JPH08112797A - Industrial robot - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the torsional force acting on the hollow member as the arm rotates. [Configuration] A wiring duct is protected by providing a cable duct 16 between the fixed base 11 and the second arm 13 and inserting the wiring cable into the cable duct 16. In the case of this configuration, the right end of the cable duct 16 is fixed to the fixed base 11, and the left end is rotatably attached to the second arm 13 by the bearing 15. Therefore, when the second arm 13 rotates, the bearing 15 Slips and the cable duct 16 is held stationary. Therefore, the twisting force acting on the cable duct 16 is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial robot having a hollow member provided between a base portion and an arm portion, and a wiring cable inserted into the hollow member.

[0002]

2. Description of the Related Art In an industrial robot, many wiring cables are laid by various methods, and complicated control signals are transmitted by these wiring cables. Out of these wiring cables, particularly those laid so as to straddle the joints of the arm section, stress is required when the arm section is driven, so excellent twist resistance and bending resistance are required. It Therefore, a hollow member is attached so as to straddle the joint of the arm portion, and a wiring cable is inserted into the hollow member.

FIG. 6 shows a conventional example in which this technique is applied to a horizontal articulated robot. Here, 1 is a fixed base, 2
Is a first arm that can be rotated in the horizontal direction, 3 is a second arm that can be rotated in the horizontal direction, and the fixed base 1 and the second arm 3 have left and right end portions of a hollow member 4 formed of a cable duct. Are fixed respectively. In the case of this configuration, the wiring from the control device to the robot body is normally taken in from the fixed base 1 and connected to the motors and sensors of each axis, but the biaxial motor 3a for rotating the second arm 3 and the like. , Second
The wiring for the electric parts arranged on the upper surface of the arm 3 is
It is performed through the inside of the hollow member 4.

[0004]

In the above-mentioned conventional structure, since both ends of the hollow member 4 are fixed to the fixed base 1 and the second arm 3, the first arm 2 and the second arm 3 are fixed.
When is rotated, a stress (particularly a twisting force) is applied to a part of the hollow member 4.
Concentrates. Therefore, both ends of the hollow member 4 are vertically raised from the second arm 3 and the fixed base 1 and the top of the hollow member 4 is loosened in a semi-circular shape to disperse the twisting force acting on the hollow member 4. ing. Therefore, the hollow member 4
The amount of protrusion in the vertical direction becomes extremely large, especially the first
When the arm 2 is long, the weight of the hollow member 4 and the wiring cable may increase, and the hollow member 4 may fall down.

Therefore, as shown in FIG. 7, the hollow member 4
Is divided into a hollow member 4a located between the fixed base 1 and the first arm 2 and a hollow member 4b located between the first arm 2 and the second arm 3, and both hollow members 4a and 4b.
It was necessary to insert the wiring cable inside, and as a result, the number of parts increased and the configuration became complicated.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an industrial robot which can reduce the amount of overhang of a hollow member without increasing the number of parts and complicating the structure. Is.

[0007]

An industrial robot according to claim 1, wherein a base portion, an arm portion rotatably provided with respect to the base portion, and a space between the base portion and the arm portion. A hollow member provided in the hollow member and a wiring cable inserted into the hollow member, and the end of the hollow member on the arm portion side is rotatably attached to the arm portion, and with respect to the arm portion. The feature is that it is inclined.

According to another aspect of the industrial robot of the present invention, a base portion, an arm portion rotatably provided with respect to the base portion, and a hollow member provided between the base portion and the arm portion. And a wiring cable inserted inside the hollow member, the end of the hollow member on the base side is rotatably attached to the base, and the end on the arm side is inclined with respect to the arm. It has a feature where it is made.

[0009]

According to the means of claim 1, since the end of the hollow member on the arm side is rotatably attached to the arm, when the arm rotates with respect to the base, the arm of the hollow member is rotated. The side end slides with respect to the arm, and the hollow member is held stationary. Therefore, the twisting force acting on the hollow member is reduced, and by vertically rising both ends of the hollow member, the top of the hollow member is loosened in a semi-circular arc shape, unlike the conventional art. It is possible to reduce the amount of protrusion of the hollow member by inclining the end portion on the side with respect to the arm portion.

