JPS61146486A - Multi-joint arm structure - 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] [Field of Application of the Invention] The present invention relates to a multi-articulated arm structure, and more particularly, to an improved structure for assembling the arms together in an articulating robot having a plurality of arms. .

[Background of the invention]

An articulatory robot with multiple arms is configured so that the hand provided at its tip can be moved to any position, and various types have been proposed and put into practical use (for example, 53-L: 36258, JP-A-55-112789).

However, this type of articulated robot has the disadvantage that each arm is originally heavy and is also equipped with an electric motor, speed reducer, etc. to rotate the arm, which increases the weight of the entire robot. Moreover, when assembling the robot, it is necessary to assemble each arm in sequence, which increases assembly man-hours and labor.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and can reduce the weight of the entire robot.

It is also an object of the present invention to provide a multi-articulated arm structure that reduces the number of steps and labor required for assembling the arms together.

[Summary of the invention]

In order to reduce the weight of each arm, since the load is applied to the tip of the arm, the present invention shifts the center of gravity to the base of the arm and uses the relationship of the beams to give the arm a tapered shape. The point is that we focused on Another advantage is that it is not necessary to unitize each arm and assemble them one after another.

Therefore, the multi-articulated arm structure of the present invention has at least two
In an articulation robot that has a book arm, and the two arms are a first arm and a second arm whose base is connected to the tip of the first arm, the base of the second arm is An electric motor and a reducer having an output shaft extending to the tip of the first arm are attached, the output shaft of the reducer is fixed to the tip of the first arm, and the first
The first arm is characterized in that a boss through which the output shaft of the reducer is inserted is fixed at a position facing the arm, and a recess into which the boss fits is formed at the tip of the first arm, thereby achieving the above object. It was made.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the accompanying drawings. 1 and 2 show an embodiment of a horizontal articulation robot to which the multi-articulation arm structure of the present invention is applied.

In this horizontal articulation robot, the base of a first arm 2 is connected to the upper part of a fixed base 1, and the second arm is connected to the tip of the first arm 2.
The bases of the arms 4 are connected.

The first arm 2 is rotated horizontally about the base by driving the electric motor 3 installed on the first arm 2, and the second arm 2 is rotated by driving the electric motor 5 installed on the 27th arm 4. 4 can be rotated horizontally around the base.

Further, an electric motor 6 for rotating the hand is provided at the tip of the second arm 4, and a vertical cylinder 8 is attached to the output shaft 7 of the electric motor 6 so that a rod can move forward and backward in the axial direction. A hand 9 for gripping an article is attached to the rod of the cylinder 8. This hand 9 is configured to be able to be opened and closed by sucking and discharging compressed air. Then, the upper and lower cylinders 8 and the hand 9 are driven by the electric motor 6.
is rotated, and the hand 9 is moved in the vertical direction by moving the rod of the upper and lower cylinders 8 back and forth.

Therefore, in the multi-articulated arm structure of the embodiment, the second arm 4
An electric motor 5 and a reduction gear 10 are attached to the base of the motor. The electric motor 5 is mounted on the base of the second arm 4, and its rotating shaft 51 is connected to the hole 4 formed in the second arm 4.
It is located at 1. The hole 41 is for arranging the speed reducer IO.

The speed reducer 10 includes an eccentric hub 11 that is eccentrically fixed to a rotating shaft 51 of an electric motor 5, and is attached to the outer periphery of the eccentric hub 11 via a bearing 12, and has teeth (not numbered) on the outer periphery.
a cylindrical planetary gear 13 having a cylindrical planetary gear 13 and teeth (not shown) that mesh with the teeth of the planetary gear 13 on the inner periphery;
a ring 14 fixed to the circumferential side of the planetary gear 1;
The output shaft 15 is integrally fixed to the bottom of the arm 3 and extends to the first arm 2.

When the rotating shaft 51 of the electric motor 5 is driven, the eccentric hub 11 rotates eccentrically, and at the same time, the planetary gear 13 rotates as if rolling on the inner circumference of the ring 14. Output shaft 15 for a rotational speed of 51
The rotation speed can be reduced.

Therefore, the central axis of the output shaft 15 is eccentric with respect to the central axis of the planetary gear 13 relative to the eccentric position of the eccentric hub 11 with respect to the motor rotating shaft 51, and is arranged at a position concentric with the central axis of the ring 14. There is. In addition, in the embodiment, the planetary gear 1
The number of teeth of ring 14 is two fewer than the number of teeth of ring 14,
The meshing position between the planetary gear 13 and the ring 14 is set to shift by two gears each time the eccentric hub 11 rotates once.

The output shaft 15 of the reduction gear 10 is fixed to the tip of the first arm. That is, the output shaft 15 has its distal end fitted into the hole 21 passed through the distal end of the first arm 2, and the key 19 provided to prevent rotation around the shaft and the key 19 to prevent the output shaft from coming off in the axial direction. It is fixed to the first arm 2 by a bolt 20 provided for this purpose.

Therefore, when the electric motor 5 is driven, the output shaft 15 of the reducer 10 tries to rotate, but since the output shaft 15 is fixed to the 17th arm 2, the electric motor 5 rotates, that is, the second arm 4
rotates around the output shaft 15.

However, when the output shaft 15 is fixed, if a large bending load is applied to the tip of the second arm 4, there is a possibility that the output shaft 15 will be unable to withstand the large bending load.

For this reason, a boss 16 is fixed to the base of the second arm 4 on the bottom surface facing the first arm 2, through which the output shaft 15 is inserted. The boss 16 has a boss main body 16a.

