routing extends in a direction harder to hinder the rotation.
The cable routing connecting part is a part that can connect the cable routing inside of the arm and the cable routing outside of the arm. That is, in the robot, the cable routings present inside and outside of the arm provided with the cable routing connecting part are connected via the cable routing connecting part. It is preferable that the cable routing connecting part is adapted to connect the cable routings for transferring objects to be transferred. When the cable routings are conductors (the objects to be transferred are power, signals, or the like), the cable routing connecting part is a connector that secures conduction between the cable routings. Or, when the cable routings are pipes (the objects to be transferred are fluids or the like), the cable routing connecting part is a joint that may communicate the fluids between the pipes.
Further, the cable routing connecting part is present within the circle (circle of movement) having the radius as the distance between the part of the arm farthest from the rotation axis and the rotation axis and centered at the rotation axis. That is, the cable routing connecting part projects from the outer periphery to the outside so as to connect the cable routings inside and outside of the arm, and the height and the orientation with respect to the rotation axis of the cable routing connecting part are adjusted and, as a result of the adjustment, the cable routing connecting part is designed to be within the circle of movement.
Note that the circle of movement is a circle defined by the distance between the part of the arm farthest from the rotation axis and the rotation axis, and the maximum range that the arm reaches when the arm rotates about the rotation axis (the other parts are fixed). Therefore, the outside of the circle when the circle is moved to an arbitrary distance along the rotation axis is a region that the arm does not reach. Therefore, presence of the cable routing connecting part within the circle of movement refers to presence of the cable routing connecting part within the circle when the cable routing connecting part and the arm are projected on a plane perpendicular to the rotation axis.
Furthermore, the cable routing connecting part may be configured such that the cable routing connecting part is capable of connecting the cable routing from a direction in which an object to be connected to the cable routing is present, and a tilt angle of a connection direction of the cable routing to the cable routing connecting part with respect to the rotation axis may be equal to or less than 45 degrees. That is, the object to be connected is connected to one end of the cable routing present outside of the arm and the cable routing connecting part is connected to the other end. Further, in comparison between the direction perpendicular to the rotation axis and the rotation axis, the connection direction of the cable routing to the cable routing connecting part is not directed toward the former, but directed toward the latter. Therefore, the cable routing present outside of the arm is harder to spread in the radial direction with the rotation of the arm, and the arm may be rotated in a state in which the cable routing is present near the arm. Accordingly, the arm may be rotated in a state in which the cable routing is harder to cause the restriction on the drive range of the arm.
Note that the cable routing connecting part is configured to be capable of connecting the cable routing outside of the arm from the direction in which the object to be connected to the cable routing is present. That is, the cable routing connecting part is directed toward the object to be connected to the cable routing, and it is not necessary to bend and direct the cable routing in the opposite direction to the object to be connected toward the object to be connected. Accordingly, the cable routing may be routed from the inside to the outside without excessive stress on the cable routing and may be connected to the object to be connected.
The phrase that the cable routing connecting part is capable of connecting the cable routing from the direction in which the object to be connected to the cable routing is present means that the connection of the object to be connected from the opposite side in a line segment in parallel to the rotation axis is excluded, and thereby, it is sufficient that the cable routing can be connected to the cable routing connecting part without excessive bending. It is sufficient that the object to be connected to the cable routing is a part in which an object transferred by the cable routing is used and, e.g. an end effector, various arms, or the like that moves using power and signals as objects transferred by the cable routing is assumed.
Note that, when the tilt angle of the connection direction of the cable routing to the cable routing connecting part with respect to the rotation axis is equal to or 45 degrees, the cable routing directed away from the rotation axis is suppressed, and thus, it is sufficient that the tilt angle is equal to or 45 degrees. Therefore, it is sufficient that the tilt angle is an angle at which the cable routing directed away from the rotation axis is suppressed and the drive range of the arm is less restricted, e.g., equal to or less than ten degrees. Note that the tilt angle constantly takes a positive value because the tilt angle is an angle between the connection direction and the rotation axis and it is preferable that the distal end of the cable routing connecting part is directed in the circumferential direction of the circle of movement of the arm, however, the distal end of the cable routing connecting part may be directed in the rotation axis direction. According to the configuration, the restriction on the circle of movement of the arm by the cable routing connecting part may be more effectively suppressed while collision of the cable routing with the arm is suppressed.
