Abstract:
An industrial robot capable of being decomposed into multiple units at the time of conveyance of the robot and being conveyed individually in units: wherein each of the units has a holding bracket for conveyance means to hold the unit in order to convey the unit.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of priority based on Japanese Patent Application No. 2007-252053, filed on Sep. 27, 2007, disclosure of which is incorporated herein in its entirety by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the invention 
         [0003]    The present invention relates to an industrial robot that can be decomposed into multiple units at the time of conveyance or transport of the robot and can be thus conveyed or transported in individual units. 
         [0004]    2. Description of Related Art 
         [0005]    A vehicle such as a truck is used for transporting an industrial robot over a long distance from the production plant to the site of utilization of the robot. When the robot is bulky and of heavy weight, the limit of the loading capacity of the vehicle may be exceeded, and it may become necessary to decompose the robot into multiple units in order to transport it. When the robot is of heavy weight, it has to be conveyed or transported in units to the place of installation in the factory by using forklifts or cranes. 
         [0006]      FIG. 5  is a view of a robot  50  being conveyed by a forklift  53 . Bracket  52  is provided on robot  50  on the front side of forklift  53  so as to be held by forward projecting fork  54 . Bracket  2  is provided near base  51  of robot  50 . With fork  54  of forklift  53  inserted in bracket  52 , the entire robot can be lifted by raising fork  54 . At the time of conveyance, robot  50  is conveyed in a compact and balanced attitude, so-called conveyance attitude. This attitude is selected to minimize total height and total length etc. of robot  50  in order to prevent the robot  50  from tumbling during the conveyance and to increase the conveyance efficiency. 
         [0007]      FIG. 6  is a view of robot  50  shown in  FIG. 5  being conveyed by crane  55 . In place of the bracket  52  shown in  FIG. 5 , a pair of eye bolts  57 ,  57  are provided on robot  50 . With a rope  56  of the crane passed through the pair of eye bolts  57 ,  57 , entire robot  50  is hung up by raising crane  55 . 
         [0008]    In an assembly line for automobiles or in a production line of construction material, robots of increasingly large size and high loading capacity are needed for enhancing conveying capability of robots and expanding the operational range of robots. However, when a robot is of large volume or of heavy weight, transport of robots by a truck or in a container, or conveyance of robots by using a forklift or a crane in a factory may become difficult due to limitation of weight or size. Therefore, when a conveyable robot of super heavy weight is to be conveyed (transported), it is necessary to decompose the robot into multiple units for conveyance. 
         [0009]    An example of industrial robot consisting of multiple decomposable units in prior art is known from the disclosure in Japanese Patent Publication No. S62-277293. It is disclosed in this example of prior art that “an industrial robot  1  is composed of a plurality of modules  2 ,  3 ,  4  having operational functions which can be assembled and installed on a base or working stage  5  for installation”. 
         [0010]    When a conveyable robot of super heavy weight is to be conveyed, the robot needs to be decomposed into multiple units for conveyance, and if the individual units are not provided with brackets or eye bolts, it may become a problem that much time is consumed in preparation of load for lifting or hanging up of the units. 
         [0011]    Further, when individual units are to be assembled into the robot at the installation site, much time may be consumed in connection of cables wired on individual units. It is also a problem that, if a servo motor is mounted to a unit, the position information may have to be set anew. 
       SUMMARY OF THE INVENTION 
       [0012]    It is an object of the present invention to provide an industrial robot that can be decomposed into multiple units and can be thereby conveyed efficiently and safely. 
         [0013]    Also, it is an object of the present invention to provide an industrial robot which, when multiple units are to be assembled into the robot at the installation site, permits connection of cables wired on individual units to be carried out easily, and permits the position information of a servo motor to be retained. 
         [0014]    In order to attain above objects, in accordance with an aspect of the present invention, there is provided an industrial robot that can be decomposed into multiple units which can be individually conveyed or transported at the time of conveyance or transport of the robot, each of the units comprising a holding bracket for the unit to be held by conveyance means conveying the unit to the destination location. 
         [0015]    In accordance with the above construction, even if the robot is of heavy weight and has a large volume, since the robot is composed of multiple units, it can be decomposed into individual units at the time of conveyance or transport, and can be conveyed in units. Therefore, the robot can be conveyed without replacing the conveyance means or modifying the existing conveyance means. Here, conveyance means are intended to mean equipment such as a forklift or a crane. Since, at the time of conveyance, the conveyance means hold the holding bracket provided on each of the individual units, conveyance operation can be carried out easily without wasting time in load preparation and each unit can be conveyed to the destination point with the unit held in a specified attitude. Therefore, the multiple units obtained by decomposition of the robot can be conveyed efficiently and safely without giving rise to problems such as tumbling of the units. 
