KR101547761B1

KR101547761B1 - Index table

Info

Publication number: KR101547761B1
Application number: KR1020140050476A
Authority: KR
Inventors: 김동우; 백광일; 안성철
Original assignee: (주)대호텍
Priority date: 2014-04-28
Filing date: 2014-04-28
Publication date: 2015-08-26

Abstract

The present invention relates to an index table. The index table of the present invention can increase delivery efficiency through large torque, and can perform accurate position decision by minimizing error as to deceleration rate of high precision even though the index table is manufactured in a compact size with light weight, by using a harmonic decelerator comprising a wave generator, a flexible gear and an internal gear as a decelerator of a tiling unit. Especially, damage of the flexible gear constituting the harmonic decelerator is prevented by forming a disc on a tiling output axis during rotation braking in order to maintain a rotated angle after divided rotation, and thus braking reliability can be ensured. Also, the index table can obtain deceleration efficiency of super high precision by increasing the deceleration ratio further by comprising a pulley and a belt between an output axis and a tilting input axis of a rotation motor together with the deceleration ratio by the harmonic decelerator.

Description

Index table {INDEX TABLE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an index table for rotating a rotary table to divide a rotary table on which a workpiece is mounted at a predetermined rotation angle.

Generally, a machine tool is provided with a spindle to be rotated, a tool is mounted on an end of the spindle, and a workpiece is mounted on the table so that the workpiece is processed by the tool while the spindle or the table moves.

Particularly, in a machine tool such as a CNC lathe or a machining center, an index table is used to adjust the work position of the workpiece while rotating at a precisely divided angle for machining the workpiece. That is, the index table is a device in which the rotary table provided on the upper portion of the index frame is intermittently rotated at an accurate division angle so as to effectively perform batch continuous operations such as machining, assembling, and transfer of workpieces as workpieces.

The index table includes an index frame, a rotary table installed on the index frame, the work table being seated and fixed, and the index frame to be divided and rotated in the vertical direction as a reference axis; And a split rotating means for rotating the table in a divided manner.

The present invention relates to an index table, and more particularly, to a split rotating means of an index table according to the related art, including a rotating motor and a speed reducer for transmitting rotation speed of the rotating motor to the rotating table, Use a worm gear reducer of the configuration.

If the gear ratio of the output shaft relative to the input shaft of the speed reducer is 100: 1 or more, the above-described gear deceleration is inevitable, and the braking of the input shaft of the speed reducer This braking means is installed on the input shaft of the gear reducer.

The speed reducer through the first plurality of multi-speed gears of the speed reducers used in the split rotating means of the index table according to the related art has a problem in that the transmission efficiency is lowered because the number of decelerating stages is increased in order to increase the reduction ratio by connecting various kinds of gears , There is a problem that the error increases due to the sum of the backlash generated for each stage. Second, the worm gear reducer has the advantage of reducing the size of the multi - gear reducer because it can obtain a large gear ratio from 1/5 to 1/70 with one set of gears. However, as the gear ratio becomes larger, the size of the worm wheel becomes larger, There is a falling problem.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems described above and to provide a speed reducer that reduces the rotational force of a rotary motor and transmits the reduced speed to a rotary table, And to provide an index table for making decisions.

Other objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments with reference to the accompanying drawings.

According to another aspect of the present invention, there is provided an index table comprising: an index frame; a rotary table installed on the index frame to fix and fix the workpiece, A rotary motor fixedly installed in the index frame and rotating in the normal and reverse directions, a rotary input shaft receiving rotation force of the rotary motor, a harmonic reducer transmitting and decelerating a rotary force of the rotary input shaft, And a rotation output shaft for transmitting a rotation force decelerated by the harmonic decelerator to the rotation table.

