JPH06344244A - Indexing device - Google Patents

Abstract

PURPOSE:To position an index table without any backlash with good accuracy during its stop and to increase the backlash during its rotation so as to rotate the index table with a small driving force. CONSTITUTION:An input shaft 6, a worm shaft 21 and an index table 5 are supported on a main body 2. A driving adapter 4 is installed on a main shaft 3, and with clutches 8, 9 connected to each other, the input shaft 6 and the worm shaft 21 are rotated in one body to rotate the index table 5 through a worm 7 and a worm wheel 11. The worm 7 is formed by axially dividing a worm into two parts, and a movable worm element 40 is moved to approach to and separate from a fixed worm element 39 by a parallel key 23. In the condition of both elements 39, 40 approaching each other, the tooth flank of the worm wheel 11 is brought in pressure contact with the fixed worm element 39, and in the condition of both elements separated from each other, a backlash is generated between the tooth flank of the work wheel 11 and the fixed worm element 39.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indexing device used in a machine tool such as a machining center, and more specifically, an indexing device for indexing and rotating an indexing table via a worm mechanism by a drive adapter mounted on a spindle. It is about.

[0002]

2. Description of the Related Art Generally, in this type of indexing device,
In order to accurately index the indexing table, it is necessary to reduce the backlash of the worm mechanism. As a conventional technique focusing on this necessity, for example, a double lead worm is adopted, a worm is divided into left and right parts so that the teeth of the worm wheel are approached to both sides, and a worm wheel is changed from a direction orthogonal to the axis to a worm wheel. Known are those that are pressed (Japanese Patent Publication No. 4-36823), those that press worms arranged on two orthogonal axes on the left and right tooth surfaces of a worm wheel (Japanese Patent Laid-Open No. 58-171229).

[0003]

However, according to the prior art, in any case, since the worm rotates the indexing table in a state in which the worm is in close contact with the tooth surface of the worm wheel so that the backlash is small, Not only was the rotation load increased and the parts on the drive source side increased in size, but it was also necessary to use high-precision worms and worm wheels to prevent galling during rotation.

Therefore, the object of the present invention is to eliminate the backlash when the indexing is stopped and to position the indexing table with high accuracy, and to increase the backlash during the indexing rotation to facilitate the indexing table with a small driving force. It is to provide an indexing device that can be rotated.

[0005]

In order to solve the above-mentioned problems, the present invention comprises a main body installed on a machining table of a machine tool and a drive adapter detachably mounted on a spindle of the machine tool. The main body supports an indexing table and an input shaft, and a worm and a worm wheel for rotation transmission are interposed between the input shaft and the indexing table, and a drive adapter is connected to the input shaft. In an indexing device for rotating an indexing table through a worm and a worm wheel by rotating an input shaft with rotation, the input shaft is movably supported in the axial direction, and a drive adapter is supported by a spring means. The worm is biased to the side and the worm is divided into two in the axial direction to be composed of a fixed worm element and a movable worm element, and the movable worm element is fixed as the input shaft moves. Provided with an interlocking member that moves toward and away from the child, the tooth surface of the worm wheel presses against the fixed worm element when both worm elements are approaching, and the tooth surface of the worm wheel and the fixed worm element when both worm elements are separated. Is configured to cause backlash between.

[0006]

In the indexing device of the present invention, when the indexing table is stopped, the interlocking member moves the movable worm element toward the fixed worm element, and the movable worm element presses the tooth surface of the worm wheel against the fixed worm element. . For this reason,
Backlash between the worm and the worm wheel is removed, and the indexing table is accurately positioned at the indexing position. When the indexing table rotates, the interlocking member moves the movable worm element away from the fixed worm element, and backlash occurs between the tooth surface of the worm wheel and the fixed worm element. Therefore, the rotational load of the input shaft is reduced, and the indexing table can be rotated with a relatively small driving force,
If necessary, the rotation phase of the index table can be easily corrected.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, the overall configuration will be outlined. As shown in FIG. 1, the indexing device of the present embodiment includes a main body 2 installed on a machining table 1 in a machine tool such as a machining center and a spindle 3 of the machine tool. The drive adapter 4 is detachably mounted. As the processing table 1, not only the integrated table installed on the bed of the machine tool but also a pallet that is placed on the bed in a replaceable manner can be used.

