JPS5919695A - Industrial 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 industrial robot that requires an electrical connection between a fixed part and a movable part of a manipulator mechanism.

The general configuration of an industrial robot consists of a manipulator mechanism for arbitrarily moving the position and posture of the wrist, a control section for controlling this manipulator mechanism, and a control signal for the manipulator mechanism and the position of the manipulator mechanism. The position and posture of the wrist are controlled to the target state in conjunction with the feedback signal from the detector.

Therefore, such industrial robots typically require a large number of electrical signal connections between the fixed part and the movable part of the manipulator mechanism.

FIG. 1 shows an example of such an industrial robot.

This robot is an example of a so-called four-section parallel link articulated robot, in which 1 is a fixed base, 2 is a rotating table, 3 is a rotating base, 4 is an upper arm, 5 is a parallel link, 6 is a forearm, and 7
8 is the bending axis of the wrist (not shown), 8 is the torsion axis,
, 9.10 is a cable.

The robot operates as a robot by changing the position and posture of the wrist by rotating the turning table 2, swinging the upper arm 4, moving the parallel link 5 up and down, and rotating the shafts 7 and 8.

As is clear from FIG. 1, in such a robot, a large number of cables 9, 10, etc. are required from the movable part of the manipulator mechanism, such as the turning base 3, to the fixed part, such as the fixed base 1. The transmission lines included in these cables include many signal lines that are susceptible to noise, such as signal lines from the position detector of the manipulator mechanism q.

Therefore, in the past, the portion included in the turning base of these cables was made into a curl cord, and a shielded cable was made in which a large number of core wires were shielded all at once.

However, such a cable shield cannot sufficiently eliminate noise interference, and it cannot prevent noise interference between signal lines of different signal transmission systems. The object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a system that is resistant to noise interference and operates reliably under any environment. The aim is to provide industrial robots that have been developed.

In order to achieve this object, the present invention includes a plurality of two-core shielded wires whose core wires are a pair of insulated wires twisted together.
The cable sheathed together is a curled cord, and the curled cord constitutes an electrical connection between the fixed part and the movable part in the manipulator mechanism of the robot. Another feature is that electric wires are used as the transmission path for the balanced transmission method.

Embodiments of the industrial robot according to the present invention will be described below with reference to the drawings.

FIG. 2 is a cross-sectional view showing one embodiment of the present invention, showing only the fixed base 1 and rotating table 2 of the robot shown in FIG. 1. In the figure, 20 is a rotating drive motor. , 21 is a speed reduction mechanism, 22 is a cable, 23 is a curl cord portion of the cable 22, 24 is an internal connection portion,
25 is the upper clamp 1, 26 is the lower clamp, 27 is the connection plug, C1 to C4 are the core wires (shielded wires) of the winter pull 22
, C11 is the first insulated wire, C12 is the second insulated wire,
C13 is a shield jacket.

The rotational driving force from the motor 20 is transmitted to the swing table 2 via a speed reduction mechanism 21, which is called a monomonic drive or the like.

The cable 22 is clamped to the upper inner side of the turning table 2 by an upper clamp 25, and is clamped to the lower inner side of the fixed base 1 by a lower clamp 26, and between these clamps 25 and 26 is a curl cord part 23. It has become. Therefore, when the swivel table 2 rotates with respect to the fixed base 1, the curl cord portion 23 only expands and contracts, thereby allowing the connection by the cable 22 to be made without interfering with the rotation of the swivel table 2. I can do it.

As shown in FIG. 3, the cable 22 has four core wires C1 to
From C4, these core wires C1 to C4 are the first
Insulated wire C11, insulated wire C12 of wire C12, and shield jacket C13 that envelops them all together.
It consists of The sheath S is filled around these core wires C1 to C4 so that no voids remain. Further, at this time, the first and second insulated wires C1l and 012 constituting each of the core wires C1 to C4 are twisted together to form a so-called twisted pair wire.

Therefore, according to this embodiment, these core wires C1 to C4
Since the two electric wires C11 and C12 included in each are independently shielded, the intrusion of noise can be sufficiently reduced by using these as signal lines for the position detector. The robot can be sufficiently prevented from malfunctioning even when used in an environment with a high noise level.

By the way, in this embodiment, each of the core wires C1 to C4
The insulated wires C1l and C12 included in the insulated wires constitute a twisted pair.

Therefore, when these are used as signal lines for the position detector, if a so-called balanced transmission system is constructed, even greater noise resistance (=4) can be provided.

FIG. 4 shows an example of a balanced transmission system applicable as an embodiment of the present invention.

