JP2620911B2 - Industrial robot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an industrial robot such as a medium-sized vertical articulated arc welding robot, for example, in which a robot main body and a plurality of drive motors for driving a wrist device as a hand device are connected. The present invention relates to a cable wiring device that connects and supplies power to each drive motor.

[0002]

2. Description of the Related Art FIG. 7 is a perspective view of a conventionally known vertical articulated industrial robot equipped with a biaxial wrist device for performing "bending motion" and "twisting motion", and FIG. "
FIG. 11 is a perspective view of a conventionally known vertical articulated industrial robot provided with a three-axis wrist device in which “twisting motion” is added to “twisting motion”. These industrial robots have a support B on which a pair of arms A ₁ and A ₂ that move forward and backward are swingably mounted.
And a wrist D attached to the distal end of the _one arm A1 and performing, for example, a bending motion and a twisting motion provided with a welding torch C, and a bending motion servo for applying a bending motion (arrow X) to the wrist D. A motor E, a twisting servomotor F that applies a twisting motion (arrow Y) to the wrist D, and a swinging motion (arrow Z) that is added to the wrist D as shown in FIG. It is constituted by a swing axis H and the like.

[0003]

A recent industrial robot of this type is, for example, a two-axis wrist device shown in FIG.
The remote-drive system in which the servomotor E for bending motion and the servomotor F for twisting motion are separated from the wrist D causes the servomotor G for swinging motion to move near the wrist D, as in a three-axis wrist device shown in FIG. Is being shifted to the so-called direct drive system with high precision, but when the drive system of the wrist device is changed to the direct drive system, and the number of axes of the wrist device increases, the cable in the narrow robot arm There is a drawback that the wiring becomes extremely difficult.

[0004] The present invention has been made in view of the above point, and is intended to facilitate the wiring of a cable for connecting a plurality of drive motors for driving a robot body and a wrist device and supplying power to each drive motor. The purpose is to provide a robot for use.

[0005]

According to the present invention, there is provided an industrial robot comprising: a column attached to a robot body; a second robot arm having a hollow portion supported by the column;
A first robot arm having an inner shaft portion inserted into the second robot arm and rotatably supported by the second robot arm; and a first robot arm mounted on the second robot arm and rotating the inner shaft portion. A first drive motor for transmitting and driving the first robot arm, a third robot arm rotatably supported at a free end of the first robot arm, and a third robot arm mounted on the first robot arm, A second drive motor for driving the robot arm; a fourth robot arm rotatably supported by the third robot arm; and a third drive mounted on the third robot arm for driving the fourth robot arm. A drive motor, wherein the first robot arm and the third robot are rotated relative to the second robot arm in an outer peripheral hollow portion of an inner shaft of the first robot arm. Each of said second drive motor and a third driving motor that rotates together with Toamu is obtained by housing the cable for supplying power.

[0006]

According to the present invention, the second robot arm which rotates relative to the second robot arm and co-rotates with the first robot arm and the third robot arm is provided in the outer hollow portion of the inner shaft of the first robot arm. Since the cables for supplying power to the drive motor and the third drive motor are accommodated, the wiring of the cables becomes extremely easy, does not hinder the movement of each arm, and does not cause troubles such as catching with peripheral devices. . Further, since the layout of the cable for supplying power to the first drive motor integrated with the second robot arm directly supported on the support of the robot body may be freely selected, the degree of freedom in design is increased.

[0007]

1 to 6 show one embodiment of the present invention. FIG. 1 is a front view of an industrial robot, FIG. 2 is a plan view thereof, and FIG. 4 is a sectional view taken along line IV-IV in FIG. 2, FIG. 5 is an enlarged sectional view taken along line VV in FIG. 4, and FIG. 6 is a perspective view showing one half of the first robot arm. First, in FIGS. 1 to 4, reference numeral 1 denotes a conventionally known vertical articulated robot main body, 2B
Is a second robot arm having a hollow portion attached to the robot main body 1 via the support 1A and the support 1B, and 2A is a second robot arm.
This is the first robot arm supported by the robot arm 2B. The first robot arm 2A, the inner shaft portion 2A ₂ inserted through the inside of the second robot arm 2B are formed, the bearing 3,
4 rotatably supported by the second robot arm 2B. The first driving motor 5 is mounted to the rear end of the second robot arm 2B, are concentrically connected directly to the end of the inner shaft portion 2A ₂ of the first robot arm 2A via reduction gear 6, the The entire robot arm 2A is rotationally driven.

[0008] At the free end of the first robot arm 2A,
At right angles to the first robot arm, the third robot arm 1
2 is rotatably supported by bearings 14 and 15. A second drive motor 7 is mounted at a substantially intermediate portion of the first robot arm 2A, and a sprocket wheel 9 rotatably supported by bearings 10 and 11 is decelerated on the second drive motor 7. Directly connected via the device 8. The third robot arm 12 is rotationally driven by the second drive motor 7 via the sprocket wheel 9, a transmission component 13 such as a chain, a timing belt, and a rod, and the sprocket wheel 12 a.