An indexing table 5 for indexing a work (not shown) to a processing position and an input shaft 6 driven by a main shaft 3 via a drive adapter 4 are rotatably supported on the main body 2. A worm 7 and a worm wheel 11 for transmitting rotation are provided between the input shaft 6 and the indexing table 5. The drive adapter 4 is provided with a drive clutch 8 and the input shaft 6 is provided with an input clutch 9, and the input shaft 6 is rotated by the drive adapter 4 in accordance with the rotation of the main shaft 3 when the both clutches 8 and 9 are engaged. Then, the indexing table 5 is indexed and rotated via the worm 7 and the worm wheel 11. Also, the main body 2 and the input shaft 6
A correction mechanism 10 for correcting the rotation phase of the indexing table 5 is provided between and.

Next, the structure of each part will be described in detail. The drive adapter 4 is made by a well-known automatic tool changing device.
It has a body 12 that can be attached to and detached from
3 is screwed on. The drive clutch 8 is supported inside the support cylinder 13 via a bearing 14, and the drive clutch 8
A one-way clutch 15 that transmits the rotation of the body 12 by the main shaft 3 to the drive clutch 8 in only one direction is interposed between the support cylinder 13 and the support cylinder 13. The drive clutch 8 is provided at its lower end surface with a meshing portion 16 having a mountain portion and a valley portion arranged in a ring.

When the indexing table 5 is indexed by utilizing the rigid tap function of the spindle 3 (a function for synchronizing the axial movement amount of the spindle and the rotation angle, which is usually used for screw machining). Is the drive adapter 4 is the spindle 3
Two types of one-way clutch 15 in which the meshing directions are reversed are used so that the one-way clutch 15 can be rotated to the right and left. The drive adapter 4 can also be used when using the rotation angle control function of the spindle 3 (function of rotating the spindle forward or backward at a fixed position in the axial direction). When using the rotation angle control function, a drive adapter 17 as shown in FIG. 5 may be used. Unlike the drive adapter 4, the drive adapter 17 does not include a one-way clutch,
A drive clutch 19 is fixedly provided on the lower end surface of the body 18. Then, these drive adapters 4 and 17 are stored in a predetermined position of a tool magazine (not shown) during machining of the machine tool and selectively mounted on the spindle 3 by an automatic tool changer in response to an indexing command. .

As shown in FIGS. 1 and 3, the input shaft 6 is
Is inserted inside the worm shaft 21 so as to be slidable in the axial direction and is interposed between the two as a spring means 22.
Is urged upward by and is rotatably connected to the worm shaft 21 by a parallel key 23. The worm shaft 21 is supported by a bearing holder 24, a thrust bearing 25, an upper radial bearing 26, and a lower radial bearing 27 so as not to be axially movable with respect to the main body 2 but rotatable about a vertical axis. The input clutch 9 is formed on the upper end surface of the input shaft 6 in a shape similar to the meshing portion 16 of the drive clutch 8, and a slit 28 through which the parallel key 23 is inserted is formed in the middle portion in the axial direction. ing.
The worm shaft 21 is formed with a key hole 29 having a size such that the parallel key 23 is loosely fitted therein. An oil seal 31 that seals the worm shaft 21 is attached to a cover 30 that is superimposed and fixed to the bearing holder 24.

As shown in FIG. 2, the indexing table 5 is mounted on the front surface of the rotating body 33 with bolts 34, and the worm wheel 11 is integrally formed on the outer periphery of the rotating body 33. The rotating body 33 is rotatably supported by a pair of front and rear bearing holders 35 fixed to the main body 2 via bearings 36 so as to be rotatable about a horizontal axis, and is sealed by an oil seal 37 attached to each bearing holder 35.

