JPS5877467A - Driving mechanism of robot arm - 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 a robot arm drive mechanism.

An example of a conventional arm drive mechanism for a robot has a structure as shown in FIG. This transmits the rotation of the motor 1 to the forearm 4 via the crank 2 and the link 5,
This is a configuration for driving the forearm 4. In the above configuration, the second
Figure (ω, (b).

As shown in the operating principle diagrams of the arm drive mechanism in (C) and (d), the force y that drives the arm 4 increases as the forearm 4 rotates, that is, as the range of movement increases. Decrease. When the output of the motor 1 is F and the rotation angle of the forearm 4 is - (# is equal to the pressure angle of the arm driving force), the arm driving force F' becomes F'÷p - case.

0: When the angle is 90°, the driving force of the forearm 4 becomes F'=0,
Forearm 4 no longer works. As mentioned above, in the arm drive mechanism using - number of cranks and links, if the range of motion of the forearm 4 is increased, the pressure angle of the arm drive force also increases, and the arm drive force decreases relative to the output of the motor. , when the rotation angle of arm 4 increases, K means that the load on the motor increases. As mentioned above, the arm drive mechanism using two cranks and links has some problems regarding the load on the motor and the range of movement of the arm.

This invention was made in view of these conventional problems, and the output of the motor is transmitted through two sets of cranks, that is, double cranks, having a phase difference of 90 degrees. The purpose of this invention is to solve the above problems by expanding the movable range of the arm of the robot and reducing the load on the motor by using a drive mechanism that converts the arm into a driving force.

The present invention will be explained below based on the drawings.

FIGS. 5 to 5 are a longitudinal sectional view showing the structure of an embodiment of the present invention, a sectional view taken along line A-A in FIG. S, and a sectional view taken along line B-B in FIG. , the same or equivalent items are given the same reference numerals. Rotation of motor 1 is 90°
A double crank 2-1 and two links sa and sb having a phase difference of , and an intermediate double crank 2-3,
It is transmitted to the forearm 4/ through the links 5e and 5f, causing the forearm 4' to rotate about the axis 5. The rotation of another motor 1', which is provided symmetrically with the motor 1, is also K 9 as described above.
It is transmitted to the upper arm 6 via the double crank 2-2 having a phase difference of 0° and the two links 5c, 5d, and rotates the upper arm 6 about the axis 7. In addition, the upper arm ゛6
The reason why an arm drive shaft is not provided on the arc length of the rotating shaft 7 is to provide a fee drive shaft (not shown) in that part. For links sa and sb, link 5a is link 5b.
It is installed at different levels in order to increase the range of movement, so that it can overcome the problem.

Further, the forearm 4 can maintain a constant posture regardless of the position of the upper arm 6 by a parallelogram link mechanism composed of the upper arm 6, the intermediate crank 2-2, and links 5e and 5f. In addition, the drive motor 111' of each arm is
In order to reduce the weight of the arm, it is installed independently from the arm.

As mentioned above, if an arm drive mechanism with a double crank and link having a phase difference of 90c' is used, the sixth
As shown in the operating principle diagrams of one embodiment of the robot arm mechanism according to the present invention in Figures (a), (b), (C), and (d), the pressure angle 0 of the arm driving force F' is θ = 45.
It cannot be greater than °. In other words, Fig. 6(a) K
yp-suyo K, since the crank is double installed,
As one pressure angle increases, the other pressure angle decreases, and when both are equal, the pressure angle is maximum. At that time, the pressure angle θ is 45°, and the arm driving force F””Fcosθ
≧F cos 45°.

As explained above, if an arm drive mechanism with double cranks and links with a 90° phase difference is used, even if the rotation angle of the arm increases, that is, the range of movement can be increased. is never larger than 45°, and the effect is that the load on the drive motor can be reduced. Further, the five effects of the present invention are that the operating range of the robot's arm can be expanded, and the performance and efficiency of the robot can be improved.

[Brief explanation of drawings]

FIG. 1 is a side view showing the configuration of a conventional robot arm drive mechanism, FIG. 2 is a diagram showing the operating principle of the conventional robot arm drive mechanism, and FIG. 5 is a diagram showing the operating principle of the conventional robot arm drive mechanism. FIG. 4 is a longitudinal sectional view showing the configuration of an embodiment of the present invention.
FIG. 3 is a cross-sectional view taken from a human side, FIG. 5 is a sectional view taken along the line B--B in FIG. Explanation of symbols 1.1'...Motor 2...Crank 2-
1.2-2... Double crank 2-3... Intermediate double crank 5a, 5b, 5c, sct, se, 5f-Link 4... Forearm 5, 7... Axis 6... Upper arm 2 goods ((1> (0) 23 Figure 1'4 Figure 1'4 Figure 5 Calm 4 Year 6I21 ζρ) (C)

Claims (1)

[Claims] A robot arm drive mechanism characterized in that the rotational input of a drive motor is transmitted to the arm by a double crank having a phase difference, the link and k, and the rotational output of the motor is given to the arm.