Further, the cable routing connecting part may be capable of connecting the cable routing from the direction in which the object to be connected to the cable routing is present, and the connection direction of the cable routing to the cable routing connecting part and the rotation axis may be in parallel. That is, the cable routing connecting part is adapted to connect the cable routing outside of the arm in a direction in parallel to the rotation axis of the arm itself provided with the cable routing connecting part. In the configuration, the cable routing present outside of the arm is connected to the cable routing connecting part, and the cable routing is harder to spread in the radial direction with the rotation of the arm and the arm may be rotated in a state in which the cable routing is present near the arm. Accordingly, the arm may be rotated in a state in which the cable routing is harder to cause the restriction on the drive range of the arm.
Furthermore, a first rotating arm rotatably provided with respect to the arm and a second rotating arm rotatably provided on the first rotating arm to which an end effector can be attached may be provided. That is, the cable routing connecting part may be provided in the third arm from the end effector. The two arms (the first rotating arm and the second rotating arm) present between the arm to which the cable routing connecting part is attached and the end effector are generally designed to have a sufficiently smaller outer size in order not to hinder the movement of the end effector. Therefore, it is preferable that the cable routings are not contained in these arms present closer to the end effector wherever possible.
On the other hand, in the third arm from the end effector (the arm in which the cable routing connecting part is provided), obviously, it is preferable that the outer size is smaller. Accordingly, as one embodiment of the invention, the cable routing connecting part may be provided for routing the cable routing present inside of the third arm from the end effector to the outside. According to the configuration, it is not necessary to secure a space containing the cable routing in the arm near the end effector and the outer size of the arm near the end effector may be made smaller.
Further, a plurality of the cable routing connecting parts may be provided in positions rotation symmetric with respect to the rotation axis. For example, when the number of cable routing connecting parts is two, the cable routing connecting parts are provided on a certain diameter of a circle around the rotation axis. When the number of cable routing connecting parts is three, the cable routing connecting parts are provided on a circumference of a circle around the rotation axis and angles between radii connecting the respective cable routing connecting parts and the rotation axis are 120 degrees (=360/3). According to the configuration, the cable routing connecting parts are not eccentrically located on the circle around the rotation axis, and formation of an inferior-to-superior relationship that a specific cable routing connecting part of the plurality of cable routing connecting parts is advantageous for routing of the cable routings, but the other cable routing connecting parts are disadvantageous may be suppressed regardless of the rotation angle of the arm.
Note that, in the configuration in which the plurality of cable routing connecting parts are present in rotation symmetric positions with respect to the rotation axis, the members around the cable routing connecting parts may be formed to have the same rotation symmetry with the cable routing connecting parts. According to the configuration, the commonality of the respective members may be provided in response to the rotation symmetry (e.g., in the case of two-fold symmetry, the casing of the arm around the cable routing connecting parts etc. may be formed by two common parts).
Furthermore, the plurality of cable routing connecting parts may have the same shape. According to the configuration, the plurality of cable routing connecting parts may be formed using common parts and the manufacturing cost may be suppressed.
Further, an aspect of the invention may be configured as a robot including an arm that rotates about a predetermined rotation axis as a rotation center, and a cable routing connecting part that can connect a cable routing inside of the arm and a cable routing outside of the arm, wherein the cable routing connecting part may be provided in the arm and can connect the cable routing from a direction in which an object to be connected to the cable routing is present, and a tilt angle of a connection direction of the cable routing to the cable routing connecting part with respect to the rotation axis may be equal to or less than 45 degrees. That is, the robot in which the tilt angle of the connection direction of the cable routing to the cable routing connecting part with respect to the rotation axis is equal to or less than 45 degrees regardless whether or not the cable routing connecting part is within the circle of movement of the arm may be formed. The tilt angle may be equal to or less than ten degrees as described above, or zero degrees (in parallel).
Furthermore, the robot to which the invention is applied may be provided as a robot system including a control unit that controls the robot and cooperates with various apparatuses etc. and various configurations can be employed.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Here, embodiments of the invention are explained in the following order.
