JPS5959386A - Joint unit - 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 (i) Technical Field of the Invention The present invention relates to a joint unit that constitutes an entire automatic machine such as a robot arm that performs joint motion. (2) Background of the technology Automatic machines controlled by computers are capable of complex movements depending on the purpose, and in advanced machines, it is even possible for multiple branches to perform different movements in coordination with each other.

Its systems and programs are rapidly evolving. From the perspective of such control, it is expected that the degrees of freedom of movement will become more realistically permissible and closer to the limbs of animals. If we were to imitate a human finger, it would be necessary to have at least five degrees of freedom in just one finger. It is not easy to design such a multi-joint mechanism, and the mere mechanism of bending and rotating sounds is complicated. The instructions are on the order of +7 radians, and in advanced models, sensors can be installed to detect vibrations accompanying motion and send them back to the computer, or to detect external force at the blade edge and adjust the motor current. is also required. In addition to this complex mechanism, there are a large number of cables for power and signals, and appropriate allowances are made to ensure that they do not completely inhibit the movement of the mechanism internally, and that the cables do not break due to the stress associated with the movement. The problem of having to wire a long wire is extremely difficult. The idea of a mechanical unit exists as a solution to this problem. In other words, instead of designing a complex mechanism as a whole, in the extreme, one unit of money is allocated to each joint, and the mechanism is decomposed in units of y).
It is a method that allows for assembly, and the unit design allows for the specified movement within it, while at the same time making it easy to connect the units to each other from the beginning. The power and signal cables needed to pass through should also be stored and connection means should be provided at both ends. Make sure that the cables are long enough so that they are not damaged by the movement of the unit, but that they are firmly fixed at the connections. As long as the connecting means is strong in this manner, even if the unit is assembled by connecting the parts in multiple stages, the design of the mechanism can be expressed simply by symbols. In addition, the difficulty in handling cables, which tends to be a problem in the reliability of multi-stage and complex joint mechanisms, can be handled only in relatively simple parts such as unit manufacturing, and the manufacturing process involves mass production of the same product. It comes out. Such a unit must (1) be able to respond to minute movements in response to digital commands, (2) require as little energy as possible to maintain that state when in a stopped state, and (3) be able to withstand external forces in the direction of movement or Requirements include being able to detect all the acceleration associated with one's own movement, and (4) having a relatively elongated external shape to resemble the joints of an animal.

3) Prior Art and Problems As a bending drive mechanism for performing joint motion of a conventional articulation unit, a screw feeding mechanism directly connected to a motor is used. In this mechanism, a moving body made of a nut is screwed onto a screw shaft directly connected to a motor, and this moving body is reciprocated by the rotation of a threaded rod and combined with this moving body to pivot a rotating body for joint operation. It is something. However, although screw feeding is suitable for linear movements such as expansion and contraction, it is not suitable for use as is for bending movements of joints. Generally, this is converted into bending motion by a link, as seen in excavator devices using hydraulic cylinders, but in this case, the conversion ratio changes depending on the angle. Although it is possible to calculate and correct this with the control computer, it is a complicated calculation involving trigonometric functions, etc., and control is not easy. Still, such a screw feeding mechanism cannot easily detect external force in the direction of movement, acceleration, and the like.

(4) Purpose of the Invention The present invention has been made in view of the shortcomings of the prior art. Provided for all purposes.

(5) Structure of the Invention In order to achieve this object, the present invention has a means for connecting the joint units to each other at both ends, a threaded rod rotated by a motor in the middle, and a threaded rod that is screwed to the threaded rod and reciprocates along the threaded rod. A bending drive mechanism consisting of a movable body, which can be connected in multiple stages to enable bending joint movement, is connected to a belt that engages the entire rotating body of the movable body, and is connected to a belt that engages with the rotating body of the movable body, and It is configured to perform flexion joint motion.

(6) Embodiment of the Invention FIG. 1 is an exploded perspective view of a joint unit according to Kinai 1#. Motor 2 was installed on the first day of the main body, and this motor 2 rotates! The screw rod 3 is coupled to 811.

