JPH08150591A - Industrial robot - Google Patents

Abstract

PURPOSE: To provide an articulated industrial robot capable of easily changing a normal axis motor of a vertical driving mechanism. CONSTITUTION: A vertical driving shaft (ball screw) 3 is arranged in parallel with a support 1 and a rail 2. A normal axis motor 6 is set on its lower part and it is connected to the vertical driving shaft 3 through an Oldham's coupling 14. A nut 15A of a slide base 15 and the vertical driving shaft 3 are screwed to each other, and a cutout to avoid a motor is provided at a part toward the vertical driving shaft 3 on a lower half of the base. An arm installation part is provided on the side of this cutout, and an arm 31 is equipped on it. A timing belt 13 is wound by arranging a pulley on an upper end part of the support 1, and balance on both sides is taken by respectively engaging one end of the belt with the slide base 15 and the other end of the belt with a bob 8. An upper end of the vertical driving shaft 3 is made an equipping part of a handle for emergency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an articulated industrial robot, and more particularly to a vertical drive mechanism for the robot.

[0002]

2. Description of the Related Art A conventional example of a vertical drive mechanism for an articulated robot is shown in FIG. In the figure, 1 is a pillar, 2 is a rail attached to the pillar 1, and 3 is a ball screw as a vertical drive shaft arranged in parallel with the rail 2. The vertical drive shaft 3
It is rotatably supported by bearings 4 and 5 at the upper and lower ends of the column 1. 6 is a vertical axis motor, 7 is an encoder, 8
Is a weight, 21 and 22 are pulleys, 23 is a chain, 24
Is a coupling for connecting the vertical drive shaft 3 and the rotary shaft of the vertical shaft motor 6 and is provided above the vertical drive shaft 3. Reference numeral 25 is a slide base that rotatably supports the turning shaft, 31 is an arm whose one end is fixed to the turning shaft, and 32 is a turning shaft motor that rotationally drives the turning shaft. The slide base 25 includes a nut 25A screwed with the vertical drive shaft (ball screw) 3 and a block 25B that engages with the rail 2 to prevent the slide base from rotating. 32 are installed. Slide base 2
5 is a chain 23 wound around pulleys 21 and 22.
Is locked at one end thereof and is balanced by the weight 8 at the other end of which the chain 23 is locked.

In the drive mechanism having such a structure, when an operation command is given to the vertical shaft motor 6, the vertical drive shaft 3 is rotated by its rotational force, and the slide base 25 is moved up or down depending on the rotation direction. Moving. That is, the arm 31 moves up and down. When the arm 31 moves up and down, the weight 8 moves in the opposite direction. Therefore, the load on the vertical axis motor 6 is reduced. The range of vertical movement approximately corresponds to the height of the column 1. Further, the arm 31 turns according to the operation command to the turning axis motor 32.

[0004]

However, if the vertical shaft motor 6 is installed above the vertical drive shaft 3 in order to lower the arm 31 close to the lower end of the column 1, the motor 6 is replaced when the motor 6 fails. It is inconvenient because the work must be done in an inconvenient posture. Further, when the motor 6 breaks down, even if a person tries to work on behalf of the robot, the vertical drive shaft 3 cannot be manually turned, so the arm 31 becomes an obstacle to the work. Furthermore, since the weight 8 for balancing and the slide base 25 are connected by the chain 23,
Noise increases during operation.

Therefore, an object of the present invention is to provide an industrial robot in which the vertical axis motor can be easily replaced without affecting the vertical movement range of the arm.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a ball screw as a vertical drive shaft and a nut of a slide base on which a turning drive mechanism is mounted are screwed together, and the vertical drive shaft is rotationally driven by a vertical shaft motor. In an industrial robot that vertically moves the slide base, the vertical shaft motor is installed under the vertical drive shaft, while a cutout is provided in the slide base near the vertical drive shaft to avoid the vertical motor. Characterize.

[0007]

[Operation] When the vertical drive shaft is rotated by the rotational force of the vertical shaft motor to lower the arm, the vertical shaft motor comes into the cutout portion of the slide base even if the slide base approaches the lower end of the column. Continued lowering of the slide base is allowed. Therefore, the arm can be lowered to a height close to the lower end of the column. That is, the required vertical movement range is secured.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the embodiments shown in the drawings.

