Robot having a line distribution board

A robot includes a plurality of lines respectively having connecting portions, which are connected to an outer apparatus, at end portions, and at least one line distribution board to which the connecting portions of the plurality of lines are attached. The line distribution board includes a plurality of line distribution board elements, which can be separated from each other, and to which the connecting portion of at least one of the plurality of lines is attached.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a robot having a line distribution board to which a plurality of lines connected to an outer apparatus are attached.

2. Description of the Related Art

An industrial robot is provided at its wrist portion with detachable outer apparatus, such as a welding gun and a hand for holding a workpiece, depending on its application. A plurality of lines, which are necessary according to the type of an end effector, for example, cables for supplying power or sending signals, or tubes for supplying cooling water or air used for driving, are arranged in the robot. In many cases, these lines are attached to a single line distribution board through connectors attached to end portions of the lines.

Japanese Patent JP-B-4349320 discloses a technique for facilitating a replacing process of a supplying unit and a wiring process, which is necessary for the replacing process, by selectively connecting an inner cable connected to the supplying unit for supplying power, air or gas, and an outer cable connected to outer apparatus with each other.

According to the configuration in which lines are attached to a single line distribution board, in the case where it is necessary to replace a line due to changes in usage or the like, the line distribution board itself has to be replaced. Therefore, even though some of the cables are not required to be replaced, all of the cables have to then be detached from the line distribution board. After completion of the replacing process, these cables are attached again to the line distribution board. Accordingly, due to the cable detaching process and the cable attaching process, which are not essential, the time necessary for the cable replacing process is increased and the cost is also increased.

According to Japanese Patent JP-B-4349320, a connector must be attached to each line beforehand, which results in increased cost. In addition, as the application of the robot is diversified, various types of outer apparatus are used with the robot, and cables used for such outer apparatus are manufactured according to various standards. Accordingly, in order to make it possible to use for various applications without replacing the lines such as cables, it is necessary to provide lines with great versatility. However, such lines are expensive, which results in increased cost.

Accordingly, there is a need for an industrial robot which facilitates replacement of lines, depending on the application.

SUMMARY OF THE INVENTION

According to a first aspect of the present disclosure, a robot comprising: a plurality of lines respectively having connecting portions, which are connected to an outer apparatus, at end portions; and at least one line distribution board to which the connecting portions of the plurality of lines are attached, the line distribution board including a plurality of line distribution board elements, which can be separated from each other, and to which the connecting portion of at least one line of the plurality of lines is attached, is provided.

According to a second aspect of the present disclosure, the robot according to the first aspect further comprises at least one second line which is different from the plurality of lines, wherein the line distribution board includes a holding portion capable of holding the second line at an intermediate portion of the second line.

According to a third aspect of the present disclosure, in the robot according to the second aspect, the second line includes a power line and a signal line connected to a servo motor for driving the robot.

According to a fourth aspect of the present disclosure, in the robot according to any one of the first to third aspects, the line distribution board has a housing shape formed from the plurality of line distribution board elements when attached to each other.

These and other objects, features and advantages of the present invention will be more apparent in light of the detailed description of exemplary embodiments thereof as depicted by the drawings.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the accompanying drawings, embodiments of the present invention will be explained below. In the following drawings, in order to understand the present invention, constituent elements may be changed in size in relation to one another. The same or corresponding elements are designated with the same referential numeral.

FIG. 1is a side view of a robot10of an embodiment of the present invention. The robot10includes: a base12; a turning portion14attached to the base12so that it can be turned; a lower arm16pivotably supported by the turning portion14at a base end16aso that the lower arm16can pivot back and forth (to the right and left inFIG. 1); an upper arm18attached to a tip end portion16bof the lower arm16arranged on the opposite side of the base end16a; and a wrist portion20attached to a tip end of the upper arm18. Dashed lines J1, J4, J6and black dots J2, J3, J5shown inFIG. 1represent rotational axes of the robot10. The robot, to which the present invention can be applied, is not limited to the specific type of robot shown in this specification by way of example, but may be any known type of robot.

FIG. 2is a side view of the robot10showing lines arranged inside the robot10shown inFIG. 10. InFIG. 2, only the following elements are shown by solid lines: a line bundle30shown with hatching; a first line distribution board50and a second line distribution board52, to each of which at least one line in the line bundle30is attached; a branch line32branching from the line bundle30and connected to a servo motor22for driving the upper arm18and the wrist portion20; and fixtures60,62and64for fixing the line bundle30. Other elements are shown by dashed lines. The first line distribution board50is attached to the base12. The second line distribution board52is attached to the base end portion of the upper arm18.

