JPH0536197B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an articulated industrial robot,
In particular, it relates to the support structure of the arm and the wiring means within the arm.

PRIOR ART In general, this type of multi-jointed robot supports a plurality of arms in a rotatably coupled state at the base portion of the robot. These drive sources are usually attached to the joints of the respective arms, and therefore are attached at positions remote from the basic part of the robot. When this arm performs a pivoting motion, the motor serves as a load for the rotational motion, and also generates a large inertial force when the arm stops moving. For this reason, it is difficult to ensure the positioning accuracy of the robot arm, and the mounting portion on the base end side of the robot needs to have sufficient rigidity to prevent it from tipping forward.

On the other hand, wiring for the power source of the motor, piping for driving air such as a chuck at the tip of the arm, etc. are housed inside the arm in consideration of the working environment and safety. For example, in Japanese Patent Publication No. 58-37117, the joint portion of the arm is hollow, and the cable inside the arm is passed through the hollow shaft. However, the manipulator of the above-mentioned publication does not have a general multi-joint structure, and although its joints are hollow shafts, a motor is incorporated in the joints.
Therefore, the inertia during rotational movement of the joint portion is large, making it unsuitable for high-speed movement.

OBJECTIVES OF THE INVENTION An object of the present invention is to reduce the weight of the arm and the inertia during movement as much as possible to increase the operating speed while preventing the arm from tipping forward toward the robot side. By accommodating piping, it increases adaptability in special work environments.

Structure of the Invention Therefore, the present invention incorporates drive motors for a plurality of arms into a base portion of a robot, and balances the multiple arms on one side and the motors of each arm on the other side, with the center line of the base as a boundary. It is placed in Therefore, the inertia of the robot arm during movement is related only to its own structural weight and is not affected by the gravity of the motor as a driving source. Therefore, the arm moves at high speed and its positioning accuracy is increased as much as possible. Furthermore, since the plurality of arms and their motors are in a balanced state with the center of the base as a boundary, the base end of the robot is not subjected to any force in the forward tilting direction and can be installed in a stable state.

The rotational force of the motor is transmitted from the base body through the inside of the arm to each arm by a rotation transmission means such as a belt. These rotational transmission means are connected from one arm to the interior of the other arm by a hollow shaft at the joint of each arm. Therefore, the mechanical elements of the rotation transmission means are completely housed inside the arm and can withstand work in special environments. Moreover, lubricating oil for rotating parts,
Dust and the like during wear do not scatter from the inside of the arm to the outside, so this articulated robot can also handle work inside a clean room. In addition, a working member such as a chuck is attached to the tip of the arm, but the power source or pressurized air source as a driving source is routed through the inside of the arm by wiring or piping, and then guided through the hollow shaft of the joint. It will be destroyed.
Therefore, these wirings or pipes are not directly exposed to the outside, are protected from special working environments, and do not impede movement of the arm. This wiring or piping is guided inside the arm by a guide member so as not to interfere with the rotation transmission means. Therefore, the rotation transmission means and the wiring or piping are neatly housed inside the arm and do not interfere with each other's movement.

Configuration of Embodiment Hereinafter, the configuration of an embodiment of the present invention will be specifically described based on the drawings.

The articulated robot 1 of the present invention is supported on a support stand 3 of a base 2 so as to be vertically movable. This support stand 3 is a hollow body, and supports the slider 4 in a vertically movable manner by means of an internal feed screw unit, etc. The slider 4 has a first casing 5, a second casing 6, and a third casing 7 fixed in a combined state at its upper end. These casings 5, 6,
7 are combined in a U-shape when viewed from the side, and inside the motor 8 for driving the first arm 11, a motor 9 for driving the second arm 12, and a motor 9 provided at the tip of the second arm 12. A motor 10 for driving a hollow shaft 13 for working is housed therein.

The motor 8 is attached downward at the connecting portion of the casings 5 and 6, and is connected to the input side of the speed reducer 14 by a timing belt/pulley 17. This reducer 14 is of a harmonic drive type, and is attached to the first casing 5 on the same axis as the vertical rotation center of the first arm 11. It is attached to the lower surface of the arm 11. Further, the upper surface side of the first arm 11 is rotatably supported by a hollow shaft 18 with respect to a bearing portion of the casing 7 on the center of rotation of the first arm 11 . Note that this first arm 11 is open at the top and bottom, and has an upper cover 19 and a lower cover 20.
The hollow shaft 21 is rotatably supported around the vertical axis by a bearing portion formed on the lower surface side of the tip, and the lower end portion of the hollow shaft 21 supports the second One end of arm 12 is held. Further, like the first arm 11, this second arm 12 is closed by an upper cover 22 and a lower cover 23, and the hollow shaft 13 is vertically supported by a bearing portion on the lower surface side of the tip. It is rotatably supported. This hollow shaft 13 is attached to a working member such as a chuck by means of an attachment plate 24 on the lower surface.

