JPH0637877Y2 - Rotary indexing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary indexing device, and more particularly to a rotary indexing device that allows rotation of a work when an external force is applied to the work.

2. Description of the Related Art A rotary indexing device that grips a work and indexes it at a predetermined rotational position is often used when positioning the work in an automatic processing machine, an assembly device, or the like. Further, such a rotary indexing device generally comprises a gripping device that is rotatably provided around a center line of a work and grips the work, and a rotation drive device that rotationally drives the gripping device around the center line. The work is gripped by the gripping device, and the gripping device is rotationally driven by the rotary drive device.

By the way, since the gripping device and the rotary drive device are usually always connected, for example, in order to position the rotational position of the indexed work with higher accuracy, a different operation from the rotary indexing device is performed. When the work is driven to rotate further by the means, relative rotation occurs between the gripping device and the work to scratch the work, or the work is damaged when the relative rotation does not occur. Therefore, in such a case, an electromagnetic clutch or the like is provided between the gripping device and the rotary drive device, and the gripping device and the rotary drive device are disconnected as necessary to disconnect the gripping device. A rotary indexing device is used that allows rotation of the workpiece with the workpiece.

However, such a rotary indexing device is not only complicated and large-scaled, but also requires a series of cycle times because it is necessary to control the operation of an actuator for switching a clutch or the like. There was a problem such as becoming.

The present invention has been made in view of the above circumstances. The purpose of the present invention is that the gripping device can be used when an external force is applied to a work without requiring switching control such as a clutch. It is to be able to rotate with the work.

Means for Solving the Problems In order to achieve such an object, the present invention is a rotary indexing device for gripping a work and indexing it at a predetermined rotational position, comprising: (a) a centerline of the work. A gripping device that is rotatably provided and that grips the workpiece, (b)
The gripping device is provided so as to be rotatable relative to the centerline, and is rotated about the centerline, and (c) is interposed between the rotary member and the gripping device, and is always The gripping device is rotated together with the rotating member by the frictional force, but when a rotating force is applied to the workpiece gripped by the gripping device from the outside, the gripping device acts on the rotating member against the frictional force. And a friction member that permits relative rotation with respect to each other.

In such a rotary indexing device, the gripping device is normally rotated integrally with the rotating member by the frictional force of the friction member, and the workpiece gripped by the gripping device is predetermined. When an external force is applied to the workpiece gripped by the gripping device while being indexed to the rotation position, the gripping device is rotated relative to the rotating member against the frictional force of the friction member, so that the gripping device grips the workpiece. The relative rotation between the device and the work is prevented, and thus the work is prevented from being scratched or damaged.

Here, the rotary indexing device of the present invention allows the relative rotation of the work when an external force is applied to the work only by interposing a friction member between the rotary member and the gripping device. Therefore, as compared with the case where a clutch or the like is provided, the device can be configured simpler, cheaper, and more compact, and switching control is unnecessary, so that a series of cycle times can be shortened.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a front view of a work positioning device for positioning a work in an axial direction and a rotation direction. A rotary indexing device 12 and a positioning device 14 are arranged on a base 10 so as to face each other. . Further, between them, a pair of receiving members 18 on which the work 16 is placed and a carry-out device 20 for carrying out the positioned work 16 are provided. The work 16 has a columnar shape, and has a small diameter portion 22 at the right end and a flat arc portion 24 at the left end. Then, the work 16 is rotatably supplied around the center line on the pair of receiving members 18 in a state where the rotation position around the center line is unknown by a manual operation of an operator or a supply device (not shown).

The rotary indexing device 12 has a guide rail on the base 10.
Base member movably in the left-right direction via 26
It is arranged on 28. The base member 28 is urged to the left by an urging means (not shown), and is always held at the left end position where it abuts a stopper (not shown). Further, as is apparent from the sectional view of FIG. 2, on the base member 28, four bearings 30, 32, 34, on the extension line of the center line of the work 16 supplied on the receiving member 18. A spindle 38 is arranged via a shaft 36 so as to be rotatable about the axis and immovable in the axial direction.

The tip end of the spindle 38 is divided into two forks, and a pair of turning arms 42a, 42b are provided so as to be rotatable around pins 40a, 40b that are perpendicular to a plane including the axis thereof. Swivel arm 42
a and 42b are L-shaped, and a clamp claw 44 is provided at one end thereof.
While a and 44b are rotatably attached, a notch is formed at the other end to engage with a pin 48 provided at the tip of drawbar 46. The draw bar 46 is inserted through the inside of the spindle 38 so as to be movable in the axial direction, and a rear end portion thereof is connected via a thrust bearing 50 so as to be relatively immovable in the axial direction and relatively rotatable about the axis. Is provided. This connector 52 is a base member 28.
The rotation around the shaft center is disabled by the engagement with the pin 54 that is erected on the shaft 54 and is screwed to the output rod 58 of the drive cylinder 56. The drive cylinder 56 is arranged on a plate 60 fixedly mounted on the base member 28.