In
The base 20 has a general shape in which a main body 20a nearly in a cylindrical shape and a rectangular part 20b nearly in a rectangular shape are coupled. In
The third arm 13 has a nearly rectangular parallelepiped shape and is supported by the supporting parts 12b with the third arm sandwiched by the supporting parts 12b so as to rotate about a rotation axis extending in the right-to-left direction in
The fourth arm 14 includes a main body 14a and supporting parts 14b, and is supported by the third arm 13 so that the main body 14a may rotate about a rotation axis extending in the front-to-back direction in
A plurality of the cable routings for transferring power, signals, fluids (air) to the other parts can be connected to the base 20. That is, the cable routings are connected to the base 20 and the cable routings are routed inside of the base 20, and thereby, power, signals, fluids, etc. are transferred to the base 20 and an arbitrary arm of the first arm 11 to the sixth arm 16 and used.
These cable routings are routed from the inside of the base 20 to the inside of the first arm 11, the cable routings are routed from the casing of an arbitrary arm to the outside, and thereby, the arm closer to the distal end (with the higher number) than the casing may be downsized. Accordingly, in the embodiment, cable routing connecting parts 14c that can connect the cable routings inside of the fourth arm 14 and the cable routings outside of the fourth arm 14 are provided in the fourth arm 14.
In
That is, in the embodiment, the pipes as the cable routings are routed from the base 20 to the inside of the fourth arm 14 via the first arm 11, the second arm 12, and the third arm 13. The cable routing connecting parts 14c may connect the cable routings inside of the fourth arm 14 (not shown) to cable routings 14d present outside of the fourth arm. In the cable routings 14d, the end parts opposite to the cable routing connecting parts 14c are connected to the end effector. Note that, in
The cable routing connecting parts 14c in the embodiment may connect the cable routings 14d in directions in parallel to the directions in which the cable routing connecting parts 14c extend. In
That is, a circle having a radius as a distance Rm between a part P4 (see
As shown in
Further, in the above described configuration, the tilt angles of the connection directions Dc with respect to the rotation axis Ax4 are about three degrees. Here, the tilt angles take only positive values and the respective cable routing connecting parts 14c are directed toward the circumference of the rotation circle in the two cable routing connecting parts 14c. Therefore, compared to the case where the respective cable routing connecting parts 14c are directed in the rotation axis Ax4 direction, the cable routings 14d can be easily connected to the cable routing connecting parts 14c.
Further, regarding the tilt angle of three degrees, the tilt angle is in a range of 45 degrees or less and ten degrees or less. Therefore, in comparison between the direction perpendicular to the rotation axis Ax4 and the direction in parallel to the rotation axis Ax4, the cable routing connecting parts 14c are not directed toward the former, but directed toward the latter. Therefore, the cable routings 14d present outside of the fourth arm 14 are harder to spread in the radial direction with the rotation of the fourth arm 14, and the fourth arm 14 may be rotated in a state in which the cable routings 14d are present near the fourth arm 14. Accordingly, the fourth arm 14 may be rotated in a state in which the cable routings are harder to cause the restriction on the drive range of the fourth arm 14.
Note that the fourth arm 14 is a member elongated in the rotation axis direction and rotatably supported by the third arm 13 and twisted. Regarding the arm twisted in the robot, even when the entire length of the arm itself is longer, the radius around the rotation axis at the center can be made smaller and the circle of movement is easily made smaller. However, for example, in the configuration in which the cable routings extend in the direction perpendicular to the rotation axis of the arm as in Patent Document 1, the circle of movement of the arm becomes larger and the advantage of the twisted arm that downsizing is easier is diminished. On the other hand, in the embodiment, the tilt angles of the cable routing connecting parts 14c are equal to or less than 45 degrees, preferably equal to or less than ten degrees and the cable routing connecting parts 14c are contained within the circle of movement of the arm, and thereby, the advantage of the twisted arm that downsizing is easier is not diminished.