FIG. 1 shows an embodiment of a main part (vertical drive mechanism) of an industrial robot according to the present invention. In the figure, 1 is a pillar, 2
Is a rail attached to the column 1, and 3 is a vertical drive shaft (ball screw) arranged in parallel with the rail 2. The vertical drive shaft 3 is rotatably supported by bearings 4 and 5 at a position approximately above the upper end of the column 1 and slightly above the lower end thereof. 6 is a vertical shaft motor installed below the vertical drive shaft 3, 7 is an encoder, 8 is a weight, 11 and 12 are pulleys, 13 is a timing belt, and 14 is the vertical drive shaft 3 and the rotary shaft of the vertical motor 6 is connected. For this purpose, an Oldham type coupling is used in this embodiment. A slide base 15 rotatably supports the turning shaft. The slide base 15 is provided with a nut 15A that is screwed with a ball screw as the vertical drive shaft 3 and a block 15B that engages with the rail 2 to prevent the slide base from rotating. A portion 15C is provided, and a portion on the left side (close to the vertical drive shaft 3) in the drawing is cut out to avoid the vertical shaft motor 6. Further, one end of the timing belt 13 wound around the pulleys 11 and 12 is locked to the upper end of the slide base 15, and the timing belt 13
Is balanced by a weight 8 having the other end locked. Reference numeral 31 is an arm whose one end is fixed to the turning shaft, 32 is a turning shaft motor that rotationally drives the turning shaft, and 33 is an emergency handle. The emergency handle 33 is detachable, and is usually detached and fitted with the upper end of the vertical drive shaft 3 protruding above the bearing 4 in an emergency such as a motor failure.

In the drive mechanism having such a structure, when an operation command is given to the vertical shaft motor 6, the vertical drive shaft 3 is rotated by its rotational force, and the slide base 15 is moved up or down depending on the rotation direction. Moving. That is, the arm 31 moves up or down. When the arm 31 moves up and down, the weight 8 moves in the opposite direction, and the load on the vertical shaft motor 6 is reduced. At the same time, the movement of the timing belt 13 becomes smooth, and the noise is reduced. When the slide base 15 approaches the lower end of the column 1 when the arm descends, the vertical axis motor 6 enters the cutout portion and the descending continuation is permitted. Therefore, the arm 31 is lowered to a height near the lower end of the support column 1. Further, the arm 31 turns according to the operation command to the turning axis motor 32.

In an emergency, when the emergency handle 33 is attached to the upper end of the vertical drive shaft 3 and the brake built in the motor is released and the handle 33 is turned, the vertical drive shaft 3 rotates and the arm 31 moves upward. Or move down. Therefore, if the arm 31 is moved to a desired height, the manual emergency work can be performed quickly and appropriately. When replacing the motor, the connection by the Oldham type coupling 14 is disconnected and the motor is pulled out in the lateral direction.

[0012]

As described above, according to the present invention, the vertical shaft motor is installed in the lower part of the vertical drive shaft and is connected to the vertical drive shaft through a specific coupling, while avoiding the motor on the slide base. Since the notch is provided, the vertical axis motor can be easily replaced without affecting the lower limit of the arm vertical movement range. In addition, since the emergency handle can be attached to the upper end of the vertical drive shaft by installing the lower part of the vertical shaft motor, it is possible to move the arm up and down by manual operation in an emergency. It can be implemented accurately. Further, noise can be reduced by using the timing belt.

[Brief description of drawings]

FIG. 1 is an embodiment (main part) of an industrial robot according to the present invention.
FIG.

FIG. 2 is a side view showing a conventional example of a vertical drive mechanism of an articulated robot.

[Explanation of symbols]

 1 ... Strut 3 ... Vertical drive shaft (ball screw) 6 ... Vertical shaft motor 8 ... Weight 13 ... Timing belt 14 ... Oldham type coupling 15 ... Slide base 15A ... Nut 31 ... Arm

Claims (1)

[Claims] 1. An industry for vertically moving a slide base by screwing a ball screw as a vertical drive shaft and a nut of a slide base on which a turning drive mechanism is mounted, and rotationally driving the vertical drive shaft by a vertical shaft motor. An industrial robot characterized in that a vertical axis motor is installed below the vertical driving axis, and a cutout is provided in a portion of the slide base near the vertical driving axis to avoid the vertical axis motor.