The harmonic reducer includes an elliptical wave generator coupled to the rotation input shaft and rotated together with the wave generator, and the wave generator is inserted into the cup-shaped elastic body and is harmonized while being deformed by rotation of the wave generator. Wherein the flexible gear is formed in a ring shape on the inner circumferential surface thereof in a number greater than the outer teeth of the flexible gear, And the teeth of the flexible gear are separated from the teeth of the teeth of the flexible gear at the short shaft portion of the flexible gear, and the rotary gear of the flexible gear is decelerated by receiving the rotational force of the flexible gear, And an internal gear to transmit the internal gear.

The rotary output shaft may further include a disc brake which is fixed to the inner side of the index frame and which brakes the disc to fix the rotary output shaft. do.

It is preferable that the motor further comprises a driven pulley coupled to the output shaft of the rotary motor and rotated together with the driven pulley and a driven pulley coupled to the rotary input shaft and rotating together with the driven pulley and a belt for transmitting the rotational force of the driven pulley to the driven pulley. do.

Also, the reduction ratio of the driven pulley to the driven pulley is 1: 2, and the reduction ratio of the rotation input shaft to the rotation output shaft is 1:80.

INDUSTRIAL APPLICABILITY The index table according to the present invention uses a harmonic reducer composed of a wave generator, a flexible gear and an internal gear to reduce the rotational force of the rotary motor to transmit the rotary gear to the rotary table. , The error can be minimized even with a high-precision reduction ratio, and accurate positioning can be achieved.

Particularly, in order to maintain the rotated angle after the split rotation, a disk is formed on the rotary output shaft during the rotary braking and the rotary output shaft is braked by the disk brake to prevent breakage of the flexible gear constituting the harmonic drive, can do.

In addition, a pulley and a belt are provided between the output shaft of the rotary motor and the rotary input shaft together with the reduction ratio by the harmonic speed reducer, so that the reduction ratio can be further increased to obtain the ultra high precision deceleration efficiency.

1 is a perspective view showing an embodiment of an index table according to the present invention,
Figure 2 is a side cross-sectional view of the embodiment of Figure 1,
FIG. 3 is a cross-sectional view of a recessed portion of the rotary input shaft assembly and the rotary output shaft assembly shown in FIG. 2,
4 is a side cross-sectional view showing another embodiment of the index table according to the present invention,
5 is an exploded perspective view of the harmonic drive according to the embodiment of FIGS. 2 to 4,
FIG. 6 is a front view showing an operation process of the embodiment of FIG. 5;

Hereinafter, preferred embodiments of the index table according to the present invention will be described in detail with reference to the accompanying drawings.

1 to 6, the index table includes an index frame 100, a rotary table 200, a rotary motor 300, a rotary input shaft 400, a harmonic reducer 500, and a rotary output shaft 600 And may further include a disc brake 700, a driven pulley 800, a driven pulley 900, and a belt 950. [ The harmonic speed reducer 500 also includes a wave generator 510, a flexible gear 520 and an internal gear 530.

First, the index table according to the present invention is installed inside a machine tool such as a CNC lathe or a machining center. For machining a workpiece using a tool, the workpiece is seated and fixed on a rotary table 200 that adjusts the working position of the workpiece while rotating at a precisely divided angle. As shown in FIG. 1, the rotary table 200 is installed on the index frame 100 and rotates about the reference axis in the vertical direction of the index frame 100. A rotary motor 300, a rotary input shaft 400, a harmonic reducer 500, and a rotary output shaft 600, which will be described later, are included in the index frame 100 to rotate the rotary table 200 in a divided manner.

2 to 6, the rotary motor 300 is fixedly installed in the index frame 100 and rotates forward and reverse. The rotary input shaft 400 receives the rotational force of the rotary motor 300, The speed reducer 500 includes a wave generator 510, a flexible gear 520 and an internal gear 530 to receive and decelerate the rotational force of the rotary input shaft 400. The rotary output shaft 600 is connected to the rotary table 200 And transmits rotation torque decelerated by the harmonic speed reducer 500 to the rotary table 200.