On the other hand, the motors 9 and 10 are attached to the input sides of reduction gears 15 and 16, respectively, and the reduction gears 15 and 16 are connected to the first arm 11.
It is arranged on the opposite side of the arm members, that is, the first arm 11 and the second arm 12, with the center line of rotation as the boundary, and is a connecting part of the casings 6 and 7,
It is mounted upward by a mounting plate 25.

A reducer 15 for driving the second arm 12
The rotation is transmitted by a timing belt pulley 26 to a hollow shaft 27 housed inside the hollow shaft 18. This hollow shaft 27 is similar to the hollow shaft 1
8, is concentrically and rotatably supported by a ball bearing, and its rotation is controlled by a timing belt pulley 28 housed inside the first arm 11.
This is transmitted to the hollow shaft 21, and finally transmitted as a 360 degree rotational motion of the second arm 12.

Similarly, the rotation of the output side of the reducer 16 for driving the hollow shaft 13 is controlled by the timing belt/pulley 29.
As a result, the signal is transmitted to the hollow shaft 30 which is housed concentrically inside the hollow shaft 27. This hollow shaft 30 is
It is rotatably supported by a ball bearing inside the hollow shaft 27, and its rotation is transmitted to the hollow shaft 32 provided at the intermediate portion of the first arm 11 by a lower timing belt pulley 31. This hollow shaft 32 is rotatably supported by a ball bearing in a bearing housing formed integrally with the first arm 11, and is supported by a timing belt/pulley 33 at its upper end. The signal is transmitted to the upper end of a hollow shaft 34 that is housed concentrically inside the shaft 21. This hollow shaft 34 is rotatably supported by a ball bearing with respect to the hollow shaft 21, and its rotation is controlled by a timing belt/pulley 35 at the lower end.
The signal is thereby transmitted to the working hollow shaft 13. The timing belt pulleys 28 and 35 are wound between the pulleys via tension pulleys 36 and 37, respectively, in order to absorb slack in the belt portions.

Note that the lower surface of the casing 5 is closed by a cover 38, and the upper surface of the casing 7 is
Each is covered by three covers 39 and 40. This one cover 39 covers the hollow shaft 1
On the center line of 8, 27, 30, the rotational position detector 4
1 is fixed. A detection end of the rotational position detector 41 is connected to the central shaft 42 and fixed to the upper surface of the lower cover 20 of the first arm 11 in order to detect the rotational position of the first arm 11 .

The first arm 11, the second arm 12, and the casings 5, 6, and 7 also have a guide member 45 in order to guide the electric wire 43 for wiring and the tube 44 for piping to the required position in the internal space. It is stored. These guide members 45 are inserted into the respective casings 7 by means of rods 46 at appropriate positions.
Alternatively, it is fixed to the first arm 11 and the second arm 12.

These guide members 45 are connected to the hollow shaft 3, respectively.
A recessed guide hole 47 is formed at portions 0, 32, and 34. Therefore, the electric wire 43 for wiring and the tube 44 for piping are guided to necessary positions through the guide hole 47 and the interior of the intermediate shafts 30, 32, and 34. As shown in FIG. 3, the guide member 45 inside the second arm 12 forms rising walls 48 at both left and right edges, and guides the wiring wire 43 or piping tube 44 to the timing belt. The hollow shaft 2 passes through the inside of the pulley 35.
It leads to the inside of 1. Electric wire 43 for this wiring
is for power supply, and tube 44 is for power supply.
Used for suction to prevent dust from forming at joints.

Operation of the Invention Next, the operation of the multi-jointed robot 1 will be explained together with the operation of the invention.

When operating the articulated robot 1, slider 4
is set in advance to an appropriate height by the feed screw unit. In this state, by driving the motors 8, 9, and 10, the first arm 11, the second arm 12, and the hollow shaft 13 perform turning and rotational movements necessary for a predetermined work. That is, when the motor 8 rotates, the rotation is decelerated by the reducer 14 and transmitted to the first arm 11, so that the first arm 11 performs a turning motion on a horizontal plane about the axis of the hollow shaft 18. conduct. Also, the motor 9
When the timing belt rotates, the rotation is caused by
The pulley 26 and the hollow shaft 27 are connected to the timing belt.
It is transmitted to the second arm 12 via the pulley 28 and the hollow shaft 21. Therefore, this second arm 12 performs a 360 degree turning movement on a horizontal plane with the center line of its hollow shaft 21 as the center of rotation. By the pivoting movement of these arm members, that is, the first arm 11 and the second arm 12, the hollow shaft 13 at the tip is moved with high precision to the required working position on the horizontal plane. Note that the backlash of the timing belt pulleys 17, 26, 28, 29, 31, 33, 35, etc. can be corrected by closed loop feedback control.