The worm 7, which meshes with the worm wheel 11, is composed of a fixed worm element 39 and a movable worm element 40, which are axially divided into two, as shown in FIGS. 1, 3, and 6. The fixed worm element 39 is integrally formed on the outer circumference of the worm shaft 21, and the movable worm element 40 is axially slidably inserted into the small diameter portion 41 of the worm shaft 21 below the fixed worm element 39. A pair of holes 42 facing each other are provided in the lower peripheral wall of the movable worm element 40, and the parallel key 23 is provided in each hole 42.
Both ends are inserted and retained by the ring 43. The movable worm element 40 is provided with the parallel key 23, and the parallel key 23 and the key hole 29 of the worm shaft 21
Worm shaft 21 with a stroke corresponding to
It is finely connected to.

The parallel key 23 constitutes an interlocking member for moving the movable worm element 40 toward and away from the fixed worm element 39 as the input shaft 6 moves. Then, when the input shaft 6 is arranged at the rising end position (solid line position in FIG. 1), the lower end of the slit 28 of the input shaft 6 engages with the parallel key 23, and the parallel key 23 is lifted by the urging force of the spring 22. Then, as shown by the solid line in FIG. 6, the movable worm element 40 approaches the fixed worm element 39 side, and the movable worm element 40 urges the worm wheel 11 to rotate, so that the tooth surface of the worm wheel 11 has several teeth. Is pressed against a fixed worm element 39 serving as a positioning reference. In this pressure contact state, the upward movement of the input shaft 6 is stopped by the parallel key 23. When the input shaft 6 is pushed down by the drive adapter 4, the movable worm element 40 separates downward from the fixed worm element 39 by its own weight or the like and is fixed to the tooth surface of the worm wheel 11 as shown by the chain line in FIG. Backlash is generated between the worm element 39 and the worm element 39.

As shown in FIGS. 1 and 4, the correction mechanism 10 is composed of an upper correction plate 45 and a lower correction plate 46. The upper correction plate 45 is fixed to the inside of the main body 2 by a bolt 47, and the lower surface thereof has a correction portion 48 formed by alternately arranging chamfered peaks 48a and valleys 48b in an annular shape. There is. The lower correction plate 46 is attached to the lower end of the input shaft 6 via the support 49 and the bolt 5
The correction unit 51 is attached by 0, and the upper surface thereof has a correction unit 51 having a peak portion 51a and a valley portion 51b formed in a shape complementary to the correction unit 48 of the upper correction plate 45. Correction unit 4
The number of 8, 51 is set so that the indexing table 5 is rotated at least by the minimum indexing amount (for example, 1 degree) by the rotation amount (72 degrees in the drawing) required to shift the meshing by one.

When the input shaft 6 descends, the lower correction plate 46 separates from the upper correction plate 45, and when the input shaft 6 rises, the correction portion 51 of the lower correction plate 46 meshes with the correction portion 48 of the upper correction plate 45. At this time, the input shaft 6 and the worm shaft 21 are corrected and rotated by the chamfering action of the ridges 51a and 48a, and the fixed worm element 3
The rotation phase of the indexing table 5 is corrected via 9 and the worm wheel 11. In addition, in order to adjust the rotation phase of the index table 5 and the input shaft 6,
The lower correction plate 46 has an elongated hole 52 and is assembled to the support body 49 by a bolt 50 so as to be positionally adjustable in the circumferential direction.

Next, the operation of the indexing device of this embodiment constructed as described above will be described. When the work needs to be indexed during machining, first, the drive adapter 4 is attached to the spindle 3 by the automatic tool changer. Then the spindle 3
Is moved in the X- and Y-axis directions to a position directly above the input shaft 6, and then is lowered in the Z-axis direction in a non-rotating state, the drive clutch 8 is engaged with the input clutch 9 in the middle of the lowering, and in that state, The input shaft 6 is pushed down by the drive adapter 4 against the biasing force of the spring 22.