The harmonic drive 500 includes the wave generator 510, the flexible gear 520, and the internal gear 530 as shown in FIGS. 2 to 6, and is composed of only three parts, , Since a large number of teeth are engaged at the same time, a larger torque can be obtained, the transmission efficiency is good, and highly accurate positioning is possible.

As shown in FIGS. 2 to 6, the wave generator 510 constituting the harmonic speed reducer 500 is constructed such that a thin-walled ball bearing is assembled to the outer periphery of an elliptical cam, the inner ring of the bearing is fixed to the cam, And generates a waveform at the time of rotation while being elastically deformed. The wave generator 510 is connected to the rotation input shaft 400 and rotates together to transmit a waveform generated by the elastic deformation to the flexible gear 520.

As shown in FIGS. 2 to 6, the flexible gear 520 is a thin, cup-shaped metal elastic body, and the wave generator 510 is inserted into the cup-shaped interior, and the rotation of the wave generator 510 And the outer teeth 521 are formed on the outer circumferential surface.

As shown in FIGS. 2 to 6, the internal gear 530 has a ring-shaped inner circumferential surface formed with a greater number of teeth teeth 531 than the outer teeth 521 of the flexible gear 520, The outer gear teeth 521 of the flexible gear 520 and the inner teeth teeth 531 are engaged with each other at the long axis of the flexible gear 520. At the short axis of the flexible gear 520, The outer tooth row 521 of the flexible gear 520 and the inner tooth row 531 are separated from each other and are transmitted to the rotary output shaft 600 by receiving the rotational force of the flexible gear 520 in harmonic motion.

6, when the wave generator 510 coupled with the rotary input shaft 400 is rotated, the harmonic drive 500 rotates the internal gear (not shown) at the long axis portion of the elliptically deformed flexible gear 520 530 and the position of it engages sequentially. When the wave generator 510 rotates 360 degrees, the internal gear 530 rotates in the opposite direction by the difference in the number of teeth between the internal tooth train 531 and the external tooth train 521, and deceleration is performed due to the rotation in the opposite direction. The difference in the number of teeth between the tooth row 521 of the flexible gear 520 and the tooth row 531 of the internal gear 530 is 2n (n is a positive integer).

The rotational force of the rotary motor 300 is transmitted to the rotary input shaft 400 and the rotary input shaft 400 is coupled to the wave generator 510 of the harmonic reducer 500 to rotate together. The internal gear 530 engaged with the flexible gear 520 rotates in the opposite direction to rotate the rotary table 200 through the rotary output shaft 600. As a result, At this time, the workpiece that is seated according to the rotation of the rotary table 200 is rotated. In order to maintain the rotation angle of the rotary table 200, a braking unit must be provided.

When the multi-stage gear is used as the split rotating means of the conventional index table, the rotation input shaft 400 is provided with the braking portion. When the deceleration is performed through the harmonic speed reducer 500 as in the present invention, The first flexible gear 520 is liable to be broken as a cup-shaped metallic elastic body and the internal gear 530 to the second flexible gear 520 is inevitably lost and the braking function is lost .

Therefore, when the index table according to the present invention performs the braking function through the rotation output shaft 600, the above-mentioned problem does not occur. Therefore, in order to implement the present invention, as shown in FIGS. 2 to 4, 600 includes a disk 610 protruding from an outer circumferential surface in an annular plate shape and is fixed to the inside of the index frame 100 and rotates the rotation output shaft 600 by braking the disk 610 And a disc brake 700 for fixing the disc brake 700.

The harmonic reduction gear 500 can reduce the installation ratio of the rotary motor 610 to a very high precision and a high reduction ratio even with a small size and light weight. . 2 to 4, a main pulley 800 coupled to the output shaft of the rotation motor 300 rotates together with a driven pulley 900 coupled to the rotation input shaft 400 and rotated together therewith, And a belt 950 for transmitting the rotational force of the driven pulley 800 to the driven pulley 900.