The line bundle30is a bundle of lines which include a plurality of cables or tubes prepared for various outer apparatus attached to the wrist portion20of the robot10. For example, the line bundle30includes a first line (hereinafter referred to as “option cable”) for establishing a supply path for supplying power, water, air or other gas to the outer apparatus attached to the wrist portion20. The line bundle30also includes a second line including a cable for supplying power to a servo motor mounted on the drive shaft of the robot10(hereinafter referred to as “power cable”), and a cable for transmitting signals related to positional information of the servo motor (hereinafter referred to as “signal cable”). However, the line bundle30is not limited to this specific example. As shown in the drawing, the line bundle30is attached at its one end30ato the first line distribution board50on the side of the base12, and attached at the other end30bto the second line distribution board52on the side of the upper arm18.

FIG. 3is a partially enlarged perspective view showing a line distribution board of an embodiment of the present invention. By way of example, the second line distribution board52, which is attached to the base end portion of the upper arm18, and its periphery are shown in an enlarged view. The second line distribution board52is formed from a first line distribution board element52A, and a second line distribution board element52B. The first line distribution board element52A and the second line distribution board element52B are screwed to the main body of the robot10, independently of each other. Although the second line distribution board52is explained by way of example, it should be noted that the first line distribution board50may have the same configuration as the second line distribution board52.

FIG. 4shows an exemplary arrangement of the line bundle30in the embodiment shown inFIG. 3. In the embodiment shown in the drawing, the line bundle30includes six option cables34ato34f, power cables36ato36cfor supplying power to the servo motor22(seeFIG. 3), and signal cables38ato38cfor transmitting signals related to the positional information of the servo motor22. The line bundle30is held by the first holding member70. The power cables36ato36cand the signal cables38ato38care held by the second holding member72.

Two option cables34aand34bbranch from the line bundle30at positions between the first holding member70and the second line distribution board52. At end portions of the option cables34a,34b, circular connectors40aand40bare provided. The circular connectors34aand34bare screwed to the first line distribution board element52A and connected to the connector on the side of the corresponding outer apparatus. The remaining four option cables34cto34fbranch from the line bundle30in the same manner, but end portions of thereof are screwed to the second line distribution board element52B through circular connectors40cand40dand rectangular connectors40eand40f. These connectors40cto40fare connected to the connectors on the side of the corresponding outer apparatus in the same manner. In this regard, the manner in which the respective connectors40ato40fare attached to the first line distribution board element52A and the second line distribution board element52B is not limited to a particular embodiment, as long as it provides sufficiently strong fixing at the time of operation of the robot10, while they can be easily detached as necessary. Further, it may also be possible to provide a plug connector (not shown) at an end portion of the option cable and a relay adapter (not shown) of a panel attachment type on a line distribution board element. In this case, when the plug connector is fitted to the inside of the line distribution board at one end portion of the relay adapter, the option cable is attached to the line distribution board element. Outside the line distribution board, the outer apparatus is connected to the other end of the relay adapter.

The power cables36ato36cand the signal cables38ato38cextend between a first holding member70and a second holding member72, separately from the option cables34ato34f. The power cables36ato36cand the signal cables38ato38care held by the second holding member72in the intermediate portion. End portions of the power cables36ato36cand the signal cables38ato38care respectively connected to the corresponding servo motors22.

The first holding member70and the second holding member72may be configured to fix the cable by screwing with the cable being sandwiched between plate members facing each other, or by binding the cable with a band. However, they are not limited to any particular type of holding means.

The first line distribution board element52A and the second line distribution board element52B can be attached to and detached from the robot10, independently of each other. Accordingly, for example, when the option cables34aand34bneed be replaced, only the first line distribution board element52A has to be detached from the robot10, in order to replace the option cables34aand34b. During the replacement, the second line distribution board element52B and the option cables34cto34fconnected therewith remain attached to the robot10. The power cables36ato36cand the signal cables38ato38cconnected to the servo motor22are fixed to the robot10by means of the second holding member72, which is provided separately from the line distribution board52. Therefore, there is no need to detach these parts at the time of replacing the option cables. According to the present embodiment, in which the line distribution board is formed from a plurality of line distribution board elements which can be attached to and detached from the robot, independently of each other, only cables required to be replaced can be selectively detached to carry out the replacement. This facilitates the replacement process and reduces the time required therefor, resulting in reduced cost.

FIG. 5shows an exemplary arrangement of lines in another embodiment. Matters that have already been explained referring toFIGS. 3 and 4are omitted as necessary. In this embodiment, instead of the second holding member72(seeFIG. 4), a holding portion80capable of holding the power cables36ato36cand the signal cables38ato38cis provided in the first line distribution board element52A.

The power cables36ato36cand the signal cables38ato38care held by the holding portion80between the first holding member70and the end portions of these cables. A position where the cables are held by the holding portion80is not particularly limited, provided that it is sufficiently distant from the end portions of the cables.

The configuration of the holding portion80is not particularly limited. The holding portion80may have any configuration, as long as the holding portion80is adapted to prevent the lines from being displaced at the time of operating the robot. For example, as shown in the drawing, the cables may be bound by a band82. Alternatively, the cables may be sandwiched between plate members facing each other, which are fixed together by screwing.