It consists of a flange portion 16b projecting from the top thereof, and a spigot portion 16c projecting from the top of the flange portion 16b. The boss 16 has a pilot part 16c fitted into the hole 41 of the second arm 4, and a flange part 16b.
is attached to a groove formed on the bottom surface of the second arm 4, and the output shaft 15 is inserted into the boss body 16a.

On the other hand, a recess 17 that fits the boss 16 is formed at the tip of the first arm 2 . The recess 17 is located in the first arm 2
At a position corresponding to the boss 16 at the tip, there is a recess with a diameter larger than the outer diameter of the boss 16, and the boss 16 is fitted into the inside of the recess through a bearing 18.18.

At this time, the depth QI of the recess 17 is set to be larger than the length Q2 of the output shaft 15 fixed to the first arm 2.

By fitting into each other, the boss 16 and the recess 17 can absorb the bending load generated on the second arm 4, thereby attenuating the lateral load acting on the output shaft 15. . Therefore, the axis of the boss 16 is located on the axis of the ring 14 and also on the axes of the output shaft 15 and the recess 17.

Note that the connection structure between the first arm 2 and the base 1 is similar to the connection structure between the first arm 2 and the second arm 4, so
The details will be omitted.

Since the multi-articulated arm structure of the embodiment has the above configuration, when the rotating shaft 51 of the electric motor 5 is driven.

The output shaft 15 is rotated at a reduced speed by a speed reducer lO connected thereto. As a result, since the output shaft 15 is fixed to the first arm 2, the second arm 4 is fixed to the first arm 2.
is rotated.

At this time, since the electric motor 5 and the speed reducer 10 are attached to the base of the second arm 4, the center of gravity of the second arm 4 is shifted toward the base. Therefore, the second arm 4
Since the second arm 4 can be made into a tapered shape whose width gradually narrows toward the tip, the weight of the second arm 4 can be reduced, and since the first arm 2 is also configured in substantially the same way, the first arm 2 can also be made lighter. That is, the weight of each arm can be reduced.

Furthermore, when a large bending load is applied to the second arm 4,
Since the bending load acts on the output shaft 15, the output shaft 15
And there is a possibility that the reducer 10 may be deformed or damaged. However, the boss 16 through which the output shaft 15 is inserted is fixed to the second arm 4, and the four parts 1 fitted with the boss 16 are fixed to the first arm.
7 is formed, the boss 16 and the recess 17 work together to attenuate the bending load acting on the output shaft 15, thereby reliably preventing the output shaft 15 from being deformed. Moreover, in that case, the fitting between the boss 16 and the recess 17 can prevent the height of the connecting portion between the second arm 4 and the first arm 2 from increasing.

Furthermore, when assembling the first arm 2 and the second arm 4, an electric motor 5. Since the reducer lO and the boss 16 are assembled in advance and the output shaft 15 thereof is fixed to the tip of the first arm 2 with the key 19 and bolt 20, etc.,
Both can be easily assembled. Therefore, each of the arms 2 and 4 can be made into a unit.

Furthermore, in the illustrated embodiment, the first arm 2 is disposed on the base 1, and the second arm 4 is disposed on the first arm 2, so that interference between the arms 2 and 4 is prevented when the respective arms 2 and 4 rotate. This can be prevented, and the range of movement of the arm can be increased accordingly.

FIG. 3 shows another embodiment of the multi-articulated arm of the present invention. This embodiment differs from the first embodiment in that there is a bearing 18.1 between the output shaft I5 of the reducer 10 and the boss 16.
8 is interposed therebetween, and the boss 16 is directly fitted into a recess 17 provided at the tip of the first arm 2. In this embodiment, when a bending load is applied to the second arm 4, the bending load is absorbed by the bearing 18, 18 interposed between the boss 16 and the blade shaft 15, so that the bending load is not affected by the bending load. It was designed so that it would not be subject to
Basically, the same effects as in the first embodiment can be obtained.

(Effects of the Invention) As described above, the present invention has at least two arms, and the two arms are a first arm and a first arm.
a second arm having a base disposed on the tip of the arm; an electric motor and a reducer having an output shaft extending to the tip of the first arm are attached to the base of the second arm; The output shaft is fixed to the tip of the first arm, and a boss through which the output shaft of the reducer is inserted is fixed to a position opposite to the first arm at the base of the second arm, and a recess that fits with the boss is fixed to the second arm. Formed at the tip of one arm, this allows each arm to have an ideal tapered shape as a beam where the load is applied to the tip, making it possible to reduce weight, thereby reducing the weight of the entire robot. Can be done. Also,
Since the height of the joint between the arms can be reduced,
The connecting portion can be made compact. Furthermore, since each arm can be made into a unit structure, it is no longer necessary to assemble the arms to the base one after another, reducing assembly man-hours and labor. By combining different arms, etc., it is possible to easily provide products that meet various needs.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an embodiment of an articulated robot to which the multi-articulated arm structure of the present invention is applied, FIG. The figure is an enlarged cutaway view of essential parts showing another embodiment of the multi-articulated arm structure of the present invention. DESCRIPTION OF SYMBOLS 1... Base, 2... First arm, 3... Electric motor for driving the first arm, 4... Second arm, 5... Second
Arm drive electric motor, 10... reduction gear, 15...
Output shaft of reducer, 16...boss, 17...recess.

Claims (1)

[Claims] In an articulation robot having at least two arms, the two arms are a first arm and a second arm whose base is connected to the distal end of the first arm. An electric motor and a reducer having an output shaft extending to the tip of the first arm are attached to the base, the output shaft of the reducer is fixed to the tip of the first arm, and the first A boss through which the output shaft of the reducer is inserted is fixed at a position facing the arm, and a recess that fits with the boss is fixed to the first position.
A multi-articulated arm structure characterized by being formed at the tip of the arm.