On the other hand, when the motor 10 rotates, the rotation is
Timing belt pulley 29, hollow shaft 30, timing belt pulley 31, intermediate hollow shaft 3
2. Timing belt pulley 33, hollow shaft 34
and is transmitted to the working hollow shaft 13 via the timing belt pulley 35. Here, the working hollow shaft 13 imparts rotational movement to the mounting plate 24, and a chuck or the like attached thereto performs the necessary work.

During such turning movements of the first arm 11 and the second arm 12, the motors 8, 9, 10 as their driving sources are housed on the base side of all the robots, that is, inside the casings 5, 6, 7. Because of this, their inertia is getting smaller.
Therefore, movement can be controlled with light force and without inertia. Moreover, these motors 8,
9 and 10 are attached in a balanced state on the side different from the first arm 11 and the second arm 12 with respect to the pivot center of the first arm 11. It does not fall down in the direction of the first arm 11 and the second arm 12 and is in a stable state. In addition, the first arm 11, the second arm 12, and the hollow shaft 1 for work are provided.
The driving means 3 and the electric wires 43 for wiring and tubes 44 for piping that accompany them are all housed inside the casings 5, 6, 7, the first arm 11, and the second arm 12, and are directly exposed to the outside. Without,
Since it is held by the guide member 45, this articulated robot 1 can be fully used even in special environments. Further, since the electric wires 43 and tubes 44 are not exposed to the outside, they do not interfere with adjacent devices when the multi-joint robot 1 moves, improving safety and simplifying its appearance.

Modifications of the Invention In the above embodiment, the second arm 12 is attached below the first arm 11. For this reason, the timing belt pulley 31 inside the first arm 11,
33 are vertically separated via an intermediate hollow shaft 32. However, the second arm 12 is the first arm 11.
When mounted on the top surface, the intermediate hollow shaft 32 is unnecessary, and one timing belt pulley 31 is wrapped directly around the pulley of the hollow shaft 34, so one timing belt can be omitted.

Further, the above embodiment is designed with the intention that the base 2 and the support stand 3 will be attached to a floor surface or the like. However, this multi-jointed robot 1 can also be used with the top and bottom inverted, with the base 2 facing the ceiling.

Effect of the invention The present invention provides the following unique effects.

First, the motors serving as the drive sources for the first arm and the second arm are not provided at the joints of the respective arm members, but are mounted on the base side in a balanced state with the center of rotation of the first arm as the border. , the weight of the first arm and the second arm can be reduced, the motor torque thereof may be small, and the inertia is small when the motion is stopped;
Positioning control with high accuracy is possible.

Next, the means for transmitting rotational force is built into the inside of the arm, and the wiring or piping is led to the required position through the hollow shaft of the joint, so the means for transmitting rotational force and wiring are not exposed to the outside. Therefore, interference with other adjacent devices can be prevented when the robot moves, and stable operation can be expected in special environments. In particular, rotating parts are a source of dust, but since the arm is completely sealed,
This articulated robot is suitable for working in a clean room. Furthermore, since the wiring or piping is contained within the arm by the guide member so as not to interfere with the rotation transmission means, interference between them during movement of the robot can be reliably prevented.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the articulated robot of the present invention, FIG. 2 is a vertical sectional view of a part of the articulated robot, and FIG.
The figure is a plan view of the guide member. 1...Articulated robot, 2...Base, 3...Support stand, 5, 6, 7...Casing, 8,
9, 10...Motor, 11...First arm, 12
...Second arm, 13, 18, 21, 27, 3
0, 32, 34...Hollow shaft, 14, 15, 16...
...Reducer, 17, 26, 28, 29, 31, 3
3, 35...Timing belt/pulley, 41...
...Rotational position detector, 45...Guide member.

Claims (1)

[Claims] 1. A multi-jointed robot in which a plurality of arms are rotatably connected by joints, and an arm member having a hollow shaft for work rotatably supported by the arm on the distal end side is rotatably supported by the base body by the joints, A motor for driving each of the arms and a motor for driving a hollow shaft for work are arranged on the opposite side of the arm with respect to the base, and the arm member and the plurality of motors are connected to each other around the joint on the base side. is mounted in a weight-balanced state, and the joint part supports the other arm via a plurality of concentric hollow shafts that support each other rotatably, and all the hollow shafts and the plurality of motors are connected by a belt. The guide member is fixed within the arm at a position where it does not touch the belt, etc., and the wiring or piping is passed through the inside of all the hollow shafts to the required position within the arm, and the guide member is connected by a rotation transmission means such as An articulated robot characterized by being guided by members.