According to the present embodiment, in which the line distribution board element is provided with the holding portion for holding the power cables and the signal cables connected to the servo motor, it is not necessary to provide a special holding member for holding these cables. Therefore, the cost can be reduced. The cable held by the holding portion may also include an option cable.

FIG. 6is a partially enlarged perspective view showing a line distribution board90of another embodiment.FIG. 7is a partially exploded view showing the line distribution board90ofFIG. 6. In the present embodiment, the line distribution board element90has a housing shape formed from a first line distribution board element90A and a second line distribution board90B assembled with each other. The first line distribution board element90A is provided with circular connectors40aand40b, each of which is attached to end portions of two option cables. The second line distribution board element90B is provided with circular connectors40cand40dand rectangular connectors40eand40f, each of which is attached to end portions of four option cables. As can be seen inFIG. 7, the first line distribution board element90A and the second line distribution board element90B have supplementary shapes to each other, so as to form a housing of a rectangular parallelepiped shape when assembled together by screws92.

According to the present embodiment, in which the line distribution board90has an outer shape of housing when assembled, foreign objects, such as dust or liquid can be prevented from entering inside the line distribution board90. This prevents problems, such as damage to the cables or short-circuiting of the cables in the line distribution board90, from occurring. In addition, by forming the line distribution board elements into the housing, it is possible to reduce unused space, allowing the line distribution board90to become compact. As compared to the plate-like distribution board, the line distribution board90of a housing shape has larger surface area, thereby providing more space for providing the connectors. Therefore, it is advantageous that the distribution board90may be used in the application where different types of option cables and/or the increased number of cables are required.

In the present embodiment, as shown inFIG. 7, the first line distribution board element90A is attached to the robot10and the second line distribution board element90B is screwed to the first line distribution element90A. However, the shapes of the line distribution board elements of the line distribution board are not limited to this specific example. Means for assembling the line distribution board elements together is not limited to screwing as illustrated, as long as a sufficiently high sealing effect for preventing foreign objects from entering is achieved. For example, a fastener made of resin may also be used.

FIG. 8shows an exemplary arrangement of lines in the embodiment ofFIG. 6. The first line distribution board element90A is provided with two option cables34aand34battached thereto through the circular connectors40aand40b, respectively. The second line distribution board element90B is provided with four option cables34cto34fattached thereto through the circular connectors40cand40dand the rectangular connectors40eand40f. Further, power cables36ato36cand the signal cables38ato38c, which are connected to the servo motor22(seeFIG. 6 or 7), are arranged through the first line distribution board element90A. The power cables36ato36cand the signal cables38ato38care held by a first holding portion94and a second holding portion96provided in the first line distribution board element90A. Alternatively, a separate holding member for holding the power cables36ato36cand the signal cables38ato38cmay also be provided in a similar way as the embodiment explained referring toFIG. 4.

In the present embodiment, the option cables, which are highly likely and/or frequently subject to replacement, are preferably attached to the second line distribution board element90B, since the second line distribution board element90B can be more easily detached than the first line distribution board element90A. Accordingly, it is advantageous that the wiring of the option cables is implemented in consideration of how easily the respective line distribution board elements can be detached. In order to form the line distribution board of a housing shape, the distribution board may include an additional constituent element, to which no cable is attached.

In the above-described embodiment, the cables are installed as an example of the option cable. However, it goes without saying that the advantageous effect of the present invention can also be achieved in the case of any line, such as a tube or the like for supplying fluid, instead of the cable. Different types of lines combined together at any given ratio may also be used. The structure of the connecting portion of the line attached to the line distribution board element is not to be limited to the illustrated exemplary connector, but may be a union or any other type of connecting means.

The shape of the line distribution board element is not limited to the illustrated example. The line distribution board is not limited to the type in which it is formed from two line distribution board elements as described before. Rather, the line distribution board may be formed from any number of line distribution board elements, i.e., three or more of them. For example, it is advantageous that the lines are divided into several groups according to expected likelihood or frequency of replacement, and the line distribution board elements are provided for each group of the lines. In addition, only one line may be connected to a single line distribution board element. Further, the present invention is not limited to the illustrated embodiment in which two line distribution boards are arranged at different positions, but it is also possible that any number of line distribution boards may be arranged at any given positions in the robot as necessary. Further, the line distribution board according to the present invention may also be used together with a known line distribution board.

EFFECT OF THE INVENTION

With the above configuration according to the present invention, only the line distribution board element of the line distribution board, to which the connecting portion of the line to be replaced is attached, can be separated and selectively replaced. This facilitates a process for replacing the line.

Although various embodiments and variants of the present invention have been explained, it will be apparent for a person skilled in the art that the intended function and effect of the present invention can also be realized by other embodiments and variants. In particular, the constituent elements of the above-described embodiments and variants may be deleted or replaced, or a known means may be added, without departing from the scope and spirit of the present invention. Further, it will be apparent for a person skilled in the art that the present invention can also be implemented in any combination of features of a plurality of embodiments disclosed herein either explicitly or implicitly.