When the output rod 58 of the drive cylinder 56 is pulled in and the draw bar 46 is retracted to the right in the figure, the pair of rotating arms 42a and 42b are symmetrically rotated, and the clamp claws 44a and 44b are used. The small diameter portion 22 of the work 16 is gripped. 1 and 2 are views showing this state. Further, when the output rod 58 is projected and the draw bar 46 is advanced to the left in the figure, the rotating arms 42a and 42b are rotated in the opposite directions to each other, as shown in FIG. Then, the clamped state by the clamp claws 44a and 44b is released. In this embodiment, a gripping device 62 for gripping the work 16 is configured including the spindle 38, the rotating arms 42a and 42b, the draw bar 46, the drive cylinder 56 and the like.

On the other hand, a ring-shaped rotary member 68 is provided at the rear end of the spindle 38 so as to be relatively rotatable via a pair of bearings 64, 66. A pair of annular grooves are formed on the inner peripheral surface of the rotating member 68, that is, the surface facing the outer peripheral surface of the spindle 38 with a slight gap, and O-rings 70 and 72 are fitted therein. These O-rings 70, 72 form a friction member, and are elastically deformed by the outer peripheral surface of the spindle 38. The friction force based on the elastic force always causes the spindle 38 and the rotating member 68 to be integrally formed. Although they are rotated, when an external force of a predetermined level or more is applied in the direction in which they are relatively rotated, the relative rotation is allowed. The external force above a certain level is a force smaller than the force that causes relative rotation between the work 16 gripped by the gripping device 62 and the gripping device 62, and more specifically, the external force is applied to the work 16. Before the relative rotation between the work 16 and the gripping device 62 when added, the spindle 38 and the rotating member 68 are added.
It is set to a size where relative rotation occurs between and.

A gear 74 is fixed to the rotating member 68.
The gear 74 is meshed with a gear 78 fixed to the output shaft of the motor with reduction gear 76. The rotary member 68 is rotated at a slow speed by the motor with reduction gear 76, and the spindle 16 and the work 16 gripped by the gripping device 62 are slowly rotated around the center line accordingly. It should be noted that the rotational force is not transmitted from the rotating member 68 side to the reducer-equipped motor 76 side, and even if the rotational force is externally applied to the rotating member 68 when the reducer-equipped motor 76 is stopped, the rotating member 68 is It does not rotate. Further, the motor with reduction gear 76 is arranged on a plate 79 fixed to the base member 28.

Returning to FIG. 1, the positioning device 14 includes an axial positioning portion 80 for axially positioning the work 16 and a work 16.
Rotation direction positioning part 82 for positioning around the center line of
It has and. The axial positioning part 80 is a drive cylinder.
The positioning rod 86 is projected rightward in the drawing by 84, and the positioning rod 86 abuts on the circular arc portion 24 of the work 16 to move the work 16 to a predetermined position. At this time, the rotary indexing device 12 holding the work 16 is moved to the right against the biasing force of the biasing means while holding the work 16.

Further, the axial positioning portion 80 has a positioning rod 86.
In the state where is contacted with the arc portion 24 of the work 16,
A proximity switch 88 is arranged so as to be located right above the arc portion 24. This proximity switch 88
As shown in FIG. 1, 24 outputs an output signal when positioned up and down.
The reducer-equipped motor 76 is controlled based on the output signal of the proximity switch 88 so as to stop the rotation of the work 16 at the rotation position where the circular arc portion 24 of the work 16 moves up and down. This position corresponds to a predetermined rotational position.

The rotation direction positioning portion 82 is provided with a pair of positioning arms 90a and 90b which are brought into contact with both side surfaces of the arc portion 24, as is apparent from FIG. 4 showing the IV-IV cross section of FIG. . These positioning arms 90a, 90b are rotatably arranged around their axes through pins 92a, 92b parallel to the center line of the work 16, and are pinion 96a meshed with the rack 94. 96b are fixed respectively.
The rack 94 is vertically driven by a drive cylinder 98, whereby the positioning arms 90a and 90b are symmetrically rotated around the pins 92a and 92b, and the work 16
The work 16 is accurately positioned at a rotational position in which the circular arc portion 24 is vertically pressed by clamping the circular arc portion 24 from both sides.

Next, the operation of this embodiment will be described.

When the work 16 is supplied onto the receiving member 18, first, the drive cylinder 56 of the gripping device 62 is operated and the draw bar 46 is retracted, whereby the pair of clamp claws 44a and 44b.
Thus, the small diameter portion 22 of the work 16 is gripped. Subsequently, the drive cylinder 84 of the axial positioning unit 80 is operated and the positioning rod 86 is projected, whereby the work 16 is axially positioned.

