JPS6190894A - Robot - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a robot used for various industrial applications, and more particularly to a robot having a rotating arm and a joint structure between the rotating arm and a robot base or adjacent arms. be.

2. Description of the Related Art Robots having arms with a joint structure similar to that seen in the human body and a hand portion at the tip of the arm have been widely used in recent years to grasp and transport objects and perform certain tasks using the objects.

That is, it has advantages such as saving labor in manual work, and performing high-speed work and high-load work in cooperation with manual work.

Generally, a drive source consisting of a hydraulic actuator, pneumatic actuator, or an electric motor is used for the five movements of the arm or hand of a robot, but robots used for household use or office processing use an electric motor. Since it is easy to operate and can be driven simply by connecting it to a power outlet, it is advantageous in terms of introducing it as a driving source.

In addition, in robots that use an electric motor as a drive source, it is common to have a mechanism in which the driving force is transmitted from one electric motor to multiple arm actuating parts using a gear mechanism, belt/pulley mechanism, steel cable, etc. According to the structure, the operation of the arm or hand disposed far from the driving electric motor is disadvantageous in terms of high-speed and high-precision positioning.

Therefore, in order to overcome this disadvantage, a robot has already been proposed in which a motor is attached to each joint of the mouth and each arm is driven.

However, in a robot with this latter joint structure,
Since a structure is employed in which an electric motor having an appropriate output specification is externally mounted on each joint, each joint has the disadvantage that it is inevitably large in size.

FIG. 1 is a diagram showing an example of the configuration of a robot in which one electric motor is mounted on each joint structure.

The example in FIG. 1 shows a gutter with two-stage arms.

Now, this robot is equipped with an electric motor MAI that moves the first stage arm [6] above the joint 14 provided on the bracket 12 of the base body 10, and the driving force of the electric motor MAI is transmitted from the belt. It is transmitted via a pulley mechanism 18. That is, the second stage arm 24 pivots at the joint 20 in the direction indicated by the arrow. Further, another t-motor MA2 is mounted above the joint 20 of the first stage arm 16, and the driving force of this electric motor MA2 is transmitted to the second stage arm 24 via a belt/pulley mechanism 22. , the second stage arm 24 pivots in the direction shown by arrow B together with its bracket 24&. Further, the second stage arm 24 is moved by the arrow C by the electric motor MA3.
The second stage arm 24
A hand 26 is provided at the tip of the hand 26 , and the hand 26 is configured to grip an article (not shown) such as a working tool by the elastic gripping force of a leaf spring 30 provided in a gripping space 28 . Furthermore, encoders 32 and 34 are provided above each of the electric motors MAD and MA2. That is, these encoders 32, 34 are connected to rotation detection discs 32a, 34a.
and detection signal detection devices 32b and 34b, and by detecting the amount of rotation of each motor shaft, the amount of movement of the first stage arm 16 and the second stage arm 24 can be respectively detected. . 32c and 34c are detection signal transmission lines. As is clear from the configuration of this robot, all of the electric motors MAI to MA3 are mounted on the joint structure and are arranged in a state of protrusion to the outside, so as mentioned above, each joint structure becomes large. , it has the disadvantage of lack of compactness.

For this reason, as shown in, for example, Japanese Unexamined Patent Publication No. 51-104180, a robot has been proposed in which an electric motor is housed inside each joint to reduce the size of the robot.

However, in this robot, a stator having an excitation coil is fixed to the end of the first stage arm, a movable element made of an elastomagnetic material is fixed to the end of the second stage arm, and A rotating shaft rotatably supported by the arm is fixed to the intermediate portion of the second stage arm to form a joint.

Therefore, in the lo-hot of this joint structure, the arm length from the rotation axis to the ferromagnetic part is required, so the
This has the disadvantage that the enamel becomes thicker and the amount of N in the joint structure becomes extremely heavy, and the length of the arm cannot be used effectively.

Furthermore, since a ferromagnetic material is provided at the tip of the second-stage arm, when the second-stage arm is driven one rotation, the arm beyond the middle part will not collide with the first-stage arm. However, the range in which the electric motor can be arranged is small, making it difficult to achieve a wide operating range.

