JPS6052916B2 - Electric hand finger rotation device - Google Patents

Description

[Detailed description of the invention] An electric hand used for automatically attaching and detaching a workpiece such as a round bar to a processing machine has a finger at the tip that grips the workpiece in order to, for example, turn the workpiece over. It is desirable to be able to pivot the part at a constant angle.

The present invention relates to a finger rotation device for an electric hand that has a simple structure and can achieve positional accuracy when stopped.

A conventional example of a finger rotation device for an electric hand will be described with reference to FIG.

This figure shows an electric hand, in which a pair of fingers 3 that grip a workpiece 2 such as a round bar are attached to a finger case 1 that is rotatably provided at the lower end so that they can be opened and closed by operating an electric motor 4. . Said finger case 1
is rotatably supported by attaching a cylindrical pivot shaft 5 fixedly attached to the upper surface of the electric motor 4 via a bearing 6 to a cylindrical fixed part 7 surrounding the lower end of the operating shaft 4a of the electric motor 4. A cam 10 is fitted on the outer periphery of the pivot shaft 5 to engage with and operate a large gear Ba of the spur gear reduction mechanism 8 and a limit switch 9 for detecting the pivot angle of the pivot shaft 5. The large gear Ba is engaged with a small gear 8b fitted on the outer periphery of a drive shaft 11, and the drive shaft 11 is driven by an electric motor 12 via a round bar-shaped connecting shaft 13. The pinion 8b is pressed in the axial direction against a flange 11a integrally formed on the outer periphery of the drive shaft 11 by a spring 14 made up of a plurality of overlapping bellows springs, and the torque applied to the pinion 8 is lower than a certain value. It is frictionally bonded so that it can slide on the pressing surface. An electromagnetic brake 15 is provided at the lower end of the moving shaft 11,
The drive shaft 11 is braked when the finger portion completes turning, and the drive shaft 11 is held so as not to move after it has stopped. A fixed case 16 that surrounds the upper end of the outer periphery of the finger case 1 and the gear reduction mechanism 8, etc.
Stoppers 1a and 16a are provided on the lower surface of the finger case 1 to restrict the rotation angle of the finger case 1 by engaging with each other.
The finger portion rotating device is driven by an electric motor 12, and the limit switch 9 is actuated by the cam 10 just before the stoppers 1a and 16a come into contact with each other.
At the same time, the electromagnetic brake 15 is activated to perform a braking action on the drive shaft 11. After the stoppers 1a and 16a come into contact with each other due to coasting due to the inertia of the electric motor 12, they slide on the pressing surfaces of the drive shaft 11, the spring 14, and the small gear 8b to alleviate the impact of the stoppers 1a and 16a, and the drive shaft after stopping 11 is held by an electromagnetic brake 15 to prevent it from moving. Since such a structure uses a spring 14 and an electromagnetic brake 15, it is not only complicated and expensive, but also has no effect on pressing the stopper 1a against the stopper 16a, which reduces the positional accuracy of the finger when it is stopped. The drawback was that it could not be released.

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned drawbacks, it is an object of the present invention to provide a finger rotation device for an electric hand that has a simple structure and can achieve positional accuracy when stopped.

In order to achieve the above-mentioned object, this invention has a rotating shaft that is fixedly attached to a finger case provided with a stopper that regulates the rotating angle, and that is equipped with a detection mechanism that detects the rotating angle and controls to cut off the electric motor power supply. The connected gear reduction mechanism is configured to be driven by an electric motor with a worm gear reduction gear via a torsion bar that acts as a spring in the torsional direction.

Embodiments of the present invention will be described below based on the drawings.

FIG. 2 shows an electric hand using the finger rotation device according to the present invention, and the same parts as in FIG. 1 are denoted by the same reference numerals. In this figure. The electric hand that can be
The finger case 1 at the lower end is rotatably supported by attaching a cylindrical pivot shaft 5 fixedly attached to the upper surface to a cylindrical fixed part 7 via a bearing 6. A large gear 8a of a spur gear reduction mechanism 8 and a rotating shaft are disposed on the outer periphery of the rotating shaft 5. A cam 10 that engages with and operates a limit switch 9 that detects the rotation angle of the shaft 5 is fitted. The large gear 8a is a small gear 8 fitted on the outer periphery of the drive shaft 21.
b, and the drive shaft 21 is driven by an electric motor 22 with a worm gear reducer via a torsion bar 23. Said torsion bar 2
3 is formed into a rod shape with a rectangular cross section in the center, and the small gear 8
When a torque above a certain value is applied to b, it is twisted at the center,
Moreover, it is designed to be able to perform a spring action in the torsional direction. Stoppers 1a and 16a that engage with each other to regulate the rotation angle of the finger case 1 are provided on the upper outer peripheral end of the finger case 1 and the lower surface of the fixed case 16 that surrounds the gear reduction mechanism 8 and the like. According to the embodiment, the finger rotation device driven by the electric motor 22 operates the detection mechanism 24 consisting of the limit switch 9 and the cam 10 immediately before the stoppers 1a and 16a come into contact with each other to cut off the power supply circuit of the electric motor 22. By coasting due to the inertia of the electric motor 22, the stoppers 1a and 16a are brought into contact and stopped.

After the stoppers 1a and 16a come into contact with each other, the electric motor 22
The inertial energy until it stops is the torsion bar 23
is absorbed by twisting the stopper 1.
The impact on a and 16a can be alleviated. Furthermore, since the worm gear reducer can self-hold so that it cannot be reversely rotated from the output side, the finger case 1 can be held by pressing the stopper 1a against the stopper 16a by the spring action of the torsion bar 23. The pressing force of the stoppers 1a and 16a can be increased by activating the detection mechanism 24 after contact and adjusting the power circuit of the electric motor 22 to be cut off. As described above, according to the present invention, the rotation device of the finger portion of the electric hand, which is equipped with a stopper that regulates the rotation angle and a detection mechanism that detects the rotation angle, is connected to the worm gear via the torsion bar that exerts a spring action in the torsion direction. Since it is configured to be driven by an electric motor with a speed reducer, by pressing the stopper, it is possible to achieve and maintain the position accuracy of the finger part when it is stopped, and also eliminates the need for the electromagnetic brake etc. explained in the conventional example. The advantage is that the structure can be simple and inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing an electric hand using a conventional finger rotating device, and FIG. 2 is a vertical cross-sectional view showing an electric hand using a finger rotating device according to the present invention. DESCRIPTION OF SYMBOLS 1... Finger case, 1a, 16a... Stopper, 5... Rotating shaft, 8... Gear reduction mechanism, 22...
...Electric motor, 23... Torsion bar, 24... Detection mechanism.

Claims (1)

[Claims] 1. A pivot shaft fixedly attached to a finger case rotatably provided at the tip of an electric hand, an electric drive mechanism connected to the pivot shaft and driven by an electric motor, and a rotating angle of the pivot shaft that detects the rotation angle of the pivot shaft to drive the electric motor. A finger section rotating device comprising a detection mechanism for controlling power cutoff and a stopper for regulating the rotation angle of the finger case, a worm gear reducer connected to the output side of the electric motor, and a worm gear reducer connected to the output side of the motor; 1. A finger section turning device for an electric hand, characterized in that a torsion bar is provided which is connected and performs a spring action in a torsional direction, and the output of the reducer is coupled to the turning shaft via the torsion bar.