JPS6122793Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a gripping device whose gripping force can be adjusted depending on the workpiece.

Conventional workpiece gripping devices use a pressure fluid or a spring as a drive source for opening and closing the claws, and apply the force directly to the claws. Therefore, the gripping force is constant regardless of the workpiece, and the gripping force may be deformed depending on the workpiece, or the gripping force may be insufficient.

The present invention solves the above-mentioned drawbacks, and aims to make it possible to adjust the gripping force and to always grip the workpiece with the optimum force depending on the workpiece. Therefore, a differential gear mechanism is interposed between the drive source and the workpiece gripping claw opening/closing mechanism, and when the workpiece is gripped by the claws and the gripping force exceeds a predetermined value, the differential gear mechanism is activated. The support body supporting the intermediate bevel gear is rotated to prevent rotation from the drive source from being transmitted to the pawls.

The implementation of the present invention will be explained below based on the drawings. Reference numeral 1 denotes a main body of the gripping device, 2 a drive source placed on a holder 3 attached to the upper part of the main body 1, and 4 a bevel gear attached to an output shaft 5 of the drive source 2. Bevel gears 6 and 6' mesh with the bevel gear 4, and are disposed facing each other with their axes aligned. 7 is a horizontal intermediate shaft supporting these two bevel gears 6, 6', and has a vertical through hole 8 bored in the center thereof. Reference numeral 9 denotes a ring-shaped support body which is rotatably mounted between the main body 1 and the holder 3 with its axis aligned with the output shaft 5, and supports both ends of the intermediate shaft 7. . 10 has a worm 11 at one end, passes through the through hole 8 of the intermediate shaft 7, and connects the output shaft 5 perpendicularly to the main body 1 and the bevel gear 5.
a worm shaft supported with its axis aligned with the worm shaft, 12
is a bevel gear attached to this worm shaft 10,
It meshes with the two bevel gears 6 and 6' at the same time. And the bevel gear 4, the two bevel gears 6,
6', intermediate shaft 7, ring-shaped support 9, bevel gear 12
A differential gear mechanism is constructed by the following. 13,
A worm wheel 13' meshes with the worm 11 and is supported on the main body 1 symmetrically with respect to the axis of the worm shaft 10. Reference numerals 14 and 14' denote a pair of claws fixed to the respective shaft portions 15 and 15' of the worm wheels 13 and 13', which are opened and closed as the worm wheels 13 and 13' rotate. 16 indicates the rotation of the ring-shaped support 9;
A means of stopping within a range of regulated force,
A steel ball 17 is pressed against the outer periphery of the ring-shaped support 9 by a spring 18. And this pressing force is the screw 19
Adjustment is possible by 20 is an appropriate number of grooves carved in the radial direction on the upper surface of the ring-shaped support 9;
Reference numeral 21 denotes a pin that is pressed against the upper surface of the ring-shaped support 9 by a spring 22, and its rear end 23 protrudes upward, so that when the ring-shaped support 9 rotates, the groove 20 matches the position of the pin 21. When the pin 21 is in the groove 2
0, the rear end 23 actuates the limit switch 24.

Next, the effect will be explained. It is assumed that the claws 14, 14' are in an open state and the pin 21 has not fallen into the groove 20. It is also assumed that the rotation preventing means 16 is adjusted to have a force suitable for the workpiece to be gripped. When the drive source 2 is rotated by a command, the ring-shaped support 9 is stopped from rotating by an appropriate pressing force, so each bevel gear rotates and the worm shaft 10 is rotated. Therefore, the pair of worm wheels 13, 13' are rotated and the claw 1
4, 14' are closed to grip the workpiece. By this gripping, the worm 11, the worm wheel 1
3 and 13' stop rotating. When a gripping force of a predetermined value or more is applied to the workpiece due to continuous rotation of the drive source 2, the worm 11 and the worm wheel 1
3 and 13' have stopped rotating, so the bevel gear 12
Therefore, due to the action of the differential gear mechanism, the two bevel gears 6,
6' and the ring-shaped support 9 rotate about the axis of the worm shaft 10. In other words, the two bevel gears 6 and 6' rotate and revolve around their own axis. When the groove 20 coincides with the position of the pin 21 due to the rotation of the ring-shaped support 9, the pin 21 falls into the groove 20 and the limit switch 24 is activated, and the rotation of the drive source 2 is stopped by the signal from the limit switch 24.

As detailed above, according to the present invention, a differential gear mechanism is interposed between the drive source and the opening/closing mechanism of the workpiece gripping claws, so that when the workpiece is gripped by the claws, the gripping force is constant. If the value exceeds this value, the differential gear mechanism will work to prevent excessive force from being applied to the workpiece. Furthermore, since the force that prevents the action of the differential gear mechanism can be adjusted, the workpiece can always be gripped with the optimum gripping force.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view taken from FIG. 1. 2... Drive source, 4... Bevel gear, 6, 6'... Bevel gear, 7... Intermediate shaft, 9... Ring-shaped support, 1
0... Worm axis, 11... Worm, 12...
Bevel gear, 13, 13'... Worm wheel, 1
4, 14'...Claw, 16...Rotation blocking means, 24
...Limit switch.

Claims (1)

[Scope of utility model registration request] A gripping device that grips a workpiece by transmitting rotational force to open and close a pair of claws using an irreversible mechanism, the gripping device comprising: a differential gear mechanism interposed between a rotational drive source and the irreversible mechanism; a force-adjustable rotation prevention means for inhibiting rotation of an intermediate gear support of a differential gear mechanism; and a rotation prevention means that is actuated when the intermediate gear support rotates against the force of the rotation prevention means to prevent the rotational drive source from rotating. a limit switch that issues a rotation stop signal, and when the pair of claws grips the workpiece and a gripping force of a certain value or more is applied, the intermediate gear support rotates against the force of the blocking means, and A gripping device characterized by interrupting rotational transmission of a rotational drive source.