In the initial descent of the input shaft 6, the parallel key 23 separates from the slit 28 to release the pressing of the movable worm element 40, so that the movable worm element 40 is slightly separated downward from the fixed worm element 39, and the worm Wheel 1
Backlash occurs between the tooth surface of No. 1 and the fixed worm element 39. The input shaft 6 is positioned at the chain line position P1 in FIG.
When it goes down, the lower correction plate 46 is separated from the upper correction plate 45 in the correction mechanism 10, and the rotation of the input shaft 6 and the worm shaft 21 is allowed. After the input shaft 6 reaches the chain line position P1, the main shaft 3 descends while rotating clockwise while the descending amount and the rotation angle are synchronized by the right-threaded rigid tap function, and as a result, the body 1 of the drive adapter 4 is lowered.
2 rotates, but the one-way clutch 15 idles,
The drive clutch 8 does not rotate, the input shaft 6 is lowered to P2 without rotating, and the worm shaft 21 and the indexing table 5 are stopped and held.

When the parallel key 23 reaches the vicinity of the upper end of the slit 28 at the chain line position P2, the main shaft 3 is stopped by the rigid tap function and then is lifted, while being rotated counterclockwise at a rotation angle in synchronization with the lift amount. At this time,
Since the one-way clutch 15 meshes to transmit the rotation of the main shaft 3 to the drive clutch 8, the input shaft 6 and the worm shaft 21
Is rotated, and the indexing table 5 is indexed through the worm 7 and the worm wheel 11 by rotating at a predetermined angle.
Then, the rigid shaft of the spindle 3 serves to input the input shaft 6
When the input shaft 6 further rises due to the axial movement of the main shaft 3 after the original position has risen to the original chain line position P1, each correction plate 4
The correction units 48 and 51 of the motors 5 and 46 mesh with each other, and the input shaft 6, the worm shaft 21, and the indexing table 5 are corrected and rotated, and locked at the rotational position.

After the input shaft 6 is raised above P1, the main shaft 3 is raised in the Z-axis direction in the non-rotating state, and as a result, the input shaft 6 is further raised when the indexing table 5 is stopped. Then the parallel key 23 engages with the lower end of the slit 28,
The movable worm element 40 is moved to the fixed worm element 39 side by the urging force of the spring 22, and the tooth surface of the worm wheel 11 is pressed against the fixed worm element 39 by the movable worm element 40. As a result, backlash between the worm 7 and the worm wheel 11 is eliminated, and the indexing table 5 is accurately positioned with reference to the rotational phase of the fixed worm element 39 after the position correction. The indexing operation of the work by the forward rotation of is completed.

When the indexing table 5 is rotated in the reverse direction, another drive adapter 4 in which the meshing direction of the one-way clutch 15 is reversed is attached to the spindle 3 by the automatic tool changing device. In this case, when the main shaft 3 rotates counterclockwise while descending by the rigid tap function for the left screw, the one-way clutch 1
5, the input shaft 6, the worm shaft 21, and the indexing table 5 do not rotate. Further, when the main shaft 3 rotates to the right while rising after stopping, the one-way clutch 15 meshes and transmits the rotation of the main shaft 3 to the drive clutch 8. Therefore, the indexing table 5 via the input shaft 6 and the worm shaft 21. Is reversed.

As described above, according to the indexing device of this embodiment, when the indexing table 5 is stopped, the parallel key 23 moves the movable worm element 40 closer to the fixed worm element 39,
Since the tooth surface of the worm wheel 11 is pressed against the fixed worm element 39, backlash between the worm 7 and the worm wheel 11 can be eliminated, and the indexing table 5 can be accurately positioned at the indexing position. Further, when the indexing table 5 rotates, the parallel key 23 moves the movable worm element 40 away from the fixed worm element 39, and backlash occurs between the tooth surface of the worm wheel 11 and the fixed worm element 39. The rotation load of the input shaft 6 can be reduced, the indexing table 5 can be rotated with a relatively small driving force, and each component of the drive system can be downsized.
The correction mechanism 10 allows the input shaft 6, the worm shaft 21, and the indexing table 5 to be easily corrected and rotated.

