JPH0763953B2 - Robot with counter weight - Google Patents

Description

The present invention relates to a robot with a counterweight.

[Conventional technology]

Conventional robots are generally classified into Cartesian type, joint type, and composite type thereof. Both robots are used by firmly fixing the base part to the pedestal / floor with bolts. This is because the robot itself has a statically unstable shape and often falls down if it is not fixed, and there is an inertial force that is the reaction force of the acceleration motion due to the inertia of the arm during robot operation. This is to prevent the base portion from being displaced from the gantry / floor due to its inertial force. When the robot becomes large and becomes high speed, the above fixing needs to be further strengthened, and when fixing to the gantry, it becomes necessary to make the gantry heavy or fix it to the floor.

[Problems to be Solved by the Invention]

The recent speedup of robots is remarkable, and along with it,
The inertial force of the operating arm is also increasing. Although the weight of the operating arm has been reduced, in order to secure the rigidity of the arm,
I can't make it too light. Therefore, if the robot becomes faster, the pedestal becomes heavier, which goes against resource saving and consumes a large amount of pedestal material. In addition, there is an attempt to attach a robot to a transport vehicle to make it work, but since the transport vehicle moves around the floor, the transport vehicle cannot be heavier and cannot be fixed to the floor. After all, the robot is operated at a low speed and the inertial force is reduced, so that the robot cannot exhibit the ability to operate at a high speed.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, a base for supporting the motion of each of the operating arms is provided with a weight that performs an angular accelerating motion in a direction opposite to the angular accelerating motion in synchronization with the angular accelerating motion of the operating arm. The present invention provides a robot with a counterweight, which is characterized by being attached to a.

[Action]

In the present invention, since a weight for performing an angular acceleration motion in a direction opposite to the angular acceleration motion is attached to a base that supports the motion of the motion arm in synchronization with the angular acceleration motion of the motion arm, The inertial force, which is the reaction force of the angular acceleration motion during operation due to the inertia of each motion arm acting on the base, is canceled by the inertial force, which is the reaction force of the angular acceleration motion due to the weight, and the robot other than the robot weight is attached to the mount to which the robot is attached. It does not require much power.

〔Example〕

An example to which the present invention is applied will be described. When the arm of the articulated robot operates, the inertial force applied to the base is a torsional torque generated by the centrifugal force and the angular acceleration due to the weight of the arm. The centrifugal force can be solved by bringing the center of gravity near the axis of rotation of the arm, so the problem is torsional torque. In order to cancel the torsion torque, the configuration shown in FIG. 1 is adopted. FIG. 1 is a perspective view showing one arm of an articulated robot taken out.
(1) is a motor for driving the arm (3), (2) is an output shaft of the motor (1), (4) is a gear concentric with the output shaft (2), and is fixed to the arm (3). . (5) is a motor, and a weight (9) is attached to the output shaft (6) of the motor (5).
A gear (7) concentric with the output shaft (6) and meshing with the gear (4) is fixed to the weight (9). When the output shaft (2) of the motor (1) rotates counterclockwise as viewed from the output shaft (2), the arm (3) and the gear (4) also rotate counterclockwise. The motor (5) rotates clockwise when viewed from the output shaft (6), and rotates the weight (9) and the gear (7) clockwise. The ratio of the rotation speeds of the motor (1) and the motor (5) is equal to the speed ratio of the gear (4) and the gear (7). Further, the rotational inertia of the arm (3) and the rotational inertia of the weight (9) are opposite to the speed ratio of the gear (4) and the gear (7). That is, if the gear (4) and the gear (7) are 1: 1.2, the ratio of the rotational inertia of the arm (3) to the rotational inertia of the weight (9) is 1.2: 1.
Is to The rotation speed ratio between motor (1) and motor (5) is 1: 1.2. Therefore, the motor (1) and the motor (5) can smoothly rotate even if the gear (4) and the gear (7) are engaged with each other, and the product of the rotational inertia and the angular velocity becomes the same, so that the rotational inertia and the angular acceleration are The products are also equal in size.

FIG. 2 shows a diagram showing the inertial force. FIG. 2 is a view of FIG. 1 seen from above, the shape is simplified, and some parts are omitted. When the arm (3) moves with a certain angular acceleration in the rotation (10) direction, a torque obtained by the product of the rotational inertia of the arm (3) and the angular acceleration is required, and the torque is output by the output shaft (2). Tell (3). Since the torque is generated between the motor (1) and the output shaft (2), it is necessary to apply a reverse torque to the motor (1). The torque is the base torque as the torsion torque (11). Work for (8). This torsion torque is the inertial force that has been a problem in conventional robots. On the other hand, when the weight (9) moves at an angular acceleration in the opposite direction to the rotation (10), a torque obtained by the product of the rotational inertia of the weight (9) and the angular acceleration is required, and the torque is the output shaft ( 6) tells the weight (9). Since the torque is generated between the motor (5) and the output shaft (6), it is necessary to apply reverse torque to the motor (5). Work for (8). That is, since torques of the same size but opposite directions act on the base (8), the inertial force due to the torsional torque is not leaked from the base (8) to the outside, and only the inside of the base (8) is exposed. . The gear (4) and the gear (7) are not necessary if only to cancel the inertial force, but the gear is effective for ensuring the synchronism of the motor (1) and the motor (5). . Further, when the gear is removed, the change of the rotational inertia on the arm (3) side can be followed by devising the control of the motor (5).

〔The invention's effect〕

The first embodiment has been described above. In Example 1 as well, the robot is heavier, larger, and more difficult to control than the conventional robot. However, considering the usability of the robot in the future, the inertia of the motion arm leaking outside the robot is a factor that greatly hinders the development of a robot that moves around autonomously. The present invention can eliminate the factor.

[Brief description of drawings]

 Fig. 1 ...... Perspective view (1) ...... Motor, (2) ...... Output shaft (3) ...... Arm, (4) ...... Gear (5) ...... Motor, (6) ...... Output shaft (7 ) …… Gear, (8) …… Base (9) …… Weight Fig. 2 …… Structure diagram (3) …… Arm, (8) …… Base (10) …… Rotation, (11) …… Twist Torque (12) …… Torsion torque

Claims (1)

[Claims] 1. A base for supporting a motion of each motion arm of an articulated robot, in which a weight for performing the angular acceleration motion in a direction opposite to the angular acceleration motion is synchronized with the angular acceleration motion of the motion arm. A robot with a counterweight that is attached to the.