The present invention can eliminate the drawbacks of the conventional mouth/pit as described above, and can widen the range of motion.
Another object of the present invention is to provide a robot whose joint structure can be made small and lightweight.

Figures 2 and 3 show such conventional 0,;? 7
The present invention has been newly devised to overcome the neo-11 problem caused by the enlargement of the joint structure of the 0-pot joint.
This is a three-dimensional external view and an exploded view of the structure, typically showing the joint structure between L)ji, especially the joint structure between the joints and vi.

As is clear from FIGS. 2 and 3, according to the present invention, a pivot joint structure 44 is provided between the first arm 40 and the second arm 42, and the pivot joint structure 44 is electrically powered. The electric motor 46 incorporates a motor 46 so that the pivot joint structure 44 itself has a drive motor function.As clearly shown in FIG. (for example, an end bell type rolling bearing) 48.48 and a stator 50 having an excitation coil 52 are fixed, while the second arm 4
2 is formed by fixing a shaft 54 and an armature 58 consisting of a permanent magnet 56.

That is, by supplying an excitation current to the excitation coil 52 of the stator 50, the normal motor function of generating rotational force on the stain 58 is exerted, and by the interposition of the bearing members 48 and 48, the first stage arm 40 This creates a relative pivoting motion between the second stage arm 42 and the second stage arm 42. As is clear from the above-mentioned configuration and operation, the joint structure of the robot according to the present invention has no structure protruding to the outside in the joint structure portion 44, and the joint structure itself has a motor function, so that it can be made smaller and lighter. Both have the same effect. Furthermore, it is extremely preferable to form the above-mentioned electric motor 46 as a slot-wound DC motor because the required output amount and torque per unit weight can be easily controlled by controlling the amount of power supplied. be. Note that the electric motor 46 shown in FIG. 3 is an example of a brushless motor;
Bearing member 48 having a brush holder 49 as shown in the figure
' is used in place of the above-mentioned bearing member 48, and a stator 50' made of a magnet is used in place of the above-mentioned stator 50.
It is also possible to form a brush motor by fixing it to 0 and further replacing the above-mentioned armature 58 with an armature 58' with an excitation coil. Furthermore, if the electric motor 46 is formed as a pulse motor, the first stage arm 40 and the second stage arm 40 can be moved by pulse input.
Controlling the amount of relative pivoting between the two can also be easily accomplished.

Although the above example shows an example of a joint structure provided between adjacent arms, it is also possible to form a similar joint structure between the base body and the arm of the robot and between the arm and the hand. It goes without saying that this is possible, but as the joint structure becomes smaller and lighter, the robot itself becomes smaller and lighter.Especially in the case of a 15-inch robot for home use or office processing, the robot's simple external structure makes it easier to use. It is also possible to give it a smart feel.

As explained above, according to the present invention, the ends of the first stage arm and the second stage arm are configured to overlap with each other, and a rotation shaft is provided to enable rotation of both. ,
Since the υ rotation is driven by an electric motor placed between the rotating bearings, there is no need for extra arm length, and the arm length can be used effectively, and the joint structure can be made smaller and lighter. In addition, since the electric motor does not interfere with the rotational drive of the arm, the arm can have a sufficiently wide range of rotational movement, which is a particularly great effect.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an example of a conventional multi-arm robot, Fig. 2 is an external three-dimensional view of an embodiment of the robot joint structure according to the present invention, and Fig. 3 is an exploded view of the same structure. Figure 4 is a three-dimensional view between each element for explaining another embodiment. 10... base body, 16... first stage arm, 18... second stage arm, 40... 1st arm, 42... 2nd arm, 44...
- Joint 4 epsilon structure, 46... electric motor, 50... stator, 58... armature.

Claims (1)

[Claims] 1. A first arm member, a second arm member, and a shaft provided at an end of the first arm member and having both ends supported by the first arm member. and a rotary bearing provided at an end of the second arm member to rotatably support both ends of the shaft, the ends of the first arm member and the second arm member being mutually connected. and a stator fixed between the rotation bearings of the second arm member and an armature fixed between the rotation bearings of the shaft, and configured to rotate the shaft. A robot characterized by comprising an electric motor installed to drive the robot. 2. The robot according to claim 1, wherein the electric motor is a DC motor. 3. The robot according to claim 1, wherein the electric motor is a pulse motor.