The third robot arm 12 has a fourth robot arm.
A robot arm 18 is engaged, and swings according to the forward / reverse rotation of the third robot arm 12. A third drive motor 16 is directly connected to the fourth robot arm 18 via a speed reducer 17.

[0010] the inner shaft portion 2A ₂ of the first robotic arm 2A is formed on the strength required minimum to form a hollow portion 26 between the inner peripheral portion of the second robot arm 2B. Also at the free end of the first robot arm 2A, the cable insertion groove 2A ₁ for inserting a cable 23 connected to the third drive motor 16 is formed.

A plurality of cables 23, 24, and 25 are inserted through the hollow column 1A and connected at one end to a robot controller (not shown) provided on the robot body 1 side. The cable 23 is the second
Is connected to the third drive motor 16 through the cable insertion groove 2A ₁ of the hollow portion 26 and the first robot arm 2A of the robot arm 2B, also the cable 24 is first through the hollow portion 26 in the second robot arm 2B 2 drive motor 7
The cable 25 is connected to the first drive motor 5 from the upper end of the column 1A via an insertion hole 27 formed in the second robot arm 2B. In FIG. 5, reference numeral 28 denotes a support piece made of an insulating material for supporting the cables 23, 24, and 25 in a fork shape in the upper part of the support 1A. 4 and FIG.
Reference numerals 1 and 22 denote cable insertion grooves 2 of the first robot arm 2A.
A pair of covers U-shaped cross section so as to cover the A ₁ from above and below.

Since the industrial robot according to the present invention is configured as described above, when the third drive motor 16 is rotated forward and backward at a predetermined speed as shown in FIG. When a twisting motion (arrow Y) is given and the second drive motor 7 is rotated forward and backward at a predetermined speed,
As shown in FIG. 4, a bending motion (arrow X) is given to the third robot arm 12 via the sprocket wheel 9 → the transmission component 13 → the sprocket wheel 12a, and the first drive motor 5 is driven forward at a predetermined speed. When reversely rotated, the first robot arm 2A is given a swing motion (arrow Z) integrally with the second drive motor 7 and the third drive motor 16 via the speed reducer 6. At the time of each of these twisting, bending, and swinging movements, the cable routed through the hollow portion 26 in the second robot arm 2B does not hinder the movement of each arm and causes troubles such as catching with peripheral devices. In addition, since the second robot arm 2B is set to be long in the axial direction, the bending caused by the robot operation can be suppressed small, and the durability is improved.

[0013]

As described above, according to the present invention, the first robot arm and the third robot arm which are relatively rotated with respect to the second robot arm are provided in the hollow outer peripheral portion of the inner shaft of the first robot arm. Since the cables for supplying power to the second drive motor and the third drive motor, which rotate together with the robot arm, are housed, the wiring of the cables becomes easy, and the movement of each arm is not hindered, and the connection with the peripheral devices is prevented. The occurrence of troubles such as snagging is eliminated, and as a result, disconnection of the second drive motor cable and the third drive motor cable due to the swing of the first robot arm that is rotationally driven by the first drive motor can be prevented. . Furthermore, since the outer peripheral hollow portion of the inner shaft portion of the first robot arm can be set longer in the axial direction of the second robot arm, it is possible to reduce the bending of the wired cable due to the robot operation. As a result, the space occupied by the cable can be reduced, and the hollow portion can be set small, so that the size of the robot arm can be reduced and the wiring can be simplified. Furthermore, since the arrangement of the cable for supplying power to the first drive motor integrated with the second robot arm directly supported on the support of the robot body may be freely selected, the degree of freedom in design is increased.

[Brief description of the drawings]

FIG. 1 is a front view of a vertical articulated industrial robot according to an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2;

FIG. 5 is an enlarged sectional view taken along line VV of FIG. 4;

FIG. 6 is a perspective view showing one half of a first robot arm according to the embodiment.

FIG. 7 is a perspective view showing an example of a conventional vertical articulated industrial robot.

FIG. 8 is a perspective view showing another example of a conventional vertical articulated industrial robot.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Robot main body 1A, 1B Post 2A 1st robot arm 2A ₂ Inner shaft part 2B 2nd robot arm 5 1st drive motor 7 2nd drive motor 12 3rd robot arm 16 3rd drive motor 18 4th robot arm 23, 24, 25 Cable 26 Hollow part

Claims (1)

(57) [Claims] 1. A second robot having a column attached to a robot main body, a second robot arm having a hollow portion supported by the column, and an inner shaft portion inserted into the second robot arm. A first robot arm rotatably supported by the arm; a first drive motor mounted on the second robot arm and transmitting rotation to the inner shaft to drive the first robot arm; A third robot arm rotatably supported at a free end of the robot arm, a second drive motor mounted on the first robot arm and driving the third robot arm, and freely rotatable by the third robot arm A fourth robot arm supported by the first robot arm, and a third drive motor mounted on the third robot arm and driving the fourth robot arm. The outer peripheral hollow portion of the inner shaft portion of the arm, the
The first robot rotated relative to the second robot arm
On the robot arm and the third robot arm
An industrial robot containing cables for supplying electric power to the second drive motor and the third drive motor, respectively .