         [0016]    In the industrial robot as described above, it is also possible for the unit to further comprise a servo motor for operating the unit along the operating axis and an interface for cable in order to be detachably connected to a cable for supplying power to the servo motor. Since each of the individual units comprises a cable interface for connecting to a servo motor, the robot can be easily decomposed into individual units. When multiple units are to be assembled into one robot, cables wired on individual units can be easily connected. 
         [0017]    In the industrial robot as described above, it is also possible for the unit to further comprise a battery such that the battery can be connected to the cable. By enabling the battery to be connected to the cable, the position information of the servo motor can be retained at the time of decomposition into multiple units. Therefore, when multiple units are to be assembled into one robot, time required for setting of the robot can be reduced. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The above and other objects, features and advantages of the present invention will become more evident from the following description of preferred embodiments thereof with reference to appended drawings, in which: 
           [0019]      FIG. 1  is a perspective of an industrial robot according to an embodiment of the present invention; 
           [0020]      FIG. 2  is a view for explaining how individual units of the industrial robot shown in  FIG. 1  are conveyed by using a crane or a forklift; 
           [0021]      FIG. 3  is a perspective view of cables wired on the same industrial robot shown in  FIG. 1 ; 
           [0022]      FIG. 4  is a view showing comparison of height of the same industrial robot shown in  FIG. 1  with individual units composing the industrial robot; 
           [0023]      FIG. 5  is a view for explaining how an industrial robot is lifted and conveyed by a forklift; and 
           [0024]      FIG. 6  is a view for explaining how an industrial robot is hung up and conveyed by a crane. 
       
    
    
     DETAILED DESCRIPTION 
       [0025]    Now, the present invention will be described in detail below with reference to drawings.  FIG. 1  is a view of an industrial robot (hereinafter referred to as “robot”) according to an embodiment of the present invention. Robot  1  is not particularly limited, and may be a general  6 -axes vertical multi-junction type conveyable robot. Robot  1  has three units  2 ,  3 ,  4 , that is, base unit  2 , arm unit  3 , and hand unit  4 , to which robot  1  can be decomposed at the time of conveyance. 
         [0026]    In  FIG. 2 , robot  1  is shown as being decomposed into three units  2 ,  3 ,  4 . Individual units  2 ,  3 ,  4  has servo motors  15 ,  22 ,  29 ,  28  for operating the units in the direction of specified operational axes, connectors (cable interface)  8  for detachably connecting cables  5  for supplying power to the servo motors. Thus, each of individual units  2 ,  3 ,  4  is composed of a functional unit comprising at least one servo motor. Power can be supplied from batteries  14 ,  30 ,  31  via connector  8  to servo motors  15 ,  22 ,  29 ,  28 . Therefore, when robot  1  is conveyed in units, position information of servo motors  15 ,  22 ,  29 ,  28  can be obtained. 
         [0027]    Base unit  2  has fixing base  10  fixed to the floor, turntable  11  pivotally supported about a vertical axis perpendicular to fixing base  10 , table reduction gear  12  provided between fixing base  10  and turntable  11 , servo motor  15  for rotating turntable  11 , and a pair of brackets (holding bracket)  13 ,  13 . Position of brackets  13  is not particularly limited, and is selected on both sides of fixing base  10  in the present embodiment. Tubular bracket  13  is not particularly limited in shape and dimension, and can be formed in any shape and dimension corresponding to fork  54  of forklift  53 . Thus, when base unit  2  is conveyed by fork lift  53 , base unit  2  can be easily conveyed without consuming time for loading preparation. 
         [0028]    Arm unit  3  has turning base  17  interconnected detachably to turntable  11 , upper arm  18  that follows turning base  17 , servo motor  22  for driving upper arm  18 , casing  19  that follows upper arm  18 , link mechanism  20  for reinforcing upper arm  18 , and a pair of brackets (holding brackets)  23 ,  23 . Upper arm  18  is attached at one end thereof to turning base  17  rotatably about a horizontal axis. Link mechanism  20  has first parallel link  21   a,  servo motor  29  for driving first parallel link  21   a,  and second parallel link  21   b.  A pair of lift brackets  23 ,  23  has the same tubular shape as bracket  13  of base unit  2 . When arm unit  3  is to be conveyed by forklift  53 , forks  54  of forklift  53  are inserted into the pair of bracket  23 ,  23  for lifting. 
