JPS59161286A - Multi-joint 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 an improvement in an articulated robot, and particularly to one in which a force in a certain direction that can be applied to an end effector can be applied to a dog.

Articulated robots that include a four-bar linkage mechanism as part of their mechanical structure are well known. And by the power connected to this link mechanism, the final result is ENDF A A Ilr J!
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Conventionally, the unique force transmission characteristics of this mechanical configuration were constant, so the force that could be exerted in a certain direction by an end effector at a certain position was always constant.

The main purpose of this invention is to enable a multi-joint robot including a four-bar linkage mechanism to have different force direction characteristics at the end effector than in the past.

The outline of the present invention is an articulated robot using a four-bar link mechanism as a mechanical configuration for obtaining at least two degrees of freedom, wherein the four-bar link mechanism is formed by intersecting a pair of non-adjacent links. It is an articulated robot.

An embodiment of the present invention will be described in detail below with reference to the drawings.

1 is the base. A frame 2 is pivotally supported on a base 1 so as to be able to freely rotate through a rotation angle α1 around a vertical axis V. Although the details are not shown, the rotation angle α is configured to be forced by the power Ml.

Frame 2 has horizontal pivot shafts 1 on both outside sides! The first links 3, 3 are pivotally supported around the first link so as to be freely rotated by a rotation angle α3. In other words, as shown in FIG.
A shaft H8 is supported by and B3, and the link 3 is fixed to this shaft H1.

Frame 2 and axis H! A power M2 for forcing the rotation angle α2 is provided between the rotation angle α2 and the rotation angle α2. The power M2 is a known direct drive motor, the rotor R2 is a highly magnetic permanent magnet integrated with the shaft H1, the stator S integrated with the frame 2 is wound with a coil, and an electronic switching device (not shown) is wound around this coil. By applying a DC voltage through the circuit,
Configured as a brushless high-torque motor.

The second link 4 is still freely pivoted around the axis H1 at a rotation angle α. This pivoting is done by a bearing B, as shown in FIG. 2, to the frame 2, and by a bearing B to the axis H1.

Further, in order to force the rotation angle α3, a power M3 is provided on the shaft I□, and this power M3 is also a known direct drive motor. In the rotor integrated with the axis I-i 1,
The stator s3 integrated with the link 4 also has the same configuration as the power M2. Thus, the power sources M2 and M8 are both arranged side by side inside the frame 2.

5 is the third link, 6N is the fourth link, the base end of the link 5 is connected to the axis H2 parallel to the axis H1 to the tip of the link 4, and the intermediate part of the link 6 is connected to the axis I (3) parallel to the axis H1. The tips of links 5 and 6 are also pivoted by an axis H4 parallel to axis H□.Thus, links 3, 4. A linkage mechanism is configured.

The link 6 is extended to one side, and its tip is configured as a wrist 6a. The wrist 6a is further configured to be able to freely rotate α4 around an axis H5, and a power M4 is applied to force the rotation a4.
Although the details are not shown, the wrist 6a is the pivot point Hs of the link 6.
It balances the gravity of the entire sill 6 (including links 4 and 5) with respect to the pivot H3.

It is assumed that the power M4 and the wrist 6a are connected by a power transmission means (not shown). An appropriate end effector is provided at the further tip of the wrist 6a.

Further details are not shown or the rotation angle α□ is shown.

α2. A shaft encoder for detecting α6 and α4 is provided at each pivot point, and is inputted to a control means (not shown). By this control means, each power Ml to M
4, which is similar to conventionally known industrial robots.

The power M! forcing the angles α2 and α3 as described above.
and Ms are arranged in parallel to the pivot axis H1, so that the weight and moment of inertia of each link are not increased due to the power M and the gravity of M3 itself (the power M and the inertia of the rotor and stator of Ms themselves) moment is smaller than that of each link). Therefore, each control angle α to α3 of this articulated robot is controlled by a control means (not shown).
The control accuracy can be improved even if the outputs of the motive power M2 and Ms are not so controlled.

Furthermore, since the powers Ms and Ms are arranged side by side inside the frame 2 (that is, near the axis V), they do not increase the moment of inertia around the axis V so much, and therefore, it is also possible to control the angle α. It has no negative impact.

Furthermore, the directions of the links 4 and 5 can be reversed as shown by the two-dot chain line, so that the links 3 and 5 intersect.

In order to reverse it in this way, for example, the pin at the pivot point between links 4 and 5 may be removed and the pin may be refitted after the reversal, or links 4 and 5 (and links 3 and 6) may be
It is also possible to construct the apparatus so that it can be extended in a straight line, and to perform the above-mentioned reversal automatically by means of the shown control means. The meaning of this inversion is important in this invention, and will be explained in detail below.

When the powers M3 and Ma are controlled to control the rotation of the links 3 and 4, the torques generated in the powers M2 and M are vectorially combined in the link mechanism. This is then applied to the wrist 6a as a resultant force (the details of the calculation are omitted).

When the resultant force at the wrist 6a is expressed as a vector, the direction and magnitude distribution of the vector is expressed as an ellipsoid. Now, if the ellipsoidal surface when the links 4 and 5 are shown as solid lines in the diagram is drawn as a solid line, and the ellipsoidal surface when the links 4 and 5 are shown as a two-dot chain line is drawn as a two-dot chain line, as shown in the figure. The directions of the major axes of these ellipsoids are different. In other words, the wrist 6a' generates a force in the direction of the major axis, so the links 4 and 5 are adjusted depending on the purpose, for example, when pressing an object with an end effector or lifting a heavy object.
It will be understood that it is effective to change the posture of the person as described above.

This invention is not limited to the above embodiments, and
The moving cams and M may be other motors that are not direct drives, or may even be linear actuators. In short, within the scope of the technical idea of this invention, the replacement of each component with an equivalent is also included within the technical scope of this invention.

Since the present invention is as described above, it can produce a unique and remarkable effect in that the characteristics of the force in a certain direction on the end effector can be changed with a simple configuration.

[Brief explanation of the drawing]

The drawings all show an embodiment of the present invention, and FIG. 1 is an overall perspective view, and FIG. 2 is a cross-sectional view taken along the line nm in FIG. 1. 1... Base, 2... Frame, 3... First link, 4... Second link, 5... Third link, ■■l・
...Horizontal pivot shaft, M2 and M3...Direct drive motor 2-1L...Four-bar link mechanism. Applicant ShinMaywa Industries Co., Ltd.

Claims (1)

[Claims] (1) In a multi-joint robot using a four-joint mechanism as a mechanical configuration to obtain at least two degrees of freedom, the four-joint link mechanism is formed by intersecting a pair of non-adjacent links. jointed robot. ■ The pair of non-adjacent links can be configured to intersect or non-intersect.
Articulated robot described in section.