In the indexing device of this embodiment, when the rotation angle control function of the main shaft 3 is used, the input shaft 6 is lowered to the chain line position P2 by the drive adapter 17, and the one-way clutch 15 is made by the main shaft 3 at that position. The worm 7 and the worm wheel 1 are rotated clockwise or counterclockwise in the direction in which
The indexing table 5 is indexed through 1 through normal rotation or reverse rotation. Therefore, both control functions of the spindle 3 can be arbitrarily selected according to the processing conditions, and the versatility of the indexing device is improved.

In the above embodiment, the input shaft 6 and the worm shaft 21 are provided coaxially, but both shafts are arranged side by side in the main body as shown in Japanese Patent Laid-Open No. 348846/1992, and the space between the two is provided. Is provided with a rotation transmission mechanism such as a gear that allows the input shaft to move in the axial direction, and a link mechanism or the like that moves the movable worm element toward and away from the fixed worm element with the axial movement of the input shaft. An interlocking member may be provided for implementation. In the above embodiment, the one-way clutch 1
Although 5 is provided in the drive adapter 4, it may be provided in the main body side so that the rigid tap function can be used. Further, it is possible to rotate the input shaft not by the rotation of the main shaft but by the circular arc complementary movement of the main shaft as shown in Japanese Patent Publication No. 1-20303. In addition, the present invention is not limited to the above embodiment,
The shapes and configurations of the respective parts may be appropriately modified and embodied without departing from the spirit of the present invention.

[0025]

As described above in detail, according to the present invention, the worm is axially divided into a fixed worm element and a movable worm element, and the movable worm element is moved along with the movement of the input shaft. A toothed surface of the worm wheel is pressed against the fixed worm element when both worm elements are close to each other, and a toothed surface of the worm wheel and the fixed worm element are pressed when both worm elements are separated from each other. Since the backlash is generated between them, the backlash can be eliminated and the indexing table can be accurately positioned when the indexing is stopped, and the backlash is increased during the indexing rotation to reduce the indexing table driving force. It has an excellent effect of being able to rotate with.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an indexing device showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

4 is an explanatory view showing a correction mechanism of the indexing device of FIG. 1. FIG.

5 is a front view showing another example of the drive adapter used in the indexing device of FIG. 1. FIG.

6 is an enlarged sectional view showing a worm mechanism of the indexing device of FIG.

[Explanation of symbols]

1 ... Machining table, 2 ... Main body, 3 ... Spindle, 4, 1
7 ... Drive adapter, 5 ... Indexing table, 6 ... Input shaft, 7 ... Worm, 8, 19 ... Drive clutch, 9 ...
・ Input clutch, 10 ・ ・ correction mechanism, 11 ・ ・ worm wheel, 21 ・ ・ worm shaft, 22 ・ ・ spring,
23 ・ ・ Parallel key, 39 ・ ・ Fixed worm element, 40 ・
.Movable worm element, 45..Upper correction plate, 46
..Lower correction plate, 48,51 ..

Claims (1)

[Claims] 1. A main body installed on a machining table of a machine tool, and a drive adapter detachably attached to a main shaft of the machine tool, the main body supporting an indexing table and an input shaft, and an input shaft. With the worm and worm wheel for transmission of rotation interposed between the index table and the drive adapter connected to the input shaft, the input shaft is rotated by the drive adapter with the rotation of the main shaft to move the worm and worm wheel. In an indexing device for indexing and rotating an indexing table via a shaft, the input shaft is supported so as to be movable in the axial direction, and is biased toward a drive adapter by a spring means to fix the worm in two in the axial direction. A worm element and a movable worm element are provided, and an interlocking member that moves the movable worm element toward and away from the fixed worm element as the input shaft moves is provided. The tooth surface of the worm wheel is pressed against the fixed worm element when the elements are close to each other, and backlash occurs between the tooth surface of the worm wheel and the fixed worm element when both worm elements are separated. And indexing device.