2 and 3, when the rotary motor 300, the rotary input shaft 400, and the wave generator 510 rotate 80 times, for example, when the reduction ratio of the harmonic reducer 500 is 1:80, The internal gear 530, the rotary output shaft 600, and the rotary table 200 are rotated one turn. In order to increase the reduction ratio to 1: 160 in order to process a more accurate workpiece, the harmonic speed reducer 500 having the reduction ratio of 1:80 is left as it is, The deceleration ratio can be easily adjusted between the input shaft 400 and the driven pulley 800, the driven pulley 900, and the belt 950. Therefore, if the reduction ratio of the main pulley 800 to the driven pulley 900 is 1: 2 and the reduction ratio of the rotation input shaft 400 to the rotation output shaft 600 is 1:80, The rotation speed of the rotary table 200 can be increased to 1: 160 by one rotation.

As described above, the index table according to the present invention includes a speed reducer that decelerates the rotational force of the rotary motor 300 and transmits the reduced speed to the rotary table 200, to the wave generator 510, the flexible gear 520, and the internal gear 530 It is possible to increase the transmission efficiency through a large torque and to minimize the error even in a high-precision reduction ratio, so that accurate positioning can be achieved.

In particular, in order to maintain the rotated angle after the split rotation, the disk 610 is formed on the rotary output shaft 600 during the rotary braking operation, and the rotary output shaft 600 is braked by the disk brake 700 to constitute the harmonic reducer 500 It is possible to prevent breakage of the flexible gear 520 and to ensure reliability of braking.

The pulleys 800 and 900 and the belt 950 are disposed between the output shaft of the rotary motor 300 and the rotary input shaft 400 in conjunction with the reduction ratio by the harmonic speed reducer 500 to further increase the reduction ratio, Efficiency can be obtained.

The embodiments of the present invention described above and shown in the drawings should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and those skilled in the art will be able to modify the technical idea of the present invention in various forms. Accordingly, such improvements and modifications will fall within the scope of the present invention as long as they are obvious to those skilled in the art.

100: Index frame
200: Rotating table
300: Rotary motor
400: rotating input shaft
500: Harmonic reducer 510: Wave generator
520: Flexible gear 521: Outer teeth
530: internal gear 531: internal teeth
600: rotation output shaft 610: disk
700: Disc brake
800: Main pulley
900: Follow pulley
950: Belt

Claims

An index frame,
A rotary table mounted on an upper portion of the index frame and having a workpiece fixed thereon and rotated about a reference axis in the longitudinal direction of the index frame,
A rotary motor fixedly installed in the index frame and rotating forward and backward,
A rotation input shaft for receiving rotation force of the rotation motor,
A harmonic reducer for receiving and reducing the rotational force of the rotary input shaft,
And a rotation output shaft that rotates together with the rotation table and transmits a rotation force decelerated by the harmonic reduction gear to the rotation table,
The harmonic-
An elliptical wave generator coupled to the rotation input shaft and rotating together,
A flexible gear in which the wave generator is fitted into a cup-shaped elastic body, the flexible gear is routed while being deformed by the rotation of the wave generator,
Wherein an inner teeth of the flexible gear is formed on an inner circumferential surface of the flexible gear in a ring shape and the inner teeth of the flexible gear are engaged with the inner teeth of the flexible gear at the long axis portion of the flexible gear deformed by the ellipse, And an internal gear which separates the external teeth of the flexible gear from the internal teeth and receives the rotational force of the flexible gear and transmits the rotational force to the rotation output shaft,
The rotation output shaft
And a disc protruding in an annular plate shape on an outer peripheral surface,
Further comprising a disc brake fixed to the inside of the index frame and braking the disc to fix the rotation output shaft.

delete

The method according to claim 1,
A driven pulley coupled to the output shaft of the rotary motor and rotating together,
A driven pulley coupled to the rotation input shaft and rotating together,
Further comprising a belt for transmitting a rotational force of the driven pulley to the driven pulley.

5. The method of claim 4,
The reduction ratio of the driven pulley to the driven pulley is 1: 2,
Wherein the reduction ratio of the rotation input shaft to the rotation output shaft is 1:80.