According to the second aspect, since the end of the hollow member on the base portion side is rotatably attached to the base portion, when the arm portion rotates with respect to the base portion, the hollow member together with the arm portion. The end portion of the base portion on the side rotates. Therefore, since the twisting force acting on the hollow member is reduced, the end portion of the hollow member on the arm portion side is inclined with respect to the arm portion,
It is possible to reduce the amount of overhang of the hollow member.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is applied to a horizontal articulated robot will be described below with reference to FIGS. First, in FIG. 1, a fixed base 11 corresponding to a base portion is provided with a connector 11a, and a controller (not shown) is connected to the connector 11a.
The control device is mainly composed of a microcomputer, and causes the robot to execute various works based on the software configuration thereof.

The fixed base 11 is provided with a first arm 12 which is rotatable in the horizontal direction. A uniaxial motor (not shown) is connected to the control device via the connector 11a of the fixed base 11, and the control device operates the uniaxial motor to control the first arm 12 to move. It is rotated in the horizontal direction with respect to the fixed base 11. In addition, a second arm 13 corresponding to an arm portion is provided on the upper surface of the first arm 12, and the second arm 13 includes the first arm 12
It is designed to rotate in the horizontal direction. Also,
The upper surface of the second arm 13 is covered with a cover 14, and a bearing bracket 15 a is fixed to the cover 14. The bearing 15 is attached to the bearing bracket 15a.

Cable duct 16 corresponding to a hollow member
Is a large-diameter connector portion 16a directed obliquely upward,
A large-diameter connector portion 16b oriented in the vertical direction and an arc-shaped duct portion 1 connecting between the connector portions 16a and 16b.
6c, the connector portion 16a is attached to the bearing 15, and the connector portion 16b is the fixed base 1.
It is fixed to 1. Therefore, one end of the cable duct 16 (the end on the side of the second arm 13) is inclined by a predetermined angle θ with respect to the second arm 13, and when the second arm 13 rotates, the bearing 15 slips and the stationary state. Held in. still,
Reference numeral 16d is a retaining ring for retaining the cable duct 16 from the bearing 15.

The second arm 13 is provided with an inner cover 14a located inside the cover 14, and the inner cover 14a
A biaxial motor 13a is housed in a. And
A composite cable (not shown) composed of a plurality of wiring cables is connected to the connector 11a of the fixed base 11, and the composite cable is connected to the biaxial motor 13a from the inside of the fixed base 11 through the cable duct 16.
The controller uses the composite cable to drive the two-axis motor 13a.
The second arm 13 is horizontally rotated with respect to the first arm 12 by controlling the operation of the.

The second arm 13 is provided with a tool shaft 17 which is vertically movable and rotatable. Also, the second arm 1
3 includes a three-axis motor 17a located inside the cover 14.
And a four-axis motor 17b is provided. And 3
The axis motor 17a and the 4-axis motor 17b are connected to the composite cable, and the control device controls the operation of the 3-axis motor 17a through the composite cable to move the tool axis 17 up and down with respect to the second arm 13. Then, the four-axis motor 17b is operated and controlled to rotate with respect to the second arm 13.

The tool shaft 17 is provided with a gripping device 18. This gripping device 18 is connected to the control device,
The control device moves the gripping device 18 by controlling the operation of the first arm 12, the second arm 13, and the tool shaft 17, grips the workpiece by the gripping device 18, and assembles and handles parts.

According to the above embodiment, the cable duct 16
Since the connector portion 16a of the above is rotatably attached to the second arm 13, when the second arm 13 rotates as shown by the arrow in FIGS. 2 and 3, the bearing 15 slides and the connector portion of the cable duct 16 is rotated. 16a is held stationary. Therefore, even if both the first arm 12 and the second arm 13 are rotated, the amount of twist of the cable duct 16 is reduced by the amount of twist of the cable duct 16 caused by the rotation of the second arm 13, resulting in practical use. Cable duct 1 enough
The twist of 6 can be reduced.