A movable body 4 is screwed onto this threaded rod 3, and as the threaded rod 3 rotates forward and backward, i'1. make a reciprocating motion along the This moving body 4 is fixed to a continuous belt 7 which engages pulleys 5,6. The pulley 5 is connected to a connecting member 9 via a bevel gear 8. There is a power line inside the water body 1.

Cables 20 such as signal lines are arranged with extra length. A connector 1 to be connected to a cable 20 is provided on the top surface of the connection member 9.
3 is provided. This connector 13 is electrically connected to the connector 12 at the lower end of the other joint unit to be connected via the shod plug 14. Attachment pieces 10 are provided at the lower end of the wood 1 and are screwed together with screws 11 to a mating connecting member 9 to be connected. The main body 1 is covered with a cover 15. The rotation of the motor 2 causes the threaded rod 3 to rotate, which causes the pulley 5 to rotate via the movable body 4 and the belt 7, and connects the connecting member 9 via the bevel gear 8 to the joint IRB. Do all the rotational movements. Note that the bevel gear may be omitted, and the connection member 9 may be caused to swing in the direction of arrow A by the rotation of the shite pulley 5.

i 21a (・1 Tree Invention C) This is a side view of another row of the joint unit, and FIG. 433 is a longitudinal sectional view thereof.

A threaded rod 3 is directly connected to a motor 2 attached to the main body 1,
A belt 7' is fixed to the movable body 4 which is fitted onto the threaded rod 3. The belt 7' engages a fan-shaped rotating body 6 rotatable about an axis 18. As in the example described above, the rotation of the motor 2 causes the rotating body 16 to pivot through the entire belt 7', and the handling member 17, which is integrally connected to the rotating body 16f, moves as shown by arrow B. Perform joint flexion movements. Rotating body 16
A return spring 19 engages with the end of the rotating body 16 and always biases it in one direction.This return spring absorbs the looseness of the threaded rod 3 and its joint movements. The outer periphery of the spring 19 is covered with a creep 21. This sleeve 21 protects the cable 20 from tangling with the spring 19, and also functions to guide the moving body 4 and prevent rotation. The unit is the fourth example.
As shown in the figure, a multi-joint robot arm is constructed which is connected to the Enoki stage and has a hand 22 at its tip. Strain gauges 24 are all attached to the belt 7' of this joint unit so that the force during joint movement can be detected, and a magnetoresistive head (magnetic sensor) 25 is attached to the magnetic gauge 23r and provided on the main body side. It is possible to detect the position of the belt 7'.

(7) Detailed Description of the Invention As described above, in the present invention, the belt and the rotating body that engages with the belt are valved to convert the screw feeding motion caused by the motor e into a joint bending motion.

Therefore, since the rotation angle of the motor and the bending rotation angle always maintain a constant proportional relationship, the bending operation can be controlled easily. In addition, it is easy to install force sensors and position sensors, and it is possible to easily and reliably detect force 1 position, Karo velocity, etc. Based on these, advanced control of the robot arm can be performed.
Becomes J Noh.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of the joint unit according to the present invention, and FIG.
3 is a side view of another embodiment of the present invention, FIG. 3 is a side view of the position of the robot arm shown in FIG. 2, and FIG. 2...Motor; 3...7 screws, 4...
)l Hyperactivity 1, 5...ri-1), 7, 7'...
...Belt, 9. l'7・・・Welded iron, TB material, 16
...rotating body, 25... to throat, 24...
...Strain gauge, 23-...Magnetic 6 self-recording medium. Patent applicant: Fujitsu Ltd. Machikado, Patent attorney: Akira Aruki, L. Nishi, Nishi, Patent attorney: 1) Shino, Patent attorney: Yama L] Figure 1

Claims (1)

[Claims] 1. A bending drive mechanism consisting of a screw extension rotated by a motor in the middle and a movable body that is screwed into the screw and reciprocates along the screw, which has means for connecting joint units to each other at both ends, and a bending joint. 1. A joint unit movably connectable in multiple stages, characterized in that the movable body is connected to a belt that engages with a rotating body, and a bending joint motion is performed via the rotating body.