In FIG. 4, 40 is a detection signal input from a position detector, etc., 41 is a driver consisting of an unbalanced human power-balanced output amplifier, 42 is a receiver consisting of a balanced input-unbalanced output type amplifier, etc., and 43 is a receiver consisting of a balanced input-unbalanced output type amplifier. This is the detection signal output.

The driver 41 is installed near a signal source such as a position detector, converts the unbalanced signal from the input 40 into balanced outputs of normal phase and negative phase at a predetermined level and a predetermined output impedance, and converts the twisted pair into balanced outputs. The receiver 42 serves to supply a positive phase output signal to the first insulated wire C1l and a negative phase output signal to the second insulated wire C12. The balanced signal transmitted by the first and second insulated wires C11 and C12, which are provided near the part where the detection signal is to be received and which constitute a twisted pair, is set at a predetermined level and a predetermined output impedance. Convert to balanced signal and output 43
It functions to supply.

Next (・I will explain the operation.

A detection signal from a position detector or the like supplied to an input 40 is converted by a driver 41 into a positive phase signal Sll and a negative phase signal S12, which have equal levels and opposite polarities, as shown in FIG. The signal is then transmitted to the receiver 42 through two twisted electric wires C1l and 012. Then, it is returned to the υ unbalanced signal by the receiver 42 and the output 4
3 and is supplied to a predetermined input of the control device.

On the other hand, regarding the noise caused by the electric wires C11 and C12 in the transmission path from the driver 41 to the receiver 42,
As a result of these electric wires C11 and CI2 being twisted together, the noises are in phase with each other and are all at the same level, as shown by noises N11° and N12 in FIG. Therefore, the noise Nll riding on these electric wires C1l and the electric wire C
Neu on the 12 <N12. ! : When the signals are unbalanced by the receiver 42, they cancel each other out, so that they do not appear at all in the output 43.

Therefore, according to this system, the rigid noise characteristics can be sufficiently improved due to the maze shielding effect by the shield C13 and the noise canceling effect by the balanced transmission method.

By the way, in the above embodiment, the curl cord part 23 is entirely provided between the turning table 2, which is the movable part of the manipulator mechanism, and the fixed pace l, which is the fixed part of the manipulator mechanism,
This ensures movement between the movable part and the fixed part and enables reliable electrical connection. As shown, a sheath material S is used that is filled with a large number of core wires C1 to C4 so that no voids are formed. Therefore,
According to this embodiment, when a part of the cape/L-22 is used as the curl cord part 23, local stress concentration can be prevented from occurring in this part, and as a result, the curl cord part 23 can be prevented from being locally concentrated.
3, there is no risk of buckling, and a long life can be expected.

Although only one cable 22 is shown in FIG. 2, it goes without saying that a plurality of cables are actually required as shown in FIG. As for the application of the present invention, it goes without saying that it is sufficient to discuss only the transmission system for signals such as detection signals where noise interference is a problem.

As explained above, according to the present invention, it is possible to provide sufficient noise resistance to an industrial robot having a signal transmission cable between the movable part and the fixed part of the manipulator mechanism. It is possible to provide an industrial robot that can always be expected to operate reliably under any environment, excluding its shortcomings.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of an industrial robot having an electrical connection between a movable part and a fixed part of a manipulator mechanism, and FIG. 2 is a cross-sectional view showing an example of an industrial robot according to the present invention. Similarly, FIG. 3 is a sectional view showing an embodiment of the cable, FIG. 4 is a block diagram showing an example of a balanced transmission system, and FIG. 5 is a waveform diagram for explaining the operation. 1... Fixed pace, 2... Swivel table, 22... Cable, 23... Curl cord section, 24... Internal connection section , 25...
...Upper clamp, 26...Lower clamp, 27
... Connection plug, Cl-C4 ... Core wire of cape''' A/22, C11 ... First insulated wire, C12 ... Second Insulated wire, C13...
...Shield outer covering. Figure 1 Figure 3 Figure 2

Claims (1)

[Claims] 1. In an industrial robot having an electrical connection between a fixed part and a movable part of a manipulator mechanism, a curl cord having a plurality of shielded wires as a core wire is provided in the electrical connection part. 02, an industrial robot characterized in that the plurality of shielded wires are constructed of two-core shielded wires having a two-stranded insulated wire as a core wire. An industrial robot characterized in that the above-mentioned curl cord is constituted by a cable in which shielded wires are twisted together and filled with a sheath material so that no spaces are formed inside including between the shielded wires. 3. The industrial robot according to claim 1 or 2, characterized in that a transmission line of a balance transmission system is constructed by the core wire of the shielded wire.