For this reason, the life of the composite cable in the cable duct 16 is extended, and it is not necessary to loosen the top of the hollow member into a semi-circular shape. Therefore, as shown in FIG. Can be inclined with respect to the second arm 13 by a predetermined angle θ to reduce the amount of extension of the cable duct 16. As a result, the cable duct 1
Since it is difficult for 6 to fall down, even if the cable duct 16 is enlarged to fit the first arm 12, the cable duct 1
It is not necessary to divide 6 and the number of parts is reduced and the configuration is simplified. Along with this, it is advantageous when the robot is installed in a space that is limited in the vertical dimension.

Next, a second embodiment of the present invention will be described with reference to FIGS.
It will be explained based on. The same members as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted, and only different members will be described below. First, in FIG.
The cover 1 is provided on the upper surface of the first arm 12 corresponding to the arm portion.
9, the cover 19 is covered with the cable duct 16
The connector portion 16a of is fixed. A bearing bracket 20a is fixed to the fixed base 11. The bearing 20 is attached to the bearing bracket 20 a, and the connector portion 16 of the cable duct 16 is attached to the bearing 20.
b is attached.

The second arm 13 is provided on the lower surface of the first arm 12.
Is rotatably mounted in the horizontal direction. On the upper surface of the second arm 13, the cover 21 is located at the tip portion thereof.
The cover 21 is covered with the two-axis motor 13a.
A three-axis motor 17a and a four-axis motor 17b are housed. The composite cable connected to the connector 11a is connected from the inside of the fixed base 11 to the two-axis motor 13a, the three-axis motor 17a, and the four-axis motor 17b through the cable duct 16 and the inside of the second arm 13.

According to the above embodiment, the cable duct 16
Since the connector portion 16b is rotatably attached to the fixed base 11 and the connector portion 16a is fixed to the first arm 12, the twisting force does not act on the cable duct 16 as the second arm 13 rotates. First arm 1
When 2 rotates, the bearing 20 slips, as shown in FIG.
Since the cable duct 16 rotates together with the first arm 12, the twisting force does not act on the cable duct 16. Therefore, since the connector portion 16a can be inclined with respect to the first arm 12 and the amount of extension of the cable duct 16 can be reduced, the same effect as that of the first embodiment can be obtained.

Although the present invention is applied to the horizontal articulated robot in the first and second embodiments, the present invention is not limited to this, and is widely applied to a robot having a rotatable arm portion. can do.

[0023]

As is apparent from the above description, according to the industrial robot of the present invention, since the twisting force acting on the hollow member is reduced, the hollow member is tilted with respect to the arm portion and the hollow member is tilted. The amount of overhang can be reduced. For this reason, the life of the wiring cable in the hollow member is extended, and the hollow member is less likely to collapse, as well as having an effect of being advantageous when the robot is installed in a space restricted by the vertical dimension. Even when the hollow member is made large in size in accordance with the arm portion, it is not necessary to divide the hollow member, and as a result, the number of parts can be reduced and the configuration can be simplified.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing a first embodiment of the present invention.

FIG. 2 is a top view showing a state in which a first arm and a second arm are rotated.

FIG. 3 is a view corresponding to FIG. 2 showing a state in which a second arm is rotated in another direction.

FIG. 4 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 5 is a view corresponding to FIG.

FIG. 6 is a view corresponding to FIG. 1 showing a conventional example.

FIG. 7 is a view corresponding to FIG. 1 showing another conventional example.

[Explanation of symbols]

Reference numeral 11 is a fixed base (base portion), 12 is a first arm (arm portion), 13 is a second arm (arm portion), and 16 is a cable duct (hollow member).

Claims (2)

[Claims] 1. A base portion, an arm portion rotatably provided with respect to the base portion, a hollow member provided between the base portion and the arm portion, and inside the hollow member. An inserted wiring cable, wherein the end of the hollow member on the side of the arm portion is rotatably attached to the arm portion and is inclined with respect to the arm portion. Robot. 2. A base portion, an arm portion rotatably provided with respect to the base portion, a hollow member provided between the base portion and the arm portion, and inside the hollow member. And an inserted wiring cable, wherein the end of the hollow member on the base side is rotatably attached to the base, and the end on the arm side is inclined with respect to the arm. Industrial robot characterized by.