In that state, the rotary member 68 is driven by the motor 76 with a reducer.
Is slowly rotated, the spindle 38 and further the work 16 are slowly rotated around the center line by the frictional force of the O-rings 70, 72, and the arc switch 24 is moved by the proximity switch 88.
The work 16 is held at the rotational position where is detected. As a result, the work 16 is indexed to the rotational position where the arcuate portion 24 is located substantially up and down, but this is not always accurate and includes an error within a predetermined angular range about the center line.

After that, the drive cylinder 98 of the rotational direction positioning portion 82 is driven to move the rack 94 downward, so that the pair of positioning arms 90a and 90b are pressed against both side surfaces of the arc portion 24 of the work 16. Since the work 16 is preliminarily indexed to the rotational position where the circular arc portion 24 is substantially vertical as described above, the positioning arms 90a and 90b are surely pressed against both side surfaces of the circular arc portion 24, and the workpiece 16 is 24 is positioned in the exact up and down rotational position.

At this time, the work 16 is slightly rotated around its center line, but the spindle 38 of the gripping device 62 that grips the work 16 does not rotate before the relative rotation occurs between the work 16 and the gripping device 62. , O-rings 70, 72 are rotated relative to the rotating member 68 against the frictional force. Therefore, the gripping device
62 holds the work 16 and is rotated together with the work 16.

When the work 16 is thus axially and rotationally positioned, the unloading device 20 clamps the work 16 immovably in the axial and rotational directions. In that state, the drive cylinder 56 causes the clamp claws 44a, 44b to
The work 16 is released from the clamped state by
The driving cylinder 84 retracts the positioning rod 86 to the left in FIG. 1, and the driving cylinder 98 releases the pinched state of the circular arc portion 24 by the positioning arms 90a and 90b. Then, the work 16 is unloaded by the unloading device 20,
It is supplied to an unillustrated automatic processing machine, assembling device, etc. in a predetermined fixed posture.

Here, in the rotary indexing device 12 of the present embodiment, when the work 16 is positioned by the positioning arms 90a and 90b of the rotation direction positioning portion 82, the gripping device 62 that grips the work 16 is rotated together with the work 16. Because it looks like
The small-diameter portion 22 gripped by the clamp claws 44a, 44b and the circular arc portion 24 pinched by the positioning arms 90a, 90b are not scratched or damaged by excessive force.

Moreover, the rotation of the gripping device 62 is allowed by the slip between the O-rings 70 and 72 provided on the inner peripheral surface of the rotating member 68 and the outer peripheral surface of the spindle 38, so that the clutch or the like can be opened. Compared to the conventional device that allows relative rotation of these devices as needed, the device is simpler, cheaper, and more compact, and switching control is unnecessary, reducing the series cycle time. It is.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, in the above embodiment, a pair of O-rings are used as the friction member.
Although 70 and 72 are used, a friction plate or the like provided on the inner peripheral portion of the rotating member 68 so as not to rotate relative to each other may be pressed against the outer peripheral surface of the spindle 38 by a disc spring, a compression coil spring, or the like. Various other friction members can be adopted, such as using a pair of elastically deformable rings provided with small unevenness and engaged with each other.

Further, it goes without saying that the number of the O-rings can be changed and the O-rings can be embedded in the outer peripheral surface of the spindle 38.

Further, the gripping device 62 of the above embodiment is configured to grip the work 16 by rotating the rotating arms 42a and 42b, but a gripping device using various other mechanisms such as a cam mechanism may be used. Can be adopted.

Further, in the above embodiment, the work 16 is rotated after indexing in order to accurately position the work 16, but when the work 16 is rotated after indexing for other reasons, The rotary indexing device 12 can be used as well.

Although not illustrated one by one, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a work positioning device having a rotary indexing device according to an embodiment of the present invention. FIG. 2 is a sectional view of the rotary indexing device in FIG. FIG. 3 is a sectional view showing a state where the clamp claw of the rotary indexing device of FIG. 2 is opened. FIG. 4 is a sectional view taken along the line IV-IV in FIG. 12: rotary indexing device, 16: work 62: gripping device, 68: rotating member 70, 72: O-ring (friction member)

Claims (1)

[Scope of utility model registration request] 1. A rotary indexing device for gripping a work and indexing it to a predetermined rotational position, the gripping device being rotatably provided around a center line of the work and gripping the work, and the gripping device. The device is provided so as to be rotatable relative to the center line and is driven to rotate about the center line, and is interposed between the rotating member and the gripping device, and the gripping device is always provided by frictional force. The device is rotated together with the rotating member, and when a rotating force is applied to the work held by the holding device from the outside, the holding device rotates relative to the rotating member against the frictional force. And a friction member that allows the rotation indexing device.