         [0029]    Position for fixing bracket  23  is not particularly limited, and in the present embodiment, brackets  23  are fixed on both sides of turning base  17  under unit  3 . Since brackets  23  are positioned under unit  3 , unit  3  is easy to be conveyed by forklift  53 . Taking into account the conveyance attitude of unit  3 , brackets  23  are preferably provided at positions near the center of gravity of unit  3 . 
         [0030]    Hand unit  4  has gear box  24  detachably interconnected to casing  19 , forearm  25  that follows gear box  24 , wrist element  26  that follows forearm  25 , servo motor  28  for driving forearm  25  and wrist element  26 , and a pair of eye bolts (holding brackets)  27 . Forearm  25  is interconnected at proximal end thereof to the other end of upper arm  18  rotatably about a horizontal axis. To the distal end of forearm  25 , the wrist element  26  is connected rotatably about an axis parallel to the axis of forearm  25 . An conveyance hand designed in the specification corresponding to the conveyed work piece can be mounted to wrist element  26 . The conveyance hand is rotatably connected to wrist element  26 . 
         [0031]    Hand unit  4  is provided with eye bolts  27  for passing a rope therethrough. Thus, unlike base unit  2  or arm unit  3 , hand unit  4  is adapted to be hung up and conveyed by crane  55 . Whether forklift  53  is used or crane  55  is used as conveyance means, depends upon factors such as the specification or size of units  2 ,  3 ,  4 , and upon the layout of the factory, and is not limited to conveyance mode of the present embodiment. Therefore, it is also possible to provide eye bolts on base unit  2  or arm unit  3  for hanging by crane  55 , or to provide brackets on hand unit  4  for lifting by forklift  53 . It is also possible to provide both brackets for lifting by forklift  53  and eye bolts for hanging by crane  55  on each of units  2 ,  3 ,  4 . 
         [0032]    Next,  FIG. 3  shows cables  5  wired on the rear side of robot  1 . Cables  5  are connected to servo motors  15 ,  22 ,  29 ,  28 , distribution panels  9   a,    9   b,    9   c,  and batteries  14 ,  30 ,  31  by using connectors. Cables  5  have trunk cables  7   a  and guy cables  7   b.  Cables  7   a,    7   b  may include power supply lines for supplying power to servo motors  15   22 ,  29 ,  28 , signal lines for transmitting signal between servo motors  15   22 ,  29 ,  28  and an unshown controller, and connectors connected to the ends of the power supply lines and signal lines. Trunk cables  7   a  and guy cables  7   b  can be joint-connected via the connectors. Trunk cables  7   a  are wired between first distribution panel  9   a  and second distribution panel  9   b,  and between second distribution panel  9   b  and third distribution panel  9   c.  Guy cables  7   b  branch from trunk cable  7   a  and are connected to individual servo motors  15 ,  22 ,  28 ,  29 . 
         [0033]    Base unit  2  is provided with battery  14  so that, when unit  2  is decomposed, the position information of servo motor  15  for driving turntable  11  can be retained in advance. Arm unit  3  is also provided with battery  30  so that the position information of servo motors  22 ,  29  for driving upper arm  18  and link mechanism  20  can be retained. Similarly, hand unit  4  is also provided with battery  31  so that the position information of servo motors  28  for driving wrist element  26  and the conveyance hand can be retained. Therefore, when robot  1  is assembled, time required for setting robot  1  can be reduced. 
         [0034]    Connection of various cables  5  to servo motors  15 ,  22 ,  29 ,  28  and to distribution panels  9   a,    9   b,    9   c  is done via connectors (interfaces for cable)  8 . Therefore, when individual units  2 ,  3 ,  4  are conveyed, individual units  2 ,  3 ,  4  can be easily decomposed by releasing the connector connection of cables  5  to connectors  8 . When units  2 ,  3 ,  4  are assembled into one robot, the cables wired to individual units  2 ,  3 ,  4  can be easily connected to servo motors  15 ,  22 ,  29 ,  28 . 
         [0035]      FIG. 4  shows height of assembled robot  1  is compared with the height of individual units  2 ,  3 ,  4  that compose robot  1 . As compared to assembled robot  1 , base unit  2  is lower by height a, arm unit  3  is lower by height b, and hand unit  4  is lower by height c. Thus, even if robot  1  is of larger size in itself, by decomposing robot  1 , the trucks and containers for long distance transport, and forklift  53  and crane  55  for conveyance in the factory can be used unaltered, so that robot  1  can be conveyed efficiently at small cost. 
         [0036]    The present invention is not limited to the above-described embodiment, but can be carried out in various modifications without departing from the scope and spirit of the present invention.