Furthermore, in the embodiment, the fifth arm 15 as a first rotating arm is rotatably provided with respect to the fourth arm 14 and the sixth arm 16 as a second rotating arm to which the end effector can be attached is rotatably provided with respect to the fifth arm 15. That is, the cable routing connecting parts 14c are provided in the fourth arm 14 as the third arm from the end effector. The two arms (the fifth arm 15 and the sixth arm 16) present between the fourth arm 14 to which the cable routing connecting parts 14c are attached and the end effector are generally designed to have sufficiently smaller outer sizes in order not to hinder the movement of the end effector. Therefore, it is preferable that the cable routings are not contained in these arms present closer to the end effector wherever possible.
On the other hand, in the fourth arm 14 as the third arm from the end effector, obviously, it is preferable that the outer size is smaller. Accordingly, in the embodiment, a configuration in which the cable routings present inside of the fourth arm 14 are routed from the cable routing connecting parts 14c to the outside is employed. According to the configuration, it is not necessary to secure a space containing the cable routings in the fourth arm 14 near the end effector (the fifth arm 15, the sixth arm 16, and a part of the fourth arm 14) and the outer size of the fourth arm 14 near the end effector may be made smaller.
Further, in the embodiment, the two cable routing connecting parts 14c are provided in positions in rotation symmetry with respect to the rotation axis Ax4. That is, the cable routing connecting parts 14c are symmetric with respect to the rotation axis Ax4. According to the configuration, the cable routing connecting parts 14c are not eccentrically located on the circle around the rotation axis, and formation of an inferior-to-superior relationship that one of the two cable routing connecting parts 14c is advantageous for routing of the cable routings, but the other cable routing connecting part 14c is disadvantageous may be suppressed regardless of the rotation angle of the fourth arm 14.
Note that, in a configuration in which a plurality of the cable routing connecting parts 14c are present in rotation-symmetric positions with respect to the rotation axis, the members around the cable routing connecting parts 14c may be formed to have the same rotation symmetry as the cable routing connecting parts 14c. For example, in the embodiment, when part or all of the casing and the internal component elements of the fourth arm 14 are formed by members having symmetric shapes with respect to a plane containing the rotation axis Ax4, commonality of the respective members symmetric with respect to the plane may be provided. Further, in the embodiment, the two cable routing connecting parts 14c have the same shape and the plurality of cable routing connecting parts 14c may be formed by common parts, and the manufacturing cost may be suppressed.
Furthermore, in the embodiment, when the fourth arm 14 is seen from the front side toward the back side, as shown in
As described above, in the embodiment, the outer shape of the casing of the main body 14a is nearly the rectangular shape and the cable routing connecting parts 14c (14c1, 14c2) are provided in the corners thereof, and thereby, the two rectangular spaces elongated in the right-to-left direction in
As above, the cable routing connecting parts 14c that can connect the pipes as the cable routings to the pipes inside of the fourth arm 14 are explained, however, obviously, the other cable routings than the pipes, e.g. wires for transferring power and signals may be connected inside and outside of the arm. In the above described embodiment, a connector 14i that can connect wires as cable routings is provided in the fourth arm 14. That is, in the embodiment, the shape of the main body 14a as seen from the front side toward the rear side is the rectangular shape elongated in the right-to-left direction as shown in
Accordingly, in the embodiment, the connector 14i is formed in the long side part of the above described rectangular shape in the main body 14a. At least part of the wires inside of the main body 14a is connected to the connector 14i and the cable routings outside are connected to a connector 14j shown in
The above described embodiment is an example for embodying the invention, and other various configurations can be employed as long as a configuration in which the cable routing connecting parts are provided within the circle of movement of the armor a configuration in which the tilt angles of the connection direction of the cable routings to the cable routing connecting parts with respect to the rotation axis are set to be equal to or less than 45 degrees is employed. For example, the embodiment of the robot 10 is not limited to the embodiment shown in
Further, in the above described embodiment, the cable routing connecting part may be provided in an arbitrary position of an arbitrary arm. For example, the cable routing connecting part may be provided on the lower side of the fourth arm 14 shown in
Furthermore, the tilt angles of the connection directions Dc with respect to the rotation axis Ax4 may be zero degrees, i.e., the connection directions Dc and the rotation axis Ax4 may be in parallel.
As shown in
The entire disclosure of Japanese Patent Application No. 2014-200028, filed Sep. 30, 2014 is expressly incorporated by reference herein.
Number | Date | Country | Kind |
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2014-200028 | Sep 2014 | JP | national |